Visit Ecology's TMDL webpage | Read EPA's 2020 TMDL | Read Ecology's Implementation Plan Blog

The Columbia and Lower Snake rivers are listed on the state's polluted waters list for high water temperatures that are above Washington water quality standards and can harm salmon. Because the Columbia and Lower Snake rivers cross multiple state boundaries and span almost 900 miles, the EPA published the Total Maximum Daily Load (TMDL) for temperature in the Columbia and Lower Snake rivers on May 20, 2020.

We are currently in the early stages of developing an implementation plan for this TMDL. This plan will describe our strategy for meeting temperature standards and how we will partner and work together with temperatures sources to address their impacts in the Columbia and Lower Snake rivers. It will include our strategies to address key temperatures sources throughout the rivers, including our processes for working with dams, updating permits for point sources, and prioritizing tributary work to address high river temperatures and to protect salmon. 

Get involved

Public Input Survey

We have launched a public survey to allow partners and the public to provide input on a continual basis that can help inform our work as we develop the implementation plan. Participants should provide input on direct actions to help reduce heat loads listed by the TMDL, including dams, tributaries, and point sources.

We are accepting survey responses until 11:59 p.m. on Oct. 31, 2025.

Advisory Committee Meetings

To support our development of the implementation plan, we are hosting regular advisory committee meetings. Topics for each meeting will vary, though our agendas will support identifying collaborative strategies to address sources of temperature pollution. 

Advisory group meetings are open to the public, and we encourage interested people to listen in to these webinars. Time will be reserved at the end of each meeting for questions and comments from members of the public.

Upcoming Advisory Committee Meetings 

Join us on July 28, 2025 from 1 - 3 p.m. for our next advisory committee meeting. A detailed agenda will be posted on this page one week prior.

Please register on zoom in advance of this meeting. 

 Past Advisory Committee Meetings

June 17, 2025 

• Meeting agenda

March 17, 2025 

• Meeting agenda 
• Presentations: 
  • Ecology's TMDL Implementation Plan overview
  • Environmental Protection Agency (EPA) TMDL overview