Answer
7.5 MW.
Work Step by Step
Assume that the electrical power comes from steadily converting the gravitational potential energy of the water into electricity. Absent further data, assume 100 percent efficiency. The average height h of the water is half of the 48-meter depth.
$$W=mgh$$
$$P=\frac{mgh}{t}=\rho\frac{V}{t}gh=(1000kg/m^3)(32m^3/s)(9.80m/s^2)(24m)=7.5MW$$
