Tucson-area examples of requiring water harvesting as a rezoning condition: http://wrrc.arizona.edu/sites/wrrc.arizona.edu/files/PC_Regional%20Comp%20Plan%20Policy%20Major%20Plan%20Amendment.pdf (especially pages 4-6) http://wrrc.arizona.edu/sites/wrrc.arizona.edu/files/COT_Brown%20Family%20Partnership%20rezoning.pdf (especially page 4)