Figure $3$ shows a section through a long impermeable wall driven into the bed of a river;the riverbed consists of sand overlying impermeable rock. The water level to the right of the wall ispermanently lowered by steady pumping as water flows from left to right through the sand below the wall. The permeability of the riverbed sand isk$=104$m$/$s$,$ and the dimensions of the problem are provided inFigure $3.$ Calculate the rate of flow under the wall and estimate the pore pressure at a pointAnext to thedownstream face of the wall, $1\mathrm{.}0$ m above the tip.Figure $3.$ Sespage below an impormsable wall, Problem S$.$