What can be done by individuals to aid in the effort to irrigate the parts of Africa plagued by drought?

Answer 1

Young engineering students could consider taking their internships there, and assisting in the design and construction of irrigation systems. Californians would be good at that sort of thing. We have the most amazing irrigation technology around here, and feed a substantial portion of the country, and a good bit of the rest of the world, on the success of that technology.

Ought to be useful in Africa.