John Fleck is the science writer for the Albuquerque Journal, who blogs on his paper's website and independently at Inkstain. His post today included a link to a post from his Journal blog back in February (still with me?) that caught my eye. In it he discusses the idea of using water policy to manage growth in the context of New Mexico's efforts to assert regulatory authority over deep, brackish aquifers in the state that have recently seen a flurry of speculative activity, seeking to lock up these water sources to supply future development. Previously, the New Mexico State Engineer (who oversees water rights in NM), had no regulatory authority over deep, brackish aquifers because they weren't considered potential sources of usable water - they were mostly of interest to the oil and gas industry because they are associated to some degree with formations containing valuable deposits in the SE portion of the state. But I digress.
The main point of his post is that, while water scarcity would seem to be a natural constraining factor on growth in places like Albuquerque or Tucson, it does not logically follow that policies for managing the water supply are a useful proxy for managing land use and growth. This is a point frequently made by Sharon Megdal at the Water Resources Research Center at the Univ. of Arizona and I usually agree with her, because she's much smarter than me. But if you think about it, it does make sense. Land use policy should be used to manage land use decision-making, while water policies should be used to manage water supply decision-making. The problem is - these two issues need to be considered together, as part of an overall plan for managing and ensuring sustainable growth policies. This means that water policies need to take into account the water supplies reliably available and what sort of growth they can accommodate, while land use policies need to take into account the availability of water supplies and infrastructure and what effect growth of a certain type, in a certain place will have on water supply availability in the future.
An important aspect of this (because of the way laws relating to property development are structured) is that water supply issues related to development have to be considered very early in the process of development approval, because once a developer reaches a certain point, vested rights to develop the property accrue, meaning there may be no turning back (see my earlier post here). In the past, decisions about land use (zoning, planned developments, etc.) were made without considering their impact on available water supplies. It was just assumed that water would be found to support the development when the time came. This has begun to change recently and Tucson and Pima County have actually made some pretty good strides in this area. These are pretty new policies and ordinances around here and there is very little development occurring at the moment, so it remains to be seen how effective they will be and (more importantly) what sort of unintended consequences they may have. It may also be necessary to make changes at the state level for this to really be effective. But as tools for land use planning (comprehensive plans and the like) become increasingly more sophisticated (as seen here) this idea will become much more prominent.