It seems every few weeks, there is a news report that suggests that global warming will result in drying up the Colorado River and the Salt River and that the Valley of the Sun’s entire water supply will disappear. Such alarmist news might make you want to sell the house, grab the kids, and move to the Pacific Northwest.
As president of the board of the Central Arizona Water Conservation District, I want to calm your fears. We have a very different perspective. We are planning for your water future to ensure there is enough water for today’s population and its continued growth, as long as we use our water wisely.
The CAWCD is the manager of the Central Arizona Project that annually delivers about 1.5 million acre feet of water from the Colorado River to Arizona users. Currently, we are storing about one-third of that water supply in our vast underground aquifers. We use the remaining amount to supplement the other supplies from the Salt River system, groundwater and effluent reuse.
As Arizona grows, we will use more and bank less, with the potential of tapping into our banked supply to carry us through dry periods.
The seven states that share the Colorado River understand that the water from the Colorado is over allocated. Fortunately, many of the upper basin states are not using their full allocations, so that water gets captured and stored in Lake Powell and Lake Mead. These two large reservoirs can store almost four years of Colorado River runoff and provide a cushion for dry periods.
Water managers in these seven states and the United States Bureau of Reclamation work together to determine how best to manage the river so that each state can expect to receive its allotted share.
Water managers and policy makers such as the CAP board are well aware of the climate change studies. Most studies indicate that total precipitation in the Colorado Basin will decrease. These studies, however, point out that there will be less snow and more rain. Runoff from rain actually goes into the rivers and streams faster than snow melt. So, with the large reservoir storage system in the Colorado River, it really doesn’t matter how and when the water gets there. Either way the water is captured and stored for future use.
All of the seven states are working on programs to enhance and augment the water supply. The CAP is very much a part of Arizona’s participation in these programs. From cloud seeding, to new storage arrangements, to nonnative plant removal, we are aggressively working to insure that we are operating our reservoir system more efficiently and that we have active water conservation programs.
New supplies will be developed. Ocean water is being desalted and used as a potable water supply worldwide. Here in Arizona we are actively working with Mexico to consider joint projects along the Sea of Cortez in Mexico that could add water to the Colorado River system through an exchange.
So, no need to list the house for sale or to pack up the kids and move. While water managers can’t predict the weather or global climate change any better than scientists, we are planning for both growth and a wide range of climatic variability. If we continue to use our water wisely, there will be enough for all of us and for generations to come.
Susan Bitter Smith is President of the Central Arizona Water Conservation District Board that oversees operations of the Central Arizona Project.