EXERCISE • Mangla Lake had a water surface level of 650 m above a datum at the beginning of a certain month. In that month the lake received an average inflow of 250 cumecs. There was an outflow of 150 cumecs. In the same month, the lake received a rainfall of 150 mm and the evaporation from the lake surface was 5 cm. Using hydrologic equation, estimate the water surface elevation of the lake at the end of the month. Assume the lake surface area as 450 hectares and that there was no contribution to or from the groundwater storage.