Stormwater management; rural Tidewater, tiered approach to water quantity technical criteria.

Allows any rural Tidewater locality, as defined in the bill, to comply with water quantity technical criteria for certain land-disturbing activities based on the percentage of impervious cover in the watershed. The bill provides that any eligible locality electing to use certain control standards shall, by ordinance, adopt an official map that indicates the percentage of impervious cover in each watershed within the locality and shall update the map at least annually. The bill allows any such locality to apply one of the following three standards for managing water quantity to any new development project: (i) if the site, as indicated on the map, has less than 5.0 percent impervious cover, the standard shall be a particular State Water Control Board regulation; (ii) if the watershed has 5.0 percent or more but less than 7.5 percent impervious cover, the standard shall be the one-year, 24-hour release method; and (iii) if the watershed has 7.5 percent or more impervious cover, the standard shall be the energy balance method. The bill provides that any project whose construction would cause the watershed in which it is located to step up to the next higher tier shall be evaluated under the energy balance method or a more stringent alternative.