The Lower Snake: A River No Longer Working

*this page is under construction and not considered draft/final*

Water level rising in Lewiston, Idaho

The Loss of Salmon and steelhead
Community treasures lost
Dams are expensive

The lower Snake River has been fundamentally changed by four federal dams in Washington State. Although authorized as hydro electric dams, they were envisioned as a key piece in a transportation network that would make Lewiston, Idaho a sea port and provide the service of barging of goods from Idaho out the Columbia River to the Pacific Ocean. The construction of the first dam, Ice Harbor was authorized by congress in 1945. It was finally built in 1961. Four more were to follow.

Ice Harbor Dam which came on line in 1961
Lower Monumental Dam which came on line in 1969
Little Goose Dam which came on line in 1970
Lower Granite Dam which was the last constructed and completed in 1975.

Lower Granite Dam
Photo Courtesy of USACE Digitial Library

Unfortunately, these dams have turned the lower Snake River into a series of slack water reservoirs and prevented the river from working for communities in a multitude of ways. Instead of the promised economic opportunities, these dams have brought about a crisis in the region. They have destroyed the valuable salmon runs that have supported communities for years, they have destroyed unique opportunities for recreation, river access and a quality of life that attracts businesses and fuels sustainable economic growth. Finally, these dams have created a legacy of infrastructure problems that local and regional communities must try and solve with very little help from the federal government.

In fact, these dams have cost society more than they give (Revenue Stream, 388 KB PDF).

If looks closely at the values, benefits and services that a flowing river could bring, the river is worth far more as an intact, flowing system than as a segmented, broken series of lakes. Additionally, the submerged 34,000 acres of islands, river bars, rapids and riparian areas are worth far more as a living landscape than as a series of dead, slack water impoundments.

The loss of salmon and steelhead:

For generations salmon and steelhead have supported communities and culture along the Snake and Columbia Rivers. The power of these fish to continue that support still exists. However, due to the dams on the Snake River, Coho salmon are now gone and four large runs of steelhead and salmon are on the Endangered Species List. Fish runs listed as endangered are sockeye salmon, spring/summer Chinook salmon, fall Chinook salmon and wild summer run steelhead. On average only .5% to 1.5% of salmon and steelhead that begin their journey from the mountains of Idaho live to see their natal streams or hatcheries. These runs are not strong enough to ensure survival in a world in which ocean conditions may not always be optimal and climate change will raise the water temperature of low elevation reservoirs to lethal levels. (Population Graph, 180 KB PDF). In fact, Trout Unlimited (link to report on site) has actually put together a report that indicates that spring/summer chinook salmon could become extinct within our lifetime if we continue to ignore the highest cause of mortality, the four LSR dams.

Failed Federal Plans

When the federal government put the four dams on the lower Snake River, they were obliged to do so without harming its runs of salmon and steelhead. As these fish and the communities they have supported, four stocks of salmon and steelhead were listed as endangered, under the Endangered Species Act. This meant the federal government had to devise a plan (Biological Opinion) to protect these fish from the federal Columbia River power system. In the last eight years, three plans have been declared so flawed that they were illegal. The current plan or BiOp is still involved in a court challenge and awaits a ruling by Judge Redden.

Currently, the Obama Administration has a unique historical opportunity to correct the past mismanagement of Snake River Basin salmon and steelhead runs by sticking to defensible science in their own planning and putting all scientifically based measures on the table in order to recover salmon.

Why Some Dams Kill Valuable Salmon and Steelhead

Dams and salmon are not necessarily incompatible. With proper management and mitigation there are plenty of situations where dams and salmon can coexist. The Hanford Reach, for example, in south-central Washington, is home to the Columbia Basin’s last healthy, self-sustaining salmon population. This run of fall Chinook must navigate four dams on the lower Columbia twice – first as juveniles, then again as adults. These fish support tribal, commercial, and recreational fisheries, and still return in adequate numbers to spawn and sustain themselves. Proper water management in their spawning beds and dam operations when juveniles are migrating downstream minimize harm to the population and allow it to thrive while also supporting family-wage fishing jobs.

Snake River salmon and steelhead, however, face twice as many dams and twice as many harmful effects as those of the Hanford Reach. For Snake River salmon and steelhead, between 10 and 15 percent of ocean-bound smolts are killed at each reservoir/dam. After eight dams, not many of these juveniles remain to survive and grow to adulthood in the ocean. More than two decades of effort and billions of taxpayer and ratepayer dollars have been applied by federal agencies, but failed to sufficiently mitigate the impacts from the federal system of dams and their reservoirs.

These dams and reservoirs harm salmon and steelhead in a variety of ways. Spinning turbines draw in large numbers of salmon as they migrate downstream to the Pacific Ocean. Increasing levels of spill – pouring extra water over the dams during the migratory season rather than sending it all through the turbines has been a very effective strategy for reducing some of this mortality and increasing smolt survival through the hydro-system.

But the reservoirs are also a significant cause of mortality. Large currentless reservoirs capture significant amounts of sunshine and warm the waters. Increased temperatures, particularly in the summer, can kill migrating juveniles, cause high levels of physical stress, and harm the viability of eggs carried within the bodies of adult females heading upstream in search of spawning grounds.

Warm and slow-moving reservoirs also favor predators like the pikeminnow that feast on juvenile salmon. The lack of a current also means that smolts spend far more time in each reservoir, increasing their chances of being eaten. And the increased migration time can also short-circuit the young salmon’s ability to transition to life in saltwater, increasing mortality after leaving the hydro-system.

Finally, Snake River juvenile salmon also suffer significant losses after arriving in the ocean as a result, it is thought, of the cumulative aforementioned stresses from the eight dams and reservoirs. This phenomenon is called delayed mortality.

Dams are Expensive:

Operations and maintenance:

One of the serious problems these dams have created is a legacy of expense that was unforeseen by their creators a generation ago. The four lower Snake River dams, like any complex system are very expensive to operate and maintain.

They cost taxpayers and ratepayers $33.7 million a year in operation and maintenance costs. This involves clearing debris from the fore bay, repairing cracks, operation of the navigation locks and dredging for flow conveyance. The federal government has also gone to considerable expense by retro-fitting these dams with apparatus like removable fish weirs in the attempt to make them more fish friendly and meet Endangered Species Act obligations. However, every expensive innovation carries an unforeseen and unitended consequence.

Large repairs to the aging four dams:

Finally, the four major dams were put into operation between 1961 and 1974 and have an approximate lifespan of 25-50 years. Keeping them operational is very expensive. Upgrading turbines replacing turbine blades and rewinding the generators is estimated by the Army Corps of Engineers to cost $225 million dollars over 40 years. In other words major dam repairs for the life of the projects will cost taxpayers $5.6 million dollars annually.

Costs in keeping the salmon promise:

When the dams were put in, the US Army Corps of Engineers made a promise to the public not to damage salmon and steelhead that run both up and down through the Columbia River hydro-power system. This promise has both moral and legal foundations as these runs of fish are an inherent part of Washington State heritage and Congress mandated such protection. However, today these four dams and the federal government's moral and legal commitment to the public is costing ever more as salmon and steelhead continue to decline.

The federal salmon plans require program funding will ultimately cost nearly one billion dollars a year. The results thus far have been dismal with Snake River Coho salmon having slipped into extinction in the 1980’s and four other wild stocks suffering at the hands of an engineered river .

Mud in the river:

The Army Corps of Engineers has created a self-perpetuating problem whose solutions, short of dam retirement, are very expensive and unpleasant. Each year 3.2 million cubic yards of sediment (link to “flood control”) and mud pour into the Lower Granite Reservoir near Lewiston ID and Clarkston WA. The Army Corps of Engineers estimates the reservoir at 55% full and must dredge these sediments for flow conveyance and to keep 14 foot shipping lanes open. Currently solutions are being looked at that could cost between $2-35 million per year. Other, more radical options would call for raising the levees another 3-12 feet at the waterfront, raising existing bridges, modifying rails and roads in a plan that could cost taxpayers $93.4 million dollars. This option is very unpopular with residents in Lewiston, Idaho, as it would further isolate their community form the Snake and Clearwater Rivers. The costs are simply mounting with each passing year. The river must be dredged for both shipping and flow conveyance and it is the taxpayers and local communities that pay the costs. Read more here (1.5 MB PDF).