Deschutes River Alliance 2021 Science Accomplishments

Is it surprising to hear that this year’s drought conditions have contributed to better water quality in the lower Deschutes River!? The DRA has wrapped up the 2021 monitoring season and although record temperatures and historical water lows were recorded across the state, preliminary analysis of data collected this year indicates less-severe water quality violations, at least temporarily. 

This years’ water shortage across the region inhibited landowners from productive land cultivation. As a result, fewer harvests contributed to less irrigation and fertilization which are major contributors of toxic agriculture runoff from the Crooked River Basin. Therefore, low flows in the Crooked River appear to have benefitted the water quality in lower Deschutes this year.

Lab-analysis of water sampled from the mouth of the Crooked River contained less nitrates than previous years.

Better hatches of pollution-intolerant insects such as mayflies, stoneflies and caddisflies (indicator species for river health) were reported by anglers and guides on the lower Deschutes. Guides reported somewhat better trout fishing for a large portion of the year. While this is good news, such subjective observations are not a measure of the redband trout population strength. Some anglers also thought dry-fly fishing improved with the increase in observed caddis hatches, yet nymphing continued to be the most productive method according to guides.

While these observations are encouraging, severe drought conditions pose more long-term threats to the health of the ecosystem. The headwater springs of the Metolius River were measured at 50 percent of their average flow rate. Although the source of this groundwater is unknown, a distinct drop in spring water does not look favorable upon the watershed. Lower flows contribute to warmer reservoirs, reduced tributary inflow, and impact in-river cold-water refuges by making the run-of-the-river warmer and smaller. As a result, the greatest impact to water quality and quantity in the lower Deschutes stems from the controlled water released at the Tower. 

Low flows result in warmer water and can diminish reservoirs such as Prineville Reservoir, which impacts water quality and quantity in the lower Deschutes. 

Low flows in the Crooked River contributed less pollution after mixing with the much larger quantity of cooler, cleaner water from Opal Springs.

PGE likes to describe the Tower’s ability to increase winter, spring, and early summer water temperatures in the lower Deschutes River by upwards of 4 degrees C (over 7.2 degrees Fahrenheit) as a return to the “natural temperature regime.” There is nothing natural about their temperature management! This affects biological functions of fish and aquatic life: parasites reproduce faster and become more virulent while fish become more susceptible to infections among many other documented negative impacts. The DRA views touting this increase in water temperatures as an admission of PGE’s ability to negatively impact the water quality in the lower Deschutes River. 

Following a week-long stretch of water temperatures rising over 70 degrees, a clogging of the Tower forced PGE to increase their bottom-draw prompting an immediate serendipitous decline in water temperature at the Moody Gauge. When ODFW called for hoot-owl regulations to help heat-stressed fish, the DRA maintained that changes in Tower operation could lower water temperatures downstream without penalizing the sport angling economy.

PGE is effectively warming the lower Deschutes River from winter through early summer.

Warmer water temperatures negatively impact the aquatic life and exacerbate the effects of parasites on the fish community.

Serendipitous operations of the Tower (due to debris clogging) provided temporary cold-water relief to salmon and steelhead migrating during extreme heat in the lower Deschutes beginning July 11th.

A tour of Lake Billy Chinook by DRA staff on September 27th revealed that algal blooms still persist in the reservoir late into the summer. The overall effects of releasing this nutrient-laden, algal-rich water are not completely known, but the DRA science team is looking to collaborate with OSU to 

test the ability to take a real-time snap-shot of the algal community, parasitic loads and composition in the lower Deschutes River. While this concept is still novel, it would allow comparison between water quality and biotic factors at the same time which might play a key role in assessing the further decline of spring Chinook.

Outreach and collaboration with expert scientific researchers are pivotal in the success of anadromous fish rehabilitation and supporting the DRA’s mission. 

Data collection continues to be the foundation on which the Deschutes River Alliance assesses river health. Our science-based advocacy depends on high quality data and continued observation. With the 2021 monitoring season drawn to a close, the science team prepares to analyze, report and compare results obtained in 2021. Moving into 2022, the science team is looking for new opportunities to use our findings, and the possibility to report on the real-time effects water quality has on aquatic life in the Deschutes. The DRA ends 2021 with a successful monitoring season, looks to 2022 to report on our findings, and extends its thanks to all those who contributed to our ability to collect and maintain a database consisting of high-quality data.

Note: As confirmation of the quality of our data, DEQ has officially accepted our water quality data for use in the State’s required listing and reporting of water quality limited streams to EPA.