As demands on the state’s engineered water systems have risen, water supplies have declined because of dwindling snowpack and competition for water, even by wildlife.
One of the most intriguing combatants is a little freshwater fish. Water exports from the Delta to southern California have been curtailed since 2007 because of a federal court ruling to safeguard the endangered Delta smelt, a small, finger-length fish that inhabits the Delta near the pumps. These tiny fish anchor what is left of the Delta’s highly altered aquatic ecosystems.
When pumping from the Delta is high, typically in winter and spring, the number of fish killed by the pumps tends to increase. And when the number of smelt mashed by the pumps reaches a certain threshold – this year that threshold is 2,350 fish – pumping must be scaled back.