Explain why water storage dam walls are thicker at the bottom.

(N/A) The pressure exerted by a liquid column of height $h$ is given by the formula $P = h \rho g$,where $\rho$ is the density of the liquid and $g$ is the acceleration due to gravity.
As the depth $h$ increases,the pressure $P$ increases linearly.
Therefore,the pressure is significantly higher at the bottom of the dam compared to the top.
To withstand this increased hydrostatic pressure and prevent structural failure,the walls of the dam are constructed to be thicker at the bottom.