I adore hydro, but I would check to make sure that whatever project you have in mind the government will not see this as destruction of wildlife. Sepp Hotzer had such run ins with the law, but navigated around them, I would just be aware of this and perhaps look for other hydro projects in the area and see what hoops it takes to stay off the radar of the gov.
700 foot heat is amazing amount of head, I have seen some just run 4 inch pipe down from the top to the bottom and then used this water to be forced against a turbine.
I would look at this channel on youtube for awesome ideas on using water from ram pumps to gens ->
https://www.youtube.com/user/engineer775/playlists