existing land uses and projected land uses assuming full development under existing zoning and land use ordinances in the drainage area;

  • Design stormwater management measures so that the post-construction peak runoff rates for the 2, 10 and 100-year storm events are 50, 75 and 80 percent, respectively, of the pre-construction peak runoff rates. The percentages apply only to the post-construction stormwater runoff that is attributable to the portion of the site on which the proposed development or project is to be constructed.
  • Water Quality

Stormwater management measures shall be designed to reduce the post-construction load of total suspended solids (TSS) in stormwater runoff generated from the water quality design storm by 95 percent of the anticipated load from the development site expressed as an annual average, since the site is located within the watershed of a Category One Waterway.

Direct run-off from building roof tops is not considered contaminated since it has not contacted the pavement or the ground surface, and is not subject to satisfaction of the TSS removal criteria.