Groundwater & Basement Water Intrusion in Stamford, CT

Because two things arrive at once. A tropical system pushes water in from the Sound while its rainfall is running down the river toward the same place. Neither can drain past the other, so the low ground takes both. An ordinary rainstorm of the same size drains out normally. That combination is why the September peak here is much more damaging than the monthly total by itself suggests.

Substantially. Salt remains in materials after the water evaporates, keeps pulling moisture back, and corrodes fasteners, wiring, and mechanical components over time. Porous materials that held salt water generally come out rather than being dried in place, and surfaces that stay need rinsing and testing. A scope written as though it were a clean water loss will leave problems that appear months later, particularly in electrical and mechanical systems.

Essentially none of the coastal mechanism, and a different set of ordinary problems. Inland and uphill properties here deal with runoff on slopes, dense till that drains slowly, and basements cut into rock with backfill that holds water. Those are year-round issues rather than storm-season ones. General local advice about surge and river flooding does not transfer, which is worth remembering when reading anything written about the city as a whole.