How can we protect cool water in Western Washington’s forest streams?

Streams that wind through Western Washington’s forests are essential habitat for frogs, bugs, and lots of other tiny critters. These streams are also a critical source of clean, cool water downstream. This means these streams are an important part of large watershed ecosystems. For the past 26 years, the timber industry, Tribes, environmental organizations, and Washington State agencies have worked together to address pollution and meet water quality standards through the "Forests and Fish Agreement." The agreement aims to address pollution that can come from forestry activities like logging and forest road construction and maintenance, while maintaining both a viable timber industry and water quality.

This coordination primarily happens through the Forest Practices Board, an independent state agency chaired by the elected Commissioner of Public Lands. Rules adopted by the Board are implemented and enforced by Washington’s Department of Natural Resources.

One of the key components of the Forests and Fish Agreement is the Adaptive Management Program, which the Board oversees. Essentially, “adaptive management” is simply a commitment to learning by doing. The Forest Practices Board evaluates how the current forest practices rules are doing, and if the science shows that they are not protective of the environment, then the board gradually adapts the rules to better protect the environment.

It’s the responsibility of the Forest Practices Board to balance these rule changes to protect the environment and support the timber industry.

The Board currently has a draft rule out for public comment that would improve protections for certain streams in Western Washington by requiring more trees stay in place. Because Ecology has a role in protecting water quality at these sites, we have a draft analysis of the proposed Forest Practices Board rule out for public comment as well. 

Today we are sharing more about Ecology’s forestry work and a summary of our draft analysis.

Protecting cool, clean water

Supporting both a viable timber industry and cool, clean water is the work of many. The Forest Practices Board and the Department of Natural Resources oversee the Forest Regulation Program, which protects public safety, water quality, and wildlife habitat across 12 million acres of state and private forestlands. Ecology has an important role in ensuring that tree harvesting and road construction are done in a way that prevents runoff, reduces sediment, and maintains cool, shaded streams for fish and other species.

For timber harvest activities, a common form of pollution is erosion or dirt washing into streams from improperly maintained forest roads, which can cause problems for fish and other aquatic animals. Another common type of pollution is high water temperatures. Not having enough shade around streams can cause the water to warm up, which is a problem for many aquatic species.

The most important tool we have to deal with temperature concerns is to leave more trees near streams. These buffers, also called riparian areas, provide shade that helps regulate temperatures and keep the water cool. Buffers also help filter out pollutants, reduce erosion, provide nutrients for aquatic life, and can help minimize the impacts from flooding.

Current rules for forest buffers

Leaving buffers around streams may seem straightforward, but forest practices rules are complex – and so are the processes to update them. At a high level, the goal is to support working forests, clean water, and healthy riparian habitats, all at the same time.

In areas covered by the Washington State Forest Practices Habitat Conservation Plan, an established system groups streams into different classifications. Based on the stream classifications, the rules say which forest practices prescriptions and best management practices are appropriate to protect water quality and aquatic habitat. Some of the options include no-harvest and partial harvest riparian management zone stream buffers.

Through the system set up by the Washington Legislature and the Forest Practice Board, the existing buffer rule for certain Western Washington streams was researched under the direction of the Board. Studies produced in 2018 and 2021 show that the current buffer rule for perennial, non-fish bearing streams in Western Washington is not protecting water from warming.

Streams that flow year-round and don’t have fish are called “non-fish-bearing perennial” – also known as “Type Np” streams, in forest practices lingo. While these streams, by definition, do not contain fish, they play a crucial role in maintaining water quality. They support a variety of aquatic life, including amphibians, insects, and other invertebrates, and contribute to the ecosystem.

In many scenarios, the current forest practices rules for Type Np streams allow for trees to be harvested down to the edge of the stream for up to 50% of the stream length – although sensitive areas are required to have buffers. Under the current rules, there are often areas near these streams that do not have enough trees to provide shade to help prevent the water from warming after harvest.

The stream on the left (approximate location drawn in dark blue) has a continuous riparian buffer because the land around it is steep and warrants extra resource protection to help prevent soil from entering the stream. This buffer area also provides additional shade to protect the water temperature. In contrast, the stream on the right (approximate location drawn in light blue) lacks steep slopes, so the harvest there follows the current regulation that requires only 50% of the stream to have a buffer. So, some parts of it, like this area shown, do not have any trees to help keep the water cool. Science has consistently shown that streams like this are warmer than fully shaded streams.

Forest Practices Board rulemaking

Based on these findings, the Forest Practices Board voted in 2023 to work on a new buffer rule to reduce warming in non-fish bearing perennial streams in Western Washington. 

This rule is limited to a subset of the harvestable forest land in Western Washington, estimated as less than 3% of approximately six million acres covered by the Forest Practices Habitat Conservation Plan. 

To protect cool water and prevent temperature pollution, the proposed rule would require more trees around streams. The widths of the proposed buffers vary from 50 to 75 feet, depending on site conditions. The proposed rule would continue the flexibility currently in place for timber harvesting. This includes the option to create site-specific alternate plans for harvest; it allows landowners to cut corridors through riparian areas for hanging cables, and it permits building roads through riparian areas as needed to access harvestable timber.

As required by state law, the Forest Practices Board commissioned a cost-benefit analysis that found the probable benefits of the proposed rule are likely to outweigh the probable costs. 

The draft rule and information on how to comment is available on DNR’s Forest Practices website.

Will the proposed rule keep streams cool?

Under the Forests and Fish Agreement, Ecology has the responsibility to determine whether the Board’s proposed rule will protect water quality. Ecology’s draft analysis found that the Forest Practices Board’s proposed rule would substantially improve water quality for non-fish bearing perennial streams in Western Washington. This is good news. The buffer options proposed in the rule should result in minimal stream warming, and the duration of any warming that may occur is expected to be less than what happens under today’s rules.

Given this analysis, Ecology continues to support the proposed rule moving forward to a formal public review.

Public comment

While our analysis is not part of the Board’s formal rulemaking materials, we are holding our public comment period at approximately the same time as the Board’s proposed rule public review period. The draft analysis and information on how to comment is available on our forestry webpage.

Ecology invites public comment on our draft analysis from midnight July 7, 2025, until 11:59 p.m. on Aug. 18, 2025. We welcome all comments that address Ecology’s draft Tier II analysis.

Comments on the proposed rule itself need to be directed to the Forest Practices Board.

How can I comment? 

• You can submit comments online
• By US Mail (must be postmarked by August 18, 2025): 
  Watershed Management Section  
  Department of Ecology  
  PO Box 47696 
  Olympia, WA 98504-7696 

• At our public hearing on July 31 at 5:30 p.m. (details below) 

Public hearing

Our hearing will begin with a short presentation about the draft Tier II Analysis. Formal testimony will start immediately after the presentation. We encourage both questions and comments to be submitted during the public testimony period. The hearing will conclude once everyone who wants to provide testimony has had the opportunity to do so. Written comments will receive the same consideration as oral testimony.  

Online hearing – July 31, 2025, 5:30 p.m. 

Next steps 

Following the public comment period, we will review and respond to comments received. We will incorporate feedback, finalize our analysis, and provide a final Tier II Antidegradation Analysis report on our website and to the Forest Practices Board prior to the Board’s Nov. 12, 2025, meeting. We will provide a response to comments as an appendix to our final Tier II analysis report. The Board is scheduled to decide about next steps for rulemaking at the November meeting.