Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID
Significance: The Deer Flat Embankments, which impound Lake Lowell, are significant as the first large storage feature built by the U.S. Reclamation Service on the Boise Project, one of the largest of the early projects undertaken by the Federal Government following the passage of the Reclamation Act of 1902. The Boise Project is also significant in the historic development of south-central Idaho because it finally fulfilled the tremendous irrigation potential in the Boise Valley, which had been recognized, but unsuccessfully developed, by private entrepreneurs. Today the Boise Valley is one of the great areas of irrigated agriculture in the Pacific Northwest, and that agricultural base has provided the foundation for the Boise-area economy. The Deer Flat Embankments are earthfill structures which represent conventional embankment design and construction methods of the early 20th century. Inadequate resistance to the erosive action of waves on the reservoir has caused repeated deterioration of the upstream faces of the embankments, leading to significant construction activity by the Civilian Conservation Corps in the 1930s.
Survey number: HAER ID-17-B
Building/structure dates: 1906-1908 Initial Construction
Building/structure dates: 1911 Initial Construction
Building/structure dates: 1938 Initial Construction
Building/structure dates: 1959-1960 Subsequent Work
National Register of Historic Places NRIS Number: 76000666