Our stormwater manuals provide stormwater permit implementation and management guidance. To determine which manual you need, contact your municipality or permit administrator.
We are in the process of updating the Draft 2019 Stormwater Management Manual for Western Washington (SWMMWW). The updates to the manual coincide with the reissuance of the 2019 Phase I and Western WA Phase II Municipal Stormwater Permits. We will release the updated SWMMWW in July 2019.
We held a public comment period on the Draft SWMMWW from July 13, 2018 to Nov.14, 2018.
We will release the updated manual after we consider all public comments and make final changes.We will publish a Response to Comments to address comments submitted during the public comment period. You can view comments we received during the comment period.
Public hearings and workshops for the Draft Stormwater Management Manual for Western Washington were held in conjunction with the Draft Phase I and Western WA Phase II Municipal Stormwater Permits. We held four in-person hearings and one webinar for Western Washington. The public hearings provided an opportunity for the public to give formal comments on both the draft manual and draft municipal permits.
In some cases, municipal stormwater permittees have the option of either adopting portions of the appropriate Stormwater Manual or portions of a regional manual determined to be equivalent to the Ecology manual.