U.S. Army Corps of Engineers

The U.S. Army Corps of Engineers has a major role in the day-to-day business of the Columbia River, from maintaining the navigation channel to operating most of the major hydroelectric dams and helping to protect and recover salmon and steelhead.

The Army opened its first engineering office in the West at San Francisco in 1866, and that same year began working to clear the channel of the Willamette River to Portland in response to a petition to Congress by Portland city officials and an appropriation that Congress authorized in response. Snags, which are logs and trees that fall into the river and became embedded in sand or mud, and constantly shifting sandbars, were hazards to navigation. By 1869, the Corps had cleared a 17-foot-deep channel. Keeping it open required annual dredging. This was the first river and harbor work by the Corps of Engineers in Oregon.

In 1871, the Corps created the Portland District from the San Francisco District, dividing its west coast work roughly at the California-Oregon border. The first Officer in Charge of the Portland District was Major Henry M. Robert, later and, perhaps, better known for his Robert’s Rules of Order.

Through the end of the 19th century, the Corps conducted surveys of the Columbia and its tributaries, dredged and maintained the navigation channel from Astoria to Portland, then Vancouver and later Lewiston, Idaho, removed snags, rocks and other hazards to navigation, constructed jetties at the mouths of several coastal rivers including the Columbia, and constructed canals around Columbia River rapids and waterfalls at Celilo Falls and the Cascades. The Cascades Canal was completed in 1896 after 18 years of work, and the Celilo canal was completed in 1913. It took 11 years to build.

By 1918 the Corps had completed a 30-foot-deep navigation channel between the ocean and Portland. As with earlier channel improvements, this boosted commercial river traffic significantly and helped Portland grow.

Flood control and hydropower became Corps responsibilities in the 1920s and 1930s. The Flood Control Act of 1936 shifted the emphasis from building dikes and levees to contain rivers to building multiple-purpose dams to improve flood control and navigation and generate Hydropower. In 1933, the Corps began work on BONNEVILLE DAM under Title II of the National Industrial Recovery Act. Congress formally authorized the project in 1935 for the primary purposes of navigation and hydropower.

Today there are 31 federal hydropower dams in the Columbia River Basin. The Corps operates 21 of them, and the other 10 are operated by the federal Bureau of Reclamation. There are now three Corps districts within the Columbia River Basin — Portland, Seattle, and Walla Walla — under the supervision of the Northwestern Division, which is based in Portland.


The Corps installed this removable spillway weir in one of the spillbays at Ice Harbor Dam on the Snake River to improve passage survival for juvenile salmon and steelhead. The devise is hinged to the back of the dam, and the fish are carried by water over the “slide,” which can be seen in side profile in this photo at the top of the device.

Operating dams brought the Corps responsibility for providing safe fish passage for salmon and steelhead. Designing Bonneville Dam, the first federal dam completed on the Columbia, required the Corps to devise means of safely passing millions of adult fish annually over a 65-foot-high obstruction. This never had been done on such a large scale. A system of three fish ladders, with backup fish traps and elevators, was devised and constructed. It went into operation in 1938 with the completion of the dam, and it worked.

The problem of safely passing juvenile fish downstream was more difficult. Juvenile fish are small, and the passage through the thrashing water and intense pressure of power turbines can be difficult at best, lethal at worst, for the tiny fish. At Bonneville, Ivan Donaldson, one of the first fish biologists employed by the Corps, began research on fish passage in 1941. In 1942 he recommended various means of protecting juvenile fish that still are being implemented to this day, including screens in front of turbine entrances to deflect fish into bypass systems and the removal of predator fish like northern pikeminnow from the area immediately downstream of the dam. His proposals met with resistance from at least some of his superiors at the Corps. In a 1942 memo and again in a 1974 interview after his retirement, Donaldson said a Corps engineer told him that the fish were “a damn nuisance” and that the attitude of the engineers could be summed up as “to Hell with the fish, I’m here to build a dam.” Donaldson, despite his frustration with some of his superiors and co-workers, also recognized that fish passage was forced on the Corps and that, for the most part, the engineers embraced the responsibility and worked hard to make the passage facilities effective.

Harlan Holmes, a biologist with the U.S. Bureau of Fisheries, also studied fish passage at Bonneville Dam. He had helped design the fish passage facilities there and had concluded initially that turbine passage essentially was benign for juvenile salmon and steelhead. However, in 1947 Donaldson was the first biologist to conduct research on the number of fish that are killed passing through turbines, and his research contradicted a 1938 Corps report that turbine passage presented little danger to fish. Donaldson’s research showed that mortalities varied widely and that turbines could be both “literal sausage grinders” and also “a very satisfactory route for the passage of fish” (later it became clear that violent pressure changes, not the spinning blades, are the primary cause of fish kills in turbines). In 1952 he estimated juvenile fish mortality at Bonneville Dam to be about 15 percent. His report, considered controversial, initially did not appear in print, but it prompted additional research on fish mortality at Corps dams.

Research on fish passage was not a new undertaking for the Corps in the early 1950s. The Fish and Wildlife Coordination Act of 1934, and amendments to the law in 1946 and 1958, ordered the Corps to consult with the U.S. Fish and Wildlife Service and the state fish and wildlife agencies regarding damages to fish and wildlife from operation of the dams. The 1958 amendment required the Corps to give “equal consideration” to fish and wildlife conservation as to water developments in its planning. By that time the Corps had been operating its Fisheries Engineering Research Program for seven years; later its would be renamed the Fish Passage Development and Evaluation Program. This was an interagency effort to research and mitigate for losses that would result from the proposed construction of more dams on the Snake and Columbia rivers. Over time the program was expanded to include representatives of NOAA Fisheries and the Columbia River Inter-Tribal Fish Commission, along with the state fish and wildlife agencies. The Bonneville Power Administration and the Northwest Power and Conservation Council participate as observers. The program also changed names again to better reflect its focus. Today it is called the Anadromous Fish Evaluation Program.

Through this program, over the years the Corps has funded evaluation and monitoring studies of fish passage and survival at the dams, particularly for juvenile fish but also for adults. Research areas include 1) juvenile fish transportation past the dams in barges and trucks, 2) evaluating the effectiveness of devices that collect or guide juvenile fish around and through the dams, 3) the effects of gas supersaturation that occurs when water — and fish — are spilled over the dams, and 4) adult fish passage.

As a result of the Corps’ research, adult fishways — fish ladders — have been improved and juvenile fish bypass systems now are in place at all eight dams on the lower Snake and Columbia rivers. Juvenile fish are collected for barge transportation at Lower Granite, Little Goose and Lower Monumental dams on the lower Snake River and at McNary Dam on the Columbia.

Meanwhile, the Corps also continues to work on improvements to navigation, including deepening the channel in the Columbia and Willamette rivers from 40 feet to 43 feet to accommodate larger vessels. To mitigate impacts to salmon and steelhead from this dredging, the Corps planned to improve and restore wetland resting and feeding areas for fish in the lower river.

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