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In implementing these regulations the City Engineer or other Community officials may consult with the local county SWCD, state and federal agencies and other technical experts as necessary. Any costs associated with such consultations may be assessed to the applicant
or his or her designated representative.
(Ord. 2021-15. Passed 3-17-21.)
In order to control Post-Construction water quality damage and damage to public and private lands, the owner of each development area shall be responsible for developing a Post-Construction Storm Water Management Report. The plan shall be submitted to the City Engineer for review and approval for all subdivisions, new development, or re-development of
residential and non-residential parcels with a disturbed area of 1 acre or more.
The Post-Construction Stormwater Management Report Plan shall meet the following criteria:
(a) The current edition of the "Mahoning County Drainage Criteria and Storm Water Manual" and the policies, standards, specifications, and provisions contained therein shall apply to the development of all subdivisions, development, or redevelopment projects in the City.
(b) Critical storm methodology shall be as described in the most current version of the "Mahoning County Drainage Criteria and Storm Water Manual."
(c) All requirements of the most current version of the Ohio EPA NPDES General Permit shall be satisfied.
(d) In the event that the regulations found in the Mahoning County Drainage Criteria and Storm Water Manual and the Ohio EPA NPDES General Permit differ, the more stringent regulations shall be followed, as directed by the City Engineer.
(e) The BMPs used to satisfy the condition of these regulations shall meet the standards and specifications in the current edition of the Ohio Rain Water and Land Development manual or other manual that is acceptable to the City Engineer or Ohio EPA.
(f) Runoff for proposed subdivision, development, and redevelopment sites shall be calculated using the SCS method. The allowable discharges shall be determined using the critical storm method.
(g) For sites that are currently developed and scheduled to be redeveloped, the pre-developed condition shall be defined to be one hundred percent (100%) of the site as grassland for critical storm and volume storage calculations.
(h) In no case shall the post-developed runoff exceed the pre-developed runoff condition for an equivalent storm event.
(i) In no case shall a structure be located within the impoundment area of any stormwater storage facility or over any stormwater drainage or sewer line.
(j) Retention and Detention facilities within 500 feet of an existing dwelling shall be landscaped to as near predevelopment conditions as possible. The distance is measured from the outermost edge of the interior slope to the nearest existing habitable dwelling.
(k) Design and installation of all stormwater conveyance systems, storm sewers, and post-construction BMPs shall comply with all applicable federal, state, and local laws.
(l) Stormwater runoff must be managed and maintained on-site. The on-site collection system shall be designed to meet the current Mahoning County Drainage Criteria and Storm Water Manual. On-site collection system calculations shall be provided in the report. Downstream impacts shall not be allowed.
(m) Stormwater storage calculations shall be prepared in accordance with the following table:
Rain Event | 24-Hour Rainfall (in)1 | Pre-Developed Runoff (cfs) | Allowable Discharge (cfs) | Post-Developed Runoff (cfs)3 | Post-Developed Runoff with Proposed BMP (cfs)4 | Required Storage Volume (cf) |
2 Year | ||||||
5 Year | ||||||
10 Year | ||||||
25 Year | ||||||
50 Year | ||||||
100 Year |
1 24-hour rainfall rates are provided in Table 2-3 of the Mahoning County Drainage Criteria and Stormwater Manual.
2 Allowable discharge rates are based on the critical storm guidelines.
3 Post--developed runoff is based off post-construction conditions in the absence of post-construction BMPs.
4 Post-developed runoff when BMPs are installed and stormwater is routed through an approved outlet structure.
(n) A construction cost-estimate of the proposed stormwater improvements including on-site collection and post-construction BMP(s).
(o) The Post-Construction Stormwater Management Report shall be prepared and stamped by a Professional Engineer and must include hydraulic calculations that establish the adequacy of the drainage system of the proposed development site so as not to create or worsen drainage problems upstream and downstream of the site.
The construction drawings shall show the following:
(a) Site Description:
(1) The prior land uses of the site
(2) The nature and type of construction activity ( e.g., low density residential, shopping mall, highway, etc.)
(3) Total area of the site and the area of the site that is expected to be disturbed (i.e., grubbing, clearing, excavating, filling or grading, including off-site borrow, fill or spoil areas and off-site utility installation areas).
(4) Amount of the impervious area and percent imperviousness created by the construction activity
(5) Name and/or location of the immediate receiving stream or surface water(s) and the first subsequent named receiving water and the major river watersheds in which it is located.
(b) A Site Plan Showing the Location of the Following:
(1) The larger common plan of development or sale.
(2) Property lines including Owner information for the development parcel and adjacent parcels.
(3) The limits of earth disturbing activity.
(4) Existing and proposed topography shall be shown in one-foot intervals.
(5) Existing and proposed drainage patterns and facilities of the site, including any allied drainage facilities beyond the development area and the larger common plan of development of sale.
(6) The location of each proposed post-construction BMP(s), all utilities (existing and/or proposed), and all proposed on-site improvements.
(7) All pertinent surrounding natural features within 200 feet of the development site.
(8) The location of all existing and proposed easements.
(9) Existing and proposed watershed boundary lines, direction of flow, and watershed acreage.
(10) The location of any existing or planned riparian and/or wetland setback areas on the property.
A. Riparian Setback and/or wetland setback areas shall meet the requirements of the most current version of the Ohio EPA NPDES General Permit.
(c) Construction Details and Specifications:
(1) Detail drawings and specifications for all post-construction BMP(s) shall be included within the drawings. The post-construction BMP(s) outlet structure detail must be included.
(Ord. 2021-15. Passed 3-17-21.)
Future access to all permanent vegetative and/or mechanical Post-Construction water quality conservation practices (BMPs) and other areas, as required by the City Engineer, shall be secured by means of easements.
(a) The easements shall be recorded in the name of the Community and, in single-family residential developments, the homeowners association.
(b) Such easements shall be not less than twenty-five (25) feet in width, in addition to the width of the ditch, channel, or other facility it is to serve. Further, an easement of this type shall be provided on one (1) side of the flood control or storm drainage ditch, channel, or similar-type facility.
(c) Access along the initial drainage system shall be by means of easements. Such easements shall be not less than twenty-five (25) feet in width, with a minimum ten (10) foot width on either side of the centerline.
(d) Access adjacent to storage facilities shall consist of a twenty-five (25) foot easement in the case of detention (dry) basins, and a twenty-five (25) foot easement with a twenty-five foot level bench in the case of retention (wet) basins, measured from the top of the bank, and shall include the storage facility itself.
(e) Easements for the emergency flow ways shall be a minimum of twenty-five (25) feet in width, or larger if required by the City Engineer.
(f) Flood control or storm drainage easements containing underground facilities shall have a minimum width of twenty-five (25) feet.
(g) The easements shall be restricted against the planting within said easement of trees, shrubbery or plantings with woody growth characteristics, and against the construction therein of buildings, accessory buildings, fences, walls or any other obstructions to the free flow of storm water and the movement of inspectors and maintenance equipment and also restricted against the changing of final grade from that described by the grading plan.
(Ord. 2021-15. Passed 3-17-21.)
Any portion of the permanent Post-Construction water quality management systems, including on-site and off-site treatment/storage facilities that are constructed by the owner, will be continuously maintained into perpetuity.
(a) Detail drawings and maintenance plans must be provided for all Post-Construction BMP(s).
(b) The person or entity responsible for continued maintenance of all vegetative and/or mechanical BMPs for both the construction and Post-Construction phases of the development shall be identified and a written agreement shall be entered into by the City and responsible entity for continued maintenance.
(c) Long-term maintenance requirements and schedules of all BMPs for both the construction and Post-Construction phases of the development will be identified.
(d) This plan will contain long-term maintenance inspection schedules, including the printed name and contact point of the Post-Construction landowner (e.g., president of the homeowners association, store manager, apartment complex manager, etc.)
(e) This plan will identify the person or entity financially responsible for maintaining the permanent inspection and maintenance of permanent storm water conveyance and storage structures and other conservation practices.
(f) The method of ensuring that funding will be available to conduct the long-term maintenance and inspections of all permanent storm water, soil erosion and sediment control and water quality practices will be identified.
(g) Maintenance plans must ensure that pollutants collect within structural Post-Construction BMP practices be disposed of in accordance with local, state and federal guidelines.
(h) Maintenance plans shall be provided by the permittee to both the City Engineer and the Post-Construction operator of the BMP (including homeowner associations) upon completion of construction activities and prior to the City Engineer giving final approval for the completed construction.
(i) Single-Family Residential Developments: A Homeowners' Association shall be created and placed in title of the affected lands and shall be continuously responsible for Post-Construction maintenance and inspections into perpetuity unless such maintenance and inspections become officially accepted by the Community.
(j) Multi-Family, Commercial and Industrial Developments: The plans will clearly state that the owner of the property shall be continuously responsible for Post-Construction maintenance and inspections into perpetuity unless such maintenance and inspections become officially accepted by the Community.
(k) Maintenance Design. Low maintenance requirements are a priority in the design and construction of all facilities. Multi-use facilities incorporating assets such as aesthetics and recreation may be incorporated into the design of the drainage facilities. All permanent drainage, soil erosion, sediment control, water quality management systems and BMPs, including on-site and off-site structures and vegetation that are constructed or planted, must be inspected and maintained into perpetuity by the responsible party designated in the plans and the requirements of this chapter. Inspections and maintenance will be incorporated periodically throughout the year to ensure that the facilities are property operational.
(l) Perpetual Maintenance Inspections: One (1) inspection with a written report will be performed each year. The written report will be given to the Zoning Inspector by May 1st of each and every year after the Best Management Practice (BMP) has been completed.
(m) Structures that require a permit from the Ohio Division of Water: A written and stamped report from a professional engineer on the status of all structural BMPs that require a permit from the Ohio Department of Natural Resources (DNR) Division of Water. This applies to all BMPs that require a permit either at the time of construction or fall under the jurisdiction of ODNR Division of Water at any time after construction is completed.
(n) Easements. A written report from an inspector on the status of all storm water management easements for each project shall be submitted to the City Engineer by May 18th of each year into perpetuity. These reports will document if restricted plantings, fences, and structures are on the easement and will identify the location of the noted easement restriction violations.
(o) Best Management Practices (BMPS) that do not have a high risk for loss of life, bodily injury, or damage to structures or infrastructure related to imminent failure as determined by the City Engineer: A written and stamped report from a professional engineer, landscape architect or Certified Professional In Erosion and Sediment Control (CPESC) on the status of permanent soil erosion, sediment control, water quality management systems and the status of the related easements shall be submitted to the City Engineer by May 18th of each year into perpetuity.
(p) BMPs that have a potential loss of life: A written and stamped report covering the status of all BMPs that have a potential for loss of life, bodily injury, or damage to structures or infrastructure will be prepared by a professional engineer or other individual possessing a valid state license that authorizes them to design the same type of BMP for construction.
(Ord. 2021-15. Passed 3-17-21.)
In order to control pollution of water resources, the owner or person responsible for the development area shall use conservation planning and practices to maintain the level of conservation established in the following standards:
(a) Standards and Specifications: Post-Construction runoff practices used to satisfy these standards shall meet the standards and specifications in the current edition of the Rainwater and Land Development manual, NRCS Field Office Technical Guide or the local county, or the Ohio EPA, whichever is most stringent. These standards are general guidelines and shall not limit the right of the City Engineer to impose at any time additional and/or more stringent requirements nor shall the standards limit the right of the City Engineer to waive, in writing, individual requirements. If the City Engineer waives, in writing, individual requirements the new owner will provide the City Engineer with the information and documentation required to assure the Ohio EPA that the waived requirement will not degrade water quality.
(Ord. 2021-15. Passed 3-17-21.)
Where the City Engineer determines that site constraints exist in a manner that compromises the intent of this ordinance to improve the management of storm water runoff as established in this ordinance, practical alternatives may be used to result in an improvement of water quality and/or a reduction of storm water runoff. Such alternatives must be in keeping with the intent and likely cost of those measures that would otherwise be required to meet the objectives of this section. When possible, all practical alternatives shall be implemented within the drainage area of the proposed development project. Practical alternatives can include, but are not limited to:
(a) Fees shall be paid in an amount specified by the City Engineer. The Community shall apply these fees to storm water management practices that improve the existing water quality.
(b) Implementation of off-site storm water management practices.
(c) Watershed or stream restoration.
(d) Retrofitting of an existing storm water management practice.
(e) Other practices approved by the City Engineer in keeping with the intent of this section.
(Ord. 2021-15. Passed 3-17-21.)
(a) Ohio Dam Safety Laws. The provisions of the Ohio Dam Safety Laws shall be followed. Proof of compliance with the Ohio Dam Safety Law administered by the ODNR Division of Water shall be, but is not limited to, a copy of the ODNR Division of Water permit number or a copy of the project approval letter from the ODNR Division of Water or a letter from the site owner explaining why the Ohio Dam Safety Law is not applicable. The written proof will be provided to the City Engineer before a construction permit will be issued.
(b) NPDES Permits: The provisions of the National Pollutant Discharge Elimination System (NPDES) Permits for construction activity, by the Ohio EPA, shall be followed. Proof of compliance shall be, but is not limited to, a copy of the Ohio EPA NPDES Permit number or a letter from the site owner explaining why the NPDES Permit is not applicable. The written proof will be provided to the City Engineer before a construction permit will be issued .
(c) Federal and State Wetland Permits: The provisions of the U.S. Army Corps of Engineers dredge and fill permits for federally-protected wetlands shall be followed. The provisions of Ohio EPA's Isolated Wetlands Permits shall also be followed. Wetlands and other waters of the United States shall be delineated by protocols accepted by the U.S. Army Corps of Engineers and the Ohio EPA at the time of the application of these regulations. Written proof of compliance with both permit programs will be provided to the City Engineer before a construction permit will be issued. Proof of compliance shall be, but is not limited to, the following:
(1) A copy of the U.S. Army Corps of Engineers Individual Permit, if required for the project, showing project approval and any restrictions that apply to site activities; or
(2) A site plan showing that any proposed fill of waters of the United States conforms to the general and specific conditions specified in the applicable Nationwide Permit; or
(3) A letter from the site owner verifying that a qualified professional has surveyed the site and found no wetlands or other waters of the United States. Such a letter shall be noted on site plans submitted to the Community. (Ord. 2021-15. Passed 3-17-21.)
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