The construction of the Ambulance Corps in Hawthorne, Passaic County, New Jersey, affects 1.073 acres and increases the impervious coverage from 1400 square feet to 32,080 square feet. A rain basin in the form of lawn depression (see Figures 8.39 and 8.40) is designed to fully retain the entire runoff from the paved area during the 10-year, 60-minute storm, having 2 in./h intensity. Calculate the required storage volume of the rain basin.