I think it's important to note how much hardscape and channelling has been done to prevent widespread and sheet style flooding, and how they contribute to this problem of ground water recharge.

Most places that are flat enough to build are flat enough to build because of thousands of millenia of flooding, especially sheet flooding, laying down sediment and making them flat. Then humans get annoyed because the flat low places floos, so they build flood control.

There is a post further down about how Muni water really isn't an issue and I agree with this. I've put up a couple posts explaining this on Reddit and hacker news. I could rehash it if some one was interested.