A plan for two massive tunnels diverting water from the Delta has been scaled back 40 percent in size. The project would divert only 10 percent less water, however, and it remains to be seen if this proves less harmful to fish and their habitat.
The Bay Delta Conservation Plan is an unprecedented effort by state and federal water agencies to replumb the Sacramento-San Joaquin Delta, a source of water for 25 million Californians and more than 3 million acres of farmland. The goal is to improve the reliability of Delta water exports while also restoring salmon, smelt and other imperiled fish.
For two years, the plan's centerpiece has been a pair of 33-foot diameter tunnels, estimated to cost $14 billion, to divert water from five intakes on the Sacramento River. The assumption was that these screened intakes would prove less harmful to fish than the current diversions in the south Delta near Tracy.
The tunnels would divert water at 15,000 cubic feet per second, or enough to fill 10 Olympic-size swimming pools per minute.
On Wednesday, planners revealed for the first time at a public meeting that they are now looking at a 9,000-cfs project with three intakes. Those intakes would still sit on the east bank of the Sacramento River between Freeport and Courtland, and the tunnels would still be about the same diameter.
A key difference is that the tunnels now would be gravity-fed rather than pressurized. This might substantially reduce tunnel construction costs, but also may require a planned forebay to be moved north, from near Courtland to Hood, where the California Department of Water Resources already owns some land.
Each intake still requires massive diversion pumps. But the forebay would not, because the tunnels no longer would be pressurized.
Fewer pumps also means fewer construction disturbances, power lines, energy demand and greenhouse gas emissions.
"I guess it's in the eye of the beholder, but certainly in terms of cost savings and local impacts, it's going to be quite an improvement," said Jerry Meral, deputy director of the California Natural Resources Agency, which is leading the planning effort.
Delta residents remain highly skeptical of the project, even in a smaller form.
"You make it sound like the reduction to 9,000 (cfs), which we still consider to be quite massive, is some kind of concession," said Osha Meserve, a Sacramento attorney representing local groups in the North Delta.
A member of the audience later shouted from the crowd that the smaller project would still be able to "drain the river dry" under some conditions.
This prompted a sharp reply from Jason Peltier, chief deputy general manager of Westlands Water District, the San Joaquin Valley irrigator and one of the project's main beneficiaries.
"That's a ridiculous notion," Peltier said, noting the project would be bound by rules that restrict diversions when river flows are low.
Meral, however, said that reducing the project's capacity would not result in a significant overall reduction in water diversions. This is because there are few periods in the year when the larger project would be able to operate at its full 15,000 cfs capacity.
Information offered later by consulting economist David Sunding indicated that the smaller project would reduce total Delta diversions by only 10 percent, to 5.3 million acre-feet annually.
"The point of this project really is to maximize exports during high flows so you can minimize exports during low flows," Meral said.
The smaller design was prompted in part by state and federal wildlife agencies. In April, they issued "red flag memos" warning of negative effects to Delta fish species from a 15,000-cfs diversion.
As a result, the first full draft of the plan, originally expected this month, has been delayed until fall. Gov. Jerry Brown and U.S. Interior Secretary Ken Salazar plan a joint announcement about the project's key features in July.