(a) All storm water management practices will be designed so that the specific storm frequency storage volumes (e.g., recharge, water quality, channel protection, ten year, 100 year) as identified in the current storm water ordinance are met, unless the City of Wapakoneta grants the applicant a waiver or the applicant is exempt from such requirements.
(b) If hydrologic or topographic conditions warrant greater control than that provided by the minimum control requirements, the City of Wapakoneta reserves the right to impose any and all additional requirements deemed necessary to control the volume, timing, and rate of runoff.
(c) Storm water management practices for a site shall be chosen based on the physical conditions of the site. Among the factors that should be considered:
(1) Topography;
(2) Maximum drainage area;
(3) Depth to water table;
(4) Soils;
(5) Slopes;
(6) Terrain;
(7) Head; and
(8) Location in relation to environmentally sensitive features or ultra-urban areas.
(d) All storm water management practices shall be designed to convey storm water to allow for the maximum removal of pollutants and reduction in flow velocities. This shall include, but not be limited to:
(1) Maximizing of flow-paths from inflow points to outflow points;
(2) Protection of inlet and outfall structures;
(3) Elimination of erosive flow velocities; and
(4) Providing of underdrawn systems, where applicable.
(e) Every storm water treatment practice shall have an acceptable form of water quality pretreatment. Certain storm water treatment practices are prohibited even with pretreatment in the following circumstances:
(1) Storm water is generated from highly contaminated source areas known as "hotspots".
(2) Storm water is carried in a conveyance system that also carries contaminated, non-storm water discharges.
(3) Storm water is being managed in a designated groundwater recharge area.
(4) Certain geologic conditions exist (e.g., karst) that prohibit the proper pretreatment of storm water.
(f) All storm water management practices shall be designed to capture and treat storm water runoff according to Ohio Environmental Protection Agency requirements. These requirements will designate the water quantity and quality treatment criteria that apply to an approved storm water management practice.
(g) All storm water management practices must have a landscaping plan detailing both the vegetation to be in the practice and how and who will manage and maintain this vegetation. This plan must be prepared by a registered landscape architect or soil conservation district.
(h) All storm water treatment practices shall have an enforceable operation and maintenance agreement to ensure the system functions as designed. This agreement will include any and all maintenance easements required to access and inspect the storm water treatment practices, and to perform routine maintenance as necessary to ensure proper functioning of the storm water treatment practice. In addition, a legally binding covenant specifying the parties responsible for the proper maintenance of all storm water treatment practices shall be secured prior to issuance of any permits for land disturbance activities.
(i) The use of non-structural storm water treatment practices is encouraged in order to minimize the reliance on structural practices. Credit in the form of reductions in the amount of storm water that must be managed can be earned through the use of non-structural practices that reduce the generation of storm water from the site. Applicants wishing to obtain credit for use of non-structural practices must ensure that these practices are documented and remain unaltered by subsequent property owners.
(Ord. 2014-42. Passed 1-5-15.)