At last! An important issue in this section.
There are only 2 solutions... Move the water, or move the people. Neither is a cheap option.
Geothermal desalination, shafts drilled into areas of super-heated rock, sea-water injected and the resulting steam producing distilled water, there may be a way to produce electricity as well if someone works on the technology.
Stop deforestation, stop mono-culture agriculture and start rehabilitation of large-scale damaged ecosystems. Vegetation protection to break the wind and slow down water floods so water can soak in.
There's so much information and know how, we only have to put everybody to work. Do permaculture and forest gardening.
Contour bunds help collecting water
No till farming so bumblebees and all the other small creatures can survive.
Have cover crops and plant hedges, ways to protect the land from wind and water erosion.
ex :
Conservation.
