The 2012 Draft Stormwater Management Manual for Western Washington Comment Period Ends in February

Published Jan 10, 2012

Ecology began a 90-day public comment period for the Draft 2012 Stormwater Management Manual for Western Washington (SWMMWW) last November. After February 3, 2012, the comment period will be closed.

Although the Manual in and of itself is not a legally enforceable document, several of the NPDES Stormwater General Permits require its use. According to the Department of Ecology, key changes include new requirements for low impact development, revised guidelines for wetlands, new and revised construction BMPs, revised guidance on determining infiltration rates, and revised guidance for modeling in the Western Washington Hydrology Model. These changes will affect Western Washington permittees under the following General Permits: Boatyard Stormwater, Construction Stormwater, Industrial Stormwater, Municipal Stormwater, and Sand and Gravel Stormwater. For more information, contact James Tupper at