A Dam Good Irrigation Story

Ochoco Irrigation District

By Steve Lent, Museum Historian

Ochoco Irrigation District was organized in 1916. Plans were made to irrigate the Ochoco Valley as early as 1905 but because of difficulty in obtaining financing the project did not materialize. After World War I authorization was granted as a part of the Veteran’s Farm Settlement Program to construct Ochoco dam on Ochoco creek. Ochoco Irrigation district was organized by local farmers. Ochoco Dam and the water distribution canal were constructed from 1918 to 1921. Construction was done utilizing private funds.

Ochoco Dam was constructed utilizing zoned earth-fill structure that was built by hydraulic fill methods. Large hydraulic water cannons were set up to wash soil and rock debris into forms. A system of flumes transported the fill material utilizing the water forced through the hydraulic cannons at a high pressure.

It was determined that 22,000 acres were to be irrigated by water stored in the reservoir behind the dam. Unfortunately the District experienced financial difficulties in the early years of the project due to drought and later the Great Depression. The project had to be re-financed by the Reconstruction Finance Corporation and the State Engineer ordered that the acreage to be irrigated be reduced to 8500 acres.

Ochoco Dam was considered unsafe in 1947 primarily because of the method of construction. The District contracted with the U.S. Bureau of Reclamation to rehabilitate the dam and the work was completed in 1949 and 1950. The water storage in the dam and the canal delivery system provided extended opportunities for expanding productive farming into the Ochoco and McKay Creek Valley.

LaSelle Coles was the District manager in the 1950s and with the help of local farmers and area legislators began promoting construction of the Crooked River Project. Through their efforts construction on the dam on Crooked River was completed in 1961. The operation of Prineville reservoir water storage and Bowman dam was turned over to the Ochoco Irrigation District in 1962. The new dam had a total capacity of 153,000 acre feet with 60,000 acre feet reserved for flood control in the winter and spring months. Ochoco Irrigation District purchased 59,600 acre feet of storage from the Bureau of Reclamation allowing the district to increase irrigated lands to over 20,000 acres.

Ochoco Dam again was determined to have safety issues in 1994 and it was scheduled for extensive repairs by the Bureau of Reclamation under the Federal Safety of Dams Act and the District entered into a new repayment contract with the United States. The work was done to correct seepage problems within the structure of the dam which might result in dam failure and flooding of the Prineville Valley. The crest of the dam was also raised nine feet to meet criteria for a 500 year flood event. After completion of the repairs the Ochoco Reservoir has a storage capacity of 46,500 acre feet for irrigation.

The Ochoco Irrigation District and farmers utilizing the water has led to a highly productive farming system in the Ochoco Valley. Farmers pay for water delivery and maintenance of the system and management and maintenance is part of the mission of the District.