Corps of Engineers embarked on a plan to improve navigation on the river. In 1915, they completed the Celilo Canal, a portage allowing steamboats to circumvent the turbulent falls. Though the canal's opening was greeted with great enthusiasm and anticipation, the canal was scarcely used and was completely idle by 1919. Flooding by the dam As more settlers arrived in the Pacific Northwest in the 1930s and 1940s, civic leaders advocated a system of hydroelectric dams on the Columbia River. They argued that the dams would improve navigation for barge traffic from interior regions to the ocean; provide a reliable source of irrigation for agricultural production; provide electricity for the World War II defense industry; and alleviate the flooding of downriver cities, as occurred in the 1948 destruction of Vanport, Oregon. Aluminum production, shipbuilding, and nuclear production at the Hanford site contributed to a rapid increase in regional demand for electricity. By 1943, fully 96 percent of Columbia River electricity was being used for war manufacturing. The volume of water at Celilo Falls made The Dalles an attractive site for a new dam in the eyes of the Corps of Engineers. Throughout this period, native people continued to fish at Celilo, under the provisions of the 1855 Treaties signed with the Yakama Nation, the Confederated Tribes of Warm Springs, and the Walla Walla, Umatilla, and Cayuse, which guaranteed the tribes' ancient "right of taking fish at all usual and accustomed stations." In 1947, the federal government convened Congressional hearings and concluded that the proposed dam at The Dalles would not violate tribal fishing rights under the treaties. Subsequently, the government reached a monetary settlement with the affected tribes, paying $26.8 million for the loss of Celilo and other fishing sites on the Columbia. The Army Corps of Engineers commenced work on The Dalles Dam in 1952 and completed it five years later. On March 10, 1957, hundreds of observers looked on as a rising Lake Celilo rapidly silenced the falls, submerged fishing platforms, and consumed the village of Celilo, ending an age-old existence for those who lived there. A small Native American community exists today at nearby Celilo Village, on a bluff overlooking the former location of the falls. In 2008 the Army Corps of Engineers completed a survey of the Celilo Falls site using sonar technology, in response to the 50th anniversary of the flooding of the falls. The