1987 – Commercial Shellfish Growing Areas: The Washington Department of Health (WDOH) closed 18,000 acres of commercial shellfish growing area in Port Susan and South Skagit Bay primarily due to bacterial pollution from the Stillaguamish River. As a result, Snohomish County partnered with the Tulalip and Stillaguamish tribes and other local and state stakeholders to develop the Stillaguamish Watershed Action Plan.
1993 – Stillaguamish River Clean Water District: Snohomish County created the Stillaguamish River Clean Water District (CWD) to provide a stable source of local funding for water quality and water quantity management services in many of the unincorporated portions of the Stillaguamish River watershed.
2007 – Total Maximum Daily Load (TMDL) Plan: The Washington State Department of Ecology (WDOE) placed portions of the Stillaguamish River watershed on the list of impaired water bodies, and published a TMDL plan, which described recommended actions to restore water quality.
2010 – Stillaguamish Shellfish Protection Program: Snohomish County completed the Stillaguamish Shellfish Protection Program Plan. The plan defined the purpose, water quality problems, and shellfish protection goals, objectives, and actions for shellfish protection in the CWD.
2011 – Microbial Water Quality Assessment (MWQA) Program: Snohomish County developed a MWQA Program to measure the amount of fecal coliform bacteria data collected in the Stillaguamish River watershed. This led to implementation of bacterial pollution source identification and correction work in the Portage Creek area.
2013 – Pollution Identification and Correction (PIC) Program: WDOH awarded a 2½ year grant ($570,000) to Snohomish County.