From today's AZ Daily Star, a piece by Tony Davis about Arizona Department of Water Resources (ADWR) recent decision to approve the water supply for a very large new development in the Sierra Vista area. For a little background on water issues in this part of Southeast Arizona check out my previous posts here and here.
Before I take a look at what this decision means I have to point out one erroneous statement from the article. In the 3rd paragraph where it says "the department's decision gave a clear signal that it doesn't agree with the BLM's position opposing this pumping ..." that is not exactly a correct interpretation of what ADWR was saying (just based on what was reported here because ADWR doesn't have the decision posted to their website as of this afternoon, when I last checked). As stated under the reasons cited for the ruling, ADWR simply doesn't have the authority to consider the effect of federal reserved rights on an application for a designation of adequate water supply where the application involves pumping groundwater and the federal reserved rights at issue are for surface water. Arizona law doesn't recognize the connection between surface water and groundwater, except under very narrow circumstances. And the criteria that ADWR can consider in evaluating the application are pretty clearly spelled out in the administrative code. I've never noticed anything in there about compliance with federal law as it pertains to federal reserved water rights.
So as noted, this decision means that ADWR agrees that under Arizona law there is sufficient water in the aquifer in this area to permit the development to go ahead - essentially the people aren't going to run out of water. It says nothing about whether the San Pedro River and the Riparian National Conservation Area are going to run out of water. That is what the Bureau of Land Management is claiming in their challenge to ADWR's decision. And they have a valid legal argument - based on federal law under the Cappaert v. U.S. decision from 1976. But they can't really assert those claims in an administrative setting with ADWR, or at least they aren't going to get much traction with those claims in that forum. They must be (and I'm sure have been) asserted in the General Stream Adjudication and may need to be asserted in federal court to obtain an injunction to stop this development from moving forward.
The Cappaert decision means that federal law does recognize a connection between surface and groundwater and permits the federal government to protect reserved water rights from groundwater pumping outside the area of the federal reservation. It was a case that involved the Devil's Hole National Monument, home to the Devil's Hole pupfish, in western Nevada. There the federal government was able to impose limits on groundwater pumping outside the monument to protect a spring that was the only home for the pupfish. Nevada is a state that does recognize the connection between surface and groundwater and grants rights to both through prior appropriation. That difference shouldn't matter here, though. But what might matter is the fact that at Devil's Hole the connection between the Cappaert's groundwater pumping and impacts to the water level in Devil's Hole were pretty clearly established. In the San Pedro, the impacts from the pumping around Sierra Vista may not be clear for many years, and attributing a portion of that impact to any particular development will be a challenge.
The development being proposed in Sierra Vista is enormous - almost 6,000 homes - and its water demand would greatly exacerbate an already large overdraft of the regional aquifer. It's a near certainty that allowing it to move forward would, at some point, impact the river. The extent of that impact - beyond what will already occur because of pumping in the area - and when it will occur are open to speculation. But if nothing can be done about this development, then at what point will future development be stopped? Does it make a difference if this one large development is stopped but many small developments are allowed to be built? In some ways larger developments are better because it's possible to obtain greater exactions from the developer to mitigate some of the environmental impacts and economies of scale permit better management of water and wastewater for the development - permitting greater use of reclaimed water within the development. It will be interesting to see where this project goes next.