After almost nine years and expenditures of more than $1.2 million, the U.S. Army Corps of Engineers is threatening to shelve a study about increasing the height of the dam at Lake Mendocino.
Corps officials said they can't continue without additional funding and proof that the dam would be cost effective.
A preliminary cost benefit analysis states: “There is a very low likelihood that further study would find the dam raise project to be in the federal interest.” Federal interest is not met if costs outweigh value, the analysis states.
Local water officials disagree with the cost-benefit analysis and are scrambling to convince the Corps to continue the study.
“In a year where it couldn't be more plain that it needs to happen, they're walking away,” said Sean White, manager of the Russian River Flood Control and Water Conservation Improvement District. The district manages the Ukiah Valley's right to 8,000 acre feet of water in Lake Mendocino.
Persistent drought conditions have reduced lake levels to historic winter lows, and there's no significant rainfall in sight. Farmers along the Russian River, which is fed by Lake Mendocino water releases, are in danger of having insufficient water to irrigate their crops or protect them from frost.
The problem would not be as dire if Coyote Dam — which created Lake Mendocino — was raised by 36 feet, as planned since it was constructed in the late 1950s.
The additional water from raising the 160-foot tall earthen dam would increase the lake's storage capacity from about 122,400 acre feet to 199,000 acre feet, according to the Army Corps. An acre-foot of water is about 325,851 gallons.
A series of studies on completing the project have been underway for more than a decade. They've proved to be time consuming and expensive.
The Inland Water and Power Commission, the multi-agency organization responsible for funding the local share of the study's price tag, already has paid $617,000 toward the costs of the feasibility study. The Commission's members include the Russian River district, the county of Mendocino, City of Ukiah and the Potter Valley Irrigation District. Redwood Valley's water district is a member but has not contributed financially to the effort.