Engineer: Fix Deltas levees, don’t build peripheral tunnels

WALNUT CREEK
July 12, 2012 9:00pm

California taxpayers would be on the hook for billions of dollars from a plan to reroute much of the Sacramento River away from the Sacramento-San Joaquin Delta, says a letter to Gov. Jerry Brown from an engineer who has studied the proposals.

Mr. Brown is expected to announce later this month plans for a massive twin tunnel beneath the Delta to take fresh water from the Sacramento directly to state and federal irrigation systems without having it first flowing through the Delta. The goal is the same as the ill-fated peripheral canal, which California voters rejected when Mr. Brown was governor in 1982.

“One of the principal reasons that is advanced for the need for an isolated conveyance as part of the Bay Delta Conservation Plan (BDCP) is that the Delta levees are in a pathetic condition and that there will be multiple failures in a major earthquake followed by saltwater intrusion that will curtail exports from the Delta by the State Water Project and the Central Valley Project for up to three years, forcing up to 25 million people to drink and bathe in whiskey for that period of time,” says the letter from Robert Pyke, a Walnut Creek consulting engineer who specializes in non-routine geotechnical, earthquake and water resource engineering.

“While I think I understand your desire to announce a ‘preferred project’ for the BDCP within the next month, you should not do this without understanding that this reason for constructing an isolated conveyance with intakes in the North Delta is based on a series of misrepresentations and falsehoods -- in other words, that the supporters of the BDCP are lying,” says Mr. Pyke.

He says it would be less expensive to simply shore of existing levees.

“Not only would such a program generate jobs more quickly than the BDCP, but it would reduce the risk to life and property throughout the Delta, protect and enhance the Delta as a place, contribute to ecosystem restoration, and reduce the risk to many kinds of energy and transportation infrastructure in addition to water conveyance,” Mr. Pyke writes.

He says that levee failure from earthquakes is remote but cannot be completely ruled out, but more studies are needed.

“What is clear, even without further study, is that the argument that a peripheral canal is needed because of the threat to Delta levees posed by earthquakes, rests on a very shaky foundation,” says Mr. Pyke.

Comments on this story

derph 7/13/12 1:13 PM
It's all well and good that Mr. Pyke is calling all the scientists and engineers that have work on this liars, I guess everyone has their opinion but it appears to me that there is more than just the earthquake issue that are behind this moving of the intakes. Earthquakes are a major concern, there are faults that run right next to the delta - the Vacaville Fault broke in 1892 at 6.6 on the richter scale and that can't be discounted. Some of the other issues are: Endangered fish - there is no way to effectively screen the fish out of the system at the current location of the pumps because of the reverse flows, no matter what the fish in the system would be drawn through Old & Middle Rivers and there will always be reductions in the amount ot water that can be delivered to farms and people to satisfy the fisheries, and that reduction occurs at the worst time for farmers. Moving the intakes to the north would solve the fisheries issue and would allow for better management of the scant resources available in the dry years. The answer to their next arguement is that there would not be any increase and the whole Sacramento River would NOT be stolen, Decision 1641 requires certain fresh water flows at Rio Vista and Antioch and that would not change. Another issue is the impact of major storms and they potential loss of levees due to storm surge, especailly taking into account the additional sea level rise. Next, you would still have the same issues with levees because the levees are poorly constructed and made of river bottom that was piled up in the 1870s - 1930s so there is no internal structure, they are prone to seepage, underseepage and rodent damage, that is not going to change until you take out the existing levees and go down 70 ft below sea level to put in a seepage barrier and that will be VERY expensive and have a limited amount of effectiveness. I do understand Mr Pyke's desire to have the levees fixed at taxpayer expense, it's cheaper for him to have all of California fix his problem than to have to pay for it themselves but there is so much push-back from farmers because they don't want to lose any land to produciton by building a bigger levee and they don't want anything built in the river to strengthen the levees because it reduces the carrying capaity of the rivers so what are you going to do to fix the levees???? Here'ss another couple of assets that has been overlooked in this whole discussion. First - when the tunnels are built you're going to have 41 miles of 2 X 33 ft diamater tunnel material that will be available for levee work, so there would be a benefit to the people in the delta becuase their levees would be strengthened by the use of clay soils that would help to hinder seepage. Second, you can take water off of high water events in the north before the water gets to the delta islands that are most at risk and if some freeboard is added that helps to save islands. So there are some added benefits that are conviently overlooked by a lot of people.

Principal_Component#1 7/13/12 5:22 PM
Of note, Dr. Pyke has his own "Delta Fix" that would move the export pumps elsewhere in the Delta. It calls for a tunnel to transport and store water in a forebay to be exported when conditions allow. If the BDCP is successful, his idea gets scrapped. That should provide some context for readers. I'm hopeful that Californian's are getting tired of this political rhetoric...as it's gotten us where we are today. People want solutions from grown adults who can sit in a room and discuss adult topics without letting emotions hijack the process. California's water delivery system is antiquated and in need of an overhaul. The BDCP aims to provide that overhaul while satisfying water reliability and environmental sustainability concerns.