Review of Week 4 of Water Supply and Sanitation Policy in Developing Countries Part 1: Understanding Complex Problems (University of Manchester, Coursera)
Modelling household water demand is challenging in developing countries due to two reasons: first, households have multiple water sources (with different price, quality and reliability) and multiple uses; second, accurate data is extremely difficult to get for many reasons.
It is important to understand price and income elasticity in order to predict demand for water. The literature show how distance have a vast effect on the amount of water use: poor rural communities use very little water and piped connections increase water use significantly.
Several studies also demonstrate that there is low demand for water quality improvements. People are unwilling to pay even a small price for water treatment.
These are important issues to keep in mind! I think many people do not appreciate that increasing access to water is not as easy as it seems.