The project was originated by the Bitter Root Valley Irrigation Company between 1908 and 1910. The Bitter Root Irrigation District (BRID) was formed as a public corporation established under the laws of the state of Montana in 1920. The Bureau of Reclamation rehabilitated the project beginning in 1930. Additional funds for rehabilitation work were provided in 1936, 1948, and 1956.
Extensive rehabilitation to the canal and distribution system was initiated in 1963 and completed in 1967. In 1976, the district constructed protective walls on each side of the spillway section with its own funds.
Water is stored in Lake Como on Rock Creek. At full capacity, Lake Como holds 28,500 acre-feet of water. Como Dam was completed in 1910 by local irrigators and rehabilitated on its crest and upstream face by the Bureau of Reclamation in 1954. This semihydraulic earthfill dam at the end of a natural lake is 70 feet high with a crest length of 2,550 feet.
BRID services 16,665 acres along a 72 mile stretch from Lake Como to the Eagle Watch area southeast of Florence. The main canal has an initial capacity of 350 cubic feet per second. As of 2015, the District services approximately 1,400 water users.
Project facilities include a storage dam and reservoir, a diversion dam, and a main distribution canal, commonly referred to as The Big Ditch.
The goal of the District is to provide irrigation water efficiently and equitably at the least cost to its patrons.