Palouse River

Along with our partners, we're studying pollution and identifying ways to improve water quality in the Palouse River, which includes the North Fork Palouse and South Fork Palouse. The river has low dissolved oxygen, high temperatures and bacteria counts, lingering concentrations of toxic chemicals from historically-used pesticides, and PCBs. There are several projects underway to help improve and protect Palouse River water quality.

Water quality problems

According to water quality assessments, portions of the Palouse River suffer from:
  • Low dissolved oxygen.
  • Increased temperature.
  • High pH.
  • High fecal coliform bacteria (North Fork and mainstem).
  • High levels of PCBs and historical pesticides (South Fork and mainstem).

It is our responsibility to make sure Washington's rivers meet water quality standards designed to protect fish habitat and a variety of uses like agricultural water supply and recreation. Cool, clean water is important for fish-rearing and spawning. PCBs are harmful to people and build up in the food chain.

What we are doing

We have worked in the Palouse River watershed since 2005 on various studies to better understand the water quality problems and plans for fixing them. Because of the size of the watershed and different water quality impairments along the river, water quality improvement efforts are separated into several individual projects. While the studies and reports for each of these projects may be separate, activities to help improve one water quality problem also typically help the others.

To address water quality problems in the Palouse, we work with many organizations. We work with city and town wastewater treatment plants to ensure their discharges meet clean water requirements. We also work with the City of Pullman and Washington State University to track down pollution that may be getting into streams through stormwater runoff in the urban areas.

We provide grants to local conservation districts for projects that help address water quality problems in the rural parts of the watershed. Our grants help pay for planting native vegetation along streams to shade the water and keep it cooler. Streamside plants also help filter runoff to reduce sediment and other pollutants from reaching the water.

Status of water improvement projects

Palouse watershed water quality projects
Water body Parameter(s) Status
Cow Creek Dissolved oxygen, fecal coliform, and temperature Being addressed by a pollution control plan
North Fork Palouse Fecal coliform bacteria Approved TMDL
Implementation plan
North Fork Palouse Dissolved oxygen and pH Approved TMDL and implementation plan
Palouse River Fecal coliform bacteria (from Colfax to the mouth) Approved TMDL and implementation plan
Palouse River Temperature Approved TMDL and implementation plan
Palouse River Toxics Approved TMDL and implementation plan
South Fork Palouse Ammonia Approved TMDL
South Fork Palouse Dissolved oxygen, pH and temperature TMDL under development
South Fork Palouse Fecal coliform Approved TMDL
Implementation plan


Additional technical information and studies