The basin storage volume shall be sized to maintain the post-development discharge rates at the same level as the pre-development discharge rates for the full range of prescribed design storm events. If warranted by the conditions present, such as inadequate capacity of existing culverts and drainage systems immediately downstream of the site proposed for development, additional storm water management measures and/or off-site drainage improvements may be required at the discretion of the approving agency. If the basin is to be located directly on a portion of the through drainage system, volume calculations must also consider the total system flow reaching the basin from the contributing watershed, both on-site and off-site.
(Ord. 012-118, passed 10-8-2012)