The oceans have an area of ~89.2 billion acres [0]. Abstracting those 5 million acre-feet would lower sea level by 17 microns. Sea level is rising by ~3.6 mm per year [1], so you would need 211 of these setups to counteract that. Scaling up Diablo Canyon's nameplate capacity of 2256 MW, that is 475 GW. There is currently 390 GW of nuclear power in the world [2].
So, again, not unthinkable, but really quite a lot of work.
I'm thinking bigger than the Colorado river. I also think scaling up nuclear power is a good idea--the economics of managing nuclear waste imply that the cost of managing a little bit of nuclear waste is not much lower than the cost of managing a whole lot of nuclear waste, so we're already committed to most of that cost.
> And i'm not sure what you do with the water.
Use it for agriculture (presently a whole lot of agriculture depends on unsustainable access to water) and desert greening. To be clear lowering the ocean levels is a nice byproduct of producing more water, not the other way around.
Nuclear takes a long time to scale up so this certainly isn't feasible in the next 50 years even if we had the political will. It's more of an interesting long term idea.
