Smaller Delta canal could work nearly as well as massive one in the works
Mike Taugher
Contra Costa Times
07/29/2009
Studies of an aqueduct as wide as a 100-lane freeway to carry water around the Delta are showing it might not get as much bang for the buck as some advocates might think.
State water officials recently put the rough price tag at $7 billion to $15 billion, which may be tough to swallow in a cash-strapped state. More importantly, studies are showing a 50-mile-long canal through a right-of-way as wide as three football fields — a size critics compare to the Panama Canal — would be dry much more often than full. Although the Schwarzenegger administration is pushing to have key permits and plans done by the end of 2010, it is likely to be at least 15 years before it could be completed.
These details about size, cost and time — which were included in a presentation last week by the Contra Costa Water District — play to critics of the canal plan, but water officials caution that criticism of the plan's cost-effectiveness is premature and no decisions have been made.
Still, studies show a peripheral canal would provide only slightly more water than agencies have pumped out of the Delta in recent years, and then only if the canal is operated in conjunction with existing south Delta pumps. Even that amount of water assumes regulatory approval that is not assured.
Surprisingly, the difference in average water supply from the massive, 15,000 cubic-foot per second canal favored by water agencies and a less controversial
version one-third the size is marginal — less than 300,000 acre-feet on average, enough water for roughly 600,000 households or enough to irrigate 100,000 acres of crops.
"A small one does just as good as a big giant one," said Greg Gartrell, Contra Costa Water District assistant general manager.
"A small one you get done a lot faster without the threat" to water quality and the environment.
In addition to arguing for more consideration of a smaller canal, the water district is arguing for immediate action on a set of more modest — but largely ignored — measures that could improve water supplies and fisheries quickly.
Studies by the Bay Delta Conservation Plan, a committee of water agencies, regulators and environmental groups, shows the large canal would be full 4 percent of the time and would hold a trickle of 2,000 cubic feet per second or less 30 percent of the time, according the Contra Costa Water District's presentation to a group of Contra Costa business representatives.
By comparison, the smaller aqueduct could carry 5,000 cubic feet per second through a 25- to 30-foot tunnel.
Major water agencies say it is too early to make judgments about the appropriate size of a canal but added that if the Delta's vulnerable levees collapse after flooding or an earthquake, parts of the state will become entirely dependent on a canal.
"In the long-term, given the changes we will likely be seeing in the Delta, we will need to look at something in the (larger) 15,000 cfs size range," said Laura King Moon, assistant general manager of the State Water Contractors, an organization that includes Zone 7 Water Agency, Santa Clara Valley Water District and the Metropolitan Water District of Southern California.
Other advocates point out that a larger canal would be prudent for the future if environmental conditions improve and restrictions on water deliveries are eased.
King Moon did not rule out a smaller canal but was critical of the Concord-based water district's conclusions.
"They presume to know the right answer. It's not possible to know the right answer right now," King Moon said.
The conservation plan was launched in 2006 to resolve two problems for water agencies from the Bay Area to San Diego: the potential unreliability of water deliveries from south Delta pumps due to fragile levees and the increasingly tough restrictions on water deliveries to protect endangered species.
The plan seeks to build a canal, restore wetlands and enact other measures that committee members hope will be approved by regulators. King Moon said water agencies hope the canal can at least get water agencies back to the supply levels they were receiving before restrictions triggered by the collapse of endangered fish species.
Meanwhile, with the state's budget crisis addressed for now, state lawmakers are expected to turn their attention to California's water crisis so the entire slate of options is likely to be fiercely debated in coming months, particularly if public money is needed for wetlands restoration and pollution cleanup.
