To better manage water resources in the Chehalis Basin, it is important to understand the water quality in the Chehalis River and its tributaries. From 2006-2009, Partnership members worked toward monitoring water quality throughout the Chehalis, with the support of a grant from the Department of Ecology. These and other water quality studies in the Chehalis Basin (links below) have shown that many parts of the Chehalis River have high temperatures and low oxygen in the summer. Both of these conditions are harmful to aquatic life living in the river and its tributaries. Today, the Chehalis Tribe is monitoring water quality in some streams and the mainstem Chehalis River using “grab samples.” The Department of Ecology currently maintains continuous water quality measurement equipment in some locations in the upper watershed (links below).
The Partnership’s goal for water quality is to prevent degradation and improve water quality so as to have clean water for all fish, wildlife, and human uses. It will take the combined effort of people living in the whole watershed to keep the water clean.
State of the Watershed: Water Quality
Site has data on current and historic water quality for a variety of locations throughout the Chehalis
This report provides information on a water quality study based on samples taken at 94 sites around the Chehalis Basin.
This is a preliminary assessment based on one year of water quality monitoring.
Total Maximum Daily Load
Department of Ecology’s Total Maximum Daily Load webpage for the Chehalis Basin. This website describes TMDL plans that cover all of the upper watershed in WRIA 23 and address 303(d) listings for dissolved oxygen (DO), fecal coliform bacteria, and temperature (T) impairments. The site describes current water quality issues, clean-up plans, and actions being taken to fix those problems.
TMDL Implementation Plan (2004): The Chehalis/Grays Harbor Watershed Dissolved Oxygen, Temperature, and Fecal Coliform Bacteria TMDL: Detailed Implementation (Cleanup) Plan.
TMDL Effectiveness Review (2010): Upper Chehalis River Watershed Multi-Parameter Total Maximum Daily Load: Water Quality Data Review (Fecal Coliform)
Other Water Quality Reports
Water Quality Progress Review (2007-2008)
Chehalis Watershed Monitoring Plan
What you can do to help keep water clean in the Chehalis
For municipalities: Stormwater treatment funding opportunities: Sign up for the Department of Ecology’s stormwater funding listserve
For landowners: How to get involved in a stream restoration project.
The quality of our region’s waters are closely linked to how much water is available in streams. Thus, but helping to address water quantity concerns, we are also working to improve water quality.