Comprehensive Stormwater Management Plan Required: The applicant shall develop a Comprehensive Stormwater Management Plan describing how the quantity and quality of stormwater will be managed after construction is completed for every discharge from the site and/or into a water resource or small Municipal Separate Storm Sewer System (MS4). Comprehensive Stormwater Management Plans must meet the requirements in the Construction General Permit and these regulations.
(a) Preparation by Professional Engineer. The Comprehensive Stormwater Management Plan shall be prepared by a registered Professional Engineer and include supporting calculations, plan sheets, and design details. To the extent necessary, as determined by the City Engineer, a site survey shall be performed by a registered Professional Surveyor to establish boundary lines, measurements, or land surfaces.
(b) Community Procedures. The City Engineer shall prepare and maintain procedures providing specific criteria and guidance to be followed when designing the stormwater management system for the site. These procedures may be updated from time to time, at the discretion of the City Engineer based on improvements in engineering, science, monitoring, and local maintenance experience. The City Engineer shall make the final determination of whether SCMs proposed in the Comprehensive Stormwater Management Plan meet the requirements of this regulation to be used in the City of Garfield Heights.
(c) Contents of Comprehensive Stormwater Management Plan. The Comprehensive Stormwater Management Plan must contain all elements and meet all requirements specified in the Construction General Permit. It shall also meet the following requirements.
(1) Location information. The application shall note the phase, if applicable, of the overall development plan and list sublot numbers if project is a subdivision. The Site description shall include, at a minimum the following:
A. A description of the nature and type of the construction activity (e.g. residential, L.I.D. Development, shopping mall, road project, etc.)
B. The total area of the site and the area of the site anticipated to be disturbed during each phase of development including grubbing, clearing, excavation, filling, and grading, including off-site fill or borrow areas even if not within the City of Garfield Heights.
C. Description of prior land use.
D. The estimate of the impervious area and percentage of imperviousness created by the soil-disturbing activity both pre- and post-development.
E. Soil boring logs and locations, including soil series and association, hydrologic soils group, soil porosity, infiltration characteristics, depth to groundwater, depth to bedrock, and any identified impervious layers.
F. If available, the quality of any known pollutant discharge from the site such as that which may result from previous contamination caused by prior uses.
G. The location and name of the immediate water resource(s) and the first subsequent water resource(s).
H. The aerial plan view extent and description or water resources at or near the site that will be disturbed or will receive discharges from the project.
I. Describe the current condition of water resources including the vertical stability of stream channels and indications of channel incision that may be responsible for current or future sources of high sediment loading or loss of channel stability.
(2) Site maps and SCM design plans. It is preferred that all SCMs and the entire site be shown on one plan sheet to allow a complete view of the site during plan review. If a smaller scale is used to accomplish this, separate sheets providing an enlarged view of areas on individual sheets should also be provided. Existing and proposed drainage patterns and any relevant offsite SCMs should be depicted. For each SCM, include the following:
A. An individual identification number
B. Location and size
C. Final site conditions and detail drawings of stormwater inlets and permanent SCMs. Details of SCMs shall be drawn to scale and shall show relevant volumes, elevations and sizes of contributing drainage areas.
D. A completed Ohio EPA WQv Calculator Spreadsheet and/or Runoff Reduction Spreadsheet or other equivalent compliance tools provided by Ohio EPA.
E. Any supplemental information requested by the City Engineer and Building Commissioner.
(3) Required Calculations. The applicant shall submit calculations for projected stormwater runoff flows, volumes, and timing into and through all SCMs for flood control, channel protection, water quality, and the condition of the habitat, stability, and incision of each water resource and its floodplain. These submittals shall be completed for both pre- and post-development land use conditions and shall include the underlying assumptions and hydrologic and hydraulic methods and parameters used for these calculations. The applicant shall also include critical storm determination and demonstrate that the runoff from offsite areas have been considered in the calculations. For each SCM, identify the drainage area and size in acres, percent impervious cover within the drainage area, volumetric runoff coefficient, peak discharge, and the time of concentration for each subwatersheds. Pervious and impervious areas should be treated as separate subwatersheds unless allowed at the discretion of the community engineer. Identify the SCM surface area, discharge and dewatering time, outlet type and dimensions.
(4) Inspection and Maintenance Agreement. The Inspection and Maintenance Agreement required for SCMs under this regulation is a stand-alone document between the City of Garfield Heights and the applicant. This agreement shall be recorded with the County Recorder. The agreement, at a minimum, shall include:
A. The location of each SCM on the site;
B. The schedule for regular maintenance and responsible party for such, including the source of funding for such;
C. Agreed upon submission dates for maintenance reporting to the City of Garfield Heights;
D. Agreement to permit the City of Garfield Heights to enter the property to preform any corrective actions identified in the inspection report if the landowner(s), organizations, or municipality responsible for maintenance do not make the required corrections in a specified time period. The City of Garfield Heights shall be reimbursed by the land owner(s), organization responsible for maintenance for any and all expenses incurred within ten (10) days of receipt of invoice from the City of Garfield Heights.
E. A release of the City of Garfield Heights from all damages, accidents, casualties, occurrences, or claims that might arise or be asserted against the City of Garfield Heights from the construction, presence, existence, or maintenance of the storm water management practices proposed by the owner(s).
(5) Inspection and Maintenance Plan. This plan will meet the requirements of the Construction General Permit and will be developed by the applicant and reviewed by the City Engineer. Maintenance requirements of each SCM during and after construction should be included. Once the Inspection and Maintenance Plan is approved, a recorded copy of the Plan must be provided to the property owner or association that will be responsible for long-term operation and maintenance of the BMP and submitted to the City Engineer as part of the final inspection approval as described in Section 1170.12.
Alteration or termination of these stipulations is prohibited. The applicant must provide a draft of the Inspection and Maintenance Agreement as part of the Comprehensive Storm Water Management Plan submittal. Once a draft is approved, a recorded copy of the Agreement must be submitted to the City of Garfield Heights to receive final inspection approval of the site.
(6) Failure to provide the City of Garfield Heights with a recorded copy of the approved Inspection and Maintenance Agreement shall restrict the Zoning Administrator from approving Zoning Permits within the applicable project area. The City of Garfield Heights reserves the right to revoke bonding on the project until a final approved agreement is provided.
(Ord. 60-2023. Passed 8-14-23.)