hey, interesting project you have here I've read quickly through the attached, and here's my 2 cents, the helium balloons would likely work, but the moon already pulls billions of dollars worth of water around all day every day. for the billions it will cost to build the dam , you could place lots of underwater water turbines, also, wave power is an unconquered rescorce. hydraulics is also a strange and wonderful thing.. you could pump water to any head... with a big enough ram. store water in a reservoir up the mountain. .. in the mountain. .. pumped by wave action, and released on demand, again, any head could be achieved... in theory. ..going up..governed by force/area, and down by gravity, sea water in and out. . no environmental concerns. ... except fish sucked in maybe. in civil engineering, anything can be done, if you have the money. ..
there. .... text me back if you want and I'll really fry your head lol