While Harford adopted what Craig described as a provisional fee structure earlier this year, the executive said he now wants to rescind that action because "none of our questions have been adequately answered" by state or U.S. Environmental Protection Agency officials.

Craig — who previously said the state needed to obey the law even though he opposed it — said he now believes the O'Malley administration is in no position to carry out threatened penalties for noncompliance with the fee mandate.

"I would say, take us to court," he said, predicting that such a case would take five to six years to resolve. He said he would pay for existing stormwater projects out of the county budget at about the existing level rather than use the fees to ramp up activity as called for under the current county plan.

The prospect of a lawsuit is not far-fetched. Samantha Kappalman, a spokeswoman for the Maryland Department of the Environment, said the agency is reviewing each affected jurisdiction's actions and will refer noncompliant counties to the attorney general's office for possible legal action.

One of Craig's opponents for the GOP nomination for governor welcomed his shift even as he took a backhanded swipe at his previous compliance with the state law. Del. Ron George of Anne Arundel County called Craig's shift a "smart political move" but faulted his earlier stance.

"I think it would have hurt him tremendously if he didn't do it," George said. "It would scare people if you're going to be governor and you didn't make the right choice the first time."

State Republicans have derided the storm water fee as a "rain tax" and made it a rallying cry in the 2014 election.

Todd Eberly, a professor of political science at St. Mary's College, said the Republicans may be on a productive course.

"If there is going to be a sleeper issue in 2014, that's going to be it," he said.

William Dennison, a University of Maryland scientist who oversees an annual report card on the Chesapeake Bay's health, took issue with critics' characterization of the fee as a rain tax.

"It's not that the rain is doing the damage. It can rain all it wants if you have a nice forested watershed," he said. The problem lies in the fertilizer, pet waste and other pollution left on lawns and pavement that's picked up by the rain and washed into nearby streams.

"It's not about the water, it's about what the water carries," he said. "It's the dirty water tax, not the rain tax."

While Eberly said Craig could benefit from the rain tax issue by getting out in front of it early in the primary race, he expressed skepticism that a proposal to broadly scale back the state's environmental protections would help him in the general election.

"If he's going down that road, he's going to have a hard time getting to 50 percent," Eberly said.

Baltimore Sun reporter Timothy B. Wheeler contributed to this article.