Stormwater Management Plan & Elements

The Phase II Permit outlines stormwater program activities and implementation goals that permittees must complete to comply with the federal Clean Water Act (CWA).  

All Phase II jurisdictions are required to develop and implement a stormwater management plan (SWMP) that includes the required activities (minimum control measures), implement those activities within the required timeframes, and submit annual reports to Ecology to document progress towards program implementation goals.

The City of Asotin, City of Clarkston and Asotin County have signed an Interlocal Cooperation Agreement to work together to implement a regional stormwater management program that is designed to meet the requirements of the Phase II permit. Through this regional approach, they hired a regional stormwater program coordinator to assist them in implementing the Phase II Permit and meeting the requirements and deadlines of the Permit.

Stormwater Plan Elements

A Stormwater Management Plan outlines what is currently being done in each City or County to prevent stormwater pollution, and what will be done in the future. Six minimum measures must be incorporated into the plan. These measures are (click on each one for more information):

Previous Deadlines

The previous permit expired in 2012, several deadlines were met, including some that require public participation and review. Click here to see a full schedule.


City of Asotin County of Asotin City of Clarkston