$(2)$ A lake had a water sulrface elev of $103\mathrm{.}2m$ above datum at the beginning of a certain month.

In that month, the lake received an average inflow of $6\frac{m^3}{s}$ from surface runoff sources. In the same period the outflow from the lake had an average value of $6\mathrm{.}5\frac{m^3}{s}.$ Further in that month, the lake received a ralntall of $14-5mm$ and evaporation from the lake surface was estimated as $6\mathrm{.}10cm.$ Calculate the water surface elevation of the lake a the end of the month. $A=5800$ ha$.$

$G=0$