The rainfall rate in a certain city is 20 inches per year over an infiltration area that covers 33000 acres. Twenty percent of the rainfall percolates into the groundwater, with the remaining 80% running off into the river. The city uses 83000 acre-ft per year, some of which comes from the river and the remainder from groundwater. The groundwater volume of fresh water is currently at 1.1 × 105 acre-ft and is expected to last for 30 years before being completely depleted of fresh water (assume uniform withdrawal each). Assuming the groundwater lasts exactly as expected, determine the rate at which water is being withdrawn from the river by the city.
