Comments being taken on Regional Stormwater Management Manual

The Department of Ecology (Ecology) is supporting and leading an effort to update the 2004 Stormwater Management Manual for Eastern Washington, as it has been more than 10 years since the manual was written.

Stormwater has been identified as one of the largest contributors to urban pollution. The manual provides guidance on measures necessary to protect the quality of stormwater in eastern Washington. Local jurisdictions have adopted the manual to set stormwater requirements for new development and redevelopment projects in accordance with the Eastern Washington Phase II Municipal Stormwater Permit.

Upon update of Ecology’s manual, the finalized manual will become the standard for Chelan County, Douglas County, the city of Wenatchee and the city of East Wenatchee.

Land developers and designers use the manual to design permanent stormwater control plans, develop construction stormwater pollution prevention plans, and maintain stormwater infrastructure. Businesses, including industrial sites, use the manual to help design their stormwater pollution prevention plans.  The proposed 2018 Stormwater Management Manual for Eastern Washington will guide stormwater management for years to come.   Input from the public will help Ecology create guidance that protects water quality while being useful and applicable to eastern Washington communities.

The Department of Ecology is accepting comments on the draft 2018 manual until 11:59 p.m. on July 25, 2018. Send your comments or questions to Ecology at

Links to Draft Stormwater Management Manual for Eastern Washington with figures included: