Federal limits on water that can be pumped out of a major river delta for California farmers are scientifically justified, a much-anticipated report said on Friday, a finding hailed by environmentalists in the state’s epic water wars.

But the National Academy of Sciences stopped short of handing a decisive victory to environmental interests over agricultural interests. The academy said further study was required and that threats to Chinook salmon, delta smelt and other endangered fish were not entirely caused by the pumping.