'Nature gave us a lifeline': Southern California refills largest reservoir in dramatic fashion

Water cascades into Diamond Valley Lake from the DVL's inlet/outlet tower. Water cascades into Diamond Valley Lake from the DVL's inlet/outlet tower in Winchester. Bone-dry conditions last year saw the State Water Project allocation at just 5% for the second year in a row. He added that research indicates that 10% of the state's water supply will be lost to thirstier soils and a more evaporative atmosphere by 2040. MWD officials pointed to Diamond Valley Lake as an example of the foresight needed for big projects in the future.