(A) Exemptions for quantity controls may be granted so long as erosion prevention and sediment control, water quality, and cut-fill policies are adequately addressed. Exemptions may be granted for roads, utilities crossing waterways, pedestrian trails, walkways proximate to waterways, parks, and construction within the downtown historic district.
(B) Further, sites may be exempted from providing quantity controls if a watershed study demonstrates to the MS4 representative that detention ponds are not needed to protect downstream property. To evaluate the downstream effects, an engineer licensed in the State of Kentucky shall conduct a watershed study to determine the flood levels using the 100-year, one-hour storm. The study area shall extend downstream to a point ten times the area of the proposed development. Sites may be exempted if:
(1) The increase in the downstream water level is insignificant (0.1 foot or less);
(2) The downstream drainage system has sufficient capacity and is in sufficient condition to receive any increase in runoff for the 100-year storm. SUFFICIENT CAPACITY FOR A PIPE SYSTEM shall be defined as no overflows at inlets and manholes. SUFFICIENT CAPACITY FOR AN OPEN CHANNEL SYSTEM shall be defined as an open channel wide enough to carry the flow. SUFFICIENT CONDITION FOR A PIPE shall be defined as not crushed smaller than its original intended opening or silted in to limit the original intended opening.
(C) Further, sites may be exempted from providing quantity controls if a signed and notarized letter from each property owner between the development and the ultimate stormwater receiver is presented to the MS4 stating they accept all excess runoff created by the development without mitigation and agree to hold the city harmless for any damages caused by the additional runoff.
(Ord. 14-08, passed 9-3-2014; Am. Ord. 19-02, passed 5-6-2019; Am. Ord. 20-05, passed 7-20-2020)