One very wet day last summer could end up costing the city $2.4 million.

A drain-busting rainstorm on Aug. 11 backed up sewers so badly that many Queens residents were left with raw waste sloshing around their basements – and they say the city is to blame.

Now the comptroller’s office is wading through 110 property-damage claims – a quarter of sewer claims for the entire year.

In the hardest-hit area, overwhelmed drains flooded nearly every home on three blocks of 160th Street.

In nearby College Point, a couple in a car were killed when a fallen power line electrocuted them.