California, U.S. Wildlife at odds over Delta smelt

California water officials are fighting back against federal protections for an iconic Delta fish, a tactical shift that threatens to derail a cooperative attempt to fix the state's water problems.

In a petition filed with the U.S. Fish and Wildlife Service Thursday, the state Department of Water Resources argues rules should be changed because new research suggests a separate group of threatened Delta smelt has taken refuge on Liberty Island and is unaffected by water operations.

If successful, the state would avoid future releases of hundreds of thousands of acre-feet of water for the benefit of the tiny fish – water that could otherwise meet needs of users throughout California.

Liberty Island at the southern end of the Yolo Bypass, along the Sacramento River near Rio Vista, is owned by the Trust for Public Land. Its levees are breached, allowing tides to wash over the island, creating feeding and resting habitat.

New findings by DWR and state Fish and Game biologists indicate the flooded island is a year-round haven for some smelt, said DWR Deputy Director Jerry Johns. This may make the population more resilient than previously believed and less dependent on freshwater flow rules.

The research is unpublished and ongoing, he said.

The federal rules, called a biological opinion, govern water management in the Sacramento-San Joaquin Delta to prevent smelt from being killed in water export pumps. The rules were revised six months ago in response to a lawsuit by environmental groups.

DWR objects to a particular fall condition that could require as much as 400,000 acre-feet of water to be released from its Oroville Reservoir to create downstream flows beneficial to smelt. That's enough water to serve 1 million households for a year.

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