> And you don't mind that it's not a long-term solution, as silt builds up behind the dam until your dam is worthless.

You can let some of the water flow take silt away, at least the silt anywhere near the dam. That might mean you don't have a huge reservoir, but you can generate a lot of power without a reservoir at all.

(By the way, I am extremely curious why this got a downvote, and would greatly thank anyone giving a good reason.)

First unless you remove the dam it's not going to remove silt as it's dropped out because of a change in velocity.

Second dredging actually works and is vastly cheaper.

Nuclear power warms water which is then usually dumped into rivers at a temperature higher than it started at. The waste issue is problematic and the cost (especially when factoring in cleanup and waste) is prohibitive to a small country with no existing nuclear program. Our dams gave been in a while here in New Zealand and the trade offs they require are vastly more acceptable to New Zealanders than the nuclear option.