SACRAMENTO – State water officials said Thursday it could cost $10.6 billion to send water to Southern California through a proposed project of tunnels under the Sacramento-San Joaquin Delta.
The Department of Water Resources presented the cost estimate to a group of state and federal agencies studying ideas to safeguard water deliveries from the delta.
Two tunnels, about 150 feet underground, are being considered as an alternative to building a proposed canal around the fragile estuary. A third tunnel would serve as an intake tunnel, completing the 43-mile path under the delta.
Jerry Johns, DWR deputy director, described the cost as preliminary and said more design work needs to be done over the next year.
“I think it’s so preliminary at this stage, it’s hard to take the numbers seriously,” said Ann Hayden, a water expert at the Environmental Defense Fund. “The potential is there but we have a long way to go.”
Cost estimates for a proposed canal range between $8.3 billion to $9.4 billion.
A canal or tunnel would take more than six years to build, sending about 15,000 cubic feet per second at its peak from the Sacramento River to existing pumping plants south of the delta.
Funneling water under or around the delta are ideas being considered as a way to restore the delta’s ecosystem, particularly protecting endangered fish.
Currently, state and federal water agencies must follow strict pumping limitations to keep the fish from getting trapped and killed in their pumps. Those restrictions have curtailed water deliveries to Southern California, the San Francisco Bay area and Central Valley farmers.
State officials say a tunnel shows promising environmental benefits. For example, a tunnel would disturb less sensitive habitat, grasslands and farmland than a canal. Acquiring swaths of land for a canal also would be about three times as expensive as the land needed for a tunnel.
However, sending water through a canal could take twice as much energy.