Western Delta Intakes Concept

A Self-Regulating, Inclusive and Sustainable Solution for the Sacramento San Joaquin Delta

This white paper outlines a comprehensive solution to the current problems of the Sacramento – San Joaquin Delta called the Western Delta Intakes Concept (WDIC). The white paper introduced the concept that in normal to dry years, water would be extracted from the Delta only through a new forebay constructed on the eastern two-thirds of Sherman Island into which water would be drawn during periods of extraction through “permeable embankments that would replace the existing levees along the Sacramento and San Joaquin Rivers; the approach velocities to these permeable embankments would be 100 times slower than the maximum approach velocities used in the current design of fish screens”. While the intent to make extraction of water as invisible as possible to migrating fish, including both salmonids and Delta smelt, was clear, this language failed to explain two other important considerations, one involving the fact that the existing levees would be left in place, both to provide added protection to the new embankments and to create new riparian habitat, and the other involving the small proportion of total flow at Sherman Island that would be extracted.