In an effort to reduce polluted runoff, developers in Maryland must design buildings, land, roads, and other development projects using “environmental site design” methods wherever possible, pursuant to regulations adopted by the Maryland Department of the Environment. The regulations implement the Stormwater Management Act adopted in 2007.

Environmental site design means using better site planning, nonstructural techniques, and small-scale stormwater management practices to mimic natural hydrologic runoff characteristics and minimize the impact of land development on water sources.

Design methods may include conserving natural features, such as drainage patterns, soils, and vegetation; minimizing the use of impervious surfaces, such as concrete channels, paved areas, and roofs; and slowing down runoff so it has time to soak in or evaporate instead of being discharged to local waters.

Counties and municipalities have until May 4, 2010, to adopt ordinances that comport with the new stormwater program. Specifically, MDE's stormwater management regulations apply to the development or redevelopment of land for commercial, industrial, institutional, or residential use, including state and federal construction projects.

The regulations do not apply to agricultural land management; development projects that disturb less than 5,000 square feet; or modifications to existing single-family detached residential structures, provided they disturb less than 5,000 square feet.

Redevelopment subject to the regulations includes construction at “sites where existing land use is commercial, industrial, institutional, or multifamily residential and the existing site impervious area exceeds 40 percent.” Those sites will have to reduce impervious areas by at least 50 percent or take other specified steps.

Copyright 2009, The Bureau of National Affairs, Inc.