Pierce County has a surface water quality monitoring program to assess watershed health. A watershed is an area of land where all the water that is under it or on it drains to the same place. The four major watersheds in Pierce County that drain to Puget Sound are: Clarks/Cover; Key Peninsula-Gig Harbor; Nisqually and Puyallup. Pierce County regularly monitors water quality in all four watersheds. Want to know where the water from your neighborhood goes? Check out Where Does Your Water Go.
Pierce County's Surface Water Management (SWM) conducts monthly water quality monitoring at over 50 streams. The data is used to monitor water quality trends over time; more information can be found here. SWM also collects stream insects (macroinvinterbrates) from over 30 streams. The types of insects found in a stream is a way to determine the overall stream health. For more information, click here.
The monitoring section helps ensure Pierce County meets the requirements of the National Pollutant Discharge Elimination System (NPDES) Phase I Municipal Stormwater Permit. SWM collects local data to measure whether water quality is getting better or worse and identify patterns in healthy and impaired Puget Lowland streams and Puget Sound urban shoreline areas. SWM also collects data for NPDES driven modeling and Total Maximum Daily Load (TMDL
We issue an annual Surface Water Health Report Card on the health of surface water quality in each major watershed. The report card grades a number of streams on a scale of "A" to "F" based on a combination of WQI scores and BIBI scores. These factors combined provide a realistic overall understanding of stream health, and help direct our clean up efforts. The report card also includes an assessment of some lakes in the county.