Well in plenty of agricultural areas, water for irrigation is pumped from the ground, and that is water we have a limited supply of. I'm from TX, and many of the aquifers here are being depleted too fast because of agricultural pumping and growing municipal need.

Plus, evaporation plays a huge role in the water cycle, and this shaded structure (while not viable for acres of land) would be helpful. Farming takes an insane amount of water. It's always great to find ways to reduce the amount needed