I recently returned from the Arizona Hydrological Society Annual Symposium in Flagstaff where I heard one presentation of note that I wanted to talk about here. Bradley Hill - currently with the city of Flagstaff - talked about his recent work in Peoria, where they developed several policies for managing the water resources of the city. The policy that he covered in his presentation involved a rather unique (to me at least) method for linking land use and water supplies. If you are interested in the document that lays this out it can be found on Peoria's website at: http://www.peoriaaz.com/utilities/Docs/PrinciplesSoundWaterManagement.pdf
The general gist of the document is the establishment of a metric for analyzing changes to land use in the city that looks at how much water use would increase on the parcel by changing the land use, then calculating the increased value to the city (in terms of tax revenue, jobs, etc.) from the land use change. These numbers are used to measure the $ value/gallon of increased water usage for the change. It's a way of objectively valuing new development and its impact on water supplies. It's probably not perfect, but is something that should be looked at and refined in other places to develop a highly valuable policy tool for ensuring that the most value is obtained from new development when it alters water use patterns.