Solar Panels over canals, good function stacking?

Hello fellow desert Permies!

Yesterday an article popped into my news feed about a project in India that was placing Solar Panels over its canals to shade the canal and reduce evaporation.
Here's the linkSolar panels over canals

My first thought was "that's an awesome function stack" so I told my friend, who's first response was "why didn't we (Americans) think of that?!"

I spend a LOT of time driving around southern Arizona and California where I see lots of canals and an increasingly amount of solar projects. It seems that the two things often in short supply here are water and power and this could help with both.

Thoughts?

I wish I could build or do stuff like that near the creek, but the county says it's a drainage easement (100' back) & the Feds say it's a flood zone of the worst kind for about 100' back as well. The way things are looking, I may have to get permission to plant a tree if the EPA gets their way.

My mantra with solar has always been "rooftops and parking lots." Covering canals (and small reservoirs) would be a good extension of that. Another benefit is that there there are often power lines that share the right-of-way, so new power lines may not need to be built.

On a slight tangent, the Murdock canal that carries water from the Provo River, at the mouth of Provo Canyon, to the Salt Lake Valley was recently replaced with 10.5 ft diameter concrete pipe, at significant expense. A trail now runs on 17 miles of the covered canal through Utah County. The reasons for replacing the canal were safety, seepage and evaporation.

I could see something like this working here in Phoenix... but I also wonder what material they'd use for the structures. I'm curious how quickly the humidity off the canal would rust any usual metal, and other options might be too expensive or structurally weak. But, I could be overconcerned.

I like your idea of stacking functions: solar panels and irrigation canals.

Sadly, do I think your idea will ever come to fruition, no. The reasons are because of cost, politics, and wiring infrastructure.

The open irrigation are open because they are the cheapest solution. If we were really thinking about how valuable water was we would have enclosed the canals a long time ago.
The politics in that solar panel electrical infrastructure will have to be on a mix of private and public land. Everyone is going to want their piece of the pie (solar generated revenue).
The wiring infrastructure over such a long distance will be very expensive.

Perhaps this is a viable solution and you can solve what I see as the above problems. We burn tons of coal at the Navajo Generating Station to pump the Colorado River up and over a mountain range into AZ and CA.