Not many simple statements can be made about the Sacramento-San Joaquin Delta, except these: It’s hard to overstate the importance of the region’s resources to California – or the complexity of sharing those resources.
Two out of three Californians depend upon water from the Delta, but nearly every discussion of Delta water centers on fish. That is because the Delta is the largest estuary on the West Coast, a vital migratory corridor and home to several endangered species. Protecting native fish directly affects how much water can be delivered to farms and cities.
It may seem counterintuitive, but a big infrastructure project could ease the sharing of the Delta’s resources for both fish and people. We can harness what we’ve learned about the Delta ecosystem over the past 50 years to change how we divert water to better protect fish and stabilize water deliveries.
The aging pumping system in the Delta that supplies the Bay Area, the San Joaquin Valley and Southern California is located in a bad place for native fish. To protect species from the pumps themselves and the “reverse flows” the pumps create in south Delta channels, state and federal agencies propose to build new intakes with California WaterFix.
The intakes would be located along the Sacramento River, 35 miles (56km) to the north, where they could be properly screened to shield even the smallest fish. Pipelines would carry water from the intakes underground using gravity to the existing pumps that lift water into the existing southbound canals. The new Sacramento River intakes would help restore more natural east–west flows in the south and central Delta. They would allow water project operators to capture and store water in high-flow winters, after all water quality standards and measures to protect endangered species have been met.
The new WaterFix pipelines would give California’s central water delivery system more flexibility to better protect endangered fish species.
Managing the Delta for endangered species will get increasingly difficult as climate change brings sea-level rise, deeper salinity intrusion in the Delta and warmer temperatures. We must adapt our infrastructure. New intakes and pipelines will allow us to capture water in the winter, when Sacramento River flows are high and the risk of ecological harm is minimal. We can then minimize diversions in the dry seasons and drought years.
At some point in the future, sea-level rise will overwhelm the fragile Delta levee system. The effects on the Delta ecosystem are unknown, but seawater will block the export of water from the Delta. The pipelines will be the only lifeline to the Sacramento River at that time.
If we do not modernize our Delta conveyance system, the trajectory of the past few decades shows us that native fish populations will continue to decline and water supplies will be jeopardized. We cannot undo the highly engineered water systems upon which so much of California depends, but we can engineer them to work better.
The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Water Deeply.