Hydrostatic pressure is the pressure exerted by a fluid due to the force of gravity.
To understand how hydrostatic pressure can damage foundation walls, imagine how much heavier soil becomes when it’s soaked with water. When the weight of water is added to the weight of the soil, you’ve got much greater pressure pushing against a foundation wall.
Hydrostatic pressure effectively amplifies soil pressure against a foundation wall. When the pressure exceeds the foundation wall’s ability to withstand it, the wall will begin to bow, buckle, tilt inward at the top, or move inwards at the bottom.