The State of the River
by Steve Hawley
In our winter Deschutes River Alliance newsletter, we condensed a wealth of information on water quality in the lower river, offering our supporters a summary of what’s wrong with the water, and more importantly, how it can quickly be made right. This is a great place to start if you're new to the issues affecting the lower Deschutes River.
What is the Selective Water Withdrawal (SWW) Tower?
The SWW is a 270 foot tall, 30 foot-diameter tube, submerged in the forebay of Lake Billy Chinook. Ports at a couple strategic locations along its height allow Portland General Electric’s Project managers to blend water from two depths in the reservoir, near the surface and near the bottom. The rationale for these “blends,” PGE claims, is to mimic a more “natural” thermal regime as well as provide a current in the surface of the reservoir that attracts out-migrating juvenile salmon and steelhead to the fish collection facility near the SWW Tower.
PGE spent $140 million on the SWW Tower, and in one sense it has served its purpose: the Federal Energy Regulatory Commission, which issues mandatory licenses for privately-owned dams, approved the tower’s design in the early 2000’s, deeming it worthy of the federal requirement for fish passage at the Project. PGE needed the tower to get its license, and it got one, good through 2055. Yet in a larger sense, the tower has been a colossal failure. Not only has it passed few salmon or steelhead above the project, but the change in flow regimes has also made water quality in the lower river much worse, with devastating consequences.
Prior to SWW Tower operations, which began in late 2009, all water released from Lake Billy Chinook was from the bottom of the reservoir, 246 feet below the surface. Of the three rivers that feed into the reservoir, the Metolius is coldest, and since colder water is more dense than warmer water, the former sinks to the bottom of the reservoir. It was this Metolius water, some of the cleanest and coldest of any river on the continent, that primarily fed the lower Deschutes during the first 50 years of the dam’s operation.
PGE claims this year-round flow of cold water created artificial conditions in the lower river, and the current flow regime more closely resembles the flow and temperatures prior to the construction of the three dams that make up the Pelton-Round Butte Complex. But the current blend, for eight months out of the year, is 100% surface water from Lake Billy Chinook. Warm and loaded with agricultural runoff, after a decade of surface water flows from the SWW, the river is now artificially warm and contaminated with excess nutrients the vast majority of the year, and as a result, lacking the diversity and abundance of life that thrived on the lower river before 2010. By contrast, prior to Tower operations, the lower Deschutes River may have been artificially cold, but it was truly clean, healthy, and conducive to the wide array of aquatic life that had blossomed there.
In the original Water Quality Monitoring and Management Plan (WQMMP), 100% bottom water release was included in the original Tower blends. However, due to an unspecified operational limitation of the SWW Tower, it can only release a maximum of 60% water from the bottom of the reservoir. This limitation, brought on by errors in construction or design, drives many of the false claims made by PGE officials about temperature management.
Temperature: WPT?
The Deschutes River’s pre-Pelton Round Butte Project conditions during the 1950s were not optimal. This was true of waterways around the state of Oregon. Environmental laws and policies were anemic to non-existent, and a century of grazing, mining, logging, and dam building had taken its toll. Yet PGE’s Project operators are touting temperatures from this bygone era as the river’s “natural” baseline. Worse, the model that PGE uses to calculate what they call “without project temperature,” (WPT) is flawed. It uses maximum daily temperatures for both air and water to calculate the target temperature for the river. If the model had been designed to reflect reality on the river, mean or even minimum temperatures would be more accurate. In the meantime, the target temperature spit out by PGE’s model is artificially high, predisposing the river to being artificially hot.
Existing water quality data reveals water quality conditions are not more “natural” in the lower Deschutes following SWW Tower operations. On the contrary, deteriorating river conditions following Tower operations show that the current state of the lower Deschutes River is in need of much improvement in order to meet water quality standards and heal the lower Deschutes.
Increasing water temperatures in the river for the majority of the year, with only minor cooling for a short period in the fall, is not an improved condition nor healthy for the lower Deschutes River. But that management scheme is precisely what PGE touts as “natural.” The amount of cooling in the fall is very small in comparison to the warming that occurs the rest of the year.
The beneficiary of this flow regime, claims PGE, is fall Chinook. PGE claims the brief period of cooler water protects and enhances the spawning of adults and the rearing of juvenile salmon. But there’s no scientific evidence to back this claim. A temperature study on the lower Deschutes published in 1999 found no significant difference in early salmonid life cycle timing caused by temperature changes from operation of the Project compared to pre-dam conditions.
Fall Chinook return numbers in the lower Deschutes do not support the claim of any benefit to them from an effort to save cold water. A thorough analysis conducted by the DRA of fall Chinook return data, indicated that post-Tower years 2013-2021 were not significantly different when compared to the previous 36 return years, 1977-2012. Interestingly, comparing these same two time periods, fall Chinook showed a positive trend in the pre-Tower years and a negative trend in the post-Tower years through 2021.
Figure 1. Fall Chinook returns pre-SWW Tower.
Figure 2. Fall Chinook returns post-SWW Tower.
Another rationale for the WPT flow regime is the need to save cooler water, supposedly because the supply of it is limited in the reservoir. Again, there is no evidence to back this claim. A comprehensive water quality study of the Project and lower Deschutes, funded by PGE, analyzed the temperature profile in Round Butte forebay. The authors of this study found Tower operations in the forebay have led to more cold water in the deeper portion of the reservoir during mid-summer months.
However, under the current conditions even when maximum bottom water is released, bottom water must be mixed with at least 40% surface water, which is warmer from mid-March to September. So when bottom water is mixed with warm surface water, the water released into the lower Deschutes River is warmer during the summer months than it was prior to tower operations, when 100% bottom water was the only option. The little cooling relative to pre-Tower conditions in the fall is disproportionate to this warming.
Violations of the temperature standards set in the lower Deschutes to protect aquatic life (principally spawning salmonids) have increased following Tower operations. While violations of the lower Deschutes temperature standards did occur prior to Tower operations (0-5 days annually), the number of days in violation of temperature standards increased substantially following Tower operations (2-36 days annually). This is indicative of the overall warming trend post-Tower operations, which has contributed to the well-documented negative ecological shifts that have occurred following Tower operations.
pH & Nutrient Loading
pH levels in the lower Deschutes tell the story of how river conditions have declined following tower operations.
What is pH?
pH is a scale used to specify the acidity or basicity of a liquid. As an example, things with a lower pH, like grapefruit juice and vinegar, are acidic, while things with a higher pH, like bleach and drain cleaner, are basic, or alkaline. A pH level of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. The optimal pH range for most aquatic organisms is within a couple of units above and below 7 (neutral) pH.
Since the DRA started continuous water quality monitoring in 2016, most monitoring days have been in violation of the maximum standard of 8.5 set by Oregon Department of Environmental Quality (ODEQ) to protect aquatic life. Most pH violations have occurred from April through October. The number of pH violations has increased drastically following the commencement of SWW Tower operations. Furthermore, many of the daily maximum pH values are not only above the Oregon Department of Environmental Quality maximum standard of 8.5, but approach and even exceed 9.0. pH levels higher than 8.5 increase the toxicity of pollutants such as ammonia and heavy metals. pH levels of 9.0 or above are likely to harm salmonids, and any prolonged level above 9.5 is lethal to salmonids. While a level of 9.5 has not been observed by the DRA, daily maximum values regularly exceeding 9.0 is cause for concern.
Another way to think of pH is as an indicator of plant growth in the river. As algal growth increases from added nutrients—fertilizers laden with phosphorous and nitrogen, and manure from farms—the chemical reactions from photosynthesis cause the concentrations of hydrogen ions in the water to decrease, which causes pH levels to increase. Increased algal growth of certain species now prevalent in the lower Deschutes also reduces the habitat and food sources of macroinvertebrates. Increasing nitrogen levels in the water results in increased algal and aquatic plant growth.
Of the three tributaries feeding Lake Billy Chinook, the Crooked River is highest in nitrogen levels, followed by the middle Deschutes, primarily due to the relatively high agricultural use in these two basins. The DRA science team has collected samples and studied nutrient levels at the mouths of each tributary to Lake Billy Chinook since 2015. All show the same nutrient pattern as similar studies performed in the basin, with the Crooked River contributing the most nitrogen to Lake Billy Chinook, followed by the Deschutes River. These tributaries, which are warmer and sit on the surface of the reservoir for much of the year relative to the cold Metolius River, are now released directly into the lower Deschutes River through 100% surface draw that occurs 8-9 months out of the year.
The only realistic explanation for the increase in pH after 2009 is SWW Tower operations. A comparison of long-term pH data collected by Oregon DEQ in the lower Deschutes at the Warm Springs Bridge from 1989-2022 shows an immediate and sustained increase in exceedances of the 8.5 standard upon commencement of SWW Tower operations.
Since the SWW Tower began operation, pH levels have risen in the lower Deschutes River and have consistently exceeded Oregon’s 8.5 maximum standard. In 2022 alone, DRA’s data collected at river mile 99.7 (approximately 0.3 miles downstream of the reregulating dam) show 170 days that pH levels violated the 8.5 standard out of 234 days of data collection. Unfortunately, this has been the norm since the DRA started collecting seasonal continuous pH data in the lower river starting in 2016.
The increase in overall algal growth and the proliferation of two nuisance diatom species that create a thick slime-like layer on rock surfaces are significant impediments to the life cycle of any aquatic insect that crawls on rocks for a portion of its life cycle. Studies on the macroinvertebrate and algal communities by PGE and the DRA have shown a decrease in pollution-sensitive macroinvertebrates such as mayflies, stoneflies, and some caddisflies and an increase in pollution tolerant species such as worms and snails.
Many of these pollution-tolerant species serve as intermediate hosts for fish pathogens, including Ceratonova shasta, which can cause high mortality in Chinook salmon. The increased algal growth and shift in species composition has caused a ripple effect in the macroinvertebrate community (i.e. aquatic insects) and, by extension, the rest of the ecosystem, including fish.
Despite continually higher pH levels coming out of the Project relative to the three tributaries and continual violations of the pH standard in the lower Deschutes following tower operations, operators have yet to come up with a pH management plan, and enforcement agencies have turned a blind eye.
What About the Fish…& Wildlife?
Fish reintroduction—the primary goal of installing the SWW Tower—has been a dismal failure. In 14 years of tower operations, 389 combined adult and jack spring chinook can be credited to the reintroduction effort, alongside 536 steelhead, and 1,004 sockeye, half of which returned in one year, 2016. Worse, the severe decline in water quality puts at risk the future or resident trout, wild steelhead, and Chinook that spawn in the lower river. Black spot disease has proliferated in trout, due to the shift in diet from insects to snails and worms. Spring Chinook are in deep trouble.
Figure 3. Post Selective Water Withdrawal Tower returns of spring Chinook on the Deschutes River, 2012-2022. Red line indicates the goal of 1,000 fish annually.
Wild spring Chinook numbers have dwindled to such disturbingly low numbers that extinction now looks more likely than survival—unless significant changes are made in the very near future. The decline of springers in the Deschutes correlates with tower operations. Ceratonova shasta is a parasite that kills spring Chinook via spores that, when released into the water column from tiny polychaete worms, infect Chinook on contact. Prior to tower operations, C. shasta was present in the Deschutes, but in very low numbers. Post-tower operations have fostered a deadly, manifold increase of this parasite, frequently at levels presumptive for infection.
A widely accepted benchmark for the viability of any salmon population is three hundred individuals. Springers in the Deschutes have not met this minimum number for the past six years. The quarry most coveted by anglers, however, on the lower Deschutes is wild steelhead. As Figure 4 indicates, the current trend line is headed toward zero for steelhead as well. Don’t panic: this doesn’t mean there will be no wild steelhead in the river next year. But it does mean that if the current trend continues, there won’t be enough wild steelhead in future years to maintain the species in perpetuity. The life cycle of wild steelhead, in which one to four years is spent in a freshwater environment, places a premium on cold, clean water in the Deschutes River.
Figure 4. Post-SWW Tower returns of wild steelhead to the lower Deschutes River.
It’s often pointed out that Pacific salmon are in trouble throughout their range. But this trouble is exacerbated on the Deschutes by a management regime that puts warm, polluted water into the lower river eight months out of the year. The consequences of this dirtier water have been a wide range of ecological impairments, from the loss of sensitive aquatic insects, drop in song bird and swallow numbers along the river, to the declining population trends for salmon and steelhead.
What Can Be Done?
Recently DRA garnered some wins in the Oregon Department of Environmental Quality’s Rule-making process. We’re holding the line on further declines in water quality. And there is a way out of this mess: PGE’s own water quality report suggests that a “Night Blend” scenario, in which 60 percent bottom draw would flow into the lower Deschutes for the majority of the year. This would go a long way to restoring the river we all love.