[anubisresources]

I can speak for Uganda at least, since several of my contract farmers lead fairly low income lives. Can't really speak for the rest of sub-saharan Africa.

One of the biggest costs a peasant family currently has is the time it takes for the woman of the family to get to the well and back with water (in Uganda, it is always women doing this). She usually spends several hours each day doing so. Obviously, this situation is improved greatly if they're near the Nile or another river, but for those who are further afield they spend hours of potentially productive time fetching water.

An increase in the price of water could incentivize development of closer wells, better delivery methods, etc. by profit seeking companies, minimizing the time she spends going back and forth between the well and her house. She can spend that time working and generating income instead.

This will not improve household wealth in all cases, but I'm betting that something like this would help improve several of these families lots in life.