(a) Comprehensive Storm Water Management Plan Required: The applicant shall develop a Comprehensive Storm Water Management Plan describing how the quantity and quality of storm water will be managed after construction is complete for every discharge from the site and/or into a water resource. The Plan will illustrate the type, location, and dimensions of every structural and non-structural storm water management practice incorporated into the site design, and the rationale for their selection. The rationale must address how these storm water management practices will address flooding within the site as well as flooding that may be caused by the development upstream and downstream of the site. The rationale will also describe how the storm water management practices minimize impacts to the physical, chemical, and biological characteristics of on-site and downstream water resources and, if necessary, correct current degradation of water resources that is occurring or take measures to prevent predictable degradation of water resources.
(b) Preparation by Professional Engineer: The Comprehensive Storm Water 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 Village Engineer, a site survey shall be performed by a Registered Professional Surveyor to establish boundary lines, measurements, or land surfaces.
(c) Community Procedures: The Village Engineer shall prepare and maintain procedures providing specific criteria and guidance to be followed when designing the storm water management system for the site. These procedures may be updated from time to time, at the discretion of the Village Engineer based on improvements in engineering, science, monitoring, and local maintenance experience. The Village Engineer shall make the final determination of whether the practices proposed in the Comprehensive Storm Water Management Plan meet the requirements of this regulation. The Village Engineer may also maintain a list of acceptable Best Management Practices, including the most current edition of the Mid Ohio Regional Planning Commission (MORPC) Stormwater Manual, that meet the criteria of this regulation to be used in the Village of Granville.
(d) Contents of Comprehensive Storm Water Management Plan: The Comprehensive Storm Water Management Plan shall contain an application, narrative report, construction site plan sheets, a long-term Inspection and Maintenance Agreement, and a site description with the following information provided:
(1) Site description:
A. A description of the nature and type of the construction activity (e.g. residential, shopping mall, highway, etc.).
B. 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).
C. A description of prior land uses at the site.
D. An estimate of the impervious area and percent of imperviousness created by the soil-disturbing activity at the beginning and at the conclusion of the project.
E. Existing data describing the soils throughout the site, including the soil series and association, hydrologic soil group, porosity, infiltration characteristics, depth to groundwater, depth to bedrock, and any impermeable 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 land 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 of 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 map showing:
A. Limits of soil-disturbing activity on the site.
B. Soils types for the entire site, including locations of unstable or highly erodible soils.
C. Existing and proposed one-foot (1') contours. This must include a delineation of drainage watersheds expected before, during, and after major grading activities as well as the size of each drainage watershed in acres.
D. Water resource locations including springs, wetlands, streams, lakes, water wells, and associated setbacks on or within 200 feet of the site, including the boundaries of wetlands or streams and first subsequent named receiving water(s) the applicant intends to fill or relocate for which the applicant is seeking approval from the Army Corps of Engineers and/or Ohio EPA.
E. Existing and planned locations of buildings, roads, parking facilities, and utilities.
F. The location of any in-stream activities including stream crossings.
(3) Contact information: Company name and contact information as well as contact name, addresses, and phone numbers for the following:
A. The Professional Engineer who prepared the Comprehensive Storm Water Management Plan.
B. The site owner.
(4) Phase, if applicable, of the overall development plan.
(5) List of sublot numbers if project is a subdivision.
(6) Ohio EPA NPDES Permit Number and other applicable state and federal permit numbers, if available, or status of various permitting requirements if final approvals have not been received.
(7) Location, including complete site address and sublot number if applicable.
(8) Location of any easements or other restrictions placed on the use of the property.
(9) A site plan sheet showing:
A. The location of each proposed post-construction storm water management practice.
B. The geographic coordinates of the site AND each proposed practice in North American Datum Ohio State Plane North.
It is preferred that 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.
(10) An Inspection and Maintenance Agreement. The Inspection and Maintenance Agreement required for storm water management practices under this regulation shall be between the Village of Granville and the applicant and shall contain the following information and provisions:
A. The location of each storm water management practice, including those practices permitted to be located in, or within 50 feet of, water resources, and identification of the drainage area served by each storm water management practice.
B. A schedule for regular maintenance for each aspect of the storm water management system to ensure continued performance of that system as is detailed in the approved Comprehensive Storm Water Management Plan. This schedule may include additional standards, as required by the Village of Granville Engineer, to ensure continued performance of storm water management practices permitted to be located in, or within 50 feet of, water resources.
C. Identification of the landowner(s), organization, or municipality responsible for long-term maintenance, including repairs, of the storm water management practices.
D. The landowner(s), organization, or municipality shall maintain storm water management practices in accordance with this regulation.
E. The Village of Granville shall conduct inspections as necessary to verify that the storm water management practices are being maintained and operated in accordance with this regulation.
F. The Village of Granville shall maintain public records of the results of site inspections, shall inform the landowner(s), organization, or municipality responsible for maintenance of the inspection results, and shall specifically indicate any corrective actions required to bring the storm water practices into proper working condition.
G. If the Village of Granville notifies the landowner(s), organization, or municipality responsible for maintenance of the maintenance problems that require correction, the specific corrective actions shall be taken within a reasonable time frame as determined by the Village of Granville.
H. The Village of Granville is authorized to enter upon the property and to perform the corrective actions identified in the inspection report if the landowner(s), organization, or municipality responsible for maintenance does not make the required corrections in the specified time period. The Village of Granville shall be reimbursed by the landowner(s), organization, or municipality responsible for maintenance for all expenses incurred within 10 days of receipt of invoice from the Village of Granville.
I. The method of funding long-term maintenance and inspections of all storm water management practices.
J. A release of the Village of Granville from all damages, accidents, casualties, occurrences, or claims that might arise or be asserted against the Village of Granville from the construction, presence, existence, or maintenance of the storm water management practices.
Alteration or termination of these stipulations is prohibited. The applicant must provide a draft of this 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 Village of Granville to receive final inspection approval of the site.
(11) Calculations required: The applicant shall submit calculations for projected storm water runoff flows, volumes, and timing into and through all storm water management practices for flood control, channel protection, water quality, and the condition of the habitat, stability, and incision of each water resource and its floodplain, as required in Section 1197.09 of this regulation. 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 upper watershed areas have been considered in the calculations.
(12) List of all contractors and subcontractors before construction: Prior to construction or before the pre-construction meeting, provide the list of all contractors and subcontractors names, addresses, and phone numbers involved with the implementation of the Comprehensive Storm Water Management Plan including a written document containing signatures of all parties as proof of acknowledgment that they have reviewed and understand the requirements and responsibilities of the Comprehensive Storm Water Management Plan.
(13) Existing and proposed drainage patterns: The location and description of existing and proposed drainage patterns and storm water management practices, including any related storm water management practices beyond the development area and the larger common development area.
(14) For each storm water management practice to be employed on the development area, include the following:
A. Location and size, including detail drawings, maintenance requirements during and after construction, and design calculations, all where applicable.
B. Final site conditions including storm water inlets and permanent nonstructural and structural storm water management practices. Details of storm water management practices shall be drawn to scale and shall show volumes and sizes of contributing drainage areas.
C. Any other structural and/or non-structural storm water management practices necessary to meet the design criteria in this regulation and any supplemental information requested by the Village Engineer.
(Ord. 23-2010. Passed 12-15-10.)