A mean draft of 380,000 m^3/day is produced from a drainage area of 330 km^2. At the flow line, the reservoir is estimated to cover about 1600 hectares. The annual rainfall is 96.5 cm, the mean annual runoff is 22.8 cm, and the mean annual lake evaporation is 77.1 cm. Find the net gain or loss in storage and compute the volume of water evaporated in cm^3.