This document discusses calculating water pressure on dams and determining the minimum thickness required to prevent overturning. It provides equations to calculate the pressure from water (Pw) and concrete (Pc) on the dam based on factors like density, gravity, water depth (H), and contact area. To find the minimum thickness, it sets the moments about a point of interest equal, where the moment from Pc acts on half the thickness and Pw acts on a third of the water depth. Solving this equation provides a formula for the minimum thickness (T) in terms of the densities and water depth.