Change in Water Volume = Total Water Inflows - Total Water Outflows
Total Water Inflows = P x A + Stream Inflow
Total Water Inflows = 0.21 ft x 230,000 acres + 1,160,000 acre-ft
Total Water Inflows = 1,208,300 acre-ft
Total Water Outflows = E x A
Total Water Outflows = 6.1 ft x 230,000 acres = 1,403,000 acre-ft
Change in Water Volume = 1,208,300 acre-ft - 1,403,000 acre-ft = - 194,700 acre-ft