India has had good luck building solar panels over irrigation canals. The shade substantially reduces the evaporation losses in the canal system. The framing is a bit tricky of course.

California announced they were going to do the same.

Yeah the channelized sections of the Colorado would be a good candidate as well, though I personally believe the bigger solution is reintroducing beavers into the upper water shed, to increase total average flow.

How do beavers increase total water flow? I can see them causing more water to be held upstream.

It's counterintuitive, but beavers fundamentally change the soil conditions and cause a lot of the overall flow to be away from the surface.

Beavers are one of the sadly misunderstood creatures and are almost entirely responsible for all the good valley farmland we have thanks to their thousands of years of terraforming.

If you can afford the medium term loss of land, a beaver setting up a dam on your property is a good thing. Unfortunately, most cannot, or are unaware of the benefits they bring and only consider them pests.

Forests make rain, and beavers make better forests.

This is actually fantastic news. I wonder if you're also utilising their secondary purpose (shading and improving microclimat https://www.sciencedirect.com/science/article/abs/pii/S00489...)

I learned about it on this episode of Volts

Fascinating consequences

https://www.volts.wtf/p/pakistans-solar-boom