The U.S. Bureau of Reclamation is preparing a report on raising San Luis Dam to enlarge San Luis Reservoir in western Merced County.
The 2 million acre-foot reservoir is already the key west Valley holding place for irrigation water for a broad swath of farming, including 600,000-acre Westlands Water District.
Bureau Commissioner Michael Connor on Saturday mentioned his agency is working on a draft appraisal, which roughly describes the benefits, costs and feasibility of raising the dam. Connor was a panel member at the Delta Water Summit.
He did not say why the appraisal is being done now or release other details, such as how much larger the reservoir would become. His statement about the possible enlargement of San Luis was a surprise to many water agency officials and observers.
The appraisal report should be ready in October. If it appears feasible, the bureau would complete a final feasibility study within a few years.
San Luis is one of the largest off-stream reservoirs in the country, but it is only holding 16% of its capacity right now. Drought and environmental water pumping restrictions in Northern California have left it near historic lows.