Brian Cobb wrote:Why not use municipal water?
There are plenty of reasons not to use it. Some people don't like the chemicals in the water or the high impact this kind of system can have on the environment. Others don't like to feel dependent on outside sources for their basic like food and water. Then there are many (probably the majority of people living on this earth) who don't have access to municipal water. It gets a lot more complicated than that.
Storing water in the soil has so many benefits. My favourite is that it saves on labour and buying (and maintaining) irrigation systems.