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48-05 Ordinance RECORD OF ORDINANCES Dayton Leal Blank, lnc. Form No. 30043 48-OS 20 Ordinance No. Passed AN ORDINANCE TO REPEAL CHAPTER 53, STORMWATER MANAGEMENT, TO ESTABLISH CHAPTER 53, STORMWATER MANAGEMENT AND STREAM PROTECTION, AND TO ADD SECTION 153.231 (B)(5) OF THE CODIFIED ORDINANCES IN THE CITY OF DUBLIN, OHIO WHEREAS, the Ohio Environmental Protection Agency (OEPA) has promulgated new regulations in conjunction with the National Pollution Discharge Elimination System (NPDES) Phase II requirements; and WHEREAS, the OEPA has established a General Construction permit and requires the City to adopt the requirements contained in the permit; and WHEREAS, the City has determined that the drainage and development of land usually has significant impact upon the health, safety, and welfare of the residents of Dublin, Ohio; and WHEREAS, improperly managed stormwater runoff can increase the incidence of flooding and erosion which potentially endangers human life and property; and WHEREAS, impervious surfaces increase the volume and rate of stormwater runoff and potentially allow less water to percolate into the soil, thereby decreasing groundwater recharge; and WHEREAS, construction requiring the alteration of natural topography and removal of vegetation tends to increase erosion; and WHEREAS, siltation of water bodies resulting from increased erosion decreases their capacity to hold and transport water; and WHEREAS, stormwater runoff can carry pollutants into receiving water bodies, thus degrading water quality; and WHEREAS, the Community Services Advisory Commission and the Planning and Zoning Commission have reviewed the proposed amendments and have made recommendations to Council to adopt these revisions. NOW, THEREFO , BE IT ORDAINED by the Council of the City of Dublin, State of Ohio, ~ of the elected members concurring: Section 1. To repeal existing Chapter 53, Stormwater Management, of the Dublin Code of Ordinances; and Section 2. To establish Chapter 53, Stormwater Management and Stream Protection, of the Dublin Code of Ordinances as shown in attached Exhibit "A"; and Section 3. To add Section 153.231 (B) (5) of the Dublin Code of Ordinances as follows: (5) Stream Corridor Protection Zone Appeals for the Dublin Engineering Division. To hear and decide in specific cases if the terms of Chapter 53, Stormwater Management and Stream Protection, will be contrary to the public interest where, owing to special conditions on the land, a variance is necessary when a literal enforcement of the provisions of Chapter 53, Stormwater Management and Stream Protection, would result in an unreasonable hardship. In granting such variances, the Board of Zoning Appeals shall prescribe appropriate conditions and safeguards to maintain the intent and spirit of Chapter 53, Stormwater Management and Stream Protection. RECORD OF ORDINANCES Dayton Legal Blank, lnc Form No. 30043 - _ _ - _ 48-OS Page. 20 Ordinance No. Passed Section 4. That the City Engineer is directed to create and maintain a Stormwater Management Design Manual in his office that is available to the public for use when applying the regulations contained in Chapter 53, Stormwater Management and Stream Protection. Section 5. That this ordinance shall take effect and be in force from and after the earliest date allowed by law. Passed this day of ~J-e ~ 2005. Mayor -Presiding Officer Attest: /;j ,1 Clerk of Council I hereby certify that copies of this Ordinance/Resolution were posted in the City of Dublin in accordance with Section 731.25 of the Ohio Revised Code. uty C k of Council, Dublin, Ohio Office of the City Manager 5200 Emerald Parkway • Dublin, OH 43017 CITY OF DUBLIN_ Phone: 614-410-4400 • Fax: 614-410-4490 M e m o To: Members of City Council From: Jane S. Brautigam, City Manager~~y ~S Date: August 31, 2005 Initiated By: Paul A. Hammersmith, P.E., Director of Engineering/City Engineer ef- Barbara A. Cox, P.E., Assistant Director of Engineering -Development Re: Ordinance 48-05: An Ordinance to Repeal Chapter 53, Stormwater Management, to Establish Chapter 53, Stormwater Management and Stream Protection, and to Add Section 153.231 (B) (5) of the Codified Ordinances in the City of Dublin, Ohio Summary: This is the second reading of Ordinance 48-05. Revisions to Chapter 53, Stormwater Management are proposed to codify updates made by the Ohio Environmental Protection Agency (OEPA) regarding erosion and sediment control (during and after construction), create a stream corridor protection zone and clarify some issues that staff has found while administrating the current Chapter since June 1998. The proposed revisions were forwarded to both the Community Services Advisory Commission (CSAC) and the Planning and Zoning Commission (P&Z) for their review and consideration, as directed by Council at their March 7, 2005 meeting. Staff will make a presentation that will summarize the proposed revisions and outline the implications of the proposed revisions. No changes were made to the following documents that are attached again for your review: 1. Memo from CSAC containing their recommendation 2. Minutes from the various CSAC meetings when the revisions were discussed 3. Minutes and Record of Action from the Planning and Zoning Commission meeting when the revisions were presented 4. Ordinance 48-OSadopting the proposed revisions 5. Chapter 53, Stormwater Management and Stream Protection (Exhibit "A") 6. Draft Stormwater Management Design Manual 7. Map depicting areas where Stream Corridor Protection Zones may apply. Recommendation: Staff recommends approval of Ordinance 48-05: An Ordinance to Repeal Chapter 53, Stormwater Management, to Establish Chapter 53, Stormwater Management and Stream Protection, and to Add Section 153.231 (B) (5) of the Codified Ordinances in the City of Dublin. Staff is accepting of a third reading of Ordinance 48-OS on September 19~' if Council desires additional time to review the proposed revisions. Exhibit "A " CHAPTER 53: STORMWATER MANAGEMENT AND STREAM PROTECTION Section 53.010 Purpose 53.020 Short title 53.030 Jurisdiction 53.040 Definitions 53.050 Authority 53.060 Required approvals 53.070 Exemptions 53.080 General requirements 53.090 Stormwater design standards 53.100 Dedication of easements and rights-of--way 53.110 Stormwater management plan 53.120 Stormwater management plan application 53.130 Acceptance of stormwater improvements 53.140 Maintenance responsibility 53.150 Enforcement 53.200 Establishment of a stream corridor protection zone (SCPZ) 53.210 Uses permitted in the stream corridor protection zone 53.220 Uses prohibited in the stream corridor protection zone 53.230 Facilities prohibited in the stream corridor protection zone 53.240 Non-conforming structures or uses in the stream corridor protection zone 53.250 Inspection of stream corridor protection zone 53.260 Variances, Waivers or Exemptions 53.270 Appeals 53.300 Erosion and sediment control requirements for construction sites 53.310 General requirements erosion and sediment control requirements 53.320 Standards and criteria for erosion and sediment control 53.330 Soil erosion and sediment control plan requirements 53.340 Erosion and sediment control compliance responsibility 53.999 Penalty § 53.010 PURPOSE. (A) A chapter regulating stormwater from areas of new development and redevelopment for the purpose of protecting the public health, safety, and welfare; defining appropriate stormwater management objectives for the quantity and quality of stormwater runoff in the city; providing for waivers; providing requirements for the protection of water resources; imposing application fees and procedures; requiring adherence to the plans approved by the City Engineer; providing for maintenance; and providing for enforcement and penalties for violation. (B) In order to protect, maintain, and enhance both the immediate and the long-term health, safety, and general welfare of the citizens of Dublin, it is the intent of the city to enact this chapter so as to accomplish the following objectives: Page 1 of 29 Exhibit "A " (1) To prevent loss of life and loss of property due to flooding; (2) To protect, restore, and maintain the chemical, physical, and biological quality of ground and surface waters; (3) To encourage productive and enjoyable harmony between humanity and nature thus enhancing the scenic beauty and environment of the City; (4) To prevent individuals, business entities, and governmental entities from causing harm to the community by activities which adversely affect water resources; 5) To encourage the protection of natural systems, including groundwater and the use of those natural systems in ways which do not impair their beneficial functioning; (6) To assist in stabilizing the banks of streams to reduce bank erosion and the downstream transport of sediments eroded from watercourse banks; (7) To provide areas for natural meandering and lateral movement of stream channels; (8) To minimize the transport of sediments and pollutants to surface water and groundwater; (9) To provide high quality stream habitats with shade and food to a wide array of wildlife by maintaining diverse and connected riparian vegetation; (10) To provide economical benefits to the city by minimizing encroachment on stream channels and reducing the need for costly engineering solutions such as dams and riprap; (11) To protect structures and reduce property damage and threats to the safety of watershed residents; (12)To add to the quality of life of the residents of the City of Dublin and corresponding property values; (13)To ensure the attainment of these objectives by requiring the approval and implementation of stormwater management plans for all activities which may have an adverse impact upon groundwater and surface water. § 53.020 SHORT TITLE. This chapter shall be known and cited as the Stormwater Management and Stream Protection chapter, hereinafter referred to as the stormwater regulations. § 53.030 JURISDICTION. The stormwater regulations shall apply in all areas within the development jurisdiction of the city. Page 2 of 29 Exhibit "A " § 53.040 DEFINITIONS. For the purpose of the stormwater regulations, the following terms, phrases, and definitions shall apply. Words used in the singular shall include the plural, and the plural, the singular. Words used in the present tense shall include the future tense. The word SHALL is mandatory and not discretionary. The word MAY is permissive. Words not defined herein shall be construed to have the meaning given by common and ordinary use as defined by the latest edition of Webster's Dictionary. AGRICULTURE. The art or science of cultivating the ground, including the harvesting of crops, and the rearing and management of live stock; farming. APPLICANT. Any person or duly designated representative applying for a permit or other type of city, federal, or state regulatory approval to proceed with a project. AS-BUILT PLANS. The final plans amended to include all locations, dimensions, elevations, capacities, capabilities, as actually constructed and installed. BEST MANAGEMENT PRACTICES (BMPs). Schedules of activities, prohibition of practices, maintenance procedures, and other management practices (both structural and non- structural) to prevent or reduce the pollution of waters. BMP's also include treatment requirements, operating procedures, and practices to control runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. BLUE-LINE STREAM. Those streams shown on USGS 7.5' Quad maps with solid or dashed blue lines. CLEARING. The removal of trees, brush, and other ground cover from a part of the land, but shall not include mowing. COMPENSATING STORAGE. Equivalent floodplain storage provided to counterbalance floodplain filling. CONSERVATION. The wise use and management of natural resources. CONSTRUCTION. The erection, alteration, repair, renovation, demolition or removal of any building or structure; and the clearing, stripping, excavating, filling, grading, and regulation of sites with connection therewith. CONSTRUCTION ENTRANCE. The permitted points of ingress and egress to construction sites regulated under this regulation which reduce the mud, dust and dirt tracked out of the site. DAMAGED OR DISEASED TREES: Trees that have split trunk, broken tops, heart rot, insect or fungus problems that will lead to imminent death, undercut root systems that put the tree in imminent danger of falling, lean as a result of root failure that puts the tree in imminent danger of falling, or any other condition that puts the tree in imminent danger of being uprooted or falling into or along a stream or onto a structure. Page 3 of 29 Exhibit "A " DENUDE. The act of stripping, scraping, and/or scalping a site of vegetation, thus exposing bare soil. DETENTION or TO DETAIN. The retardance of, or to retard or slow, the discharge, directly or indirectly, of a given volume of stormwater runoff into surface waters in a facility that does not contain a permanent or normal pool of water. DEVELOPER. Any individual, subdivider, firm, association, syndicate, partnership, corporation, trust, or any other legal entity commencing proceedings under these regulations to effect the development of land for himself or for another. DEVELOPMENT AREA. Any contiguous (abutting) area owned by one or more person(s) or developed as a single phase or multiple phases (units) and used or being developed or redeveloped, for non-farm commercial, industrial, residential, or other non-farm purposes upon which earth-disturbing activities are planned or underway. DEVELOPMENT or DEVELOPMENT ACTIVITY. The alteration, construction, installation, demolition or removal of a structure, impervious surface or drainage facility; or clearing, scraping, grubbing, killing or otherwise removing the vegetation from a site; or adding, removing, exposing, excavating, leveling, grading, digging, burrowing, dumping, piling, dredging or otherwise significantly disturbing the soil, mud, sand or rock of a site. For the purposes of this ordinance, this pertains to any development greater than one (1) acre or any size of development if it is part of a larger contiguous development. DISCHARGE. The outflow of water from a project, site, aquifer, drainage basin or facility. DISTURBED AREA. An area of land subject to erosion due to the removal of vegetative cover and/or other earth disturbing activities. DITCH. A constructed channel for irrigation or stormwater conveyance. DRAINAGE. The removal of excess surface water or groundwater from land by surface or subsurface drains. DRAINAGE AREA. The area of land contributing surface water to a specific point. DUMPING. Grading, pushing, pilling, throwing, unloading, or placing of fill material, composed of earth, soil, rock, sand, gravel, or demolition material. EARTH-DISTURBING ACTIVITY. Any grading, excavating, filling, or other alteration of the earth's surface where natural or man-made ground cover is destroyed and which may result in or contribute to erosion and sediment pollution. EASEMENT. A grant by a property owner for the use of a specified portion of land for a specified purpose. EROSION: (A) The wearing away of the land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep. Page 4 of 29 Exhibit "A " (B) Detachment and movement of soil or rock fragments by wind, water, ice or gravity. (C) Erosion includes: (1) Accelerated Erosion: erosion much more rapid than normal, natural or geologic erosion, primarily as a result of the influence of the activities of man. (2) Floodplain Erosion: abrading and wearing away of the nearly level land situated on either side of a channel due to overflow flooding. (3) Gully Erosion: a type of erosion caused by concentrated runoff that removes soil such that channels are formed and/or become considerably deeper than what would otherwise result by normal smoothing or tilling operations. (4) Natural (Geological) Erosion: the wearing away of the earth's surface by water, ice or other natural agents under natural environmental conditions of clime, vegetation, etc., undisturbed by man. (5) Normal Erosion: the gradual erosion of land used by humans which does not greatly exceed natural erosion. (6) Rill Erosion: an erosion process in which numerous small channels only several inches deep are formed; occurs mainly on recently disturbed soils. (D) Sheet Erosion: the removal of a fairly uniform layer of soil from the land surface by wind or runoff water. (E) Stream Erosion: erosion of the bank or bottom due to the high velocity of flow within the stream. EROSION AND SEDIMENT CONTROL. Physical, mineral, procedural, and organic measures to minimize the removal of soil from the land surface and to prevent its transport from a disturbed area by means of wind, water, ice, gravity, or any combination of those forces. EXEMPTION. Those activities that are not subject to the requirements contained in this regulation. EXTENDED DRYDETENTION. A drainage facility designed to capture the water quality volume, release 50 percent of it in no less than 16 hours, and the remainder in no less than 32 hours (for a total of 48 hours). FINAL STABILIZATION. Establishment of a uniform perennial vegetative cover with a density of at least 70% of the cover for the disturbed area, or equivalent stabilization measures (such as the use of mulches or geotextiles) employed after all earth disturbing activities have been completed. FINSISHED GRADE. The final grade or elevation of the ground surface conforming to the approved site grading plan. Page 5 of 29 Exhibit "A " FOREBAYS. Areas located at detention basin inlets that are designed to trap coarse sediment particles by separating approximately ten percent of the basin volume from the remainder of the basin with a lateral sill, rock-filled gabions, a retaining wall, or horizontal rock filters. GRADING. The stripping, cutting, filling, stockpiling, or any combination thereof of earth disturbing activities, including land in its cut or filled conditions. GRUBBING. Any activity which removes or significantly disturbs the root matter within the ground. GROUNDWATER. Water below the surface of the ground whether or not flowing through known or defined channels. HYDROGRAPH. A graph of discharge versus time for a selected point in the drainage system. MAINTENANCE. The action taken to restore or preserve the as-built functional design of any facility or system. NATURAL SUCCESSION: A gradual and continuous replacement of one kind of plant and animal group by a more complex group. The plants and animals present in the initial group modify the environment through their life activities thereby making it unfavorable for themselves. They are gradually replaced by a different group of plants and animals better adapted to the new environment. NOXIOUS WEED: Any plant species defined by the Ohio Department of Agriculture as a "noxious weed" and listed as such by the Department. For the purposes of this regulation, the most recent version of this list at the time of application of this regulation shall prevail. 100-YEAR FLOODPLAIN: Any land susceptible to being inundated by water from a base flood, which is the flood that has a one percent or greater chance of being equaled or exceeded in any given year. For the purposes of these regulations, the 100-year floodplain shall be defined and approved by the City Engineer of Dublin or designee. OPEN CHANNEL. A ditch, channel, Swale, or other open conveyance that is not a stream and is used to safely convey stormwater runoff. ORDINARY HIGH WATER MARK: The point on the bank or shore to which the presence and action of surface water is so continuous as to leave a distinctive mark by erosion, destruction or prevention of terrestrial vegetation, predominance of aquatic vegetation or other easily recognized characteristic. The ordinary high water mark defines the channel of a stream. OUTDOOR ACTIVITY AREAS. Areas where pollutants are or may become more concentrated than typical urban runoff as characterized by the USEPA National Urban Runoff Program (NURP), as listed below or otherwise defined by the City Engineer: (1) Industrial material, waste handling, and storage areas, including but not limited to loading docks, fuel and other liquid storage/dispensing facilities, material bins, containers, Page 6 of 29 Exhibit "A " stockpiles, and other storage containers, waste dumpsters, bins, cans, tanks, stockpiles, and other waste containers. (2) Processing, manufacturing, fabrication, cleaning, or other permanent outdoor equipment or work areas. (3) Areas where vehicles and equipment are repaired, maintained, stored, disassembled, rinsed, cleaned or disposed. OWNER. The person in whom is vested the fee, ownership, dominion, or title of property (i.e., the proprietor). This term may also include a tenant, if chargeable under his lease for the maintenance of the property, and any agent of the owner or tenant including a developer. PARCEL or PARCEL OF LAND. A contiguous quantity of land in possession or owned by, or recorded as property of the same claimant person as of the effective date of the stormwater regulations. PERMITTEE. Any person who has been granted a permit to proceed with a project. PERSON. Any individual, firm, corporation, governmental agency, business trust, estate, trust, partnership, association, two or more persons having a joint or common business interest, or any other legal entity. POLLUTION. Any contamination or alteration of the physical, chemical, or biological properties of any waters that will render the waters harmful or detrimental to: public health, safety or welfare; domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses; livestock, wildlife, including birds, fish or other aquatic life. POST-DEVELOPMENT. The average conditions as of the completion of the development for which a permit has been applied. PRE-DEVELOPMENT. The hydrologic and hydraulic condition of the project site immediately before development or construction begins. PROFESSIONAL ENGINEER. A professional engineer licensed by the State of Ohio, skilled in the practice of civil engineering and the engineer of record for the project under consideration. PROHIBITED DISCHARGES. Any discharges which are not composed entirely of stormwater unless authorized under a discharge permit issued by the OEPA. RECHARGE. The inflow of water into an aquifer. RETENTION or TO RETAIN. The prevention of, or to prevent, the discharge, directly or indirectly, of a given volume of stormwater runoff into surface waters in a facility that has a permanent or normal pool of water. RIPARIAN AREA. A transitional area between flowing water and land covered by terrestrial vegetation that provides a continuous exchange of nutrients and woody debris between land and water. This area is at least periodically influenced by flooding. Riparian areas, if Page 7 of 29 Exhibit "A " appropriately sized and managed, help to stabilize banks, limit erosion, reduce flood size flows and/ or filter and settle out runoff pollutants, or perform other functions consistent with the purposes of these regulations. SEDIMENT. Solid material, both mineral and organic, that is or was in suspension, is being or has been transported, or has been moved from its site of origin by air, water, gravity, or ice, and has come to rest on the earth's surface either above or below water. SEDIMENT BASIN. Sedimentation control devices such as ponds or traps that are designed to collect concentrated runoff from disturbed areas, settle and retain sediment in the runoff, and discharge the runoff water to a stabilized channel or pipe. SEDIMENTATION CONTROL DEVICE. Any structure or area which is designed to hold runoff water until suspended sediments have settled. SINKHOLE. A depression characterized by closed contours on a topographic map. SITE. Any lot or parcel, or a series of lots or parcels of land adjoining or contiguous or joined together under one ownership where clearing, stripping, grading or excavating is performed. STABILIZATION. The use of BMPs, such as seeding and mulching, that reduce or prevent soil erosion by water, wind, ice, gravity, or a combination of those forces. STORM EVENT. The storm of a specific duration, intensity, and frequency. STORMWATER or RUNOFF. Refers to the flow of water which results from, and which occurs during and immediately following a rainfall event. STORMWATER FACILITY. Any natural or constructed component of the stormwater management system. STORMWATER MANAGEMENT PLAN. Refers to the approved detailed analysis, design, and drawings of the stormwater management system, including erosion and sediment controls and other management practices for construction activities, required for all construction. STORMWATER MANAGEMENT SYSTEM. All natural and constructed facilities used for the conveyance and storage of stormwater through and from a drainage area, including, but not limited to, any and all of the following: channels, ditches, swales, flumes, culverts, streets, streams, watercourses, waterbodies, wetlands detention/retention facilities, and treatment devices. STORMWATER MASTER PLAN. The technical and policy manuals and any subsequent updates or amendments thereto used by the City Engineer to administer the stormwater regulations. STORMWATER QUALITY. Any liquid, solid, or semi-solid substance, or combination thereof, that enters stormwater runoff in concentrations or quantities large enough to contribute to the degradation of the beneficial uses of the body of water receiving the discharge. Page 8 of 29 Exhibit "A " STORMWATER QUALITY TREATMENT. The removal of pollutants from urban runoff and improvement of water quality, accomplished largely by deposition and utilizing the benefits of natural processes. STREAM. A channel having awell-defined bed and bank, either natural or artificial which confines and conducts continuous or periodic flowing water in such a way that terrestrial vegetation cannot establish roots within the streambed. Includes intermittent, ephemeral and perennial streams and streams identified by USGS or NRCS maps. STREAM CORRIDOR PROTECTION ZONE (SCPZ). The area set back along a stream to protect the riparian area and stream from impacts of development, and streamside residents from impacts of flooding and land loss through erosion. SCPZs are those lands within the City of Dublin that fall within the area defined by the criteria set forth in these regulations. STRIPPING. Any activity which removes or significantly disturbs the vegetative surface cover. STRUCTURE. Anything constructed or installed with a fixed location on the ground, or attached to something having a fixed location on the ground. SUBGRADE. The top elevation of graded and compacted earth underlying roadway pavement. SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would be equal to, or would exceed, 50% of the market value of the structure before the damage occurred. SWALE. An artificial or natural waterway which may contain contiguous areas of standing or flowing water only following a rainfall event, or is planted with or has stabilized vegetation suitable for soil stabilization, stormwater treatment, and nutrient uptake, or is designed to take into account the soil erodibility, soil percolation, slope, slope length, and contributing area so as to prevent erosion and reduce the pollutant concentration of any discharge. Also see definitions for Open Channel and Ditch. TAILWATER. The water into which a spillway or outfall discharges. TEMPORARY SOIL EROSION AND SEDIMENT CONTROL MEASURES. Interim control measures installed or constructed to control soil erosion until permanent soil erosion control measures are established. TERRESTRIAL VEGETATION. Upland vegetation and facultative upland vegetation, as defined in the National Wetland Plant List. TOPSOIL. Surface and upper surface soils which presumably are darker colored, fertile soil materials, ordinarily rich in organic matter or humus debris. WAIVER. A permit of conditional exemption from the regulation in part or in whole, as specified by the approving agent, in a formal written statement. A waiver from the regulation shall not be assumed to be in effect, without the expressed written statement from the City. Page 9 of 29 Exhibit "A " WATERBODY or RECEIVING WATERS. Any natural or artificial pond, lake, reservoir, or other area which ordinarily or intermittently contains water and which has a discernible shoreline and into which surface waters flow. WATERCOURSE. Any natural or artificial waterway (including, but not limited to, streams, rivers, creeks, drainageways, waterways, gullies, ravines, or washes) in which waters flow in a definite direction or course, either continuously or intermittently; and including any area adjacent thereto which is subject to inundation by reason of overflow of flood water. WETLANDS Those areas that are inundated or saturated by surface or groundwater with a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. WORKS. All artificial structures, including, but not limited to, canals, ditches, swales, conduits, channels, culverts, pipes, and other construction that connects to, draws water from, drains water into, or is placed in or across the waters in the state. § 53.050 AUTHORITY. The City Engineer is hereby authorized to administer the stormwater regulations. The City Engineer shall maintain and update this Stonnwater Management and Stream Protection Ordinance and recommend to City Council for adoption modifications in this Stormwater Management and Stream Protection Ordinance. The City Engineer shall also develop and maintain a Stormwater Master Plan, administrative procedures, detailed design studies or procedures to reflect new construction (including building additions), and/or engineering design technology necessary to administer this Ordinance. § 53.060 REQUIRED APPROVALS. (A) The requirements of the stormwater regulations shall be implemented, and shall be satisfied completely, prior to final project approval by the City Engineer. No person shall conduct any development activity, or subdivide or make any change in the use of land, or construct any stormwater management system or structure, or change the size of an existing structure or system, except as may be exempted in § 53.070 hereof. (B) Any construction plans, specifications, building permits, or other documents approved by the City Engineer shall be constructed in accordance with all applicable state or federal permit requirements of the Ohio Environmental Protection Agency (OEPA), Ohio Department of Natural Resources (ODNR) and/or U.S. Army Corps of Engineers. No construction activity shall commence prior to obtaining applicable permits from these agencies. § 53.070 EXEMPTIONS. With the approval of the City Engineer, the following activities may be exempted from on-site stormwater runoff control. An exemption shall apply only to the requirement for on-site Page 10 of 29 Exhibit "A " stormwater detention or retention facilities. All other design elements such as the storm sewer system, road culverts, erosion and sedimentation control, and runoff quality shall not be exempted. (A) Emergency exemption. Emergency maintenance work performed for the protection of public health and welfare, however, if the earth-disturbing activity would have required an approved erosion and sediment control plan, if the activity were not an emergency, then the land area disturbed shall be shaped and stabilized in accordance with the requirements of the City. (B) Maintenance exemption. Any maintenance to an existing system made in accordance with plans and specifications approved by the City Engineer. (C)Development-related exemptions. The applicant shall provide to the City Engineer in writing a request for exemption which shall include a scaled site map, property tax number, and street address if applicable. (1) Single-family or duplex exemption. Single-family or duplex residential construction on a single lot that is not part of a larger common plan of development. (2) Any construction which adds less than 500 square feet through expansion of a building, structure or pavement which results in new impervious area on a project site. (3) It is conceivable that development situations not automatically subject to exemption may exist such that development will have none of the harmful effects of sediment deposition. Such development situations, subject to City concurrence, are eligible for a waiver from this regulation. Waiver Requests shall be made in writing to the City Engineer and shall include sufficient detail to support that granting a wavier will not be detrimental to abutting properties or to watercourses, public waters, or to the sewer System. (D)Scioto River Corridor Exemption. Parcels that are located between State Route 745 (Dublin Road) and State Route 257 (Riverside Drive) which are directly tributary to the Scioto River. (E) Regular farming activities on land intended for such use, except when these activities involve practices which increase storm water runoff and exacerbate erosion and sedimentation. (F) Tilling, planting or harvesting of agricultural, horticultural, or forest crops that employ soil conservations related to agriculture as follows: construction of terraces, terrace outlets, check dams, desilting basins, dikes, ponds, ditches, strip cropping, lister furrowing, contour cultivating, contour furrowing, and land drainage and land irrigation which does not cause an increase in storm water runoff and does not exacerbate erosion and sedimentation. (G) Minor earth-disturbing activities such as home gardens and individual home landscaping, repairs, service connections and maintenance work. Page 11 of 29 Exhibit "A " (H) Installation, maintenance or repair of any underground public utility lines when such activity occurs on an existing hard surfaced road, street or sidewalk (provided the earth- disturbing activity is confined to the area of the road, street or sidewalk that is hard surfaced), and does not involve dewatering operations that produce sediment-laden effluent discharging to surface-lands and/or surface-waters. Septic tank lines or drainage fields unless included in an overall plan for earth-disturbing activity relating to the construction of the building to be served by the septic tank system. Repair or rebuilding of the tracks with-in the right-of--way of a railroad company. (Stream Corridor Protection Zone. Stream corridor protection zones are not required if a Preliminary Plan has already been approved for a site at the time this ordinance is passed. (L) Historic Dublin. Development within this area, as defined in the Zoning Code, shall be exempt from compliance with the City's storm water quantity regulations but shall be held in compliance with the City's storm water quality regulations, described in § 53.090, if the construction activities disturb one (1) or more acres of total land. § 53.080 GENERAL REQUIREMENTS. (A) A stormwater management system shall be designed and installed for the development that will contain features to provide for flood protection, erosion control, and pollution abatement. The stormwater management system design shall conform to the Stormwater Design Standards contained in § 53.090 hereof, the stormwater Master Plan and other standards specified by the City Engineer. The intent of these design standards is to encourage environmentally sound stormwater management practices; they should go beyond providing drainage facilities. Developments that sacrifice recharge and upland controls in order to maximize the number of lots will not be allowed. The city's stormwater management perspective includes the management of both water quantity and water quality. stormwater management design shall blend into the natural environment and be aesthetically integrated into site design. (B) Streams and wetlands subject to protection under Section 404 of the Clean Water Act shall be protected from the impacts of development. Setbacks from streams and wetlands shall be established and regulated to protect structures from flooding and erosion as well as to maintain water quality within the stream and wetland. The stormwater system design shall ensure that the quantity and quality of stormwater flows directed to these stream and wetlands are maintained as previous to development. Constructed wetlands (including bio-retention basins) shall be considered subject to these requirements. Existing wetlands shall not be used for stormwater management or stormwater runoff quality treatment. (C) All development activity within a special flood hazard area designated by the Federal Emergency Management Agency (FEMA) or any other area as designated by the City Engineer shall comply with Chapter 151 of the Dublin Code of Ordinances. All development shall be designed to maintain the flood carrying capacity of the floodway such that the base flood elevations are not increased, either upstream or downstream. Furthermore, no fill shall be allowed to be placed in the 100-year floodplain without an equivalent volume of soil removed to compensate for the loss of the flood storage as defined in §53.200 (G) of this regulation. Page 12 of 29 Exhibit "A " (D) The stormwater management system shall not create an adverse impact on stormwater quantity or quality in either upstream or downstream areas. Offsite areas which discharge to or across a site proposed for development shall be accommodated in the stormwater management plans for the development. No stormwater management plan shall be approved until it is demonstrated that the runoff from the project shall not overload or otherwise adversely impact any downstream areas. (E) All proposed stormwater management systems shall be designed to prevent the pollution of groundwater resources by stormwater, promote safety, minimize health hazards, preserve natural features, and provide for recharge where appropriate. Neither submission of a plan under the provision herein nor compliance with the provisions of these regulations shall relieve any person from responsibility for damage to any person or property otherwise imposed by law. (F) Where deemed necessary by the City Engineer, the applicant shall construct storm drains to handle on-site runoff; provide on-site drainage easements; provide off-site drainage easements; and provide for the conveyance of off-site runoff to an acceptable outlet in the same watershed. However, the on-site drainage easements may not encroach on required perimeter landscaping. (G) Guidance on stream corridor protection zones (SCPZ) shall be referenced from § 53.200. (H) Illicit discharges shall not be permitted. Any natural or man-made conveyance or drainage system, pipeline, conduit, inlet, or outlet (including natural surface flow patterns, depressions or channels traversing one or more properties) through which the discharge of any pollutant (including illegal sanitary sewer connections) to the stormwater management system shall not occur unless the connection is authorized under a discharge permit issued by the OEPA. § 53.090 STORMWATER DESIGN STANDARDS. (A) General. The City Engineer shall develop and maintain administrative policies and manuals that define accepted design practices, procedures, and guidance materials that shall be used to satisfy the City's stormwater regulations. § 53.100 DEDICATION OF EASEMENTS AND RIGHTS-OF-WAY. (A) Drainage easements or rights-of--ways, as specified in the Stormwater Design Standards, shall be conveyed by the applicant at no expense to the city for the stormwater facilities within the development. (B) When a proposed stormwater management system will carry water across private land outside the development, the offsite drainage easements as specified in the Stormwater Design Standards shall be secured by the owner or applicant. Page 13 of 29 Exhibit "A " (C) When a development is bifurcated by a stream, wetland or watercourse, the applicant shall provide a drainage easement or right-of--way conforming substantially to the lines of such watercourse or open channel, which shall be a minimum width, as specified in § 53.200. (D) Easements and rights-of--way shall include suitable access as specified herein for maintenance equipment from public rights-of--ways. (E) All drainage easements, both on-site and offsite, shall be recorded on a final plat or a separate recorded document approved by the city. Recording costs shall be the responsibility of the Applicant. Recorded easements and rights-of--way documents shall be returned to the City's Finance Department. (F) Outfall ditches, channels, and detention/retention facilities shall have sufficient rights- of-way and/or easements for the facility plus an unobstructed maintenance accessway on one or both sides. Said rights-of--way and/or easements shall be contiguous to public right-of--way or easement and shall allow for suitable access by maintenance equipment. Where the right-of--way and/or easement is provided for access only, the minimum width shall be as follows: Ditch or Channel Minimum Maintenance To of Bank Width Accesswa Re uired Less than 16 feet 20 feet on one side 16 feet to 32 feet 20 feet on both sides 32 feet to 55 feet 20 feet on one side and 30 feet on the opposite side Over 55 feet 30 feet on both sides (G) Maintenance accessways shall be sloped no steeper than 1/4-inch per foot. Ponds shall have a sufficient right-of--way/easement to allow for installation plus an unobstructed maintenance accessways all around the perimeter of the pond. (H) A 20-foot easement centered on a storm sewer shall be conveyed to the City when the storm sewer is not located within dedicated rights-of--way. Easements shall be contiguous to public rights-of--way and shall allow for suitable access by maintenance equipment. (I) Overland flood routing paths shall be used to convey stormwater runoff from the 100-year, 24-hour storm event to an adequate receiving water body, stormwater system or stormwater detention basin such that the runoff is contained within the drainage easement for the flood routing path and does not cause flooding of residential or commercial buildings or related structures. Flood routing paths shall be evaluated using the peak 100 year water surface elevation such that it lies at least one foot below the finished floor elevation of adjoining structures. When designing the flood routing paths, the conveyance capacity of the site's storm sewers shall be taken into consideration. Penalty, see § 53.999 § 53.110 STORMWATER MANAGEMENT PLAN. (A) A Stormwater Management Plan and Erosion and Sediment Control Plan shall be submitted for review and approval by the City Engineer. Details regarding the contents of the Page 14 of 29 Exhibit "A " documents will be created and maintained by the City Engineer in a manual or administrative policy. § 53.120 STORMWATER MANAGEMENT PLAN APPLICATION. (A) It is strongly recommended that the applicant and the project engineer meet with city staff prior to generating detailed design calculations and construction drawings in order to review and plan design requirements for a particular project. This application is not a separate submittal from the stormwater management plan requirements outlined in Section 53.110. (B) It is the responsibility of the applicant to include in the stormwater management plan application sufficient information for the city to evaluate: (1) The environmental and hydraulic characteristics of the affected areas; (2) The potential and predicted impacts of the proposed activity on community waters; (3) The effectiveness and acceptability of those measures proposed by the applicant for eliminating or reducing adverse impacts; and (C) The stormwater management plan application shall contain: (1) The name, address, and telephone number of the owner and applicant, and the entity that will maintain the system; (2) The maps, charts, graphs, tables, photographs, narrative descriptions, explanations, and citations to support references, as appropriate to communicate the information required by this chapter; and (3) Construction plans and specifications for all components of the stormwater management system shall be included in the stormwater management plan application, which shall be prepared or directly supervised by, signed, and sealed by a professional engineer. § 53.130 ACCEPTANCE OF STORMWATER IMPROVEMENTS. Subsequent to the applicant satisfying the requirements of the stormwater regulations and other applicable ordinances, and the issuances of appropriate permits and/or approvals, the applicant shall, during construction, arrange for and schedule the following inspections by the city. (A) During the clearing operation, excavation, after significant rainfall, and at other times determined by the City Engineer, to assure that effective control practices relative to erosion and sedimentation are being followed. (B) All public underground conveyance and control structures prior to backfilling, and all taps of private underground conveyance systems into public conveyance systems. Page 15 of 29 Exhibit "A " (C) Final inspection when all public systems required under the approved stormwater management plan have been installed. (D) The professional engineer for the project shall submit a signed and sealed set of as-built plans, on electronic disk and reproducible mylar brand polyester film drawing sheets, to certify the system has been constructed as designed and satisfies all conditions of the stormwater management plan. Where changes have been made to the stormwater management system which deviate from the approved construction plans, the Professional Engineer shall submit supporting documentation with the as-built plans, which proves that the stormwater system shall be in compliance with the stormwater regulations. (E) Maintenance and compliance inspections of stormwater management systems shall be conducted on a routine, periodic basis, as deemed appropriate by the city, or as complaints arise concerning the system. By seeking and obtaining plan approval under the stormwater regulations, the operator and owner shall be deemed to have consented to inspections by the city and other appropriate regulatory agencies or departments upon presentation of proper identification by the representative(s) of the agency(ies) conducting the inspections. (F) Public improvements. Public stormwater conveyance and control systems may be accepted for public use after the following minimum conditions have been met: (1) The applicant shall provide to the City Engineer security according to § 152.045 of the Dublin Code of Ordinances; (2) The applicant shall provide to the City Engineer as-built plans according to § 53.130(D) of the stormwater regulations; and (3) The as-built plans have been reviewed and approved by the City Engineer. (G) Private improvements. Private stormwater conveyance and control systems may be approved for use after the following minimum conditions have been met: (1) The applicant shall provide to the City Engineer as-built plans according to § 53.130(D) of the stormwater regulations; and (2) The as-built plans have been reviewed and approved by the City Engineer. It shall not be legal to use the property (as opposed to the structure) until the as-built plans have been received and approved by the City Engineer and the stormwater improvements have been completed as shown on the approved as-built plans. § 53.140 MAINTENANCE RESPONSIBILITY. (A) The installed stormwater system shall be properly maintained and operated by the legal entity responsible for maintenance in order to achieve compliance with the conditions outlined in this ordinance. All stormwater management plan applications shall contain documentation sufficient to demonstrate that the operation and maintenance entity is the legal entity empowered and obligated to perpetually maintain the stormwater management facilities. Details of this documentation, including maintenance responsibilities and agreements, shall be included in the Notes section of development plans and where applicable on the final plats. Final plats shall be Page 16 of 29 Exhibit "A " recorded in Delaware, Franklin, or Union County at no expense to the City and shall constitute a covenant running with the land and shall be binding on the legal entity responsible for maintenance. Where final plats are not recorded, stormwater management plan and development plan documentation regarding obligations to perpetually maintain stormwater management facilities shall be maintained by the City Engineer. The city considers the following entities acceptable to operate and maintain stormwater management facilities: (1) Local governmental units, including the county, municipalities, or Municipal Service Taxing Units. (2) Non-profit corporations, including homeowners associations, property owners associations or condominium owners associations, under certain conditions which ensure that the corporation has the financial, legal, and administrative capability to provide for the long-term operation and maintenance of the facilities. (3) The property owner or developer is normally not acceptable as a responsible entity, especially when the property is to be sold to various third parties. However, the property owner or developer maybe acceptable under one of the following circumstances: (a) The property is wholly owned by said applicant and the ownership is intended to be retained. This would apply to a farm, corporate office, or single industrial facility, for example. (b) The ownership of the property is retained by the applicant and is either leased to third parties (such as in some shopping centers), or rented to third parties (such as in some mobile home parks), for example. (B) The stormwater management system shall be maintained by the legal entity. Public improvements shall have adequate easements, in accordance with § 53.100 hereof, to permit the city to inspect, and if necessary, to take corrective action should the legal entity fail to maintain the system properly. The City maintains the right to assess costs of labor and materials for such corrective action to the responsible party in accordance with usual and customary costs in place at the time of action. (C) Maintenance of stormwater facilities shall allow the stormwater management system to perform as originally designed and permitted by the city and other appropriate governmental agencies and as set forth in the written plan. (D) Maintenance shall include compliance with city building and construction codes, and all other applicable codes. § 53.150 ENFORCEMENT. Guidance on enforcement of this ordinance, including those responsibilities agreed to under the maintenance agreements, shall be referenced in Section 153 of the Zoning Code. If at any time the City Engineer determines that the project is not in accordance with the approved plan, or if any project subject to the stormwater regulations is being carried out without an approved plan, the City Engineer is authorized to: Page 17 of 29 Exhibit "A " (A) Give the legal entity written notice of the corrective action required to be taken. Should the legal entity fail within 30 days of the date of the notice to complete such corrective action, the City Engineer may enter upon the property, and take the necessary corrective action and assess fees for such action to the violator. If fees are not paid by the violator at the time the service is provided, the City has the right to pursue collection of fees through certification to the County Auditor, remittance to a collection service, or any other appropriate pursuit for payment. (B) Take appropriate corrective action in the event of an emergency situation which endangers persons or property, or both, as determined to exist by the City Engineer. (C) Issue written notice to the applicant specifying the nature and location of the alleged noncompliance, with a description of the remedial actions necessary to bring the project into compliance within five working days. (D) Issue astop-work order directing the applicant or persons in possession to cease and desist all or any portion of the work which violates the provisions of the stormwater regulations if the remedial work is not completed within the specified time. The applicant shall then bring the project into compliance. § 53.200 ESTABLISHMENT OF A STREAM CORRIDOR PROTECTION ZONE. (A) Stream Corridor Protection Zones (SCPZs) are established as provided in this section. (B) Streams addressed by this ordinance are those that meet the definition of "stream" in Section 53.040 of these regulations. (C) The SCPZ width shall be the width of the FEMA-designated 100-year floodway plus 20 feet, or in areas where a floodway has not been designated, a width defined by the following according to the contributing drainage area: MINIMUM SCPZ WIDTH BY CONTRIBUTING DRAINAGE AREA OF STREAM Contributin Draina a Area ac SCPZ Width ft <100 25 101-250 38 251-500 50 501-800 63 801-1200 75 1201-2000 88 >2000 100 In most instances the calculated stream corridor protection zone shall be placed at the ordinary high water mark on each side of the channel and extend outward. This will result in a total SCPZ width of two times the minimum SCPZ width (stated in the guidance table above) plus the width of the stream. However, individual site conditions including, but not limited to, topography and slope must be considered when determining the precise location of the stream corridor protection zone and shall be left to the City's discretion. Page 18 of 29 Exhibit "A" (D) The width of the SCPZ may be extended to include slopes that are greater than 15% and begin at a point within the SCPZ. The maximum width of the SCPZ extension shall be to the top of the slope or to a point up slope, as measured horizontally, where the width of the SCPZ is doubled, whichever is less. Slope protection widths may be extended beyond these limits at the City's discretion on a case-by-case basis. (E) The following are exempt from the terms and protection of this ordinance: grassy swales, drainage ditches created at the time of a subdivision to convey stormwater water to another system, the drainage systems, and stream culverts. (F) The following shall apply to the SCPZ: (1) The width of the SCPZ shall be measured in a horizontal direction outward from the ordinary high water mark of each designated watercourse. (2) Except as otherwise provided in this regulation, SCPZs shall be preserved in their natural state. (3) The applicant shall be responsible for determining if jurisdictional wetlands have been identified within any proposed development site. Where existing wetlands protected under federal or state law are identified within the SCPZ, the SCPZ shall consist of the full extent of the wetlands plus any additional setback distance mandated by state or federal permit. (4) The applicant shall be responsible for delineating a rough layout of the SCPZ, including any expansions or modifications as required by B through D of this section, and identifying this setback on all preliminary subdivision or land development plans, and/or building permit applications. Final development plans shall delineate the SCZP by a metes and bounds survey. This final delineation shall be subject to review and approval by the City Engineer or designee. As the result of this review, the Engineer or designee may require further studies from the applicant. (5) Prior to any earth-disturbing activity, the SCPZ shall be clearly delineated with construction fencing or other suitable material by the applicant on site, and such delineation shall be maintained throughout earth-disturbing activities. The delineated area shall be maintained in an undisturbed state unless otherwise permitted by these regulations. All fencing shall be removed when a development project is completed. (6) If earth-disturbing activities will occur within 50 feet of the outer boundary of the SCPZ, the SCPZ shall be clearly delineated by the applicant on site with construction fencing, and such delineation shall be maintained throughout earth-disturbing activities. (7) No approvals or permits shall be issued by the City Engineer or designee prior to delineation of the SCPZ in conformance with these regulations. (8) Upon completion of an approved subdivision, the SCPZ shall be permanently recorded on the plat records for the City of Dublin. (G) In order to preserve floodplain storage volumes and thereby avoid increases in water surface elevations along FEMA regulated streams, filling within FEMA delineated 100-year Page 19 of 29 Exhibit "A " floodplains may only occur outside of the floodway plus 20 feet- and must be compensated by removing an equivalent volume of material. Compensating storage shall be determined by the volume of material removed above the ordinary high water table and below the 100-year flood elevation established for that area. Compensating storage shall be provided within the legal boundaries of the development. No stormwater management facilities required by the City shall be permitted in the floodplain unless, at City's discretion, the applicant demonstrates that it does not remove floodplain storage when operating at its design capacity. First consideration for the location(s) of compensatory floodplain volumes should be given to areas where the stream channel will have immediate access to the new floodplain within the limits of the development site. Embankment slopes used in compensatory storage areas must reasonably conform to the natural slopes adjacent to the disturbed area. The use of vertical retaining structures is specifically prohibited. (H) Degraded SCPZs shall be regraded and revegetated such that riparian habitat is recovered and the streambank stabilized in a manner suitable for the native site conditions. (I) Stream Relocation (1) Streams may be relocated if the applicant's design demonstrates, to the satisfaction of the City, that the following criteria are met: (a) Maintain or improve geomorphic stability. (b) Maintain or improve flood storage capacity. (c) Maintain or lower regulatory flood water surface elevations. (d) Enhance aquatic and riparian habitats. (e) Provide increased recreational opportunities. (f) Produce zero or positive impacts on water and land resources. (g) Minimize operations and maintenance requirements. (h) Maximize safety conditions. (2) The project's design shall be performed by a qualified Professional Engineer with experience in fluvial geomorphology. (3) If floodplain boundaries change as a result of the relocation, the requirements of Chapter 151:Flood Control become applicable. (J) SCPZ's shall be clearly delineated on preliminary development plans, final plats, final development plans final construction drawings, building permit site plans and stormwater management plans. Final plats or applicable portions of the final development plan documentation shall be recorded in Franklin, Deleware, or Union County at no expense to the City and shall constitute a covenant running with the land. Page 20 of 29 Exhibit "A " § 53.210 USES PERMITTED IN THE STREAM CORRIDOR PROTECTION ZONE. (A) Open space uses that are passive in character shall be permitted in the SCPZ including, but not limited to, those listed in 1 through 3 of this section. No use permitted under these regulations shall be construed as allowing trespass on privately held lands. Alteration of this natural area is strictly limited. Except as otherwise provided in these regulations, the SCPZ shall be preserved in its natural state. (1) Recreational Activity. Passive recreational uses, as permitted by federal, state, and local laws, such as hiking, non-motorized bicycling, fishing, hunting, picnicking and similar uses and associated structures including boardwalks, pathways constructed of pervious material, picnic tables, playground equipment, athletic fields, and wildlife viewing areas. (2) Removal of Damaged or Diseased Trees. Damaged or diseased trees may be removed. Because of the potential for felled logs and branches to damage downstream properties and/or block ditches or otherwise exacerbate flooding, logs and branches resulting from the removal of damaged or diseased trees that are greater than 6 inches in diameter, shall be anchored to the shore or removed from the 100-year floodplain. (3) Revegetation and/or Reforestation. The revegetation and/or reforestation of the SCPZ shall be allowed without approval of the City Engineer or designee. (B) Projects involving public utilities, transportation infrastructure, stormwater management, stream bank stabilization, or other projects where an environmental and public benefit is provided (including excavation for providing compensatory floodplain volume immediately adjacent to the channel) may be permitted within the SCPZ once the design has been approved by the City Engineer and/or all other applicable review authorities. (C) Disturbances within the SCPZ (including provision of compensatory floodplain storage adjacent to the stream) as a result of a permitted use must be mitigated through revegetation/reforestation. (D) Crossings of streams and SCPZs for roadways shall be minimized. Crossings shall be approved at the discretion of the City Engineer if the applicant can demonstrate that alternative roadway locations are infeasible and that disturbances within the SCPZ will be minimized and mitigated. § 53.220 USES PROHIBITED IN THE STREAM CORRIDOR PROTECTION ZONE. The following uses are specifically prohibited within the SCPZ: (A) Construction. There shall be no structures of any kind, except as permitted under these regulations. (B) Dredging or Dumping. There shall be no drilling, filling, dredging, excavation, or dumping of soil, spoils, liquid, or solid materials, except for noncommercial composting of uncontaminated natural materials and except as permitted under this regulation. Page 21 of 29 Exhibit "A" (C) Roads or Driveways. There shall be no roads or driveways, except as permitted under these regulations. (D) Motorized Vehicles. There shall be no use of motorized vehicles of any kind, except as permitted under these regulations. (E) Disturbance of Natural Vegetation. There shall be no disturbance of natural vegetation within the SCPZ except for the following: (1) Maintenance of lawns, landscaping, shrubbery, or trees existing at the time of passage of this regulation. (2) Cultivation of lawns, landscaping, shrubbery, or trees in accordance with an approved Landscaping Plan submitted in conformance with this regulation. (3) Conservation measures designed to remove damaged or diseased trees or to control noxious weeds or invasive species. (F) Nothing in this section shall be construed as requiring a landowner to plant or undertake any other activities in the SCPZ provided the landowner allows for natural succession. (G) Parking Spaces or Lots and Loading/Unloading Spaces for Vehicles. There shall be no parking spaces, parking lots, or loading/unloading spaces. (H) New surface and/or subsurface sewage disposal or treatment area. SCPZs shall not be used for the disposal or treatment of sewage except for: (1) Undeveloped parcels that have received site evaluation approval and / or permit approval prior to the enactment of this ordinance. (2) Dwellings served by disposal /treatment systems existing at the time of passage of these regulations when such systems are properly sited (approved site evaluation) and permitted or in accordance with the Delaware, Franklin, or Union County Health Department and / or the Ohio Environmental Protection Agency. Existing failing systems which are located within the SCPZ can be upgraded with approval of the Franklin County Health Department and / or the Ohio Environmental Protection Agency. (I) Fences and Walls. There shall be no fences or walls. (J) Agriculture. There shall be no agricultural activities. (K) Industry/commercial business. There shall be no industrial or commercial businesses operated. (L) Ditching/diking. There shall be no ditching or diking of soil in order to convey water. (M) Removal of topsoil, sand, gravel, rock, native ground cover/vegetation, oil or gas. There shall be no removal of any of these substances nor any other change in topography other than what is caused by natural forces (with the exception of permitted uses or as approved by the City Engineer). Page 22 of 29 Exhibit "A " (N) Herbicides/ pesticides. There shall be no use of herbicides or pesticides except as approved by the City Engineer. § 53.230 FACILITIES PROHIBITED IN THE STREAM CORRIDOR PROTECTION ZONE. The following facilities are prohibited within the SCPZ: (A) Buildings/structures; (B) Swimming pools; (C) Signs; (D) Billboards; (E) Utility lines or pipes (with the exception of necessary public sanitary, water, stormwater and public utility transmission lines as approved by the City); (F) Electric lines (with the exception of transmission lines); (G) Telecommunications lines (with the exception of transmission lines); (H) Cable TV lines (I) Stormwater management facilities; and (J) Other improvements deemed unacceptable to the City. § 53.240 NON-CONFORMING STRUCTURES OR USES IN THE STREAM CORRIDOR PROTECTION ZONE. (A) Non-conforming structures and uses within the SCPZ, existing at the time of passage of these regulations, that are not permitted under these regulations may be continued but shall not be expanded, changed or enlarged except as set forth in this title. (B) If damaged, destroyed, terminated or abandoned, these structures or uses may be repaired or restored within six months from the date of damage /destruction or the adoption of these regulations, whichever is later, at the property owners own risk. (C) A residential structure or use within the SCPZ existing at the time of passage of these regulations may be expanded subject to the following provisions: (1) The expansion conforms to existing zoning regulations. (2) The expansion must not impact the stream channel or the floodway plus 20 feet limit. Page 23 of 29 Exhibit "A" (3) The expansion must not exceed an area of 15% of the footprint of the existing structure (or use) that lies within the SCPZ. Expansions exceeding 15% of the footprint within the SCPZ must be obtained through the variance process. (D) Non-residential structure (or use) expansions will be permitted only through the variance process. § 53.250 INSPECTION OF STREAM CORRIDOR PROTECTION ZONE. (A) The Stream Corridor Protection Zone shall be inspected by the City Engineer or designee: (1) When a preliminary subdivision plat or other land development plan is submitted to the City of Dublin. (2) When a building or zoning permit is requested. (3) Prior to any earth-disturbing activity to inspect the delineation of the SCPZ as required under these regulations. (4) When evidence becomes available that the provisions of these regulations become violated. (B) Violations of these regulations will be handled as noted in Section 53.210 C. § 53.260 VARIANCES, WAIVERS AND EXEMPTIONS (A)Exemptions from this section shall be in accordance with Section 53.070 (E) and the following: (1) Application for variances, waivers or interpretations regarding where SCPZ's may apply or SCPZ width shall be submitted to the City Engineer for examination and adjudication. The applicant may be required to provide analytical data or other scientific evidence to support variance requests. (2) The City Engineer reserves the right to exempt some development areas from this regulation provided that best engineering judgement is used to protect property from flooding or erosion damage. § 53.270 APPEALS (A) Appeals regarding prohibited uses and facilities, or rulings regarding modification of non-conforming structures, within SCPZ's, may be made to the Board of Zoning Appeals. § 53.300 EROSION AND SEDIMENT CONTROL REQUIREMENTS FOR CONSTRUCTION SITES Page 24 of 29 Exhibit "A " (A) This regulation of the City of Dublin, shall apply to earth-disturbing activities within the jurisdiction of the City of Dublin at the City Engineer's discretion, unless otherwise excluded within this regulation under Section 53.070 or unless expressly excluded by state law, including: land used or being developed for commercial, industrial, residential, recreational, public service or other non-farm purposes. (B) Earth disturbing activities associated with construction contribute to the pollution of public waters through soil erosion and sedimentation. Other construction activities may cause the discharge or deposition of construction materials and wastes into storm drains and surface waters. Control programs designed to minimize these problems should incorporate the planning, inspection, enforcement, and best management practices defined in § 53.300 through § 53.399. § 53.310 GENERAL EROSION AND SEDIMENT CONTROL REQUIREMENTS. (A)All development activity subject to these regulations shall be provided with erosion and sediment control (ESC) practices during all phases of construction. (B) No construction activity such as grading, cutting, or filling shall be commenced until erosion and sedimentation control devices have been installed to the satisfaction of the City Engineer. (C) Stormwater discharges during the five-year design storm shall be released to natural channels at anon-erosive velocity of less than three feet per second unless the channel is stabilized or otherwise able to withstand higher velocities, as determined by the City Engineer. (D)No person shall cause or allow earth- disturbing activities on a development area except in compliance with the standards set out in this regulation and the applicable items below: (1) An erosion and sediment control plan shall be submitted as part of the Stormwater Management Plan and approved prior to any earth-disturbing activities on development areas, including those development areas being a part of a larger common plan of development or sale. The person proposing such earth- disturbing activities shall develop and submit for approval a plan, as part of the final site improvement plans, containing erosion and sediment pollution control practices so that compliance with other provisions of this regulation shall be achieved during and after development. Such a plan shall address specific requirements contained with this regulation. (2) The erosion and sediment control plan must contain a description of the controls appropriate for each construction operation covered by this regulation and the operator(s) must implement such controls. The terms must clearly describe for each major construction activity (a) appropriate control measures and the general timing (or sequence) during the construction process that the measures will be implemented; and (b) which contractor is responsible for implementation (e.g., contractor A will clear land and install perimeter controls and contractor B will maintain perimeter controls until final stabilization). The erosion, sediment, and storm water management practices used to satisfy the conditions of this regulation Page 25 of 29 Exhibit "A " shall meet the standards and specifications in the current edition of Ohio's Rainwater and Land Development manual or other standards acceptable to the City Engineer. (3) Owners and/or operators of projects subject to OEPA's Permit No.: OH0000002 for storm water discharges associated with construction activities shall provide a copy of its OEPA notice of intent (NOI) submission and storm water pollution prevention plan (SWP3) to the City Engineer upon request. (4) The standards outlined herein are general guidelines and shall not limit the right of the City to impose additional, more stringent requirements, nor shall the standards limit the right of the City to waive individual requirements. § 53.320 STANDARDS AND CRITERIA FOR EROSION AND SEDIMENT CONTROL (A)The standards and criteria for ESC facilities will be contained in the same administrative policies and manuals, developed and maintained by the City Engineer, that define accepted design practices, procedures and guidance materials for stormwater management systems. § 53.330 SOIL EROSION AND SEDIMENT CONTROL PLAN REQUIREMENTS (B) The ESC Plan for the site shall be an integral part of the site's stormwater management plan. ESC Plan requirements and approval processes are defined in §53.110. § 53.340 EROSION AND SEDIMENT CONTROL COMPLIANCE RESPONSIBILITY (A) Responsibility. (1) ESC Plan approval does not constitute assurance that the proposed BMPs will perform in the manner indicated by the design. The responsibility of the proper functioning operation and maintenance of the BMPs remains with the owner. The owner shall be responsible for providing any additional means or methods necessary to meet the intent of these regulations. (2) It shall be the responsibility of the site owner to provide notification to the City 48-hours prior to commencement of initial site earth-disturbance. In addition, the site owner shall provide notification to the City, at least 48-hours prior to any work within or across a stream channel or SCPZ. Furthermore, within 45-days after Site Final Stabilization has been achieved, it shall be the responsibility of the site owner to inform the City Engineer that site activities are complete. (B) Performance Liability. No provision of this standard shall limit, increase or otherwise affect the liabilities of the developer nor impose any liability upon the City not otherwise imposed by law. Page 26 of 29 Exhibit "A " (C) Ownership and Maintenance. The person(s) or entity responsible for the continued maintenance of temporary and permanent erosion control measures shall, prior to any earth -disturbance, be identified to the satisfaction of the City. This party, both during and after site development, shall be responsible for: (1) Carrying out all provisions as approved on the erosion and sediment control plan and required by this standard, (2) Promptly removing all soil, miscellaneous debris and other materials that may become spilled, dumped or otherwise deposited on any public thoroughfares during transport to and from the development site, and taking precautions to inhibit the deposition of sediment into any sewer system or natural watercourse. (3) In addition, the developer shall assume responsibility and all costs for removing any sedimentation deposited in downstream drainage ways or facilities deemed objectionable by the City to the proper functioning of these downstream areas. (4) The applicant shall provide a description of maintenance procedures needed to ensure the continued performance of control practices and shall ensure the responsible party has adequate funding to conduct maintenance activities as deemed necessary. (5) All temporary and permanent erosion and sediment control practices shall be designed and constructed to minimize maintenance requirements. They shall be maintained and repaired as needed to assure continued performance of their intended function. All sediment control practices shall be maintained in a functional condition until all up slope areas they control reach final stabilization. Final stabilization shall be determined by the City Engineer. (D)Inspection and Enforcement. (1) General Inspection Requirements: (a) The City Engineer may inspect all site development activities, including erosion and sediment control devices and facilities while a development site, when subject to this regulation, is under construction. When facilities are not constructed according to approved plans, the City Engineer has the explicit authority to compel compliance with the approved plan and the objectives and standards of this regulation. (b) A copy of the approved erosion and sediment control plan shall be maintained on site, or in a location easily accessible by the applicant and the City's inspector. (2) Final Inspection: Prior to final inspection, the developer's engineer shall provide the site grading plan documenting the intended site final grades. (3) General Inspection Procedures: (a) Erosion and sediment control practices for construction sites shall be inspected periodically by the City to ensure they are being properly Page 27 of 29 Exhibit "A " maintained and, if not, the City may compel the owners to make the necessary repairs at the expense of the owner. When inspections reveal the need for repair, replacement, or installation of erosion and sediment control BMPs, the following procedures shall be followed: (b) When practices require repair or maintenance: If an internal inspection reveals that a control practice is in need of repair or maintenance, with the exception of asediment-settling pond, it must be repaired or maintained with three (3) days of the inspection. Sediment settling ponds must be repaired or maintained within ten (10) days of the inspection. (c) When practices fail to provide their intended function: If an internal inspection reveals that a control practice fails to perform its intended function as detailed in the ESC plan and that another, more appropriate control practice is required, the plan must be amended and the new control practice must be installed within ten (10) days of the inspection. (d) When practices depicted on the ESC plan are not installed: In an internal inspection reveals that a control practice has not been implemented in accordance with the schedule, the control practice must be implemented with ten (10) days from the date of the inspection. If the internal inspection reveals that the planned control practice is not needed, the record must contain a statement of explanation as to why the control practice is not needed. (4) Internal Inspections: (a) At a minimum, all controls on the site shall be inspected at least once every seven calendar days and within 24 hours after any storm event greater than one-half inch of rain per 24 hour period. The owner shall assign qualified inspection personnel (those with knowledge and experience in the installation and maintenance of sediment and erosion controls) to conduct these inspections to ensure that the control practices are functional and to evaluate whether the ESC Plan is adequate and properly implemented in accordance with the proposed permit schedule or whether additional control measures are required. The qualified inspection personnel shall inspect the following: (b) Disturbed areas used for storage of materials exposed to precipitation shall be inspected for evidence of or the potential for pollutants entering the drainage system. (c) Erosion and sediment control measures identified in the approved erosion and sediment control plan shall be observed to ensure proper operation. (d) Discharge locations shall be inspected to determine whether erosion and sediment control measures are effective in preventing significant impacts to the receiving water resource or wetlands. Page 28 of 29 Exhibit "A " (e) Locations where vehicles enter or exit the site shall be inspected for evidence of off-site vehicle tracking. (5) Inspection Reports: Inspectors shall prepare written reports after every inspection. The inspection report shall describe: (a) The date and location of the site inspection (b) Whether or not the approved plan has been properly implemented and maintained. (c) Any practice deficiencies or erosion and sediment control plan deficiencies; and the agreed upon type(s) of corrective action necessary to rectify any identified deficiencies. (d) If a violation exists, the City will decide upon the type of enforcement action taken. (e) The site manager shall sign and receive a copy of the report before the inspector leaves the site. (6) Enforcement. The City Engineer agency shall notify the on-site personnel or the owner/developer when deficiencies are observed, describing the nature of the deficiency, the agreed upon corrective action, and the time period in which to have the deficiency corrected. If after a reasonable amount of time for voluntary compliance, the corrective actions are not undertaken to the satisfaction of the City, the City may issue a Notice of Violation pursuant to Dublin City codes Section 153 and proceed with other enforcement remedies as provided by this and other applicable provisions of the Dublin City Codes. Where the violations and/or deficiencies represent an immediate and substantial threat to the public health, safety or welfare, the City may immediately proceed with enforcement remedies as provided by Dublin City Codes Section 153 and other applicable provisions of the Dublin City Codes. (E) Record Keeping. The applicant shall maintain for three (3) years following final stabilization the results of these inspections, the names and qualifications of personnel making the inspections, the dates of inspections, major observations relating to the implementation of the erosion and sediment control plan, a certification stating whether the facility is in compliance with the ESC plan, and information on any incidents of non- compliance determined by these inspections. § 53.999 PENALTY. (A) Whoever violates any provisions of this chapter is guilty of an unclassified misdemeanor with a maximum fine of $2,500 andlor six months in jail with each day of violation as a separate offense. Page 29 of 29 i s' DRAFT Sto rmwate r Mana ement g Desi n J Manual September XX, 2005 Paul A. Hammersmith, P.E. Director of Engineering/City Engineer CITE' DL=~il,i~. DRAFT THIS PAGE INTENTIONALLY LEFT BLANK City of Dublin . Stormwater Management Design Manual 2 September XX, 2005 DRAFT Table of Contents Introduction 5 Purpose 5 Applicability 5 Hydraulic design criteria 6 Detention/retention facilities 6 Studied areas 6 Unstudied areas 7 Storm sewers 8 Culverts and bridges ...............................................................................10 Open channels ........................................................................................11 Stormwater runoff quality ......................................................................12 Filter Strips and Swales 13 Wet detention basins and stormwater wetlands 14 Extended dry detention basins 16 Media filters 16 Other BMPs 17 Mosquito Control Considerations 17 Floodplain encroachment calculations 17 Sinkholes 18 Stormwater Management Plan 18 General Requirements 18 Map Content 19 Calculations 20 Erosion and Sediment Control 22 Plan Content 23 Calculations 25 Standards & Criteria for Erosion 8~ Sediment Control 25 APPENDIX 30 City of Dublin .Stormwater Management Design Manual 3 September XX, 2005 DRAFT THIS PAGE INTENTIONALLY LEFT BLANK City of Dublin • Stormwater Management Design Manual 4 September XX, 2005 DRAFT Introduction Purpose The purpose of this manual is to provide City standards and maintain uniformity in design standards for stormwater management. This also allows the City to provide effective and efficient review of design data. Stormwater management is an evolving science. The goal of the City is to be responsive to updating its standards to reflect the most innovative, creative and cost-effective practices available. To achieve this goal, this manual will be revised and updated as necessary to reflect accepted new standard practice s in the area of stormwater management. Applicability This manual applies to all projects in the City. This includes the alteration, construction, installation, demolition or removal of a structure, impervious surface or drainage facility; or clearing, scraping, grubbing, killing or otherwise removing the vegetation from a site; or adding, removing, exposing, excavating, leveling, grading, digging, burrowing, dumping, piling, dredging or otherwise significantly disturbing the soil, mud, sand or rock of a site. This manual will be effective on September XX, 2005. Any projects that occur after this date must comply with this manual and the adopted Chapter 53, Stormwater Management and Stream Protection. City of Dublin • Stormwater Management Design Manual rJ September XX, 2005 DRAFT A. Hydraulic design criteria 1. The City's Stormwater Master Plan shall be used to provide design flows and detention requirements for major drainage systems within the City. 2. For on-site drainage systems, hydrograph routing methods shall be used to design stormwater detention facilities, and either hydrograph routing or peak flow methodologies may be used to design stormwater conveyance facilities. 3. Hydraulic Design Criteria (53.090(B)(1)): Rainfall intensities are to be obtained from the "Rainfall Frequency Atlas of the Midwest", 1992. Rainfall intensity- duration-frequency curves, which were developed from this Atlas and which can be used to determine rainfall intensities, are graphically depicted in the Appendix. B. Detention/retention facilities. A detention/retention facility shall be installed on all development projects, unless the applicant demonstrates that the project will not increase the peak rate of runoff; volume, or frequency of the runoff hydrograph of the site prior to development. Detention/retention facilities shall be designed in the following manner: 1. Studied areas. Parcels located within drainage sub-basins established in the Stormwater Master Plan, or any subsequent update thereto shall comply to the runoff release rate for each frequency storm specified in the Stormwater Master Plan. a. Critical storm controls. Determine the total volume of runoff from a 1-year, 24-hour storm, occurring over each of the site's drainage areas before and after development. b. Determine the percent of increase in runoff volume due to development and using this percentage, select the critical storm from the table: CRITICAL STORM DETERMINATION If the Percent of Increase in Runoff Volume is The Critical Storm Runoff Equal to or Rate Will Be Greater than And less than Limited to: 10 1 year 10 20 2 year 20 50 5 year City of Dublin • Stormwater Management Design Manual s September XX, 2005 DRAFT 50 100 10 year 100 250 25 year 250 500 50 year 500 100 year c. The peak rate of runoff from the critical storm occurring over the developed site shall not exceed the peak rate of runoff from a 1-year, 24-hour storm occurring over the same area prior to development, as defined in the Stormwater Master Plan. Storms of less frequent occurrence (longer return period) than the critical storm, shall have the peak rate of runoff not greater than for the same storm under pre- development conditions. 2. Unstudied areas. Detention/retention facilities designed for parcels located outside drainage sub-basins established with the Stormwater Master Plan, or any subsequent update thereto shall comply to the following minimum design criteria: a. Development of sites other than single-family and less than or equal to 2.0 acres shall not release Stormwater runoff greater than 0.2 cubic feet per second per acre of development. On-site detention storage shall be provided to achieve these peak flow rates. b. Development sites greater than 2.0 acres (including single-family lots) shall provide runoff controls as defined by the MORPC Stormwater Design Manual. 3. Stormwater detention and retention ponds which are considered by Ohio Department of Natural Resources (ODNR) to be dam structures regulated under the dam safety laws of the State of Ohio shall be designed to safely pass the design flood events as defined by ODNR. Where fill berms are proposed, calculations supporting the stability of the fill berms are to be submitted by a licensed professional engineer with demonstrated experience in geotechnical engineering. The applicant shall design all raised bermed Stormwater ponds according to current ODNR dam safety criteria (refer to § 53.060 hereof). 4. If the site has multiple drainage basins, the drainage basin divides that exist prior to development shall be used to determine predevelopment rates of discharge for each drainage area of the site. 5. Fenced Stormwater facilities are strongly discouraged within the city and shall only be permitted if approved by the city. The city will consider fencing Stormwater facilities only where steep slopes which potentially endanger human life are City of Dublin •Stormwater Management Design Manual 7 September XX, 2005 DRAFT unavoidable. If fencing is required, the design shall conform to the City's fence code (Chapter 153 of the Zoning Code) along the right-of--way boundary around the entire perimeter, including maintenance berms with access for maintenance vehicles. Other designs may be permitted subject to the review and approval of the City Engineer. 6. Areas adjacent to stormwater detention and retention basins and ponds shall be graded to restrict the entrance of stormwater except at planned locations. Where retention/detention basins are located on the project periphery, the developer may be required to provide additional landscaping or screening to adequately protect abutting properties. 7. The minimum requirement for maintenance berms is as follows: PONDS MINIMUM MAINTENANCE ACCESSWAY REQUIRED With erimeter fencing 20 feet around perimeter Without perimeter fencing 15 feet around perimeter Access easement 20 feet along a designate corridor between the pond and a public right-of--way (lessor accessways are subject to the approval of the City Engineer 8. Detention/retention basins designed to meet the requirements of this chapter shall also be designed to meet the stormwater runoff quality requirements. 9. Headwalls shall be required at all storm sewer inlets or outlets to and from stormwater management facilities. Stone and/or brick approved by the City Engineer shall be provided on all visible headwalls. C. Storm sewers. 1. Public storm sewers shall be designed such that they do not surcharge from runoff caused by the 5-year, 24-hour storm, and that the hydraulic grade line of the storm sewer stays below the gutter flow line of the overlying roadway, or below the top of drainage structures outside the roadway during a 10-year, 24-hour storm. 2. Private storm sewers shall be designed such that they do not surcharge from runoff caused by the 2-year, 24-hour storm, and that the hydraulic grade line of the storm sewer stays below the gutter flow line of the overlying roadway, or below the top of drainage structures outside the roadway during a 5-year, 24-hour storm. The system shall be designed to meet these requirements when conveying the flows from the contributory area within the proposed development and existing flows from offsite areas that are upstream from the development. City of Dublin • Stormwater Management Design Manual $ September XX, 2005 DRAFT 3. Stormwater runoff from offsite areas that discharge to or across a development site shall be conveyed through the stormwater facilities planned for the development site at their existing peak flow rates during each design storm. No stormwater management plans will be approved until it is demonstrated that offsite runoff will be adequately conveyed through the development site in a manner that will not exacerbate upstream or downstream flooding and erosion. 4. The minimum inside diameter of pipe to be used in public storm sewer systems is 12 inches. Smaller pipe sizes may be used in private systems, subject to the approval of the City Engineer. 5. All storm sewers shall be designed and constructed to produce a minimum velocity of 3.0 feet per second (fps) when flowing full. The City Engineer may impose additional hydraulic design criteria for any storm sewer system or portion thereof designed at a supercritical slope and/or with afull-flow velocity in excess of 10 fps; in addition, the outlet ends of all storm sewers shall be provided with sufficient energy dissipaters and erosion protection. 6. The following maximum lengths of pipe shall be used when spacing access structures of any type: PIPE SIZE STRUCTURE SPACING 12 to 18 inches 300 feet 24 to 36 inches 400 feet 42 inches and larger 500 feet 7. All storm sewer systems shall be designed taking into consideration the tailwater of the receiving facility or waterbody. The tailwater elevation used shall be based on the design storm frequency. 8. The hydraulic grade line for the storm sewer system shall be computed with consideration for the design tailwater on the system defined in the Stormwater Master Plan and the energy losses associated with entrance into and exit from the system, friction through the system, and turbulence in the individual manholes, catch basins, and junctions within the system. 9. The minimum cover for storm sewers within the right-of--way shall be one foot measured from the top outside of pipe to the bottom of underdrain at the back of curb. Should underdrains not be required, the minimum cover shall be one foot measured from the top outside of pipe to the top of subgrade at the back of curb. Outside street right-of--way, a minimum two feet of cover shall be provided measured from the top of finished ground surface to the top outside of pipe. 10. The maximum distance for overland flow shall be 300 feet before entering a storm structure. Except, that the maximum overland drainage area tributary to the storm structure shall be no greater than 1.5 acres. City of Dublin • Stormwater Management Design Manual 9 September XX, 2005 DRAFT 11. The maximum spacing of curb inlets shall not exceed 300 feet, or that spacing which shall permit a maximum permissible spread. Spread calculations shall be provided with all storm drainage calculations. Maximum permissible spread is 6' from edge of pavement for streets less than 28 feet measured back to back of curb. A 12-foot clear lane shall be maintained for streets wider than 28 feet. A design storm of 5-years shall be used for determine allowable spread. 12. Yard inlets shall be spaced no farther apart than every third lot. Side and back yard drains and inlets shall be constructed per the City Standard Drawing. The property shall be graded in such a way to provide that the stormwater can reach the inlet through a swale or another measured as approved by the City Engineer. 13. The inverts of all curb inlets, manholes, yard inlets, and other structures shall be formed and channelized. 14. Storm inlets, yard inlets or catch basin grates shall be of a type to permit safe crossing by bicycles as approved by the City Engineer. 15. In areas where public safety concerns (specifically with children) and welfare are an issue, the City Engineer may require that any storm sewer outlet greater than 18 inches in diameter accessible from stormwater management facilities or watercourses shall be provided with safety grates, as approved by the City Engineer. 16. Headwalls shall be required at all storm sewer inlets or outlets to and from open channels or lakes. Stone and/or brick approved by the City Engineer shall be provided on all visible headwalls. D. Culverts and bridges. 1. Roadway stream crossings other than bridges shall be designed to convey the stream's flow for the 25-year, 24-hour storm, with a maximum headwater depth that does not cause flooding or significantly pressurize the culvert, as defined by the Ohio Department of Transportation. 2. The minimum inside diameter of pipes to be used for culvert installations under roadways shall be 12 inches. The minimum inside diameter of pipes to be used for driveway crossings shall be 12 inches. 3. The maximum slope allowable shall be a slope that produces a 10-fps velocity within the culvert barrel. Erosion protection and/or energy dissipaters shall be required to properly control entrance and outlet velocities. City of Dublin • Stormwater Management Design Manual 'I ~ September XX, 2005 DRAFT 4. All culvert installations shall be designed with consideration for the tailwater of the receiving facility or waterbody. The recurrence frequency of the tailwater elevation shall be the same as the culvert design storm frequency. 5. The determination of the required size of a culvert installation can be accomplished by mathematical analysis or by the use of design nomographs. 6. Headwalls shall be required at all culvert inlets or outlets to and from open channels or lakes. Stone approved by the City Engineer shall be provided on all visible headwalls. 7. The minimum cover for culverts within the right-of--way shall be one foot measured from the top outside of pipe to the bottom of underdrain at the back of curb. Should underdrains not be required, the minimum cover shall be one foot measured from the top outside of pipe to the top of subgrade at the back of curb. Outside street right-of--way, a minimum two feet of cover shall be provided measured from the top of finished ground surface to the top outside of pipe. The structural design of culverts and bridges shall be the same as that required by the Ohio Department of Transportation. 8. Bridges shall be designed such that the hydraulic profile through a bridge shall be below the bottom chord of the bridge for either the 100-year, 24-hour storm, or the peak 100-year flood elevation, whichever is more restrictive. 9.100-year HGL (53.090(E)(1)): Demonstrate that the hydraulic grade line resulting from the 100-year, 24-hour storm does not encroach on the roadway above the culvert or above the low chord of bridge. The HGL shall be shown graphically on the storm sewer construction plans or on a tabulation spreadsheet. 10. Velocities (53.090(E)(3)): Tabulate the culvert flow velocities, and demonstrate that the velocities do not exceed 10 feet per second within the culvert barrel.. 11. Tailwater and energy loss (53.090(E)(4-6)): List all tailwater assumptions and their source for applicable design storm events. List the energy loss assumptions at the entrance/exit of the structure. E. Open channels. 1. Where applicable, streams within the City shall be preserved and protected according to criteria in Section 53.200. Requirements for increasing the conveyance capacity, repairing streambank erosion damage, restoring floodplain storage, and/or rehabilitating aquatic or riparian habitat shall be determined by the City Engineer based on the Stormwater Master Plan or other site-specific criteria necessary to protect the public health, safety and welfare or satisfy pertinent state and federal regulatory requirements. City of Dublin • Stormwater Management Design Manual 11 September XX, 2005 DRAFT 2. Wherever possible, drainage tributary to streams, wetlands, lakes, and detention facilities shall be maintained by an open channel with landscaped banks designed to carry the 10-year, 24-hour stormwater runoff from upstream contributory areas. The City Engineer may increase the design storm as conditions require. 3. Alterations to streams and other open channels within FEMA floodplains shall be designed according to the requirements of Chapter 151 of the Dublin Code of Ordinances along with the requirements contained with this chapter. All open channels shall be designed with one foot of freeboard above the design water surface elevation of the open channel flowing full. 4. Flood relief channels shall be designed to convey the runoff from the 100-year, 24-hour storm, such that a positive discharge of this runoff to an adequate receiving stream or conveyance system results without allowing this runoff to encroach into proposed or existing residential dwellings or places of business. 5. Roadside ditches along existing roadways may be required by the city to be enclosed if ODOT standards for safety and maintenance cannot be satisfied. 6. Capacity (53.090(F)(1)): Demonstrate that the hydraulic grade line resulting from the 10-year, 24-hour storm does not rise to within one foot of the top of bank. 7.100-year HGL (53.090(F)(2)): Demonstrate that the water elevation resulting from the 100-year, 24-hour storm does not encroach into proposed or existing residential dwellings or places of business. The flood elevation shall be shown on the Stormwater Management Map for the project. F. Stormwater runoff quality. 1. No person shall: a. Construct, maintain, operate, and/or utilize any illicit connection. b. Cause, allow or facilitate any prohibited discharge. c. Act, cause, permit, or suffer any agent, employee, or independent contractor to construct, maintain, operate or utilize any illicit connection, or cause, allow or facilitate any prohibited discharge. 2.Outdoor activity areas within the development site shall be delineated on the Stormwater Management Plan, and the activities that will be conducted within them shall be described in the Plan. 3. Runoff from outdoor activity areas shall not be allowed to co-mingle with runoff from the remainder of the site, and shall be directed to separate treatment systems, as approved by the City Engineer. City of Dublin •Stormwater Management Design Manual ~ 2 September XX, 2005 DRAFT 4. The site shall be designed to direct runoff from areas other than outdoor activity areas to one or more of the following stormwater quality treatment best management practices (BMPs): a. Swales; b. Filter strips; c. Wet detention basins; d. Extended dry detention basins; e. Media filters; or f. Other approved BMPs. 5. The design water quality volume for these BMPs shall be the runoff from the first three-quarter inch of rainfall of each and every storm event. Runoff calculations in this section shall use runoff quality coefficients appropriate for storm events of less than 1 inch of precipitation under average antecedent moisture conditions. 6. In addition, BMPs shall be designed to accommodate flows exceeding their design capacity, either by bypassing excess flows, conveying excess flows through the facility without disrupting its stormwater quality control effectiveness, or storing excess flows as necessary to achieve the drainage, flood control, and erosion control objectives of this chapter. 7. Filter Strips and Swales a. Drainage areas of all swales and filter strips shall not exceed five acres or possess slopes greater than 2.0 percent. They shall be designed to convey a hydrograph with the following characteristics: 1. Vh = A*r*P (acre-feet), where: 2. Vh =hydrograph volume, acre-feet 3. A =area tributary to the basin, acres 4. r =runoff quality coefficient 5. P =mean storm precipitation volume = 0.0625 feet 6. Hydrograph duration = 2 hours b. Hydrograph peak shall be calculated according to the Rational Formula methodology. c. Maximum depth of flow shall be no greater than three inches. d. Swales and filter strips shall be lined with fine, turf-forming, water- resistant grasses to slow and filter flows. e. Hydrograph volume (53.090(H)(4)): Show the calculation of hydrograph volume (Vh) as described in the Ordinance. City of Dublin • Stormwater Management Design Manual 13 September XX, 2005 DRAFT £ Hydrograph intensity (53.090(H)(4)): Show the calculation converting the hydrograph volume to an intensity (in inches per hour) over two hours. This calculation can be made by multiplying the hydrograph volume (in acre-feet) by 6, then dividing this quantity by the area (in acres) tributary to the Swale. g. Intensity-duration-frequency curve (53.090(H)(4)): Show the intensity- duration-frequency curve that is used to determine the intensity corresponding to the time of concentration. This is accomplished by drawing a curve parallel to the "Rainfall Frequency Atlas of the Midwest " intensity-duration-frequency curves that contains the point with a 2-hour duration and the intensity calculated in Step 2 above. An example curve is shown on Attachment D of this document. h. Design flow rate (53.090(H)(4)): Show the calculation of the swale/filter strip design flow rate using the Rational Formula. The intensity used in the calculation is obtained from the curve drawn in Step 3 above, at a duration equal to the time of concentration for the tributary area. i. Geometry (53.090(H)(4)): Show the calculation of the swale/filter strip cross-section geometry using the Manning Equation. Demonstrate that the flow depth is no greater than three inches for the design storm calculated above. J• 8. Wet detention basins and stormwater wetlands a. Shall consist of a permanent pool volume (Vb) that does not drain between storm events, plus an extended detention volume of approximately equal size above the permanent pool, plus a sediment storage volume at least 20 percent of the volume of the permanent pool. The permanent pool and extended detention volumes shall each be sized according to the following equation: 1. Vb = 0.75A*r *P (acre-feet), where: 2. Vb =permanent pool or extended detention volumes, acre-feet 3. A =area tributary to the basin, acres 4. r =runoff quality coefficient 5. P =storm precipitation depth = 0.0625 feet 6. b. Therefore, the total volume of the facility = Vb + Vb + 0.2V6 = 2.2Vb c. The outlet shall be designed to release the entire extended detention volume in no less than 24 hours. A method shall also be provided to drain City of Dublin •stormwater Management Design Manual 14 September XX, 2005 DRAFT the permanent pool volume to facilitate the removal of accumulated sediments and other maintenance activities. The outlet shall also be designed to minimize clogging, vandalism, and maintenance. d. The basin design shall incorporate the following features to maximize multiple uses, aesthetics, safety, maintainability, and compatibility with the urban landscape:. e. Basin side slopes above the permanent pool shall have a run to rise ratio of 4:1 or flatter. One foot of freeboard shall be provided. f. To promote growth of wetland vegetation over 25 to 50 percent of the pond surface area, an aquatic bench, with 10:1 side slopes, shall be provided, with a maximum depth of 18 inches below the proposed normal pool water surface elevation and a minimum of five feet wide. The aquatic bench shall be planted with hearty plants comparable to wetland vegetation which are able to withstand prolonged inundation. g. Basin depths in open water areas shall not exceed 12 feet to prevent thermal stratification. h. A forebay or other sediment removal devices designed to allow larger sediment particles to settle shall be placed at basin inlets. The forebay volume shall be equal to approximately 10% of the extended detention volume (Vb). Hard-bottomed forebays shall be required for those facilities maintained by the City. Alternative bottoms for all other forebay facilities maintained non-municipal parties shall be approved by the City Engineer and contingent upon providing details of a maintenance plan which addresses related potential access issues. i. Astable vehicular access way shall be provided to forebays and outlets. j. The wet ponds or wetland shall be designed and maintained in a manner that maintains to improve water quality (oxygen levels) such that unwanted vegetation, stagnation and mosquito colonies are prevented and the water quality remains habitable for aquatic species. The City Engineer shall develop and enforce design and maintenance criteria that achieve this objective which may include but is not limited to aquatic habitat design features, vegetation control measures and mechanical aerators. k. Stormwater wetlands may be used in place of the permanent pool if designed and constructed according to recognized wetland design principles. The wetland shall have a water volume equal to the required volume for the permanent pool, and shall consist of depressed, heavily planted areas designed to maintain flow during dry periods in order to support aquatic vegetation. The amount of surface area required for a City of Dublin • Stormwater Management Design Manual 15 September XX, 2005 DRAFT stormwater wetland is typically larger than that of a wet pond due to the limited allowable depths required for wetland design. 9. Extended dry detention basins a. Shall consist of an extended detention volume and a sediment storage volume at least 20 percent of the volume of the permanent pool. The extended detention volume shall be sized according to the following equation: 1. Vb = A*r*P, where: 2. Vb =extended detention volumes, acre-feet 3. A =area tributary to the basin, acres 4-. r =runoff quality coefficient 5. P =storm precipitation volume = 0.0625 feet 6. b. Therefore, the total volume of the facility = Vb + 0.2Vb = 1.2Vb c. The sediment storage volume shall be no less than 20 percent of the extended detention volume. The outlet shall be designed to release 50 percent of the extended detention volume in no less than 16 hours, and the remainder of the extended detention volume in no less than 32 hours (for a total of 48 hours). d. The outlet shall also be designed to minimize clogging, vandalism, and maintenance. The basin design shall incorporate the following features to maximize multiple uses, aesthetics, safety, maintainability, and compatibility with the urban landscape: e. Basin side slopes shall have a run to rise ratio of 4:1 or flatter and vegetated to prevent bank erosion and minimize drowning risk. Bottom channels shall be graded shall be such that it drains within 72 hours to prevent standing water. One foot of freeboard shall be required. f. A forebay or other sediment removal device designed to allow larger sediment particles to settle shall be placed at basin inlets. The forebay shall be equal to approximately 10% of the extended detention volume (Vb)• g. Astable vehicular access way shall be provided to forebays and outlets. 10. Media filters a. Shall consist of a settling basin followed by a filter basin filled with sand, peat, or amended soil or other media with a diameter between 0.02 and City of Dublin • Stormwater Management Design Manual 16 September XX, 2005 DRAFT 0.04 inches, as approved by the City Engineer. The settling basin shall have a settling volume calculated using the following: 1. Vb = A*r*P, where: 2. Vb =settling volume, acre-feet 3. A =area tributary to the basin, acres 4-. r =runoff quality coefficient 5. P =storm precipitation volume = 0.0625 feet b. The settling basin shall also include a sediment storage volume no less than 20 percent of the settling volume. The settling basin shall also have a length to width ratio of at least 2 to 1, and a depth between 3 feet and 10 feet. The outlet of the settling basin shall be sized to release the entire settling volume within 40 hours (extended drawdown time). The filter basin shall be designed with a surface area of 600 square feet per tributary impervious acre, a filter depth of 1.5 feet, and a maximum water depth above the filter surface of 6 feet. 11. Other BMPs may be recommended to satisfy the requirements of this chapter if the stormwater management plan for the site demonstrates to the satisfaction of the City Engineer that these BMPs achieve effluent quality and runoff volume reduction equivalent to approved. BMPs can be adequately maintained and satisfy other sections of the stormwater regulations. 12. Mosquito Control Considerations. Growth of aquatic vegetation shall be restricted to the periphery of detention ponds. The presence of a mechanical aerator (Section 53.090 (H) (5)), such as a fountain in the middle of the pond, may be used to make the site more attractive, deter the growth of unwanted vegetation, and make the habitat more suitable for fish. In general, grading of stormwater drainage structures shall be such that water is not retained for longer than 72 hours. G. Floodplain encroachment calculations shall be presented in the following format: 1.100-year HGL (53.080(B)): Demonstrate that development in a FEMA Special Flood Hazard Area (SFHA) flood plain does not increase the 100-year flood elevations. Show calculations or computer model output that demonstrates the pre-development and post-development flood elevations. Developer should include an SFHA permit and the appropriate fee with the Stormwater Management Plan. 2. Compensating storage (53.080(B)): Demonstrate that any volume of fill placed in the 100-year floodplain is compensated with an equal volume of material City of Dublin •Stormwater Management Design Manual ~ 7 September XX, 2005 DRAFT removed above the ordinary high water table and below the 100-year flood elevation. Show the volume calculation for the fill and the compensating storage. H. Sinkholes. 1. Construction in Sinkhole Drainage Areas: The immediate area around a sinkhole should be disturbed as little as possible. The use of mechanized equipment near the sinkhole should be avoided. Sink areas are known to be unstable for construction. Structures placed on soil foundations in sink areas may be subject to both settling and collapse of the sink. Uncontrolled fill placement may present additional settlement hazards. It shall be required that appropriate geotechnical studies be done and measures taken to insure structure foundations are designed to take into account potential sinkhole locations and instability. Such studies shall account for potential foundation problems for both undisturbed sink areas and those previously filled by others. 2. The floodplain line for a sinkhole is defined by the sinkhole lip elevation. Therefore, the storage volume beneath this elevation is the sinkhole floodplain storage volume. The pre-development floodplain storage volume must be preserved under post development conditions. If any fill is added in the floodplain outside the no-fill lines, compensating excavation in the floodplain shall be required. 3. The no-fill line shall be established by the contour line or interpolated contour line for the elevation that defines 60% of the floodplain storage volume. The area encompassed by this line shall be defined as a no-fill zone for all construction activities. No construction fill will be allowed in this zone. 1. Stormwater Management Plan 1. General Requirements. a. A stormwater management plan shall be prepared by the applicant for each proposed development activity and approved by the City Engineer in accordance with Section 53.120 if the plan demonstrates that the proposed development activity has been planned and designed, and shall be implemented and maintained to meet the performance criteria described herein. b. This stormwater plan shall be part of the overall submitted improvement plan and not a separate submittal. Supporting calculations for each design storm specified in § 53.090 hereof shall be submitted (hard copy and original copy) and will contain, as a minimum, a runoff hydrograph for the undeveloped and developed site, stage-storage calculations for the City of Dublin • Stormwater Management Design Manual ~ 8 September XX, 2005 DRAFT detention facility, stage-discharge calculations for the outlet structure, and a runoff hydrograph after routing through the proposed detention facility. All routing calculations shall account for tailwater conditions of the receiving facility, and shall be submitted to the city. c. The Stormwater Management Plan shall be a bound report containing all pertinent stormwater calculations for detention/retention basins, storm sewers, culverts, open channels, and other stormwater management system features, including best management practices (BMPs) specified in the Stormwater Ordinance. The Stormwater Management Map shall be included in a sleeve page or pocket of the report. The construction plans shall be submitted with the report, but not attached to it. The report shall contain divider pages with labeled tabs that clearly identify the calculations contained in each section. 2. Map Content. a. The project engineer shall include in the construction plans a master stormwater management map showing all existing and proposed features, including trees. The map is to be prepared on a 24-inch by 36-inch sheet on a scale not to exceed 1" = 400'. Listed below are the features that are to be included on the map. 1. based on state plane coordinate system 2. existing and proposed contours at one-foot intervals 3. north arrow and scale 4. predevelopment and postdevelopment subbasins overlaid on the same map including on and offsite contriburary area. The acreages shall be shown. 5. Downstream recieivin waterway of drainage system 6. predevelopment and post developemtn overland flow paths to and from the management basins 7. soil type by subbasin including hydrologic soil group designation of A, B, C or D 8. Hydrologic boundaries, including all axeas flowing to the proposed project. 9. Project boundaries and area. 10. Sufficient topographical information with elevations to verify the location of all ridges, streams, etc. (one-foot contour intervals within the project's boundaries and for proposed offsite improvements). 11. High water data or critical flood elevations on existing structures upstream of, within, and downstream of the project. 12. Notes indicating sources of high water data and critical flood elevations. City of Dublin • Stormwater Management Design Manual 19 September XX, 2005 DRAFT 13. Notes pertaining to existing standing water, areas of heavy seepage, springs, wetlands, streams, and hydrologically sensitive areas. 14. Existing stormwater management features (ditches, pipes, roadways, ponds, and BMPs). Existing stormwater management features are to be shown a minimum of 1,000 feet downstream of the proposed development unless the ultimate outfall system is a lesser distance. 15. Subdivision layouts with horizontal and vertical controls. 16. Proposed and existing stormwater management features, including locations of inlets, swales, pipes, detention/retention facilities, BMPs, ponding areas, and all works. 17. Delineation and area of pre-development and post-development sub-basins. 18. Delineate retention/detention facilities and ingress/egress areas for facilities maintenance. 19. General type of soils by sub-basin and location of soil borings. 20. Ten-, 25-, and 100-year flood elevations for any areas in or within 100 feet of the property. The source of these elevations shall also be shown on the plans. 21. Description of current ground cover, land use, and an estimate of the impervious area and percent imperviousness created by the construction activity by sub-basin. 22. Delineate the stream corridor protection zone along any streams within or adjacent to the site. 3. Calculations. Stormwater calculations (hard copy and original copy), signed and sealed by a professional engineer (registered in the State of Ohio) that the plan has been prepared in accordance with the regulations of the ordinance, and in accordance with good engineering practices and principles for all stormwater works, including design high water elevations for all applicable storm events. Software/models that utilize this methodology and technique and which are deemed acceptable to the City include but are not limited to SWMM, TR-55, PONDPAK, HEC-1, etc. The City will not accept methodologies that do not perform dynamic routing of hydrographs, which include but are not limited to the Bowstring Methodology, Mass Diagram Analysis, etc. The calculations shall include the following: a. Pre- and post-development stormwater flows and stages for the site and retention/detention ponds for all design storm frequencies pertinent to the project based upon the requirements of the stormwater regulations, including, but not limited to, the following: 1. Critical Storm Calculation (53.090)(C)(1-2)): Show the calculation of the total volume of runoff from a 1-year, 24-hour storm, before and after development. Show the calculation of City of Dublin • Stormwater Management Design Manual 2~ September XX, 2005 DRAFT percent increase in runoff volume, and reference Table 53-01 to determine the critical storm. 2. On-Site and Off-Site Area Allocation(s) (53.090)(C)(1-2)): Show the allocation of on-site and off-site area contributory to the facility for each Stormwater Master Plan sub-basin as follows: Area Allocation Table Exam le Sub-Basin On-Site Area Off-Site Area Total (acre) Identifier # acre (acre 5560 5.4 0.0 5.4 5570 10.5 0.0 10.5 5580 2.4 12.2 14.6 Total acre) 18.3 12.2 30.5 3. Pre-development hydrograph, post-development runoff hydrograph to the stormwater pond, and the routed post-development hydrograph discharged from the Stormwater pond. 4. Pre-development and post-development runoff volumes. 5. Stage-area-storage calculations for the Stormwater pond. 6. Stage-discharge calculations for the outfall control structure, including tailwater assumptions. 7. Release rate calculation (53.090)(C)(1-2)): Calculate the maximum release rate for each design storm using the critical storm criteria and referencing Appendix C of the Stormwater Master Plan and the Area Allocation table. Include a summary of the release rates as follows: Stormwater Management Summary Table 1 year 2 year 5 year 10 year 25 year 50 year 100 year Predeveloped Q Postdeveloped Q Allowable Release Actual Release Pond Depth/Elev 8. Show the calculation that is used to determine the maximum release rate for each storm. 9. Stormwater quality control BMP volumes and recovery calculations. Show calculations or model output that demonstrates the release of the extended detention volume over the time period specified in the Ordinance. City of Dublin •Stormwater Management Design Manual Z~ September XX, 2005 DRAFT b. Soil storage or curve number calculations per sub-basin, including impervious calculations. c. Time of concentration calculations per sub-basin. d. 100-year floodplain compensating calculations, if applicable. e. Storm sewer, culvert, open channel and BMP tabulations, including, but not limited to, the following: 1. Location and type of structures. 2. Length of facility and dimensions, including diameter, height, and/or width for pipes. 3. Cross-sections for-open channels. 4. Sub-basin areas tributary to each structure. 5. Runoff coefficients or curve numbers per sub-basin for both the pre-construction and post-construction site conditions. 6. Time of concentration to the inlet of each structure. 7. Each stormwater flow to and from the stormwater structure or junction point. 8. Hydraulic gradient for the applicable storm event, including losses through structures with friction and local loss coefficients. 9. Estimated receiving water elevation with sources of information, if available. 10. Velocities for all facilities and details for provisions to control erosion. f. Construction plans including, but not limited to, the following: 1. Overall project plan of roads, lots, and retention or detention facilities. 2. Cross-section of retention/detention facilities and BMPs. 3. Typical Swale, ditch, or canal sections. 4. Drainage rights-of--way. 5. Road plan and profile with groundwater elevation shown in profile. 6. Overall project grading plan (at 1-foot contours) and individual lot grading plans. 7. Density of the project. J. Erosion and Sediment Control 1. When required by this regulation, a soil erosion and sediment control plan shall be prepared for the earth disturbance activities. Furthermore, in accordance with the appropriate requirements of § 53.310, the plan shall be prepared, submitted to the City, and approved by the City, prior to any earth- disturbance. City of Dublin • Stormwater Management Design Manual ZZ September XX, 2005 DRAFT 2. The plan shall serve as a basis for all subsequent grading and stabilization and be incorporated as part of the final construction drawings. 3. Plan Content. a. Any person seeking approval of an earth disturbance proposal shall, on a map rendered from a base derived from the site Stormwater Management Plan or site grading plan, at a scale not to exceed 1" - 100', provide the following information: 1. A description of the nature and type of the construction activity (e.g., low density residential, shopping mall, highway, etc.) 2. Total area of the site and the area of the site that is expected to be disturbed (i.e., grubbing, clearing, excavation, filling or grading, including off-site borrow areas). 3. Existing data describing the soil and, if available, the quality of any discharge from the site. 4. A description of prior land uses at the site. 5. An implementation schedule which describes the sequence of major construction operations (i.e., grubbing, excavating, grading, utilities and infrastructure installation) and the implementation of erosion, sediment and storm water management practices or facilities to be employed during each operation of the sequence. 6. The name and/or location of the immediate receiving stream or surface water(s) and the first subsequent named receiving water(s) and the aerial extent and description of wetlands or other special aquatic sites at or near the site which will be disturbed or which will receive discharges from disturbed areas of the project. 4. For subdivided developments where the Stormwater Management Plan does not call for a centralized sediment control capable of controlling multiple individual lots, a detail drawing of a typical individual lot showing standard individual lot erosion and sediment control practices. This does not remove the responsibility to designate specific erosion and sediment control practices in the Stormwater Management Plan for critical areas such as steep slopes, stream banks, drainage ways and stream corridor protection zones. 5. Location and description of any storm water discharges associated with dedicated, on-site asphalt and concrete plants covered by this permit and the best management practices to address pollutants in these storm water discharges. 6. A description of the intended maintenance plan with associated frequencies shall be required for the site. 7. Site map showing: City of Dublin . Stormwater Management Design Manual 23 September XX, 2005 DRAFT a. Limits of earth-disturbing activity of the site including associated off-site borrow or spoil areas that are not addressed by a separate NOI and associated Stormwater Management Plan. b. Soils types should be depicted for all areas of the site, including locations of unstable or highly erodible soils. c. Existing and proposed contours. d. A delineation of drainage watersheds expected during and after major grading activities as well as the size of each drainage watershed, in acres. e. Surface water locations including springs, wetlands, streams, lakes, water wells, etc., on or within 200 feet of the site, including the boundaries of wetlands or stream channels and first subsequent named receiving water(s) the permittee intends to fill or relocate for which the permittee is seeking approval from the Army Corps of Engineers and/or Ohio EPA. f. Existing and planned locations of buildings, roads, parking facilities and utilities. g. The location of all erosion and sediment control practices, including the location of areas likely to require temporary stabilization during the course of site development. h. Sediment and storm water management basins noting their sediment settling volume and contributing drainage area. i. Permanent storm water management practices to be used to control pollutants in storm water after construction operations have been completed. j. Areas designated for the storage or disposal of solid, sanitary and toxic wastes, including dumpster areas, areas designated for cement truck washout, vehicle fueling, and lay down areas. k. The location of designated construction entrances where the vehicles will access the construction site. 1. The location of any in-stream activities including stream crossings. 8. Additionally, the plan, as part of the overall stormwater management plan, shall provide space for signatures of City of Dublin officials. These signature blocks shall be placed on the stormwater management plan drawings. City of Dublin . Stormwater Management Design Manual 24 September XX, 2005 DRAFT 9. Statement identifying the name, address, and telephone number of the person(s) preparing the plan, the owner of the property where the grading is proposed and the developer and/or person responsible for the development area. 10. A statement indicating that the owner will notify the City forty-eight (48) hours before commencing any earth-disturbing activity. At the time this notice is given, the owner shall identify the site manager. 11. The City Engineer may waive specific requirements for plan detail or may require additional information to show that work will conform to basic requirements of this regulation. 12. Calculations a. Any person seeking approval of an Erosion and Sediment Control Plan shall submit design computations and applicable assumptions for all structural measures for erosion and sediment control. Volume and velocity of flow shall be provided for all surface water conveyance. This information shall also be provided for surface water outlets. Specific guidance for Erosion and Sediment control calculations referenced in Section 320 b. K. Standards 8~ Criteria for Erosion ~ Sediment Control. (A)Non-Structural Preservation Methods. The ESC plan must make use of practices that preserve the existing natural condition as much as feasible. No construction shall be allowed within the Stream Corridor Protection Zone defined by these regulations unless explicitly allowed under Section § 53.210. In addition, construction operations shall be phased in order to minimize the amount of disturbed land at any one time. Within zones designated for active construction, tree preservation areas under § 153.140 through 148 or other protective clearing or grubbing practices shall be designated. (B) Timing of Sediment-Control Practices. Sediment control practices shall be functional throughout earth-disturbing activities. Sediment ponds (including sediment basins and traps) and perimeter controls intended to trap sediment shall be implemented as the first step of grading and within seven days from the start of grubbing. They shall continue to function until the upslope development area is re-stabilized. (C) Stabilization. Disturbed areas must be stabilized as specified in the sections that follow. (1) Permanent Stabilization PERMANENT STABILIZATION Area requiring permanent When to implement controls City of Dublin • Stormwater Management Design Manual 25 September XX, 2005 DRAFT stabilization Any areas that will lie dormant for Within seven days of the most one year or more recent disturbance Any areas within 50 feet of a stream Within two days of reaching final and at final grade grade Any other areas at final grade Within seven days of reaching final grade within that area (2) Temporary Stabilization TEMPORARY STABILIZATION Area requiring temporary When to implement controls stabilization Any disturbed areas within 50 feet of Within two days of the most recent a stream and not at final grade disturbance if the area will remain idle for more than 21 days For all construction activities, any Within seven days of the most disturbed areas that will be dormant recent disturbance within the area for more than 21 days but less than For residential subdivisions, one year, and not within 50 feet of a disturbed areas must be stabilized at stream least seven days prior to transfer of permit coverage for the individual lot(s). Disturbed areas that will be idle over Prior to the onset of winter weather winter (3) Where vegetative stabilization techniques may cause structural instability or are otherwise unobtainable, alternative stabilization techniques must be employed. (D) Construction Access Routes. Measures shall be taken to prevent soil transport onto surfaces or onto public roads where runoff is not checked by sediment controls. Off-site tracking of sediments and dust generator shall be minimized, as required under the City's Ordinance, §97.38. (E) Sloughing and Dumping. (1) No soil, rock, debris, or any other material shall be dumped or placed into a stream or into such proximity that it may readily slough, slip, or erode into a stream, unless such dumping or placing is authorized by the City Engineer and when applicable, the U.S. Army Corps of Engineers, for such purposes as, but not limited to, construction of bridges, culverts, and erosion control structures. (2) Unstable soils that, in the opinion of the City Engineer, are prone to slipping or landsliding shall not be graded, excavated, filled or have loads imposed upon them unless the work is done in accordance with a qualified professional City of Dublin • Stormwater Management Design Manual 26 September XX, 2005 DRAFT engineer's recommendations to correct, eliminate, or adequately address the problems. (F) Cut and Fill Slopes. Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. Consideration shall be given to the length and steepness of the slope, soil type, upslope drainage area, groundwater conditions, and slope stabilization. (G)Stabilization of Outfalls and Channels. Outfalls and constructed or modified channels shall be designed and constructed to withstand the expected velocity of flow from apost- development, five-year frequency storm without eroding. (H)Establishment of Permanent Vegetation. Permanent vegetation shall not be considered established until ground cover is achieved which, in the opinion of the City Engineer, provides adequate cover with a density of at least 70% and is mature enough to control soil erosion satisfactorily and to survive adverse weather. (I) Sediment deposition. Sediment deposition caused by accelerated stormwater runoff over a development site or by accelerated erosion due to the sloughing or sliding of surface soil that has been exposed by grading, dumping, stockpiling or any other excavation-related earth disturbances shall be retarded and confined to within the boundaries of the development site, during site development. (J) Sediment Control Practices During Construction. The ESC plan shall include a description of structural practices that shall store runoff during construction, allowing sediments to settle and/or diverting flows away from exposed soils or otherwise limiting runoff from exposed areas. Structural practices shall be used to control erosion and trap sediment from a site remaining disturbed for more than 14 days. Such practices may include, among others: sediment settling ponds, silt fences, earth diversion dikes or channels which direct runoff to a sediment settling pond and storm drain inlet protection. All sediment control practices must be capable of ponding runoff in order to be considered functional. Earth diversion dikes or channels alone are not considered a sediment control practice unless those are used in conjunction with a sediment settling pond. The ESC plan must contain detailed drawings for all structural practices. (K) Timing. Sediment control structures shall be functional throughout the course of earth- disturbing activity. Sediment basins and perimeter sediment barriers shall be implemented prior to grading and within seven days from the start of grubbing. They shall continue to function until the up slope development area is restabilized according to requirements in Section §53.320(C)(1) As construction progresses and the topography is altered, appropriate controls must be constructed or existing controls altered to address the changing drainage patterns. (L) Sediment settling ponds (1) Concentrated storm water runoff and runoff from drainage areas, which exceed the design capacity of silt fence or inlet protection, shall pass through a sediment settling pond. For common drainage locations that serve an area with 10 or more City of Dublin • Stormwater Management Design Manual 27 September XX, 2005 DRAFT acres disturbed at one time, a temporary sediment settling pond must be provided until final stabilization of the site. The permittee may request approval from Ohio EPA to use alternative controls if it can demonstrate the alternative controls are equivalent in effectiveness to a sediment settling pond. It is recommended that smaller sediment basins and/or sediment traps be used for drainage locations serving less than 10 acres. (2) The sediment settling pond shall be sized to provide at least 67 cubic yards of storage per acre of total contributing drainage area. When determining the total contributing drainage area, off-site areas and areas which remain undisturbed by construction activity must be included unless runoff from these areas is diverted away from the sediment settling pond and is not co-mingled with sediment-laden runoff. The depth of the sediment settling pond must be less than or equal to five feet. The configuration between inlets and the outlet of the basin must provide at least two units of length for each one unit of width 2:1 length:width ratio). Sediment must be removed from the sediment settling pond when the design capacity has been reduced by 40 percent (This is typically reached when sediment occupies one-half of the basin depth). When designing sediment settling ponds, the permittee must consider public safety, especially as it relates to children, as a design factor. Alternative sediment controls must be used where site limitations would preclude a safe design. The use of a combination of sediment and erosion control measures in order to achieve maximum pollutant removal is encouraged. (M)Silt Fence and Diversions (1) Sheet flow runoff from denuded areas shall be intercepted by silt fence or diversions to protect adjacent properties, streams, and stream corridor protective zones from sediment transported via sheet flow. Where intended to provide sediment control, silt fence shall be placed on a level contour. The use of other sediment barriers designed to control sheet flow runoff shall be at the discretion of the City Engineer. The relationship between the maximum drainage area to silt fence for a particular slope range is shown in the following table. SILT FENCE CRITERIA Maximum drainage area (in Range of slope for a particular acres) to 100 linear feet of drainage area (by percent) silt fence 0.5 < 2% 0.25 > 2% but < 20% 0.125 > 20% but < 50% (2) Stormwater diversion practices shall be used to keep runoff away from disturbed areas and steep slopes where practicable. Such devices, which include swales, dikes or berms, may receive storm water runoff from areas up to 10 acres. (N)Inlet Protection Inlet protection BMPs shall minimize sediment laden water entering active storm drain systems, unless the storm drain system drains to a sediment settling City of Dublin • Stormwater Management Design Manual 2$ September XX, 2005 DRAFT pond. Sediment shall be removed from the storm sewer, to the extent possible, prior to final approval. (O) Other controls. (1) Non-Sediment Pollutant Controls (a) No solid (other than sediment) or liquid waste, including building materials, shall be discharged in storm water runoff. The permittee must implement all necessary BMPs to prevent the discharge of non-sediment pollutants to the stormwater management system of the site or surface waters of the state. Under no circumstance shall concrete trucks wash out directly into an open channel, storm sewer or surface waters of the state. No exposure of storm water to waste materials is recommended. (P) Compliance with other requirements The Stormwater Management Plan shall be consistent with applicable State and/or local waste disposal, sanitary sewer or septic system regulations, including provisions prohibiting waste disposal by open burning and shall provide for the proper disposal of contaminated soils to the extent these are located within the permitted area. (Q) Trench and ground water control There shall be no turbid discharges resulting from dewatering activities. If trench or ground water contains sediment, it must pass through a sediment settling pond or other equally effective sediment control device, prior to being discharged from the construction site. Alternatively, sediment may be removed by settling in place or by dewatering into a sump pit, filter bag or comparable practice. Ground water dewatering which does not contain sediment or other pollutants is not required to be treated prior to discharge. However, care must be taken when discharging ground water to ensure that it does not become pollutant-laden by traversing over disturbed soils or other pollutant sources. (R) Disposition of Temporary Practices. All temporary erosion and sediment control practices shall be disposed of within thirty days after final site stabilization is achieved or after the temporary practices are no longer needed, unless otherwise authorized by the City Engineer. Trapped sediment shall be removed or permanently stabilized to prevent further erosion. (S) Maintenance. All temporary and permanent erosion and sediment control practices shall be designed and constructed to minimize maintenance requirements. They shall be maintained and repaired as needed to assure continued performance of their intended function. The person or entity responsible for continued maintenance of permanent and temporary erosion controls shall be identified on the Stormwater Management Plan to the satisfaction of the City. City of Dublin • Stormwater Management Design Manual 29 September XX, 2005 Office of the City Manager 5200 Emerald Parkway • Dublin, OH 43017 CITY OF DUBLIN_ Phone: 614-410-4400 • Fax: 614-410-4490 M e m o To: Members of City Council From: Jane S. Brautigam, City Manager~Q,,,~ 5 . Date: August 10, 2005 Initiated By: Paul A. Hammersmith, P.E., Director of Engineering/City Engineer a~ Barbara A. Cox, P.E., Assistant Director of Engineering -Development Re: Ordinance 48-05: An Ordinance to Repeal Chapter 53, Stormwater Management, to Establish Chapter 53, Stormwater Management and Stream Protection, and to Add Section 153.231 (B) (5) of the Codified Ordinances in the City of Dublin, Ohio Summary: Revisions to Chapter 53, Stormwater Management are proposed to codify updates made by the Ohio Environmental Protection Agency (OEPA) regarding erosion and sediment control (during and after construction), create a stream corridor protection zone and clarify some issues that staff has found while administrating the current Chapter since June 1998. This is before Council for a first reading since it is a complex issue and a substantial amount of material to review. Staff will make a presentation summarizes the proposed revisions at the September 6, 2005 Council meeting. The proposed revisions were forwarded to both the Community Services Advisory Commission (CSAC) and the Planning and Zoning Commission (P&Z) for their review and consideration, as directed by Council at their March 7, 2005 meeting. The new version of Chapter 53 contains the requirements for having Stormwater controls (quantity and quality), erosion and sediment controls on a project site. It also contains assignments of review, approval, maintenance and enforcement responsibilities. Staff has created a Stormwater Management Design Manual. This manual contains the detailed design information that the development community will need to create their sites. Council may wish to review the following documents prior to the next Council meeting and contact staff with any questions or concerns 1. Memo from CSAC containing their recommendation 2. Minutes from the various CSAC meetings when the revisions were discussed 3. Minutes and Record of Action from the Planning and Zoning Commission meeting when the revisions were presented 4. Ordinance 48-OSadopting the proposed revisions 5. Chapter 53, Stormwater Management and Stream Protection (Exhibit "A") 6. Draft Stormwater Management Design Manual 7. Map depicting areas where Stream Corridor Protection Zones may apply. Recommendation: Staff recommends a second public reading of the Ordinance 48-OS at the September 6, 2005 City Council meeting when staff will make a presentation regarding the proposed revisions to Chapter 53 and the Stormwater Management Design Manual. At that time, staff will be requesting a motion on Ordinance 48- 05. 0 < ~ o' ~ ~ ~ ~ - ~ o ~ O ~ Oy d c= ~ a ~ 1\ m W ~ ~ / ~ ~ r r~ ' _ ~ _ ,y` ~ - ~ i 1 k ~T ~ ~ r t : ~ r ~ 1 / ' ~ - ~ . ~ ~ ~ M _ ~ - ~ ~ r/~ ~ r I ~ i ~ ~ ~ h ~ ~ ~ ~l ~ ~n ~ ~ 1 j ~ ~ / 'I , ~ i C~ D O~ O~~ Z ~ ~ m0~ o ~ _ „ ~ r ~ Q ~ ~ ~ ~ ~ ~ (n ~ o No a ~m~ o ~ ~ ~C7~ ~~rn OD ~ z z~ t~ o ~ v` ~ v_,' ~ o ~ m ° ~ ~ 1 ~ ~ ~ ~ ~ Q m 3 W /s co ~ I(~~~~~~ 1 1 i'~ ~ ~ r '4, ' 1~ l ~ ~ ~r - ) 7 e i} r I w ~ fl ~ 'r"' ~ _ ~ ~~t S d ~ P ,l~ ~ ~ _ ~3" r~ ~ ~ ~ s 1` ~ ~ t G ~ _ ~ ~ ~ ~ ~ ~ ~7 i ~ ~ ~ ~ 1 ~ ~ ~ ~ ~ i~ it ~J _ ~ ~ r' ~ ~ r ~ ~ g V ~ X ~ ~ ~ ¦rQ ~ ~ d ~ ~ ~ r~ N N~Orn O ~ ~ z-~ O~ ~ ~ ~ cn ~ - ~ o ~ _ ° ~ rn ~ ~ ~ ~ ~ ~ ~ ° ~ ~ D r r rn ~rn~ ~ ~ ~ ~ ~ o rn ~ rn D ~ z O~ z ~ ~ ~ ~ ~ ~ ~ ~ ~ rr-- m v ~ \ `s ~ o ~ ~ m a ~ ~ ~ f - I - ~ ~J ~ ~ ~ ~ \ C f ~ p. / _ v ~ 7 .,1, V ~~2 - ~ ~ / , ~ ~ ~ ~ ` t r I V ' ~ 1 i ~r_ ; ~ ~ ~ } _ ~ E ' ~+I_.,_ ~"".'I III ~ ~ I I ~ - L~ a'g' III ~ % ~~I fr ~i t ~ i ~ y ~ f V ' , ate, \ , i~ iii e }~YP,Ji 1~. Nil.?~_ _ l !,T~,~ ~ I ~I x., t, 1 ~ 1, D O N ~O rn O~~ z-~ O~ ~ ~ o v~ _ - ~ ~ CD ~ -o m o ~ ~ D ~ ~ ~ ~ ~ 0 r r rn ~-~(n ~ o No a ~ rn ~ m ~ C7 ~ ~ c~ ~~rn -D ~ ~ O~ z ~ DRAFT APPENDIX City of Dublin • Stormwater Management Design Manual 30 September XX, 2005 Office of the City Manager 5200 Emerald Parkway • Dublin, OH 43017 CITY OF DUBLIN_ Phone: 614-410-4400 • Fax: 614-410-4490 Nl e m o To: Members of City Council From: Jane S. Brautigam, City Manager^~_ s , Date: August 10, 2005 Initiated By: Paul A. Hammersmith, P.E., Director ofEngineering/City Engineer a Barbara A. Cox, P.E., Assistant Director of Engineering -Development Re: Ordinance 48-05: An Ordinance to Repeal Chapter 53, Stormwater Management, to Establish Chapter 53, Stormwater Management and Stream Protection, and to Add Section 153.231 (B) (5) of the Codified Ordinances in the City of Dublin, Ohio Summary: Revisions to Chapter S3, Stormwater Management are proposed to codify updates made by the Ohio Environmental Protection Agency (OEPA) regarding erosion and sediment control (during and after .construction), create a stream corridor protection zone and clarify some issues that staff has found while administrating the current Chapter since June 1998. This is before Council for a first reading since it is a complex issue and a substantial amount of material to review. Staff will make a presentation summarizes the proposed revisions at the September 6, 2005 Council meeting. The proposed revisions were forwarded to both the Community Services Advisory Commission (CSAC) and the Planning and Zoning Commission (P&Z) for their review and consideration, as directed by Council at their March 7, 2005 meeting. The new version of Chapter S3 contains the requirements for having Stormwater controls (quantity and quality), erosion and sediment controls on a project site. It also contains assignments of review, approval, maintenance and enforcement responsibilities. Staff has created a Stormwater Management Design Manual. This manual contains the detailed design information that the development community will need to create their sites. Council may wish to review the following documents prior to the next Council meeting and contact staff with any questions or concerns 1. Memo from CSAC containing their recommendation 2. Minutes from the various CSAC meetings when the revisions were discussed 3. Minutes and Record of Action from the Planning and Zoning Commission meeting when the revisions were presented 4. Ordinance 48-OSadopting the proposed revisions S. Chapter S3, Stormwater Management and Stream Protection (Exhibit "A") 6. Draft Stormwater Management Design Manual 7. Map depicting areas where Stream Corridor Protection Zones may apply. Recommendation: Staff recommends a second public reading of the Ordinance 48-OS at the September 6, 2005 City Council meeting when staff will make a presentation regarding the proposed revisions to Chapter S3 and the Stormwater Management Design Manual. At that time, staff will be requesting a motion on Ordinance 48- OS. ~ A Office of the City Manager 5200 Emerald Parkway • Dublin, OH 43017 CITY OE DUBLIN_ Phone: 614-410-4400 • Fax: 614-410-4490 Me m o To: Members of City Council From: Community Services Advisory Commission Date: August 9, 2005 Re: Proposed Revisions to Chapter 53: Stormwater Regulations On March 7, 2005, City Council forwarded an assignment to the Community Services Advisory Commission (CSAC) to review the proposed revisions to Chapter 53: Stormwater Regulations of the Codified Ordinances. CSAC held meetings on May 10, June 14, July 12 and August 9 during the proposed revisions were reviewed, considered and discussed. City staff has provided beneficial background and answers to our questions regarding the proposed revisions to the Stormwater Regulations. At the initial meeting on May 10th, we mainly focused on the proposed new section regarding Stream Corridor Protection Zones (SCPZ), Section 53.200. We went over where these are to be applied, how the zones are determined, the proposed uses in the zone, and enforcement of the requirements. We believe that the SCPZ will add a layer of protection for stream corridors that may have otherwise been adversely impacted by development where no other regulations provide for the preservation of the riparian buffers. The other proposed revisions were assessed at the second meeting held June 14t". It is our understanding that the other proposed changes to the Chapter are in line with the requirements of the current Ohio Environmental Protection Agency (OEPA) Phase 2 and General Construction permits. Also discussed were how the SCPZ relate to current open space requirements, variance/appeal procedures for the SCPZ, enforcement of the SCPZ and how to integrate an overview done by the Planning and Zoning Commission. At the July 12t" meeting, we provided staff with final comments on the proposed revisions and reviewed a draft of this recommendation to City Council. We also gave input to questions/comments we had that we wanted Planning and Zoning Commission's opinion on. We have been briefed on August 9`" of the review by the Planning and Zoning Commission and agree that the comments and changes from them only strengthen the code. In light of the benefits already realized from the existing Stormwater Regulations and the enhanced environmental benefits from the proposed revisions, we respectfully recommend adoption of the proposed revisions to amend existing Chapter 53. The newly adopted Chapter 53 is to be titled Stormwater Regulations and Stream Protection. CSAC 5/10/OS Page I of 6 Community Services Advisory Commission May 10, 2005 Minutes Commission Members Present: Robin Campbell, Melinda Carr, David Cecutti, Bill Estabrook, Todd Manifold, and Randy Roth (joined meeting at approx. 7:15 p.m.) Staff Members Present: Michelle Crandall, Director of Administrative Services, Jay Herskowitz, Asst. City Engineer - Utilities, Paul Hammersmith, Dir. of Engineering (City Engineer), and Tami Moore, Recorder Public Guests: Carrie Mayer -Dublin Schools student for a government class project I. Call to Order Vice-chairman Bill Estabrook called the meeting to order. II. Public Comments on Items Not on the Agenda None. III. Approval of Minutes of April 12, 2005 Meeting Mr. Manifold made a motion to approve as submitted the minutes of the April 12, 2005 meeting. Ms. Campbell seconded the motion, and the vote was 5-0 in favor of the motion. IV. Storm Water Management Ms. Crandall opened the presentation stating that this is an assignment referred by City Council for the Commission to review the proposed stormwater management regulations as revised by City staff. She then introduced Jay Herskowitz, Asst. City Engineer -Utilities, who was present to provide background information and the changes in the regulations. Mr. Herskowitz stated that Dublin has had a Stormwater Ordinance in effect since approximately 1998. It was developed as part of a Stormwater Master Plan project in which Engineering delineated all the water sheds in the City, identified Capital Improvement Project needs, identified operations and maintenance budget needs, and since that time have worked to implement the program. Along the way, there has been some impact from federal regulations that were passed down to the State-one being the Clean Water Act-that was amended in 2001. It revised the area of land disturbance above which erosion and sediment controls would be required. The Ordinance that was developed as part of the Stormwater Master Plan project had already addressed that issue, but had indicated the rule that was in effect at the time which was 2 acres or greater. Although utilizing the more current regulations were the day-to-day practice at Dublin, staff thought it important to revise the Ordinance to reflect the update. Several other minor inconsistencies were addressed as part of a "laundry list" of recommendations, and Dublin hired the consultant back CSAC 5/10/OS Page 2 of 6 who initially worked on the Storm Water Master Plan Project. Work was done over many months going over the Ordinance, drafting revisions, consolidating some sections in the Code and adding some entirely new sections where staff felt the need to be pro-active in terms of flood plain management. This process was completed in October of 2004, and then staff developed a report for Council who felt it was important to have an advisory group look at the proposed changes. Mr. Estabrook opened the floor for questions or discussions. Ms. Campbell questioned why when Dublin has had experts working on this for six to seven months is it being brought before this Commission? Mr. Herskowitz replied it was to have the public involved for buy-in and acceptance of the revisions. He also pointed out that there is a new Code section where Dublin is proposing to control development adjacent to streams, and the City is very sensitive to the impact that might have in terms of people's ability to develop their land. Therefore, staff reached out to several groups to get "stakeholder feedback." In addition to the public, this has also included other consulting firms, builders, etc. Ms. Crandall added that if Council had not assigned this project to CSAC, they probably would have had a Council committee review it in more detail. Mr. Estabrook asked if the review had been complete by other City entities. Mr. Herskowitz replied that the City's Land Use and Long-Range Planning (LU&LRP) staff is still reviewing it in terms of implementation and consistency with other code sections such as the tree ordinance. There is an adopted Resolution for the City to begin conservation design, and the new Code section on the stream setbacks relates to the conservation design. Ms. Crandall added that eventually the Planning & Zoning Commission would review some elements of the proposed code section relating to how it is implemented. Mr. Herskowitz stated that the City Manager asked LU&LRP to consider presenting this material, perhaps in parallel with the CSAC review or maybe after its review, and that is still being worked out. In response to Mr. Estabrook asking if they were reviewing it on the same timeline, Mr. Herskowitz replied that it has not yet been decided. Mr. Estabrook asked if there is any section of the proposed revisions that needs more attention than others? Mr. Herskowitz replied that Section 53.200 is the new proposed stream setback requirements noting that Legal has reviewed it, and it basically restricts people's ability to develop adjacent to areas where flooding may occur. Some of the Engineering staff see this simply as an extension of other rules that are already part of the City code. The stream corridor protection zones that were developed here are an attempt to mimic what essentially are the floodways of streams-the areas where the flood water velocities are more severe and where flooding potential and risks to the public are concerns. What this proposed section would do is, based on the contributing drainage area to any proposed development site, you could refer to a table in the Ordinance for the recommended setback criteria that has been developed based on a hard scientific type of review. Many jurisdictions in the Columbus area are considering this- Columbus for example-and as part of the project The Ohio State University analyzed aerial photography for streams in Central Ohio over a 30-year period and were able to predict mathematically what the meander zones are for streams based simply on the contributing drainage area. Mr. Herskowitz stated that he sees developers being able to use a recommended setback established in the regulations as a benefit to them because gathering the data is a very expensive process, and the City is essentially doing that work in areas where FEMA has not already provided data. Mr. Manifold clarified that this includes setbacks for both landscaping and a house or building. Mr. Herskowitz agreed it does and explained that the City has dealt CSAC 5/10/OS Page 3 of 6 with issues in areas that were developed in the 70's and 80's where homes encroached on channels, and the City has had to do expensive engineering studies and restoration projects. Mr. Estabrook stated that there seems to be many changes to 53.200, and Mr. Herskowitz clarified that this section is entirely new. Mr. Estabrook asked if the Army Corps of Engineers and FEMA standards are the starting point for the regulations. He also asked if this is going to provide more protection and regulation in a vast part of Dublin, or a small part of Dublin, or is this primarily designed for the newly developed areas? Mr. Herskowitz replied that it is primarily designed for areas where FEMA has not provided information. The City already has regulations to guide it in being protective of the public and the environment in areas where FEMA has conducted studies and have physically mapped those areas-being the Floodway + 20 restriction. What Ohio State and other jurisdictions are trying to come up with is how to estimate that in areas where FEMA has not provided that data. Ms. Carr asked if the City had solicited builder input on the proposed regulations. Mr. Herskowitz replied that it had and provided copies of a letter dated November 16, 2004 from the BIA, and stated that the City has addressed the issues outlined in the letter. Mr. Herskowitz noted that the stormwater management revisions were originally being reviewed along with topsoil management but since had been separated into two issues. Mr. Herskowitz went on to address a question on what other federal regulations might be impacted by this section. He stated that where an Army Corps of Engineers permit for wetlands connected to a stream or where there is an OEPA permit for disconnected wetlands, then those permit conditions govern. Mr. Estabrook asked about the process for these regulations after the City adopts them such as whether MORPC signs off on them? Mr. Herskowitz replied they do not; however, for floodplains to be modified, you must have ODNR approval. Mr. Estabrook referred to the section regarding re-aligning streams. Mr. Herskowitz stated that if someone wants to conduct a stream restoration project in a stream corridor protection zone, the City would likely permit it. It is not the intent to preclude activity that would have a positive effect. Ms. Campbell asked about whether a road widening would be permitted. Mr. Herskowitz replied that there is language that would allow the City of Dublin to conduct activities that are essential to provide a public service like roads or utilities, i.e., constructing new facilities in an existing area. The City would not necessarily relocate a stream to construct a road, but it may span it with structures. Mr. Cecutti asked Mr. Herskowitz what he would anticipate the public feedback to be. Mr. Herskowitz replied that there was a very extensive stakeholder process conducted mostly by Columbus in the Big Darby and Hellbranch water sheds to develop these stream protection zones, which are 200 feet in some cases. Dublin's are very reasonable. For example, for less than 100 acres of drainage area they are 25 feet from top of bank, and for over 1000 acres of development it may be capped at 200 feet. Ms. Campbell asked if these proposed revisions are being done in anticipation of future growth of Dublin's boundaries? Mr. Herskowitz replied that it is simply Dublin recognizing it needs to do a better job from an environmental and a flood control perspective of managing streams in urbanizing areas. It is intended to avoid the potential of the City needing to spend public money to restore or do flood control in an area that is recognized as being prone to flooding. Ms. Carr is a civil engineer and stated that she has done stream restorations where the project ends up costing millions of dollars because a stream starts to meander towards someone's house. This type of regulation helps the City to not have to deal CSAC 5/10105 Page 4 of 6 with such issues after the fact. If the builders are not showing great opposition to it, then that is a plus for the City. Mr. Manifold asked if the person who would not agree with this policy is someone wanting to build a house closer to the stream but is restricted. Ms. Carr agreed that is a potential situation as well as developer who perhaps could get two more houses in a subdivision. Mr. Herskowitz stated there is plenty of language for non-conforming uses for existing structures and have borrowed from some of the FEMA rules where if an improvement is less than 50 percent of the footprint then it might be grandfathered in. He stated that is was Engineering staff's intent that existing variance language in other parts of City codes be utilized if anyone wanted to formally have a stream corridor protection zone reconsidered. LU&LRP is helping to outline this process, and this should be determined over the next several months. Ms. Carr asked if there is any regulation currently in place where someone could designate an easement and turn it over to the City? Mr. Herskowitz replied that he works on a grant team who pursues Ciean Ohio Water Funds money to purchase land adjacent to streams or other apparent areas. The EPA has a Construction Grant Program called 319 for non-source point pollution, and that is the only type of project they will consider where conservation easements are being donated. The funds are only used for stream setback or stream slope stabilization projects or stream restoration projects. In response to a question from Ms. Carr, Mr. Herskowitz stated that those grant funds are more project-specific, and the proposed regulations are more an across-the- board attempt to deal with areas that are prone to flooding. Some have likened the stream corridor protection zone to free retention basins because the water has a place to back out, and pollutants and sediments can settle out, then when the rain is done, the water goes back into the stream. It also reduces velocity when you connect the flood plain to the channel. Mr. Estabrook referred to the stream that runs along the south side of the Dublin Cemetery asking what is being done there? Noting he was referring to a stream along Clover Ct./Monterey Dr., Mr. Herskowitz responded that the City is building retaining walls in that stream because erosion was beginning to occur near the footprints of homes so this work is being done to contain the stream. Establishment of a stream corridor protection zone would be a way to avoid this type of situation from the beginning. Ms. Campbell asked how the proposed regulations would impact easements that homeowners have given to the City of Dublin if there is a stream involved with an easement. Mr. Herskowitz replied it would not have an impact. For example, sanitary sewers are typically constructed in the low-lying areas, which would be adjacent to streams, so those easements would remain in effect. Emergency maintenance activities that City staff would need to do to maintain a facility would be a permitted use. Usually easements are areas where construction is prevented anyway because public utilities need access for maintenance. Ms. Carr referred to the regulations stating "being preserved in its natural state," asking if the City of Dublin is responsible for enforcing that? Mr. Herskowitz stated that this is still being determined, but the City has Code Enforcement Officers who are responsible for enforcing the Tree Ordinance and he suspects it would be those staff members. Mr. Herskowitz stated that the City of Dublin is required as a Phase 2 permit community to do public education and outreach. This would be a great opportunity to promote the new regulations. He also noted the flexibility of staff in working with the public to resolve problem situations. ' CSAC 5/10/05 Page 5 of 6 Ms. Campbell asked how much acreage in the City of Dublin this would impact? Mr. Herskowitz responded that the City has GIS mapping utilizing aerial photography and the blue line streams actually show up. He believes there are approximately 50 miles of streams in the City, estimating that approximately 25 miles of that are mapped by FEMA so those floodplains are already established. These regulations would affect the other approximately 25 miles of streams. Dublin will be flexible with developments that are in the pipeline now, but will try to get support where it can. Mr. Herskowitz noted that one thing that makes the Dublin regulations easier to implement is the inclusion of a table (vs. just a formula) that lists ranges. Mr. Estabrook asked if curb and gutter are required in all new-build areas in Dublin? Mr. Herskowitz responded that stormwater management systems must be proposed and reviewed with all new development. Mr. Hammersmith added that the City standard does require it on all streets as part of the storm sewer system. Mr. Herskowitz presented some handout materials to help establish what is or is not a stream. He added that the City focused on a definition that talks about "terrestrial vegetation,"which is vegetation that grows in most places except for in streams. That helps differentiate a stream from a swale, ditch or open channel where the setback would not apply. Ms. Carr asked if the City would allow developers to utilize this setback zone to meet open space dedication requirements. Mr. Herskowitz replied that he does believe it to be the intent of LU&LRP to permit this setback as part of the open space requirements. Ms. Carr asked if that would be considered beneficial or detrimental. Mr. Herskowitz replied that these might be the areas where the wetlands or streamside vegetation might tend to be so he sees it as beneficial. Ms. Carr noted that it would likely help with developer buy-in if this setback is included as part of the open space dedication. Mr. Roth noted that the City widened the floodplain a number of years ago and that it already established a no-build zone. Mr. Herskowitz replied that the Floodway + 20 (ft. on either side) is the established code. He clarified that the new regulations would pertain to areas where the floodways have not been defined by FEMA. Mr. Estabrook stated that because these proposed regulations are still under review by other entities (currently internal review by LU&LRP staff for implementation), he asked that further discussion be delayed until the June 14 meeting. If anyone has questions that arise, they could be referred to Ms. Crandall or Mr. Herskowitz. Mr. Herskowitz stated that he would follow-up specifically on the questions relating to a variance process and whether the City is allowing this land to be used towards the open space requirement. Mr. Estabrook stated that e-mail is likely the best means for this communication. Mr. Herskowitz stated that he is involved along with several other staff on the Mid-Ohio Regional Planning Commission {MORPC) Greenways Committee, and they have offered to provide a presentation to CSAC if interested. He had brought along a 6-minute videotape of the ZO-minute presentation and offered to make that available along with other materials on watercourse management, etc. Mr. Estabrook summarized that the group would first review the information in more detail and be prepared to take action at the June 14 meeting. This will provide an opportunity for Mr. CSAC 5/10/OS Page 6 of 6 Herskowitz to get answers on the issues under question, and LU&LRP the opportunity to address any issues they might have on the proposed regulations. Mr. Herskowitz noted that he is meeting with LU&LRP later in the week. Mr. Herskowitz stated that he could provide an overview for the Commission on some of the other changes outlined in his report. Mr. Estabrook asked that information be ready for the June meeting. Ms. Crandall noted that she would be providing the Commission a draft report on the summary and recommendations for Deer Management discussed at previous meetings. This report will be e-mail to CSAC members for review prior to the next meeting. Comments can be e-mailed back to Ms. Crandall or provided at the next meeting to Tami Moore. V. Next Meeting: June 14, 2005 Ms. Crandall will not be in attendance at the June 14 meeting; however, Mr. Herskowitz will be there to address the stormwater management issue. VI. Adjournment There being no further business, Mr. Manifold called for a motion to adjourn, seconded by Ms. Campbell. All in favor, the meeting was adjourned. CSAC 5/10/OS Page 1 of 6 Community Services Advisory Commission May 10, 2005 Minutes Commission Members Present: Robin Campbell, Melinda Carr, David Cecutti, Bill Estabrook, Todd Manifold, and Randy Roth (joined meeting at approx. 7:15 p.m.) Staff Members Present: Michelle Crandall, Director of Administrative Services, Jay Herskowitz, Asst. City Engineer - Utilities, Paul Hammersmith, Dir. of Engineering (City Engineer), and Tami Moore, Recorder Public Guests: Carrie Mayer -Dublin Schools student for a government class project I. Call to Order Vice-chairman Bill Estabrook called the meeting to order. II. Public Comments on Items Not on the Agenda None. III. Approval of Minutes of Apri112, 2005 Meeting Mr. Manifold made a motion to approve as submitted the minutes of the April 12, 2005 meeting. Ms. Campbell seconded the motion, and the vote was 5-0 in favor of the motion. IV. Storm Water Management Ms. Crandall opened the presentation stating that this is an assignment referred by City Council for the Commission to review the proposed stormwater management regulations as revised by City staff. She then introduced Jay Herskowitz, Asst. City Engineer -Utilities, who was present to provide background information and the changes in the regulations. Mr. Herskowitz stated that Dublin has had a Stormwater Ordinance in effect since approximately 1998. It was developed as part of a Stormwater Master Plan project in which Engineering delineated all the water sheds in the City, identified Capital Improvement Project needs, identified operations and maintenance budget needs, and since that time have worked to implement the program. Along the way, there has been some impact from federal regulations that were passed down to the State~ne being the Clean Water Act-that was amended in 2001. It revised the area of land disturbance above which erosion and sediment controls would be required. The Ordinance that was developed as part of the Stormwater Master Plan project had already addressed that issue, but had indicated the rule that was in effect at the time which was 2 acres or greater. Although utilizing the more current regulations were the day-to-day practice at Dublin, staff thought it important to revise the Ordinance to reflect the update. Several other minor inconsistencies were addressed as part of a "laundry list" of recommendations, and Dublin hired the consultant back CSAC 5/10/OS Page 2 of 6 who initially worked on the Storm Water Master Plan Project. Work was done over many months going over the Ordinance, drafting revisions, consolidating some sections in the Code and adding some entirely new sections where staff felt the need to be pro-active in terms of flood plain management. This process was completed in October of 2004, and then staff developed a report for Council who felt it was important to have an advisory group look at the proposed changes. Mr. Estabrook opened the floor for questions or discussions. Ms. Campbell questioned why when Dublin has had experts working on this for six to seven months is it being brought before this Commission? Mr. Herskowitz replied it was to have the public involved for buy-in and acceptance of the revisions. He also pointed out that there is a new Code section where Dublin is proposing to control development adjacent to streams, and the City is very sensitive to the impact that might have in terms of people's ability to develop their land. Therefore, staff reached out to several groups to get "stakeholder feedback." In addition to the public, this has also included other consulting firms, builders, etc. Ms. Crandall added that if Council had not assigned this project to CSAC, they probably would have had a Council committee review it in more detail. Mr. Estabrook asked if the review had been complete by other City entities. Mr. Herskowitz replied that the City's Land Use and Long-Range Planning (LU&LRP) staff is still reviewing it in terms of implementation and consistency with other code sections such as the tree ordinance. There is an adopted Resolution for the City to begin conservation design, and the new Code section on the stream setbacks relates to the conservation design. Ms. Crandall added that eventually the Planning & Zoning Commission would review some elements of the proposed code section relating to how it is implemented. Mr. Herskowitz stated that the City Manager asked LU&LRP to consider presenting this material, perhaps in parallel with the CSAC review or maybe after its review, and that is still being worked out. In response to Mr. Estabrook asking if they were reviewing it on the same timeline, Mr. Herskowitz replied that it has not yet been decided. Mr. Estabrook asked if there is any section of the proposed revisions that needs more attention than others? Mr. Herskowitz replied that Section 53.200 is the new proposed stream setback requirements noting that Legal has reviewed it, and it basically restricts people's ability to develop adjacent to areas where flooding may occur. Some of the Engineering staff see this simply as an extension of other rules that are already part of the City code. The stream corridor protection zones that were developed here are an attempt to mimic what essentially are the floodways of streams-the areas where the flood water velocities are more severe and where flooding potential and risks to the public are concerns. What this proposed section would do is, based on the contributing drainage area to any proposed development site, you could refer to a table in the Ordinance for the recommended setback criteria that has been developed based on a hard scientific type of review. Many jurisdictions in the Columbus area are considering this- Columbus for example-and as part of the project The Ohio State University analyzed aerial photography for streams in Central Ohio over a 30-year period and were able to predict mathematically what the meander zones are for streams based simply on the contributing drainage area. Mr. Herskowitz stated that he sees developers being able to use a recommended setback established in the regulations as a benefit to them because gathering the data is a very expensive process, and the City is essentially doing that work in areas where FEMA has not already provided data. Mr. Manifold clarified that this includes setbacks for both landscaping and a house or building. Mr. Herskowitz agreed it does and explained that the City has dealt CSAC 5/10/OS Page 3 of 6 with issues in areas that were developed in the 70's and 80's where homes encroached on channels, and the City has had to do expensive engineering studies and restoration projects. Mr. Estabrook stated that there seems to be many changes to 53.200, and Mr. Herskowitz clarified that this section is entirely new. Mr. Estabrook asked if the Army Corps of Engineers and FEMA standards are the starting point for the regulations. He also asked if this is going to provide more protection and regulation in a vast part of Dublin, or a small part of Dublin, or is this primarily designed for the newly developed areas? Mr. Herskowitz replied that it is primarily designed for areas where FEMA has not provided information. The City already has regulations to guide it in being protective of the public and the environment in areas where FEMA has conducted studies and have physically mapped those areas-being the Floodway + 20 restriction. What Ohio State and other jurisdictions are trying to come up with is how to estimate that in areas where FEMA has not provided that data. Ms. Carr asked if the City had solicited builder input on the proposed regulations. Mr. Herskowitz replied that it had and provided copies of a letter dated November 16, 2004 from the BIA, and stated that the City has addressed the issues outlined in the letter. Mr. Herskowitz noted that the stormwater management revisions were originally being reviewed along with topsoil management but since had been separated into two issues. Mr. Herskowitz went on to address a question on what other federal regulations might be impacted by this section. He stated that where an Army Corps of Engineers permit for wetlands connected to a stream or where there is an OEPA permit for disconnected wetlands, then those permit conditions govern. Mr. Estabrook asked about the process for these regulations after the City adopts them such as whether MORPC signs off on them? Mr. Herskowitz replied they do not; however, for floodplains to be modified, you must have ODNR approval. Mr. Estabrook referred to the section regarding re-aligning streams. Mr. Herskowitz stated that if someone wants to conduct a stream restoration project in a stream corridor protection zone, the City would likely permit it. It is not the intent to preclude activity that would have a positive effect. Ms. Campbell asked about whether a road widening would be permitted. Mr. Herskowitz replied that there is language that would allow the City of Dublin to conduct activities that are essential to provide a public service like roads or utilities, i.e., constructing new facilities in an existing area. The City would not necessarily relocate a stream to construct a road, but it may span it with structures. Mr. Cecutti asked Mr. Herskowitz what he would anticipate the public feedback to be. Mr. Herskowitz replied that there was a very extensive stakeholder process conducted mostly by Columbus in the Big Darby and Hellbranch water sheds to develop these stream protection zones, which are 200 feet in some cases. Dublin's are very reasonable. For example, for less than 100 acres of drainage area they are 25 feet from top of bank, and for over 1000 acres of development it may be capped at 200 feet. Ms. Campbell asked if these proposed revisions are being done in anticipation of future growth of Dublin's boundaries? Mr. Herskowitz replied that it is simply Dublin recognizing it needs to do a better job from an environmental and a flood control perspective of managing streams in urbanizing areas. It is intended to avoid the potential of the City needing to spend public money to restore or do flood control in an area that is recognized as being prone to flooding. Ms. Carr is a civil engineer and stated that she has done stream restorations where the project ends up costing millions of dollars because a stream starts to meander towards someone's house. This type of regulation helps the City to not have to deal CSAC 5/10/OS Page 4 of 6 with such issues after the fact. If the builders are not showing great opposition to it, then that is a plus for the City. Mr. Manifold asked if the person who would not agree with this policy is someone wanting to build a house closer to the stream but is restricted. Ms. Carr agreed that is a potential situation as well as developer who perhaps could get two more houses in a subdivision. Mr. Herskowitz stated there is plenty of language for non-conforming uses for existing structures and have borrowed from some of the FEMA rules where if an improvement is less than 50 percent of the footprint then it might be grandfathered in. He stated that is was Engineering staff s intent that existing variance language in other parts of City codes be utilized if anyone wanted to formally have a stream corridor protection zone reconsidered. LU&LRP is helping to outline this process, and this should be determined over the next several months. Ms. Carr asked if there is any regulation currently in place where someone could designate an easement and turn it over to the City? Mr. Herskowitz replied that he works on a grant team who pursues Clean Ohio Water Funds money to purchase land adjacent to streams or other apparent areas. The EPA has a Construction Grant Program called 319 for non-source point pollution, and that is the only type of project they will consider where conservation easements are being donated. The funds are only used for stream setback or stream slope stabilization projects or stream restoration projects. In response to a question from Ms. Carr, Mr. Herskowitz stated that those grant funds are more project-specific, and the proposed regulations are more anacross-the- board attempt to deal with areas that are prone to flooding. Some have likened the stream corridor protection zone to free retention basins because the water has a place to back out, and pollutants and sediments can settle out, then when the rain is done, the water goes back into the stream. It also reduces velocity when you connect the flood plain to the channel. Mr. Estabrook referred to the stream that runs along the south side of the Dublin Cemetery asking what is being done there? Noting he was referring to a stream along Clover Ct./Monterey Dr., Mr. Herskowitz responded that the City is building retaining walls in that stream because erosion was beginning to occur near the footprints of homes so this work is being done to contain the stream. Establishment of a stream corridor protection zone would be a way to avoid this type of situation from the beginning. Ms. Campbell asked how the proposed regulations would impact easements that homeowners have given to the City of Dublin if there is a stream involved with an easement. Mr. Herskowitz replied it would not have an impact. For example, sanitary sewers are typically constructed in the low-lying areas, which would be adjacent to streams, so those easements would remain in effect. Emergency maintenance activities that City staff would need to do to maintain a facility would be a permitted use. Usually easements are areas where construction is prevented anyway because public utilities need access for maintenance. Ms. Carr referred to the regulations stating "being preserved in its natural state," asking if the City of Dublin is responsible for enforcing that? Mr. Herskowitz stated that this is still being determined, but the City has Code Enforcement Officers who axe responsible for enforcing the Tree Ordinance and he suspects it would be those staff members. Mr. Herskowitz stated that the City of Dublin is required as a Phase 2 permit community to do public education and outreach. This would be a great opportunity to promote the new regulations. He also noted the flexibility of staff in working with the public to resolve problem situations. CSAC 5/10/05 Page 5 of 6 Ms. Campbell asked how much acreage in the City of Dublin this would impact? Mr. Herskowitz responded that the City has GIS mapping utilizing aerial photography and the blue line streams actually show up. He believes there are approximately 50 miles of streams in the City, estimating that approximately 25 miles of that are mapped by FEMA so those floodplains are already established. These regulations would affect the other approximately 25 miles of streams. Dublin will be flexible with developments that are in the pipeline now, but will try to get support where it can. Mr. Herskowitz noted that one thing that makes the Dublin regulations easier to implement is the inclusion of a table (vs. just a formula) that lists ranges. Mr. Estabrook asked if curb and gutter are required in all new-build areas in Dublin? Mr. Herskowitz responded that stormwater management systems must be proposed and reviewed with all new development. Mr. Hammersmith added that the City standard does require it on all streets as part of the storm sewer system. Mr. Herskowitz presented some handout materials to help establish what is or is not a stream. He added that the City focused on a definition that talks about "terrestrial vegetation," which is vegetation that grows in most places except for in streams. That helps differentiate a stream from a swale, ditch or open channel where the setback would not apply. Ms. Carr asked if the City would allow developers to utilize this setback zone to meet open space dedication requirements. Mr. Herskowitz replied that he does believe it to be the intent of LU&LRP to permit this setback as part of the open space requirements. Ms. Carr asked if that would be considered beneficial or detrimental. Mr. Herskowitz replied that these might be the areas where the wetlands or streamside vegetation might tend to be so he sees it as beneficial. Ms. Carr noted that it would likely help with developer buy-in if this setback is included as part of the open space dedication. Mr. Roth noted that the City widened the floodplain a number of years ago and that it already established a no-build zone. Mr. Herskowitz replied that the Floodway + 20 (ft. on either side) is the established code. He clarified that the new regulations would pertain to areas where the floodways have not been defined by FEMA. Mr. Estabrook stated that because these proposed regulations are still under review by other entities (currently internal review by LU&LRP staff for implementation), he asked that further discussion be delayed until the June 14 meeting. If anyone has questions that arise, they could be referred to Ms. Crandall or Mr. Herskowitz. Mr. Herskowitz stated that he would follow-up specifically on the questions relating to a variance process and whether the City is allowing this land to be used towards the open space requirement. Mr. Estabrook stated that e-mail is likely the best means for this communication. Mr. Herskowitz stated that he is involved along with several other staff on the Mid-Ohio Regional Planning Commission (MORPC) Greenways Committee, and they have offered to provide a presentation to CSAC if interested. He had brought along a 6-minute videotape of the 20-minute presentation and offered to make that available along with other materials on watercourse management, etc. Mr. Estabrook summarized that the group would first review the information in more detail and be prepared to take action at the June I4 meeting. This will provide an opportunity for Mr. CSAC 5/10/OS Page 6 of 6 Herskowitz to get answers on the issues under question, and LU&LRP the opportunity to address any issues they might have on the proposed regulations. Mr. Herskowitz noted that he is meeting with LU&LRP later in the week. Mr. Herskowitz stated that he could provide an overview for the Commission on some of the other changes outlined in his report. Mr. Estabrook asked that information be ready for the June meeting. Ms. Crandall noted that she would be providing the Commission a draft report on the summary and recommendations for Deer Management discussed at previous meetings. This report will be e-mail to CSAC members for review prior to the next meeting. Comments can be e-mailed back to Ms. Crandall or provided at the next meeting to Tami Moore. V. Next Meeting: June 14, 2005 Ms. Crandall will not be in attendance at the June 14 meeting; however, Mr. Herskowitz will be there to address the stormwater management issue. VI. Adjournment There being no further business, Mr. Manifold called for a motion to adjourn, seconded by Ms. Campbell. All in favor, the meeting was adjourned. CSAC 6/14/05 Page 1 of 4 Community Services Advisory Commission June 14, 2005 Minutes Commission Members Present: Robin Campbell, Melinda Carr, David Cecutti, Bill Estabrook, Todd Manifold, and Randy Roth Staff Members Present: Jay Herskowitz, Asst. City Engineer -Utilities, Paul Hammersmith, Dir. of Engineering (City Engineer), Gary Gunderman, Asst. Dir. of Land Use and Long Range Planning and Tami Moore, Recorder Guests: none I. Call to Order Vice-chairman Bill Estabrook established that there was a quorum present and called the meeting to order. II. Public Comments on Items Not on the Agenda None. III. Approval of Minutes of May 10, 2005 Meeting Mr. Manifold made a motion to approve as submitted the minutes of the May 10, 2005 meeting. Mr. Cecutti seconded the motion, and the vote was 6-0 in favor of the motion. IV. Deer Management Report Mr. Estabrook asked if everyone had received and reviewed the Deer Management Report to Council drafted by Ms. Crandall. Ms. Campbell noted a change in spelling the work "aerial". Ms. Carr stated that she had not yet completed her review of the report. Mr. Estabrook stated that the topic would remain open until later in the meeting. After the Stormwater Management review and discussion, the members returned to this topic. There were no additions or other revisions suggested. Mr. Roth made a motion to approve the Deer Management report with the word revision noted. Ms. Campbell seconded the motion, and the vote was 6-0 in favor of approval. The report will be forwarded on to City Council. V. Storm Water Management Mr. Estabrook summarized that last month the CSAC members had requested two things: 1) that any member having questions or needing additional information while further reviewing the stormwater management regulations be able to contact Jay Herskowitz directly, and noted that correspondence had successfully taken place; and 2) that Mr. Herskowitz report back to Commission members after talking to Land Use & Long-Range Planning. Mr. Herskowitz stated that he would like an opportunity to guide the Commission through his report highlighting the revisions to the Stormwater Management Regulations. He noted that the first page which provides an introduction and background had been sufficiently covered in the last meeting, and he went on to Page 2 of his memo dated May 6, 2005 "Proposed Revisions to Chapter 53 - Stormwater CSAC 6/14/05 Page 2 of 4 Management Regulations." Mr. Herskowitz went through the report highlighting the revisions and additions in each section and addressing any questions. Mr. Roth commended Mr. Herskowitz on the overall clarity of the Regulations/Ordinance and how well the definitions assisted in understanding them. Mr. Estabrook asked for clarification on the language in Section 53.070 that exempts less than 500 ft. of construction asking if that includes the building and parking area? Mr. Herskowitz read the code section clarifying that the exemption pertains to any expansion of building, structure or pavement of less than 500 sq. ft. which results in new impervious area on a project site. Related to Section 53.090, Mr. Estabrook asked if the City uses retention ponds for irrigation purposes for public right-of--way, etc. Mr. Herskowitz responded that Avery-Muirfield does have a well and pump system for irrigation. Mr. Hammersmith clarified, however, that typically wells are used to recharge the ponds and any irrigation is off the public water supply so the ponds are not used as a source for irrigation. On the same section, Ms. Carr noted the 12 ft. maximum depth on retention ponds and asked if it establishes a minimum depth. Mr. Herskowitz stated that it is site specific. Mr. Herskowitz introduced Gary Gunderman, Asst. Dir. of Land Use & Long-Range Planning. In reviewing Section 53.300, Mr. Gunderman stated that he had found language typically related to zoning as well as more technical, hydrologic data that relates to engineering and determined that it may be more appropriate to provide atwo-step variance process. Mr. Herskowitz stated that this revised process was then reviewed and approved by the City's legal staff and had just been e-mailed to CSAC members that day. It creates a new section called Appeals to address where anyone who wants to have a permitted use in a Stream Corridor Protection Zone not in compliance with the ordinance, they are provided an opportunity for Appeal. In the case of a developer wanting to dispute the width of a Stream Corridor Protection Zone or whether it should apply in a particular area, that would go to the City Engineer. Mr. Gunderman informed the Commission that because Chapter 53 does contain zoning-related issues, particularly in sections 210, 220 and 230, he would like to provide the Planning and Zoning Commission and opportunity to review it (at least informally). Mr. Herskowitz displayed a map showing areas (in red) where the new regulations would be enforced upon development, as well as areas where it does not apply because the land does not have a stream through it or it has already been platted or developed. Mr. Gunderman noted that there are areas currently outside the City not shown on the map where the regulations would be enforced if annexed. Mr. Gunderman noted that the areas shown in blue are FEMA-mapped flood zones and therefore already regulated. Also shown in blue are areas such as Heather Bluff where the land has already been preliminarily platted and the regulations will not apply. Mr. Gunderman noted that there are some areas shaded blue because they have very old plats, but the plats are not populated on all lots, and there is some potential for them to be consolidated and redeveloped. If that happened, the new regulations would then be implemented. The map also shows areas in white where there is rural housing-built before the City developed-that have potential to be consolidated and redeveloped, and the City would at least attempt to have the regulations apply (i.e. O'Shaughnessy Hills). CSAC 6/14/05 Page 3 of 4 Mrs. Campbell pointed out that a stream is constantly moving and changing and wanted to ensure that if a tract of land is changed significantly enough over time that there is flexibility in enforcement. Mr. Herskowitz replied that the Zones would protect property as a stream moved within a meander belt. Mr. Herskowitz referred back to discussion at the May 10 meeting reiterating that the BIA had been involved in reviewing the regulations and their issues had been addressed. Ms. Carr asked how the Stream Corridor Protection Zone would relate to the zoning open space requirements and asked how much this would change the nature of development in the community? Mr. Gunderman responded that conservation design standards could call for exactly the same area where these regulations would apply or a stream protection zone could perhaps delineate a larger open area. However, the regulations would not dramatically change the fundamental character of development from what we would expect under conservation design. Mr. Herskowitz stated that he would prefer to present the Stormwater Management Regulations along with a recommendation from CSAC to the Planning & Zoning Commission at the July 24 meeting, informing them that the plan is to move forward with a recommendation to Council in August. Mr. Hammersmith noted that Council wanted to make sure that a review and recommendation of the regulations moved forward in a timely manner and had requested a report back from CSAC in July. He suggested that instead there be a progress report to Council in July. CSAC will meet on July 12 to determine a formal recommendation on the regulations, then the Planning & Zoning Commission will review it on July 24. CSAC will meet again on August 9 to hear the comments from the Commission and finalize its recommendation to Council for the August 15 meeting. Mr. Herskowitz stated that he would make final revisions and provide a clean document to CSAC members by the July 12 meeting. Mr. Estabrook asked the members for any additional comments or questions. Mr. Roth praised the clarity of the document and noted that he liked what is being done regarding safety features on the design of storm water retention. He asked for clarification on whether the Stream Corridor Protection Zone is consistent with what FEMA would impose, or is Dublin taking it further? Mr. Herskowitz responded that the zone essentially mimics the City's Floodway + 20 requirement. Mr. Hammersmith pointed that these regulations help the City by establishing similar protection in areas FEMA has not studied. Mr. Roth asked if FEMA later chose to study a stream within Dublin's Stream Corridor Protection Zone, would that take precedence over this regulation- generally questioning the permanence of Dublin establishing the zone. Mr. Gunderman responded that if FEMA restudied it and decided that the flood hazard had increased and included areas along streams that had not been previously regulated by FEMA, they would be thankful that Dublin had already protected those areas similarly to what FEMA would do. Mr. Roth asked what effect diverting or piping stormwater from one area to another might have on stream corridor widths. Mr. Herskowitz stated that what the Ohio State and ODNR study found was that the most significant variable was not land use or impervious area, it was the acreage-not in determining flows, but in determining how the meander pattern occurs. The FEMA floodplain analysis does not factor in the meander. Mr. Hammersmith added that he believes the City is very conscious about erosion protection as a result of any waiver. Mr. Herskowitz provided an example of a recent project review and noted that the City is willing to consider site-specific data provided CSAC 6/14/05 Page 4 of 4 by a developer if collected in accordance with Dublin's criteria. If a waiver of a Stream Corridor Protection Zone was considered, it would likely be an adjustment of a width. Mr. Roth also asked about lots that have deep slopes where the owner may want to build up high but within the protected area and wondered if that would be dealt with by BZA. Mr. Herskowitz read a code section that reserves the right to consider slopes and widen the zone. Mr. Roth clarified he is referring to narrowing it. Mr. Gunderman responded that if a property owner wants to do so, it would require that an engineer working on the owner's behalf provide calculations to account for the difference in terrain and submit data for consideration by the City Engineer. BZA Appeals would be reserved for what Mr. Gunderman referred to as homeowner-based permitted/prohibited land use issues such as accessory structures in protected areas. Regarding this same issue, Ms. Carr asked if Dublin was looking at an area where the slope is extremely steep on one side and perhaps a variance is needed, but because of that the floodplain is all to the other side of the stream and a much wider area for the stream corridor would be desired there, could that be considered? Mr. Hammersmith responded that the conservation design element would provide for that. Mr. Gunderman added that the thing that is helpful about this process is that Dublin will almost always implement it when there is an application for a new development proposal. Proposals must include a set of site drawings and engineering calculations for stormwater runoff, and staff would site where the floodway protection area should be on the drawings. The Engineering staff could adjust the zone accordingly. There are some places where the regulations will be needed, but the City won't have that kind of a new development plan, so staff may not have that opportunity is all cases. Mr. Herskowitz added that FEMA did a technical bulletin for areas just outside of floodplains that says you are not supposed to build the face of a foundation within 20' of the floodplain limit because of a residual flooding risk unless geotechnical analysis supports it. Dublin could also consider that type of data in an effort to provide flexibility. Mr. Roth referred to the letter from the BIA dated November 16, 2004, stating that the City had considered their suggestions on topsoil management and wetlands. Mr. Herskowitz noted the third suggestion in the letter was regarding the requirement and timing for a survey stating the City agreed with the BIA's suggestion on that issue as well. There were no other major issues. Mr. Estabrook summarized the schedule as outlined previously for continuing the review and recommendation on the proposed regulations. Mr. Herskowitz stated he would e-mail the modified text to CSAC members prior to the next meeting. There were no additional questions or comments on this issue. VI. Next Meeting: July 12, 2005 Mr. Estabrook noted that attendance for both the July and August meetings may be challenging with the vacation season, but the Commission hopes to follow the plan for moving the review and recommendation on the regulations along as outlined. VII. Adjournment There being no further business, the meeting was adjourned. CSAC 6/14/05 Page 1 of 4 Community Services Advisory Commission July 12, 2005 Minutes Commission Members Present: Melinda Carr, David Cecutti, Todd Manifold and Tom Merritt, Staff Members Present: Barb Cox, Asst. City Engineer - Dev., Paul Hammersmith, Dir. of Engineering (City Engineer), Michelle Crandall, Dir. of Administrative Services and Tami Moore, Recorder Guests: none I. Call to Order Chairman Tom Merritt established that there was a quorum present and called the meeting to order. II. Public Comments on Items Not on the Agenda None. III. Approval of Minutes of June 14, 2005 Meeting Mr. Merritt noted that minutes from the June 14, 2005 meeting had been distributed electronically prior to the meeting and asked if everyone had an opportunity to review them. Several members had not yet reviewed the minutes, so Mr. Merritt recommended that the Commission review the minutes prior to the next meeting and they would be place on the agenda for approval at the August 9 meeting. IV. Stormwater Management Regulations Mr. Hammersmith introduced Ms. Cox, Asst. City Engineer - Dev., noting that due to the recent resignation of Mr. Herskowitz, she would be taking over the Stormwater Management Regulations revision process. Mr. Hammersmith stated that a draft memorandum of what would become CSAC's recommendation to City Council on the proposed revisions to Chapter 53: Stormwater Regulations, had been distributed for initial review and comment. It was noted that the date of the next CSAC meeting, referenced in the memo, was incorrect and should be August 9. The recommendation on the proposed ordinance and revisions is to be presented to City Council at the August 15 meeting. Mr. Hammersmith highlighted the key issues in the memo that generally outlines the review process that had taken place during the three CSAC meetings and the four major issues/questions that had been discussed. Mr. Merritt asked if staff anticipates the Stream Corridor Protection Zone (SCPZ) requirements being applied to any particular location in Dublin. Mr. Hammersmith replied that a draft map had been reviewed at the June CSAC meeting and is currently being updated. The map will be available for review again at the August meeting. Mr. Hammersmith noted that the SCPZ requirements will not retroactively apply wherever there is already a Preliminary or Final Development Plan approved, or in existing or established areas within the City, or where a FEMA designation already exists along stream corridors. CSAC 6/14/05 Page 2 of 4 Mr. Hammersmith acknowledged that Council had assigned CSAC the task of reviewing and considering the proposed revisions to the stormwater regulations. Because the Planning & Zoning Commission deals with many zoning and development-related issues, staff wants to involve them by providing an overview of the revised regulations and an opportunity for them to give comments back to CSAC for consideration. That meeting will be held on July 21, and then CSAC will meet again on August 9 to consider their input and prepare in final form its recommendation to City Council for the August 15 meeting. Mr. Merritt asked if staff anticipates the Planning & Zoning Commission having any major concerns regarding the stormwater regulations. Ms. Cox explained that P&Z will likely have many of the same questions brought up by CSAC, and she plans to address those in her staff report as well as inclusion of the CSAC meeting minutes to date on this issue. She noted that the P&Z meeting will begin at 6:30 p.m. on July 21, and this issue is scheduled first on the agenda with a time limit of 30 minutes. Ms. Cox stated that in general the P&Z does not review construction details so she expects more zoning-related issues like how the zone relates to the open space requirements, the permitted and restricted uses established in the SCPZ, enforcement and appeals to BZA. Ms. Cox previewed the PowerPoint presentation that will be shown to the Planning & Zoning Commission and asked for input on any revisions. Mr. Hammersmith stated that CSAC would also receive an electronic copy of the staff report going to P&Z in their Packet on July 15. Any comments from CSAC can go to Tami Moore (tmoore e,dublin.oh.us) and forwarded to appropriate staff. (Copies of the slides from the PowerPoint presentation are attached for reference.) Ms. Crandall asked if the proposed regulations included consideration for impervious pavement. Mr. Hammersmith stated that it had been researched, but there are not a lot of places it would apply in Central Ohio. Ms. Cox added that it has to be done right to work and is difficult with the rock and clay in this area. Also, it should only be done in a parking lot that would not be plowed or salted often as salt or grit will block the porous nature of the surface. It may be an application appropriate for a parking lot in a park or a facility that is not used in the winter. The proposed code revisions do not preclude it being done. Ms. Carr asked if the code regulations addressed bio-retention. Ms. Cox responded that it is permitted and Dublin has worked with a few developers who have been willing to try it. Ms. Cox said that initially staff had issues with the developer demonstrating enough information that they met the removal rate. She also noted that currently there are not different standards for that type of retention. Mr. Hammersmith added that staff will continue to clean up the ordinance prior to the August 9 meeting, and one thing that will be taken out is some of the detailed design requirements. These will be handled within the administrative code section, which may be an appropriate place to include different requirements for bio-retention. Ms. Cox continued with the PowerPoint presentation. Mr. Merritt asked if the BIA is aware of proposed revisions and the impact on the development community. Ms. Cox replied that they are aware noting that the new EPA regulations are in effect so developers have already been required to follow those requirements. Dublin's code revisions are intended to bring those requirements down to a local level to help with enforcement. In discussing the increased preservation of riparian corridors within the SCPZ, Ms. Cox talked about providing a list for comparison by the Planning & Zoning Commission to provide CSAC 6/14/05 Page 3 of 4 clarification of what is and is not permitted within the SCPZ. There was discussion about "invasive" species, and it was noted that vegetation could be removed as long as it is being replaced with something else so it doesn't disturb the stabilization. Ms. Cox discussed the requirement for new development to have the SCPZ shown on preliminary and final development plans and all subsequent building permit applications. Ms. Carr asked about the City requiring builders to supply an educational guidelines sheet to help the homeowner understand the regulations in the SCPZ. Ms. Cox replied that the City struggles with that same issue in the no-disturb and no-build zones. The City requires that the information is recorded on the plat and that serves as the official documentation. She stated that it would be difficult for the City to enforce requiring the builder to provide information to the buyer. Ms. Carr expressed the need to somehow get the word about the SCPZ restrictions to the homebuyer in a way they can understand it for it to be effective. Mr. Hammersmith agreed that better public education needs to happen for both Planning and Engineering requirements such as this, and the City will strive to find a mechanism to provide better communication. Ms. Cox noted the effort the City had made with the Ameberleigh North development with the developer displaying the master plan for the park in their model or sales trailer so potential buyers knew what would developed. Ms. Cox asked for input from CSAC on the draft presentation and for any information they may want staff to discuss with the P&Z Commission for feedback. Mr. Hammersmith noted that they would be providing feedback on P&Z's reaction to the new SCPZ regulations. Ms. Carr stated that something was discussed at a previous meeting that may affect the P&Z Commission or how the regulations are written. The issue was the potential to adjust the SCPZ if there is an area where it is really steep along one side of the stream. In this case, would Engineering staff have the ability to adjust where the creek falls within the SCPZ rather than it being centered on the creek as it appears to currently be written. Ms. Cox stated that a request to provide flexibility based on topography could be addressed in the appeal process. Ms. Carr questioned whether Engineering staff would be able to request an adjustment based on how it is currently written. Mr. Hammersmith agreed it is a good point and staff will review it. Mr. Manifold had a general question not related to the Stormwater Management topic. He asked about the mass of pipe located in the Memorial Tournament parking lot south of the Bogey Inn. Mr. Hammersmith was not familiar with any project in Dublin, but he noted that the last time he saw a similar situation it was associated with a staging area for a City of Columbus project and presumed that is likely the case. V. Next Meeting: August 9, 2005 Mr. Merritt noted that CSAC intends to complete its review of the Stormwater Management Regulations at the August 9 meeting and requested that Ms. Moore send an additional a-mail reminder to CSAC members reminding them of the meeting prior to the agenda and minutes distribution a-mail. VI. Other Ms. Crandall provided a brief update on the Deer Management issue. Council did hear CSAC's recommendations and was in favor of them. Some of the different methods were discussed, and more specifically they discussed the bow- hunting program in New Albany, noting that it would be more difficult in Dublin to find an appropriate space. Council also requested additional information about the spread of Lyme Disease. Council requested that staff work on a plan for more detailed CSAC 6/14/05 Page 4 of 4 implementation of each of the recommendations. Ms. Crandall noted that she and other staff are meeting with Dr. Burton and Mr. Reid Thompson of the Ohio Wildlife Center to discuss a strategic plan and educational components for deer management in Dublin. She also noted that the City has filled the new position of Nature Education Coordinator who will assist with this component. VII. Adjournment There being no further business, the meeting was adjourned. Dublin Planning and Zoning Commission DRAFT' Minutes Excerpt -July 21, 2005 Page 1 of 6 (Prepared 8/4/05) 1. Chapter 53 -Stormwater Regulation Proposed Revisions Barb Cox said staff was requesting that the Commission review these proposed changes, and any comments or information received tonight will be forwarded to the Community Services Advisory Commission for their consideration. Ms. Cox said also, there is a minor change needed in the Zoning Code under the powers of the Board of Zoning Appeals in Chapter 153.231. Ms. Cox said the revised Stormwater Regulations need to be in compliance with the Ohio Environmental Protection Agency's NPDF Phase 2 and the General Construction permits. Ms. Cox said Dublin's current Chapter 53 applies to all development and there are very few exemptions. She said the Stormwater quantity control is required to predetermine the release rates based on Dublin's Stormwater Master Plan. It also requires Stormwater quality control during construction and post-construction control that is permanent for the first flush of water which, which at the time of adoption of them in 1998, was considered to be a half- inch of rain. Ms. Cox said the current Code includes Stormwater Management Plan submittal information, the requirements needed in a plan, how the maintenance is supposed to operate, and that the regulations are enforceable. Ms. Cox said revisions required by the EPA include changing the volume and equations for Post Construction Permanent Runoff Control to come into compliance with the permit. She said it went up to the first 3/4-inch of rain, instead of the current '/2-inch. She said there are also different draw-down times and details on how ponds and controlled measures are to be designed. She said Dublin's standards need to be updated to meet EPA requirements. Ms. Cox said the EPA was also requiring detailed information to be in an enforceable format for erosion sediment control while projects are under construction. Ms. Cox said there are details on redevelopment sites because Dublin requires it on all projects and there are few exceptions, this is not currently outlined in the current version of the new Code because the City does not give developers options like the EPA. She said Dublin's is more stringent that what the EPA would require. Ms. Cox said revisions that staff has requested include adding the exemptions to the quantity control. She said the Historic District outlined in the Code will be used and those projects that happen in the District, currently there is a step that happens...staff takes many of those to City Council for Stormwater Waivers on just the quantity control. She said that exemption in the Code will eliminate that step and the projects can be processed faster. Ms. Cox said the current Code does not include an exemption for small site plan additions. She said if generators or parking spaces are to be added, staff would like to include these Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 2 of 6 (Prepared 8/4/05) changes as an exemption also to alleviate a full engineering study being necessary when a small addition is being added to the project. Ms. Cox said another recommended Code revision is for a Stream Corridor Protection Zone which will be discussed later. She said because of the Stream Corridor Protection Zone, the staff requests to update the title of Chapter 53. She said the minor clarifications on the details are itemized in the May 6, 2005 memo to CSAC included in the Commission packet. Ms. Cox said a new Emergent Sediment Control section was at the end of the new chapter and it consolidated all of the City requirements on Emergent Control into one section so that there is one point of reference. Ms. Cox said the EPA timeframes for stabilizing the denuded (bare area) part of the site are being added in this ordinance. She said the details on the using of the temporary sediment settling basins, etc. on the site during the construction, as required by the EPA are detailed in the revised Code. Ms. Cox said the EPA has become more stringent on the maintenance/inspection and recordkeeping done by the contractors and developers on site. She said the necessary plan information details are to be added to the revised Code. Ms. Cox said the Stream Corridor Protection Zone area is being recommended to be added to the Code to help restrict land disturbances within the stream and riparian areas. She said it was an expansion of the floodway, plus 20 requirements included in Dublin's Flood Control chapter. She said staff feels that this will accommodate the natural meandering and protects property and stream banks from erosion, and will improve the water quality in Dublin's streams. Ms. Cox said there are more restricted things that can go in the Stream Corridor Protection Zone than permitted. She said construction, drudging, vehicle storage or driving, disturbance of top soil or the vegetation, and private utilities are not permitted. She said permitted uses include open space, passive recreation areas, removal of damaged trees, re- vegetation, reforestation, and any public roadway to promote infrastructure with minimal disturbance. Ms. Cox said the Stream Corridor Protection Zones would be applied in new developments and redevelopments of projects that do not currently have an approved Preliminary Development Plan. She said they would not be retroactive into the rears of existing homes. She said they will not be applied where FEMA has already designated a floodway or a floodplain. Ms. Cox said it is for areas outside those already studied areas to try to protect the streams. She said the information will be shown on the preliminary and final Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 3 of 6 (Prepared 8/4/05) development plans, and subsequent building permit plans, similar to floodways, no-build zones and no-disturb zones (protected areas) are shown. Ms. Cox showed a slide of a map highlighting where the Stream Corridor Protections Zones would apply. Ms. Cox said the appeals process, for delineation for the actual zone, the width, and the location will be worked out with the City Engineer. She said after the fact, once established, if they are on a plat, individual property owners wanting to go into that area for a deck, shed, etc. will go to the BZA for review and approval with the revised Code. That power and duty is being added to the BZA responsibilities. Ms. Cox said the revisions will be seen as a slight increase in retention and detention basin sizes seen on the development projects due to the '/2-inch to 3/4-inch volume change and some of the detention times that they are required to do. She said more realistic quantity control measures for Historic Dublin, plus removal of a step to City Council for those waivers. She said increased preservation requirements along the streams with the Corridor Protection Zone will be seen. Those areas will have to be designated on the site plans. She said on the preliminary and final development plans lines may be seen that are fairly new because of this Code change. She said they would also be shown on single-family development final plats. Ms. Cox asked for input or recommendations from the Commission. Ms. Reiss commented that she found it difficult the staff report because so much was changing and there were so many cross outs, renumbering, etc. Ms. Cox agreed that it was difficult to read, but she wanted the Commission to see what changes were being done instead of just providing a clean copy. Ms. Reiss referred to Section 53.070, Exceptions to the requirements where it covered development related exceptions, single-family or duplex and the Scioto River Corridor exemption which was everything from SR745 to SR257. She asked why that whole area was being exempted. Ms. Cox said the area between Dublin Road and Riverside Drive was an exemption currently in the Code. She said the reason for it was that the City wanted to level out when the water gets into the Scioto River. She said those areas are directly connected to the river. Ms. Cox said if detention was done on that, it would slow up the water so that it gets into the stream/creek that goes straight to the river. She said if slowed, that peak is going to come, probably at about the same time that the peak is coming from other things up stream and it is essentially to try to get the water out of those directly connected areas quicker so that when Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 4 of 6 (Prepared 8/4/05) the areas that have been detained upstream are finally getting into the creek, into the system, everything is not going on at the same time in those properties next to the river. Ms. Cox said it would be an overload on those properties. She said it was a timing issue. Ms. Reiss said the reason EPA instituted these requirements was to increase the ug alitY of our water. She asked since these directly drain into the Scioto River which goes into Griggs Reservoir which goes directly into our drinking water supply, would not those be areas that you would want to... Ms. Cox replied that they are not exempted from the water quality control but from the water ug antitX control. She said it was the volume of water, not the cleansing of the water. She said there is not exemption from the cleaning of water of that first 3/4-inch of rain for the first construction. Ms. Cox said the only part that is being exempted is the uq antitX control and the timing of when that water exits the development's system. Ms. Reiss asked if it still had to exit clean. Ms. Cox agreed. Mr. Messineo referred to Jane Brautigam's memo to City Council dated March 1, 2005, where she stated that staff proposed that sections of the existing ordinance that reference specific quality and quantity calculation methods and design criteria be deleted and moved to an administrative design manual. He understood that the EPA had new quantity and quality standards and that was why this was being instituted. Ms. Cox said the new EPA standards were not so much for quantity as quality. Mr. Messineo asked if the proposed Code changes would reduce Dublin's current water quality. Ms. Cox said it would not reduce the current water quality. She said the difference in the '/2 and 3/4 inch was the ualit calculation. She said the first 3/4-inch of rain is what washes the parking lots, roofs, and roadways of dirt, debris, trash, litter, oils, etc. and it has to be detained and cleaned before it gets into the creek system and subsequently into the river. Mr. Messineo asked if the 3/4-inch represented a more stringent requirement. Ms. Cox agreed that it was more stringent than Dublin's current 1/2-inch. She said Dublin's Master Plan set predevelopment release rates. She said the quantity of water has to be detained down to what the Master Plan requires from each of the development sites. She said the number is conservative. Mr. Messineo asked what "this is going to be moved to an administrative design manual" meant. Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 5 of 6 (Prepared 8/4/05) Ms. Cox said that was a step that has not been addressed yet by staff. She said mathematical equations are not typically codified which was done in 1998. She said in this instance, the Code has to be changed to update the standard to what the EPA wants to be done. Ms. Cox said staff would like to pull some of the detailed engineering things out because they do get update from time to time. She said it would be easier to change Dublin's policies rather than the Code and run a reference in the Code that this design manual has to be followed. Mr. Messineo understood that current Code had a Stormwater section. Ms. Cox said it was in the Public Works section of the codified ordinances. Mr. Messineo asked if a design manual was being proposed that will be referenced as Ms. Cox said yes. She said the standard drawings work that way now. Ms. Boring asked if this was the same as the CDM (Camp, Dresser, and McKee) map. Ms. Cox said she believed the streams were taken off of the CDM map, but staff produced the map. Ms. Boring noted that the underground hydrology markings were not included. Ms. Cox said no, because it was a surface stream. Ms. Boring asked how the underground water could be protected. Ms. Cox did not recommend that it be in the Stormwater Management section because it deals with rainwater and surface runoff. She suggested it might be more of a Building Code issue with drainage what happens with basements. Ms. Boring asked if this proposed ordinance had been reviewed thoroughly by the Community Service Advisory Commission (CSAC). Ms. Cox said CSAC had reviewed it and it would go back to them because City Council had asked them to formulate a formal recommendation. Mr. Bird suggested that there be a motion made to acknowledge that the BZA taking on the appeal process. Ms. Wanner said in Chapter 253, Board of Zoning Appeals -Powers and Duties, it lists what they do. She said it was a new section that would be added for the powers of the BZA to review stormwater appeals. Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 6 of 6 (Prepared 8/4/05) Mr. Smith said Council was not looking at the Commission to give BZA the power to do this, they are just looking for its blessing as the planning authority to say they understand this alters the Zoning Code. Mr. Gerber said this looked fine. He said to go any deeper, there would need to be a workshop. He said City Council assigned this to CSAC, not the Commission. Mr. Smith said whenever the zoning code is being changed or amended, the Commission needs to be made aware of them and their approval is requested. Mr. Messineo asked if this was coming before the Commission for ratification at some point. Mr. Gerber made a motion to recommend that City Council adopt the revisions that the Community Service Advisory Commission has undertaken. Mr. Gerber made a motion that the Commission supports this. Mr. Zimmerman seconded the motion. The vote was as follows: Ms. Reiss, yes; Ms. Jones, yes; Mr. Zimmerman, yes; Mr. Saneholtz, yes; Ms. Boring, yes; Mr. Messineo, yes; and Mr. Gerber, yes. (Approved 7- 0.) Dublin Planning and Zoning Commission DRAFT Minutes Excerpt -July 21, 2005 Page 1 of 6 (Prepared 8/4/05) 1. Chapter 53 -Stormwater Regulation Proposed Revisions Barb Cox said staff was requesting that the Commission review these proposed changes, and any comments or information received tonight will be forwarded to the Community Services Advisory Commission for their consideration. Ms. Cox said also, there is a minor change needed in the Zoning Code under the powers of the Board of Zoning Appeals in Chapter 153.231. Ms. Cox said the revised Stormwater Regulations need to be in compliance with the Ohio Environmental Protection Agency's NPDF Phase 2 and the General Construction permits. Ms. Cox said Dublin's current Chapter 53 applies to all development and there are very few exemptions. She said the Stormwater quantity control is required to predetermine the release rates based on Dublin's Stormwater Master Plan. It also requires Stormwater quality control during construction and post-construction control that is permanent for the first flush of water which, which at the time of adoption of them in 1998, was considered to be a half- inch of rain. Ms. Cox said the current Code includes Stormwater Management Plan submittal information, the requirements needed in a plan, how the maintenance is supposed to operate, and that the regulations are enforceable. Ms. Cox said revisions required by the EPA include changing the volume and equations for Post Construction Permanent Runoff Control to come into compliance with the permit. She said it went up to the first '/4-inch of rain, instead of the current '/2-inch. She said there are also different draw-down times and details on how ponds and controlled measures are to be designed. She said Dublin's standards need to be updated to meet EPA requirements. Ms. Cox said the EPA was also requiring detailed information to be in an enforceable format for erosion sediment control while projects are under construction. Ms. Cox said there are details on redevelopment sites because Dublin requires it on all projects and there are few exceptions, this is not currently outlined in the current version of the new Code because the City does not give developers options like the EPA. She said Dublin's is more stringent that what the EPA would require. Ms. Cox said revisions that staff has requested include adding the exemptions to the quantity control. She said the Historic District outlined in the Code will be used and those projects that happen in the District, currently there is a step that happens...staff takes many of those to City Council for Stormwater Waivers on just the quantity control. She said that exemption in the Code will eliminate that step and the projects can be processed faster. Ms. Cox said the current Code does not include an exemption for small site plan additions. She said if generators or parking spaces are to be added, staff would like to include these Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 2 o f 6 (Prepared 8/4/05) changes as an exemption also to alleviate a full engineering study being necessary when a small addition is being added to the project. Ms. Cox said another recommended Code revision is for a Stream Corridor Protection Zone which will be discussed later. She said because of the Stream Corridor Protection Zone, the staff requests to update the title of Chapter 53. She said the minor clarifications on the details are itemized in the May 6, 2005 memo to CSAC included in the Commission packet. Ms. Cox said a new Emergent Sediment Control section was at the end of the new chapter and it consolidated all of the City requirements on Emergent Control into one section so that there is one point of reference. Ms. Cox said the EPA timeframes for stabilizing the denuded (bare area) part of the site are being added in this ordinance. She said the details on the using of the temporary sediment settling basins, etc. on the site during the construction, as required by the EPA are detailed in the revised Code. Ms. Cox said the EPA has become more stringent on the maintenance/inspection and recordkeeping done by the contractors and developers on site. She said the necessary plan information details are to be added to the revised Code. Ms. Cox said the Stream Corridor Protection Zone area is being recommended to be added to the Code to help restrict land disturbances within the stream and riparian areas. She said it was an expansion of the floodway, plus 20 requirements included in Dublin's Flood Control chapter. She said staff feels that this will accommodate the natural meandering and protects property and stream banks from erosion, and will improve the water quality in Dublin's streams. Ms. Cox said there are more restricted things that can go in the Stream Corridor Protection Zone than permitted. She said construction, drudging, vehicle storage or driving, disturbance of top soil or the vegetation, and private utilities are not permitted. She said permitted uses include open space, passive recreation areas, removal of damaged trees, re- vegetation, reforestation, and any public roadway to promote infrastructure with minimal disturbance. Ms. Cox said the Stream Corridor Protection Zones would be applied in new developments and redevelopments of projects that do not currently have an approved Preliminary Development Plan. She said they would not be retroactive into the rears of existing homes. She said they will not be applied where FEMA has already designated a floodway or a floodplain. Ms. Cox said it is for areas outside those already studied areas to try to protect the streams. She said the information will be shown on the preliminary and final Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 3 of 6 (Prepared 8/4/05) development plans, and subsequent building permit plans, similar to floodways, no-build zones and no-disturb zones (protected areas) are shown. Ms. Cox showed a slide of a map highlighting where the Stream Corridor Protections Zones would apply. Ms. Cox said the appeals process, for delineation for the actual zone, the width, and the location will be worked out with the City Engineer. She said after the fact, once established, if they are on a plat, individual property owners wanting to go into that area for a deck, shed, etc. will go to the BZA for review and approval with the revised Code. That power and duty is being added to the BZA responsibilities. Ms. Cox said the revisions will be seen as a slight increase in retention and detention basin sizes seen on the development projects due to the `/2-inch to '/4-inch volume change and some of the detention times that they are required to do. She said more realistic quantity control measures for Historic Dublin, plus removal of a step to City Council for those waivers. She said increased preservation requirements along the streams with the Corridor Protection Zone will be seen. Those areas will have to be designated on the site plans. She said on the preliminary and final development plans lines may be seen that are fairly new because of this Code change. She said they would also be shown on single-family development final plats. Ms. Cox asked for input or recommendations from the Commission. Ms_ Reiss commented that she found it difficult the staff report because so much was changing and there were so many cross outs, renumbering, etc. Ms. Cox agreed that it was difficult to read, but she wanted the Commission to see what changes were being done instead of just providing a clean copy. Ms. Reiss referred to Section 53.070, Exceptions to the requirements where it covered development related exceptions, single-family or duplex and the Scioto River Corridor exemption which was everything from SR745 to SR257. She asked why that whole area was being exempted. Ms. Cox said the area between Dublin Road and Riverside Drive was an exemption currently in the Code. She said the reason for it was that the City wanted to level out when the water gets into the Scioto River. She said those areas are directly connected to the river. Ms. Cox said if detention was done on that, it would slow up the water so that it gets into the stream/creek that goes straight to the river. She said if slowed, that peak is going to come, probably at about the same time that the peak is coming from other things up stream and it is essentially to try to get the water out of those directly connected areas quicker so that when Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page4of6 (Prepared 8/4/05) the areas that have been detained upstream are finally getting into the creek, into the system, everything is not going on at the same time in those properties next to the river. Ms. Cox said it would be an overload on those properties. She said it was a timing issue. Ms. Reiss said the reason EPA instituted these requirements was to increase the ualit of our water. She asked since these directly drain into the Scioto River which goes into Griggs Reservoir which goes directly into our drinking water supply, would not those be areas that you would want to... Ms. Cox replied that they are not exempted from the water quality control but from the water u4 antitX control. She said it was the volume of water, not the cleansing of the water. She said there is not exemption from the cleaning of water of that first 3/4-inch of rain for the first construction. Ms. Cox said the only part that is being exempted is the uq antis control and the timing of when that water exits the development's system. Ms. Reiss asked if it still had to exit clean. Ms. Cox agreed. Mr. Messineo referred to Jane Brautigam's memo to City Council dated March 1, 2005, where she stated that staff proposed that sections of the existing ordinance that reference specific quality and quantity calculation methods and design criteria be deleted and moved to an administrative design manual. He understood that the EPA had new quantity and quality standards and that was why this was being instituted. Ms. Cox said the new EPA standards were not so much for quantity as quality. Mr. Messineo asked if the proposed Code changes would reduce Dublin's current water quality. Ms. Cox said it would not reduce the current water quality. She said the difference in the %2 and 3/4 inch was the uq alitX calculation. She said the first 3/4-inch of rain is what washes the parking lots, roofs, and roadways of dirt, debris, trash, litter, oils, etc. and it has to be detained and cleaned before it gets into the creek system and subsequently into the river. Mr. Messineo asked if the 3/4-inch represented a more stringent requirement. Ms. Cox agreed that it was more stringent than Dublin's current %2-inch. She said Dublin's Master Plan set predevelopment release rates. She said the quantity of water has to be detained down to what the Master Plan requires from each of the development sites. She said the number is conservative. Mr. Messineo asked what "this is going to be moved to an administrative design manual" meant. Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 5 of 6 (Prepared 8/4/05) Ms. Cox said that was a step that has not been addressed yet by staff. She said mathematical equations are not typically codified which was done in 1998. She said in this instance, the Code has to be changed to update the standard to what the EPA wants to be done. Ms. Cox said staff would like to pull some of the detailed engineering things out because they do get update from time to time. She said it would be easier to change Dublin's policies rather than the Code and run a reference in the Code that this design manual has to be followed. Mr. Messineo understood that current Code had a Stormwater section. Ms. Cox said it was in the Public Works section of the codified ordinances. Mr. Messineo asked if a design manual was being proposed that will be referenced as Ms. Cox said yes. She said the standard drawings work that way now. Ms. Boring asked if this was the same as the CDM (Camp, Dresser, and McKee) map. Ms. Cox said she believed the streams were taken off of the CDM map, but staff produced the map. Ms. Boring noted that the underground hydrology markings were not included. Ms. Cox said no, because it was a surface stream. Ms. Boring asked how the underground water could be protected. Ms. Cox did not recommend that it be in the Stormwater Management section because it deals with rainwater and surface runoff She suggested it might be more of a Building Code issue with drainage what happens with basements. Ms. Boring asked if this proposed ordinance had been reviewed thoroughly by the Community Service Advisory Commission (CSAC). Ms. Cox said CSAC had reviewed it and it would go back to them because City Council had asked them to formulate a formal recommendation. Mr. Bird suggested that there be a motion made to acknowledge that the BZA taking on the appeal process. Ms. Wanner said in Chapter 253, Board of Zoning Appeals -Powers and Duties, it lists what they do. She said it was a new section that would be added for the powers of the BZA to review stormwater appeals. Dublin Planning and Zoning Commission Minutes Excerpt -July 21, 2005 Page 6 of 6 (Prepared 8/4/05) Mr. Smith said Council was not looking at the Commission to give BZA the power to do this, they are just looking for its blessing as the planning authority to say they understand this alters the Zoning Code. Mr. Gerber said this looked fine. He said to go any deeper, there would need to be a workshop. He said City Council assigned this to CSAC, not the Commission. Mr. Smith said whenever the zoning code is being changed or amended, the Commission needs to be made aware of them and their approval is requested. Mr. Messineo asked if this was coming before the Commission for ratification at some point. Mr. Gerber made a motion to recommend that City Council adopt the revisions that the Community Service Advisory Commission has undertaken. Mr. Gerber made a motion that the Commission supports this. Mr. Zimmerman seconded the motion. The vote was as follows: Ms. Reiss, yes; Ms. Jones, yes; Mr. Zimmerman, yes; Mr. Saneholtz, yes; Ms. Boring, yes; Mr. Messineo, yes; and Mr. Gerber, yes. (Approved 7- 0.) Office of the City Manager 5200 Emerald Parkway • Dublin, OH 43017 CITY OF DUBLIN_ Phone: 614-410-4400 • Fax: 614-410-4490 M e m o To: Members of City Council From: Community Services Advisory Commission Date: August 9, 2005 Re: Proposed Revisions to Chapter 53: Stormwater Regulations On March 7, 2005, City Council forwarded an assignment to the Community Services Advisory Commission (CSAC) to review the proposed revisions to Chapter 53: Stormwater Regulations of the Codified Ordinances. CSAC held meetings on May 10, June 14, July 12 and August 9 during the proposed revisions were reviewed, considered and discussed. City staff has provided beneficial background and answers to our questions regarding the proposed revisions to the Stormwater Regulations. At the initial meeting on May 10th, we mainly focused on the proposed new section regarding Stream Corridor Protection Zones (SCPZ), Section 53.200. We went over where these are to be applied, how the zones are determined, the proposed uses in the zone, and enforcement of the requirements. We believe that the SCPZ will add a layer of protection for stream corridors that may have otherwise been adversely impacted by development where no other regulations provide for the preservation of the riparian buffers.. The other proposed revisions were assessed at the second meeting held June 14th. It is our understanding that the other proposed changes to the Chapter are in line with the requirements of the current Ohio Environmental Protection Agency (OEPA) Phase 2 and General Construction permits. Also discussed were how the SCPZ relate to current open space requirements, variance/appeal procedures for the SCPZ, enforcement of the SCPZ and how to integrate an overview done by the Planning and Zoning Commission. At the July 12th meeting, we provided staff with final comments on the proposed revisions and reviewed a draft of this recommendation to City Council. We also gave input to questions/comments we had that we wanted Planning and Zoning Commission's opinion on. We have been briefed on August 9th of the review by the Planning and Zoning Commission and agree that the comments and changes from them only strengthen the code. In light of the benefits already realized from the existing Stormwater Regulations and the enhanced environmental benefits from the proposed revisions, we respectfully recommend adoption of the proposed revisions to amend existing Chapter 53. The newly adopted Chapter 53 is to be titled Stormwater Regulations and Stream Protection. PLANNING AND ZONING COMMISSION RECORD OF ACTION JULY 21, 2005 CITY OF DUBLIN_ lad Uu aid Leq Raga Phnaiag 5800 Shier-IGags Road DubBn, Ohio 43016-1136 Phone: 614.410-4600 Fmr.6l4-410.4747 Web Sib: www.duldin.oh.us The Planning and Zoning Commission took the following action at this meeting: 1. Chapter 53 -Stormwater Regulation Proposed Revisions Engineering Division presentation of proposed revisions to Chapter 53, Stormwater Regulations. MOTION: To recommend that City Council adopt the revisions to Chapter 53 -Stormwater Regulations, and also adopt a minor addition to Section 153.231, which authorizes the Board of Zoning Appeals to grant variances to portions of Chapter 53. VOTE: 7 - 0 RESULT: The motion was approved, and both revisions will be forwarded to City Council with a positive recommendation. RECORDED VOTES: Ms. Reiss Yes Mr. Saneholtz Yes Ms. Boring Yes Mr. Messineo Yes Ms. Jones Yes Mr. Zimmerman Yes Mr. Gerber Yes STAFF CERTIFICATION INNk~~~Z(rY" Anne Wanner Senior Planner