Restore the Delta will give geotechnical engineer Robert Pyke the last word this year on meeting the co-equal goals for the Delta. This is not because we know with certainty his Western Delta Intakes alternative is necessarily THE answer. We don’t have the data yet to take a stand. But it is a thoughtful alternative offered by someone with impressive expertise, and we want to see ALL alternatives considered, including the alternative of NO new conveyance.
Dr. Pyke’s Western Delta Intakes Concept (WDIC) would locate new intake facilities in the Western Delta to allow flows to pass through the Delta in a natural way before surplus flows are extracted. In “A Self-Regulating, Inclusive and Sustainable Solution for the Sacramento San Joaquin Delta,” a paper made available earlier this month, Dr. Pyke provides details about his proposal.
He begins with an excellent overview of the history of the water projects, how we got to where we find ourselves today, and why the Bay Delta Conservation Plan (BDCP) is not a good solution. Page 10 of this paper shows a map of the proposed WDIC, and a table on page 13 compares the WDIC to the BDCP and to a proposal based on the Delta Protection Commission’s Economic Sustainability Plan that would focus on levee improvements.
Dr. Pyke notes that manmade alterations and large export flows have created an environment in the Delta that favors nonnative species, and that variability of precipitation in California is as significant as the fact that most of the precipitation falls in the northern part of the state. He argues that for ecosystem recovery and sustainable exports at existing levels, any solution for the Delta must incorporate six principles:
- It should restore natural flows through the Delta as much as possible.
- It should extract less water when flows are low and only surplus water when flows are higher.
- It should include additional wet year storage south of the Delta.
- Project operations should be self-regulating and not rely on difficult-to-enforce legal assurances or guarantees.
- The project should be relatively simple to design, permit, and construct.
- It should not have physical facilities that intrude on the character of the Delta.
BDCP fails on all these counts.
Dr. Pyke’s WDIC proposal includes a large forebay on Sherman Island into which water would be drawn through permeable embankments, which would serve as fish screens. Tunnels would convey water to a new Brushy Creek Reservoir adjacent to the Clifton Court Forebay. The project might also include a pumped storage hydro-electric facility between the Brushy Creek Reservoir and a further enlarged Los Vaqueros Reservoir to make the project energy positive. Dr. Pyke proposes using currently drawn-down groundwater basins or other storage south of the Delta to store water extracted from the WDIC in wet years, providing for as much as a six-year drought.
Under this proposal, no water would be extracted if Delta outflows dropped below the level needed to protect water quality. The Delta Cross Channel gates would be converted to a boat lock to prevent Sacramento River salmon being diverted into the Delta. A lined canal would allow fresh water to be recirculated from the state and federal aqueducts into the San Joaquin River above Vernalis as necessary.
Dr. Pyke proposes restoring Franks Tract with habitat in conjunction with dredging the deepwater ship channels and other Delta channels. He wants to further upgrade Delta levees to develop continuous shaded riparian habitat. He proposes funding a world-class biological and water quality monitoring system throughout the Delta.
The WDIC wouldn’t take any endangered species, so it wouldn’t require state or federal incidental take permits.
We’d like to see a cost estimate for the WDIC. Since the tunnels that Dr. Pyke proposes would be less than half the length of the BDCP’s Peripheral Tunnels, the cost should be correspondingly lower.
Dr. Pyke comments on the Delta Protection Commission’s proposal for levee upgrades as recommended in the Economic Sustainability Plan and for habitat improvements compatible with existing farming operations. He sees these measures as a “no regrets” first stage of the WDIC. Restore the Delta sees them as a reasonable first step for ANY future project in the Delta. At a cost of $2 to $4 billion, this is certainly the least expensive way to begin.