Hydroelectric, of course.
Is it just me, or would it make more sense for them to save the water in holding ponds, and then release it into the ocean if and only if the plant fails inspection. (But, if it passes inspection, that water is good to go.)
10 miles uphill? Doggone it....BUT! There’s a downhill side, right? EASY! Just put some turbine generators in the pipes on the down hill side and let the 54 MG/day run it!......../s
Obviously you are not a bureaucrat.