2006-016 Ordinance - Laserfiche WebLink

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~,w„_,. Ordinance No. 2006-16 water and the movement of inspectors and maintenance ecLuipment and also restricted against the changing of final grade from that described by the grading plan. 928.08 MINIMUM STANDARDS. In order to control pollution of water resources, the owner of 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 for the local county, or the Ohio EPA, which ever is most stringent. (b) Water Quality Basins: 1) Pool Geometry: The minimum length-to-width ratio for the pond is 3:1 (the length will be three (3) times the width). (2) Riser in Embankment: The riser shall be located within the embankment for purposes of maintenance access. Access to the riser will be by manholes. (3) Water Drains: Each retention basin shall have a drainpipe that can completely drain the pond. The drain shall have an elbow within the pond to prevent sediment deposition from plugging the drain. (4) Adjustable Gate Valves: Both the Water Quality and the Storm Water Management Basin drains shall have adjustable gate valves. Valves shall be located inside of the riser at a point where they will remain dry and can be operated in a safe and convenient manner. During the annual inspections the valves shall be fully opened and closed at least once, and the certifying official shall attest to this on the inspection form. To prevent vandalism, the handwheel shall be chained to a ringbolt or manhole step. (5) Principal Spillway: Each principal spillway shall be designed in accordance with the Natural Resources Conservation Service (NRCS) standards and specifications for the office serving the local county. Each principal spillway shall have the capacity to pass the 100 year design storm flows. The inlet or riser size for the pipe drops shall be designed so that the flow through the structure goes from weir flow control to pipe flow control without going into orifice control in the riser. The crest elevation of the primary spillway shall be no less than one foot below the emergency spillway crest. Premium joint pipe is required and a removable trash rack shall be installed at each location. Anti-seep collars shall be provided for all pipe conduits through an embankment. (6) Emergency Spillway: An emergency spillway shall be provided on each Water Quality and Storm Water Management basin. Emergency spillways shall convey flood flows safely past the embankment, and shall be designed in accordance with NRCS standards and specifications for the office serving the local county. 15