Finally! Implementation of a great idea!

 This idea has been around awhile. I think the payback is quick - although not quick enough for immediate action.

Covering the aqueducts will save a lot of water. Those canals go through some of the hottest and driest sections of the country. You can save water from evaporation as it will be shaded and cooler. AND it creates energy in an area that is not used at all!

Next, Interstate verges should be covered.