A little-known insurance clause could spell trouble for many residents in North and South Carolina, where a storm surge of up to 14 feet is expected as Hurricane Florence sweeps through, according to a report.

As a result of the “anti-concurrent causation clause,” many people could soon discover that their policies don’t cover damage from the tidal water driven by high winds, CBS News reported.

“The vast majority of homeowner insurance policies have this exclusion,” said Amy Bach, head of United Policyholders, a San Francisco-based consumer insurance advocacy group.

She predicted that the clause will “put policyholders in a fight with their insurers right from the get-go.”

According to the clause, if two events — like wind and water damage — occur close together but only one of them is covered, the insurer doesn’t have to pay for either one.

“If two separate events occur, such as wind and flood, and cause damage within a short period of time, but only one is insured, then the order in which it occurred is irrelevant, and your insurer will not pay for either one,” Robert Hunter, director of the Consumer Federation of America, told CBS.

This is true even if damage from the wind is tallied at $100,000 and the flood loss is only $5,000, he added.

Forecasters predict that Florence’s storm surge could cause more damage than its winds, particularly if the storm hugs the coastline and veers southward into Georgia.

But some in the insurance industry believe the clause will not be problematic.

“Anti-concurrent causation wording generally will have no bearing on a major portion of the damages,” major insurance broker Willis Towers Watson said in a statement.

The clause is “causing a great deal of confusion for consumers,” said Clearsurance CEO Michael Crowe. “In situations where it’s included in a policyholder’s contract, often consumers simply aren’t aware.

“Insurance policies are full of legal, technical jargon that makes them difficult to read, and so many consumers may not understand what this clause means for their coverage,” he said.