The federal government can’t duck its responsibility to protect animals protected under the Endangered Species Act by handing off authority to the states. This is the main message of a friend of the court brief filed by Earthjustice and the National Wildlife Federation at the US Supreme Court today.

The Supreme Court is considering two consolidated cases in which Defenders of Wildlife argued successfully that, when the Environmental Protection Agency delegates administration of the Clean Water Act to a state — as it does, routinely and legally — it must ensure that the state does not issue permits that violate the federal endangered species act. The government, for its part, argues that the Clean Water Act and the Endangered Species Act are in conflict and that, therefore, the EPA has no obligation to enforce the ESA.

In one instance at issue in the case, Arizona issued permits that appear to have negative impacts on several protected species that live near and depend on the San Pedro River in the southern part of the state.

“It’s simply common sense,” said Jan Hasselman of Earthjustice, coauthor of the brief. “Protecting listed species includes protecting their habitat and their water supply. Allowing states to ignore the Endangered Species Act flies in the face of reason.”

The Supreme Court will hear oral arguments in April.

Earthjustice represents the American Fisheries Society, Association of Northwest Steelheaders, California Sportfishing Protection Alliance, California Trout, Federation of Fly Fishers, Institute for Fisheries Resources, Miami Beach Rod & Reel Club, Native Fish Society, Northwest Sportfishing Industry Alliance, Pacific Coast Federation of Fishermen’s Associations, Trout Unlimited, and Washington Fly Fishing Club.