Portland General Electric’s long awaited lower Deschutes River water quality study was recently released. At over 600 pages it took me some time to get through, here are my initial impressions. This study is critically important to the ongoing effort to reintroduce anadromous fish into the upper Deschutes Basin and the operation of the Selective Water Withdrawal tower. Also note that the Deschutes River Alliance’s lawsuit against PGE/CTWS (dismissed but under appeal) is based on allegations of water quality violations. The author of the water quality study will present and answer questions at the upcoming Fisheries Workshop.
In my opinion, this comprehensive study uses significant scientific rigor to mostly confirm what was already generally understood:
- Global heating is raising the temperature of tributaries flowing into Lake Billy Chinook (Metolius, middle Deschutes, and Crooked rivers).
- The Crooked River is the major source of poor water quality from human sources. This is primarily in the form of nitrates, the dominate source of which is agricultural runoff. (See note 1 below.)
- Warm water, ample sunshine, nitrates, and naturally occurring phosphorus (from volcanic rock) combine to provide excellent habitat for algae. Photosynthesis from the algae increase pH levels. These levels have been increasing in the lower Deschutes since before SWW operation.
- The SWW is meeting its goals of creating a more natural temperature profile in the lower Deschutes, which benefits fish, but it is also increasing the amount of algae passed down from LBC. There have been no documented ill effects from this increase. The potential for negative impacts exists, however, particularly if the algae increases. (Annual surveys by ODFW have shown no ill effects on fish. A previous macroinvertebrate study confirmed the continuation of ample food for fish.)
That’s a cursory summary of a long, detailed study. There’s lots more in there, but I think it sums it up well enough for anglers.
The big question is, what do we do about it? Do we shut down the SWW as some advocate and thereby end the hope of reintroduction? I certainly hope not. Reintroduction is not progressing as anyone had hoped but there is still a chance for success. At the same time, the lower Deschutes still fishes great for trout. As the modeling in the study indicates, there may be SWW operational changes that could reduce algae in the lower river, but they likely would be modest if temperature goals are to be maintained, which is the primary goal for the SWW. (See note 2 below.)
The solution seems obvious to me: clean up the Crooked River by eliminating agricultural runoff and otherwise reduce nitrates. This will reduce algae in LBC and in the lower Deschutes. I have advocated for this many times in the past. Unfortunately, others seem more focused on lawsuits and shutting down the SWW than pursuing solutions that would benefit the lower Deschutes, Lake Billy Chinook, and the Crooked.
It is also critical to understand that the Crooked River is the preferred destination for returning chinook and steelhead. The vast majority of these fish attempt to go up the Crooked River only to be blocked by Opal Springs Dam. Fortunately, after many years of effort a fish ladder over the dam is nearing completion. When it becomes operational later this year there is the potential for significant uptick in reintroduction success. A clean Crooked River would be a huge plus.
Cleaning up the Crooked is not a pipe dream. As I have extensively written about, the US Fish & Wildlife Service is currently working with local irrigation districts and the City of Prineville on a Habitat Conservation Plan which will cover the entire Deschutes Basin. That plan could be expanded to cover agricultural runoff into the Crooked since that pollution impacts reintroduced salmon, steelhead, and ESA-listed bull trout.
There has been no mention of controlling agricultural runoff in the draft HCP information that has been released to date, so including it will take public pressure. I once again call on others concerned about the Crooked River, Lake Billy Chinook, and the lower Deschutes River to get involved with the HCP process and help apply that pressure. Unfortunately, based on the information made available thus far, the most likely outcome is that the HCP will not meet environmental needs and will be challenged in court. I hope the litigants will include controlling agricultural runoff to their list of grievances.
Note 1: Along with agriculture, there are other sources of nitrates, including two golf courses on the Crooked River. I won’t tell you how I get there, but I like to fish the lower Crooked River the first few miles above Lake Billy Chinook. Years ago on one of my first trips down into that canyon I saw an amazing waterfall coming out of the side of the cliff. On subsequent trips the waterfall was completely gone or a huge gush of water. It turns out that it is caused by excess watering by the golf course on the edge of the canyon. From my perspective this is terrible but it’s small scale compared to the amount of agricultural runoff.
In addition to controlling runoff, effort should be put into wetland restoration which could provide natural nitrate reduction.
Note 2: One of the discussions in the study was using a “curtain” to block algae from entering the SWW. This could be an effective method of reducing algae transportation to the lower river but the SWW would then end up taking water from below the curtain, impacting the desired temperature profile. The curtain would also cause even greater buildup of algae in LBC, a very popular reservoir for recreation.