The earthen dam was completed in 1908 by the United States Bureau of Reclamation, with a height of 74 feet and 4165 feet long at its crest.  The Upper Embankment is the largest of a set of four dikes here impounding the water of the Boise River in offstream storage. The other dams are:
- the Deer Flat Middle Dike (ID # ID00277), completed 1911, 18 feet high, 1262 feet long
- the Deer Flat Lower Dike (ID # ID00278), completed 1908, 48 feet high, 7270 feet long
- the Deer Flat East Dike (ID # ID82902), completed 1911, 18 feet high, 3806 feet long
The Boise Project was among the first undertaken by the Bureau of Reclamation after its formation in 1902. President Theodore Roosevelt created a national bird refuge at Deer Flat Reservoir, now Lake Lowell, with a February 25, 1909, executive order.  The refuge was one of 17 federal reclamation projects referenced in the order, each of which used manmade aquifers to provide safe havens for migratory birds. The effort to include the Canyon County site was spearheaded by James H. Lowell, then-president of the local Payette-Boise Water Users Association.
The "globally important" Deer Flat National Wildlife Refuge for migratory fowl and other wildlife consists of two sections which contains open water, edge wetlands, grasslands and riparian and forest habitats. The largest portion of the refuge consists of Lake Lowell and its environs. The second portion comprises the Snake River islands located in non-contiguous localities along the river in Canyon, Owyhee, Payette, and Washington counties (Idaho) and Malheur and Baker counties ( Oregon). The visitors' center on the northern Lake Lowell shoreline is the hub of activity for visitors and those volunteers who donate their time and services to wildlife conservation projects. 
- Dooley, Bryan. "Deer Flat Refuge celebrates 100 years." Idaho Press-Tribune. 31 May 2009. Main 8, 9.
- "Deer Flat National Wildlife Refuge". U.S. Fish and Wildlife Service.
- Media related to Deer Flat Upper Embankment at Wikimedia Commons