Lost River Diversion Dam is an important dam for ranchers and farmers of the Klamath Basin who rely on the diverted water from Lost River to irrigate crops and ranch lands in the area.
I was able to locate an annual report from 1916 (Issue 15) by the Bureau of Reclamation (known then as the Reclamation Service) which notes the construction of this diversion dam was completed in 1912. The water diverted from Lost River flows into the Griffith (G) Canal. G Canal was also completed in 1912. The report also mentions that the Lost River Diversion Dam was built to divert flood waters from nearby Tule Lake into G channel and into Klamath River, eight miles west of this dam.
The report's exact words read:
The successful reclamation of the north end of the bed of Tule Lake depends on preventing the larger part of the spring floods of Lost River from entering the lake. The Clear Lake Reservoir, completed in 1910, retains the flood water of the Upper Lost River, the evaporation and inflow seepage and inflow being equal. The runoff below the reservoir in Lost River varies from 25,000 to 120,000 acre-feet annually. It was planned to handle this by building a dam at the north end of Stukel Mountain (Mount Laki) and a diversion channel 8 miles long thence to Klamath River directly west, thus diverting excess water before it could reach Tule Lake. The dam was located at Wilson Bridge, 10 miles southeast of Klamath Falls, Oreg., and the plans were approved July 26, 1910; bids were opened for the dam December 29, 1910, and the contract was awarded to George C. Clark.
The dam is a U-shaped, multi-arch, concrete structure, with an interior pool 110 feet long by 60 feet wide. It is 34 feet above the bed of the river, and earth embankments connect it with higher ground on each side. It contains 5,600 cubic yards of concrete and 13,140 cubic yards of earth embankment. The headgates for the diversion channel are on the north side of the dam and those for the G Canal on the south side. Water was stored above the dam in April, 1912, and diverted in May, 1912, but the dam was not completed until October, 1912.
The diversion channel, 8 miles long, extends west through the Lost River and Klamath Valleys to Klamath River. The excavation covered 467,400 cubic yards of material. Bids were opened December 15, 1910, and the contracts awarded to W. H. Mason and James W. Jory for the excavation. The work was not pushed as it should have been and was not completed until May 1, 1912. The channel has a capacity of 420 second-feet, and since its completion has diverted the flood water of Lost River, excepting the peaks of the floods, thus assisting greatly in the reclamation of the bed of Tule Lake.
Some great history here at this dam. It should be noted that there appears to be a pump house of some sort at this dam but it looks to be boarded up and not in use any longer.