They could be doing something about the water shortage. A good thing to do would be to erect solar panels over the surfaces of all the reservoirs involved to cut evaporation, and supply power from those when they are producing instead of draining more water out.

Build out enough solar panels, and they can pump water back up at peak times.

Desalinating water and pumping it up would be a bigger project involving a lot of pipe. Before that, put up solar panels to shade the canals, and desalinate water for where the canals lead to.