A new study from the Washington Department of Ecology shows that years of local efforts to reduce pollution in the Spokane River are producing a healthier river.

Since 2010, Ecology and partners across the region have worked together to reduce excess phosphorus, a nutrient that causes algal blooms in the Spokane River watershed. High levels of phosphorus in the water lead to low dissolved oxygen and increased algal blooms, which means it is difficult for fish to breathe. Algal blooms can also harm people and wildlife. 

"There’s still more work ahead to restore and protect the watershed,” said Brook Beeler, Ecology’s Eastern Region director. “But this report shows how instrumental collaboration has been in moving this work forward and it’s encouraging to see our progress.”

Major investments have been made in the watershed to reduce nutrient pollution. Ecology has awarded substantial funding to the community partners to improve water quality, including $15 million for restoration in the Hangman Creek watershed and more than $85 million to local governments for wastewater and combined sewer overflow improvements for the facilities that discharge directly into the Spokane River. 

Ecology is working with partners to limit nutrient pollution from nonpoint sources and Spokane River’s tributaries and improve oxygen levels in Lake Spokane, which is affected by Long Lake Dam. Several projects in the watershed are improving water quality by restoring habitats, improving forest practices to reduce runoff, stabilizing streambanks, and expanding outreach to connect landowners with resources that help them protect water quality.

“We’re seeing the results of decades of investment in wastewater treatment, and that’s something to celebrate. But the river’s recovery also depends on addressing the impacts of nonpoint pollution and Long Lake Dam,” said Katelyn Scott, who serves as water keeper for the nonprofit group Spokane Riverkeeper. “To restore the river and bring back native fish, we have to think bigger and act bolder.” 

Effectiveness study measures progress 

In 2010, Ecology adopted a water cleanup plan to reduce phosphorus in the Spokane River watershed. The plan lists partners and actions that will help achieve this goal.

To measure progress made under the cleanup plan, Ecology completed an effectiveness study that looks at dissolved oxygen and nutrients in the Spokane River and Lake Spokane.

Key results from the study include:

• Water quality permits: Five wastewater treatment plants and industrial facilities have reduced their phosphorus discharge by over 90%. This reduction directly reflects the efforts of these facilities to install nutrient control technologies that limit phosphorus discharges. Today, the amount of phosphorus flowing from the Spokane River to Lake Spokane during summer is typically less than 0.01 mg/L, compared to levels between 0.01-0.02 mg/L during the previous decade. 
• Nonpoint pollution: Tributary and nonpoint sources of pollution to the river have also decreased because of long-term investments and community actions. However, nonpoint sources, particularly Hangman Creek, remain as the largest sources of phosphorus. For example, during March – May 2022, Hangman Creek contributed 74% of the total load entering the Spokane River.
• Lake Spokane: It is likely too soon to draw conclusions about the benefits of the phosphorus reductions upstream of Lake Spokane. As of 2022, we had not yet observed improved dissolved oxygen levels in the lake. In the 1970s, when a large phosphorus reduction occurred, Lake Spokane dissolved oxygen took at least five years to fully respond.

Collaboration in the Spokane River watershed has led to significant improvements. The work continues as Ecology and partners follow actions laid out in the cleanup plan.