The massive water diversion tunnels proposed in the Sacramento-San Joaquin Delta have undergone another major design change aimed at appeasing local residents: The three intakes planned on the Sacramento River will no longer require pumps.
The project, known as the Bay Delta Conservation Plan, has been in the works for eight years and is estimated to cost $25 billion. It calls for a pair of giant tunnels, 40 feet in diameter, that would draw water out of the Sacramento River and route it 30 miles away to existing state and federal diversion canals near Tracy. The goal is to improve reliability of water supplies drawn from the estuary while also restoring its natural environment.
Instead of giant electric pumps, the plan now calls for water to enter the three huge intakes by gravity flow. This, in turn, means most tall buildings can be eliminated at each intake. And there will be no need for permanent new high-voltage power lines. New power lines are still required to serve the tunneling machines, but these would be considered temporary: They would be removed after the 10-year construction period.
The project still includes massive water pumps, but they would now be at the project’s southern end, at Clifton Court Forebay, an existing reservoir near Tracy. They would move water from the new tunnel outlets to existing canals that distribute water across the state.
http://www.sacbee.com/news/local/environment/article4644687.html