According to a much-awaited report by the National Academy of Sciences (NAS) committee, the federal restrictions in the hub of California’s water system – pertaining to water that can be pumped out of a leading river delta, for the state’s farmers – are scientifically justified.

The academy, which was assigned the task of assessing the basis of federal fish protections that are restraining the pumping of water supplies from the Sacramento-San Joaquin delta, noted that the pumping was not the only reason behind the threat caused to Chinook salmon, delta smelt and other endangered fish.

However, the 64-page report, prepared by 15-expert committee reviewing the situation on the insistence of the US departments of Interior and Commerce and Sen. Dianne Feinstein (D-Calif.), does not imply a divisive win for the environmentalists and calls for a further study.

Giving due consideration to the agricultural interests, the evaluation highlights that there are no quick fixes in the delta, which serves as a channel to ship water to the San Joaquin Valley, the California’s agricultural heartland.

Commenting on the pumping limits, which are said to have intensified water shortages caused by the state’s three-year drought, the committee chairman Robert Huggett, professor emeritus at the Virginia Institute of Marine Sciences at the College of William and Mary, said: “It's going to take a while to see any kind of change in this system.”