Bonneville Lock and Dam consists of several run-of-the-river dam structures that together complete a span of the Columbia River between the U.S. states of Oregon and Washington at River Mile 146.1. The dam is located 40 miles (64 km) east of Portland, Oregon, in the Columbia River Gorge. The primary functions of Bonneville Lock and Dam are electrical power generation and river navigation. The dam was built and is managed by the United States Army Corps of Engineers. Electrical power generated at Bonneville is distributed by the Bonneville Power Administration. Bonneville Lock and Dam is named for Army Capt. Benjamin Bonneville, an early explorer credited with charting much of the Oregon Trail. The Bonneville Dam Historic District was designated a National Historic Landmark District in 1987.
In 1896, prior to this damming of the river, the Cascade Locks and Canal were constructed, allowing ships to pass the Cascades Rapids, located several miles upstream of Bonneville.
Prior to the New Deal, development of the Columbia River with flood control, hydroelectricity, navigation and irrigation was deemed as important. In 1929, the US Army Corps of Engineers published the 308 Report that recommended 10 dams on the river but no action was taken until the Franklin D. Roosevelt administration and the New Deal. Now at this time, America was in the Great Depression, and the dam's construction provided jobs and other economic benefits to the Pacific Northwest. Inexpensive hydroelectricity gave rise, in particular, to a strong aluminum industry. During the New Deal and funded from the Public Works Administration, in 1934, two of the larger projects were started, the Grand Coulee Dam and the Bonneville Dam. 3,000 workers in non-stop eight-hour shifts, from the relief or welfare rolls were paid 50-cents an hour for the work on the dam as well as raising local roads for the reservoir.
To create the Bonneville Dam and Lock, The Army Corps of Engineers first built one of the of the largest scale models in history of the purposed dam, the section of river it was to be located on, and its various components to aid in the study of the construction. First a new lock and a powerhouse was constructed which were on the south (Oregon) side of Bradford Island, and a spillway on the north (Washington) side. Coffer dams had to be built in order to block half of the river and clear a construction site where the foundation could be reached. These projects, part of the Bonneville Dam were completed in 1937.
Both the cascades and the old lock structure were submerged by the Bonneville Reservoir, also known as Lake Bonneville, the reservoir that formed behind the dam. The original navigation lock at Bonneville was opened in 1938 and was, at that time, the largest single-lift lock in the world. Although the dam began to produce hydroelectricity in 1937, Commercial electricity began its transfer from the dam in 1938.
A second powerhouse (and dam structure) was started in 1974 and completed in 1981. The second powerhouse was built by widening the river channel on the Washington side, creating Cascades Island between the new powerhouse and the original spillway. The combined electrical output of the two power houses at Bonneville is now over 1 million kilowatts.
Despite its world record size in 1938, Bonneville Lock became the smallest of seven locks built subsequently at different locations upstream on the Columbia and Snake Rivers; eventually a new lock was needed at Bonneville. This new structure was built on the Oregon shore, opening to ship and barge traffic in 1993. The old lock is still present, but is no longer used.
Environmental and social implications
The Bonneville Dam blocked the migration of white sturgeon to their upstream spawning areas. Sturgeon still spawn in the area below the dam and the lower Columbia River supports a healthy sturgeon population. Small very depressed populations of white sturgeon persist in the various reservoirs upstream.
To cope with fish migration problems, the dam features fish ladders to help native salmon and steelhead get past the dam on their journey upstream to spawn. The large concentrations of fish swimming upstream serves as a tourist attraction during the spawning season. California Sea Lions are also attracted to the large number of fish, and are often seen around the base of the dam during the spawning season. By 2006, the growing number of crafty sea lions and their impact on the salmon population have become worrisome to the Army Corps of Engineers and environmentalists. Historically, pinnipeds such as sea lions and seals hunted salmon in the Columbia River as far as The Dalles and Celilo Falls, 200 miles (320 km) from the sea, as remarked upon by people such as George Simpson in 1841.
Creating electricity was sensitive at the time of the Bonneville Dam's construction. Constructed with federal dollars, the Franklin D. Roosevelt administration wanted the electricity to be a public source of power and prevent energy monopolies. Advocates for private sale of the electricity were of course opposed to this as they did not want the government to interfere. In 1937, the Bonneville Project Act was signed by Roosevelt, giving the dam's power over to the public and creating the Bonneville Power Administration (BPA). A rate of $17.50 per kilowatt-year was maintained for the next 28 years by the BPA.
From Oregon Live: NOAA reauthorizes killing of California sea lions at Bonneville Dam
Oregon, Washington and Idaho will be allowed to resume killing California sea lions at Bonneville Dam this spring, the National Oceanic and Atmospheric Administration said today.
The agency authorized removal of up to 92 sea lions annually through May 2016 but estimates that 25 to 30 will be taken each year. The authorization allows taking only sea lions having a "significant negative impact" on salmon and steelhead.
Bonneville Dam, the first dam on the Columbia, is an ideal spot for the sea lions to feed in the spring as spring chinook and steelhead congregate to climb fish ladders, and an estimated one-third of the salmon and steelhead eaten are listed under the Endangered Species Act, NOAA says. Biologists estimate that California sea lions have eaten from 1.5 percent to 4 percent of returning adult salmon at the dam each year.
Predation peaked in 2010, when about 6,000 adult salmon were eaten. Last year, about 3,600 fish were eaten. The states have trapped and removed 38 California sea lions since 2008, killing 28 and relocating 10 to aquariums and zoos.
NOAA first authorized the states to kill sea lions in 2008. In response to a Humane Society of the United States lawsuit, a federal appellate court suspended the program in 2010, with the court questioning why NOAA allowed commercial and sport fishermen to catch more salmon than sea lions consume at the dam.
NOAA temporarily reinstated the program last year, but pulled the plug after the Humane Society filed another lawsuit.
NOAA said Thursday that fisheries are heavily regulated and have been curtailed sharply, with limits on the take of both hatchery and wild fish, while pinniped predation is unregulated.
Sea lion "predation rates are proportionately higher when salmon runs are lower, which is exactly the time the salmon runs should receive greater protection," the agency said, and "sea lions feed indiscriminately, which can have a greater impact on the wild fish that are so vital to recovery."
If there is no further court action, the authorization will take effect March 20.
Sharon Young, the Humane Society’s marine issues field director, said she and the group’s attorneys are wading through NOAA’s decision. Spring runs are stable or increasing, she said, one sea lion was at the dam at last check and sea lion consumption has dropped.
“It’s not really clear to me what the emergency is here,” Young said. “It just makes no sense.”