Hubbard Dam, located about 12 miles southwest of Boise, Idaho, was originally constructed in 1902 by private interests. The Bureau of Reclamation purchased the facility in 1911 as part of the Boise Project. This is an earthfill structure 23 feet high creating a reservoir area of 450 acres with an active capacity of about 4,060 acre-feet. Water is delivered to the reservoir by the New York Canal. The dam and reservoir are operated and maintained by the Boise Project Board of Control as a reregulating facility for irrigation water deliveries in the adjacent area. It also provides emergency short-term storage for dewatering the New York Canal should a failure in the canal occur downstream. In 1998, as a result of a Safety of Dams investigation, the reservoir was restricted to a level of 2765.0 feet, with a capacity of 573 acre-feet.
Hubbard Dam is centrally located in the Western Snake River Plain (WSPR) physiographic province. The WSRP is a 50 to 70 km wide trough that trends northeast across southwestern Idaho. The WSRP is characterized by mid to late Cenozoic fluvial lacustrine sedimentation, voluminous basaltic volcanism, low relief and extremely low rates of seismicity.