Saturday, Sept. 22, 2007 | Reporter Rob Davis (“With Water Scarce and Habitats Threatened, a Plan Resurfaces” Sept. 21) poses the question: can an Isolated Conveyance (peripheral canal) provide water exports and ecological improvements for the California Delta? Davis quotes UC Davis Ecologist Dr. William Bennett as providing an answer: “Putting a peripheral canal on the table is not a dumb suggestion in that vein.”
I believe Dr. Bennett spoke as a good scientist with that reply. The merits of the Isolated Conveyance should be put on the table for discussion, but that’s a far cry from recommending it as a workable solution for the California Delta. Dr. Bennett does not recommend any of the currently proposed water conveyance plans for the Delta.
Dr. Bennett provided specific criticism of the Isolated Conveyance at the “CALFED Science Workshop No. 1: Science Related to an Isolated Facility” held in Sacramento on August 22, 2007. There, Dr. Bennett showed that the spawning ground of the Delta Smelt lay in close hydrologic proximity to water intakes of the proposed Isolated Conveyance near Hood. This canal (or a cross-Delta canal at the same location) would simply suck up and kill an increased number of Delta Smelt larvae.
At the CALFED workshop Dr. Bennett was very clear on the subject of adopting an older plan like the peripheral canal without evaluating its environmental effect by investigation and experimentation. The Delta environment can be modeled as an ecological and hydrological system. As Dr. Bennett said, “We can unleash the conceptual and simulation modeling that has been going on … then we begin to get an idea of how the system works. Without that sort of track record about how the system works we’re basically just guessing.”
Who knows? An Isolated Conveyance may have some environmentally sound benefits, maybe not. A workable and environmentally sound water export system will be the result several years of careful scientific development.