Two sheet piles were driven $4m$ apart into clayed sand as shown in Figure $7\mathrm{.}14,$ and a $2-$m depth of soil between the two sheet piles was removed. To facilitate some proposed construction work, the region between the sheet piles is being dewatered where the water level is lowered to the ground $($excavation$)$ level by pumping out the water continuously. Some equipotential lines have been drawn.

Complete the flow net. Assuming the hydraulic conductivity of the clayed sand as $2**{10}^{-4}c\frac{m}{s},$ estimate the volume of water that has to pump out per day. Assuming the length of evacation looking into the paper is $10m($at right angle to the cross$-$section shown per day$)(3$ marks$)$