A growing population in some of the world’s driest areas is leading many people to study the economics of water. Why is a diamond expensive and water free? It’s a famous question posed in economics.
Actually that may not persist much longer.
To get an idea of how much renewable water a country has, go to Worldbank/World Development Indicators database.
Type freshwater as a search term.
Or check p.142 of the paper copy of World Development Indicators.