California Delta Tunnels Don't Stand Up to Federal Analysis

Initial studies from the U.S. Fish and Wildlife Service and the National Marine Fisheries Service do not project confidence in Governor Brown's signature water infrastructure proposal.

The California WaterFix project is a proposed overhaul of the state's water conveyance system, consisting of two large tunnels beneath the California Delta. An ongoing concern has been how tunnel operations might strain the regional ecosystem, particularly endangered species of salmon and smelt. The proposal has already been scaled back in an effort to reduce its environmental impact.

In late 2016, the state Department of Water Resources released a biological assessment concluding that the plan "minimized" potential harm to endangered species. 

The federal analyses released in March differed, finding that up to 7 percent of an endangered fish population could be killed by tunnel operations. Moreover, they suggested that the conservation measures proposed in the plan—restoring 15,000 acres of habitat—would not be sufficient to offset the damage.

In the Sacramento Bee, officials noted to Matt Weiser that the draft reports are not yet complete, and the tunnel proposal itself is still being revised.