A federal judge says Ameren sued its insurance company too soon after the Taum Sauk reservoir collapsed five years ago.

Ameren wants $30 million from its insurance company to help pay for the rebuilding of the reservoir. But a judge says Ameren should have gone to arbitration with the insurance company before filing a suit.

Energy Insurance Mutual also says the lawsuit was filed in the wrong place — that it should have been filed in New York. The company has paid Ameren almsot $69 million.