Watershed health — Unlisted Washington update

We investigated the health of stream in the Unlisted Washington Status and Trends Region in 2010 and 2019. In these study years, we saw the region's streams mostly in poor biological condition, with the highest physical indicators involving stream substrate.


Large river surrounded by dry grassy hills.

Use the map to navigate our reports by Status and Trends Region.

Click the map to see other regional reports!

Regional summary

  • Benthic Index of Biotic Integrity scores for the Unlisted Region show a majority of streams to be in poor biological condition.
  • The most prevalent indicators for streams in the Unlisted Region were increased sand and fine sediments, increased nutrient concentrations, and increased substrate embeddedness.

Biological condition

Invertebrate biological condition of streams did not change meaningfully from 2010 to 2019 in the Unlisted Region. We did see a shift from fair to poor condition in 2019, as compared to 2010, but this is a small change. Most notably from these findings, it shows that both years of sampling have a majority of stream kilometers classified as being in poor biological condition.

Graph showing a majority of streams being categorized as poor using B-IBI score.

We used B-IBI ratings from 2010 and 2019 to obtain the percentage of stream kilometers in good, fair, and poor conditions for the Unlisted Region. Error bars represent 95% confidence intervals.

Significant physical and chemical indicators

In 2010 and 2019, four indicators were categorized as poor for over 50 percent of the stream extent assessed. In 2019, two of those indicators were over 80 percent, including bed stability and percent sand fines.  Nitrogen, phosphorus, and average embeddedness were also poor in a high percentage of stream extent sampled, remaining over 50 percent for both 2010 and 2019.

To interact with this graph and learn more about these physiochemical indicators, hold your mouse over each bar.

This interactive graph shows the percentage of stream kilometers assessed with poor physiochemical conditions in the Unlisted Region for 2010 and 2019. The x-axis represents the percentage of river extent in poor condition. Error bars show 95% confidence intervals.

Flip through our field photos!

Crewmembers with stadia rods at a pristine River.

Crews measure bankful heights to understand high flows at Dragoon Creek.

A crewmember with a net and a bug jar collecting a sample of stream bugs.

Collecting macroinvertebrates gives us a snapshot of stream health at the Little Pend Oreille River.

A frog in a crew member's hands

The Columbia spotted frog thrives in cool slow-moving water at Flodelle Creek.

A fish in a photarium

Longnose dace are indicators of good water quality at Hangman Creek.

A crew member with a stadia rod in the center of a shaded creek.

Measuring wetted depths at Crab Creek allows us to gain a stream profile and roll up the data for a picture of stream health.

Two people with stadia rods and another with a live well to hold fish.

One team at Bulldog Creek measures wetted widths at 10 transects, while another collects vertebrates.

Three mussels in a sandy stream bottom.

Freshwater mussels like these in the Little Pend Oreille River are excellent indicators of healthy water quality. They are long-lived and sensitive to environmental changes.

A crew member scrubbing a rock at a pristine creek.

Crews collect periphyton, the green slime on stream rocks, at Marble Creek to understand the health of the stream and to learn more about algae's role.

Crew members and two large rafts pulled over to on stream bank.

Crews use the "Wide Protocol" and float on large sites, such as at the Little Spokane River.

A large trout on a measuring board.

A healthy adult rainbow trout from Colockum Creek indicates cool clean water.

A closeup view of a stream bug in a bug net

A stonefly is an indicator of health at the Little Pend Oreille River.

A crew member with a tablet in a large creek

Crews collect data at Rock Creek on a mobile tablet. Later, these data are verified for quality assurance.

A large fish in a photarium

This tench from Marshall Creek is an invasive species that outcompetes native fish for food resources. They prefer warm and shallow slow-moving water.

A large pristine river with shrubs and grasses.

Palouse River provides habitat for fish and other aquatic species that rely on its continuous water supply.