Twelve water agencies filed suit against the U.S. Fish and Wildlife Service over a critical habitat ruling that could cost 1 million Southern Californians a third of their water supply.

At issue is the Service’s December 2010 ruling to double the critical habitat area for the Santa Ana Sucker, an endangered fish that lives in the Santa Ana River in western Riverside, San Bernardino and Orange counties.

“The expanded critical habitat area for the Sucker is unnecessary and will assuredly lead to increased water costs for our customers,” said Patrick Milligan, president of San Bernardino Valley Municipal Water District, adding, “The decision was based on sloppy science and a flagrant disregard for the requirements of the Endangered Species Act and other federal laws.”

“Western and neighboring districts are working very hard to expand local water sources while at the same time joining forces with other agencies to help protect endangered species by nurturing existing habitats,” explained John Rossi, general manager of Western Municipal Water District in Riverside.

The collaborating water agencies believe that the Service violated several tenets of the Endangered Species Act (ESA), which requires the federal agency to consult with and work cooperatively with state and local agencies; to base its decisions on the best available science; and to balance the needs of endangered species with the needs of humans who are likely to be affected by critical habitat rulings.

But when it came to designating an expanded critical habitat area for the Sucker, the Service not only failed to consult with or work cooperatively with state and local agencies, but it based its decisions on unscientific survey data, unpublished reports that have not been peer reviewed as well as published reports that, ironically, contradict the Service’s arguments.

According to the water agencies’ complaint filed in U.S. District Court in Santa Ana, the Service ignored extensive written concerns submitted by public agencies, which warned that the expanded habitat area would not only threaten the water supplies of 3 million Southern California residents, but undermine the Inland Empire economy as well.

Indeed, the expanded habitat ruling superimposes federal restrictions that make it difficult to operate and maintain water collection, recycling and groundwater recharge operations in and along the Santa Ana River.