Paul's Note - August 13, 2021

For years, the alarm has been sounding about water levels in Lake Mead. Well, the water level is now low enough to trigger a Tier 1 shortage. 

Those of you who don’t follow water issues might be asking what water levels nearly 400 miles away has to do with water users here in Tucson. The answer is that the water level in Lake Mead is used to determine what’s available for users such as farmers and cities that are entitled to allocations like Phoenix and Tucson. 

The Colorado River is chiefly filled by snowmelt in the Rocky Mountains. The same drought conditions (exacerbated by climate change) that have affected us in Southern Arizona are happening in the Rockies. The level of those snowpacks we depend on have been dropping since 2000.  

The results have been seen in Lake Mead, where the water level has dropped 60% during that time. A “Tier” system was established: drops to certain levels mean that some users get their allocations reduced or eliminated. The level has gone down to 1075 feet, putting us at a Tier 1 shortage. That means that early next year agricultural users in Pinal County will see their allocation cut by 65%. 

The City of Tucson will not see a reduction in our allocation this year (140,000 acre feet). Municipal users as well as tribes won’t get cut until the later tiers (although we could reach 1050 feet, tier 2, as soon as 2023). Still, our water is part of an integrated system. As part of an agreement with the state, Tucson will be supplying 5000 acre feet of water to agricultural users in Pinal County (the biggest of which are industrial farms growing crops for export) from water we have banked. We also are helping them with groundwater infrastructure, chiefly wells. 

Additionally, there are hundreds of millions of dollars in fixed costs. For example, there are items like maintenance of the canals and pumps. There is also the power bill. The CAP delivers water 336 miles, mostly up hill. Those power costs remain largely the same (it’s the largest single user of electricity in the state) regardless if the CAP stops delivering to some users along the way. As customers lose their allocations and are no longer paying into that bill, those costs are borne by other users, namely municipalities like Tucson. I asked Tucson Water at the council meeting on Tuesday how much our increased costs will be for this year’s allotment of Colorado River water. They estimate $3 million. 

At the presentation at the Council meeting, Tucson Water addressed how water could be delivered to customers should Colorado River water not be available. They said five years before we hit overdraft, the level where we are pumping more than is being replenished. By the way, that’s ground water that we have recently discovered is contaminated with a substance called PFAS. 

I hope that this doesn’t come off as too dire. I grew up here and in my time, Tucson has developed a great conservation ethic. We don’t have lawns covering every acre of our front yards like in other cities. We’ve developed some policies to encourage use of rainwater and grey water that I’ve been proud of. Still, we need to get ready for some tough times to come and there is more that needs to be done.