The lift from the river to your tap
Water from the Colorado River at Lake Havasu enters the Central Arizona Project, the roughly 336 mile canal that the Central Arizona Water Conservation District runs to carry water to Phoenix, Tucson, and the farms in between. Over the full run, the water is lifted on the order of nearly 3,000 feet, per the project's own description. Gravity does some of the work on the downhill stretches. The uphill stretches run on pumps, and the pumps run on whatever power the district can buy.
For years, much of that power came from the Navajo Generating Station, the large coal plant near Page that closed in 2019. Since then CAP has bought electricity from a mix of sources, which ties the cost of your water more directly to the price of power than most residents realize. When power is expensive in a July heat wave, moving water is expensive too. That is the link this desk keeps coming back to.
What the lift costs, in watts
At last public report, the Central Arizona Project is the single largest consumer of electricity in Arizona. Its yearly draw runs on the order of a couple of terawatt-hours (a terawatt-hour is a billion kilowatt-hours, roughly what a few hundred thousand Arizona homes use in a year). The exact figure moves with how much water is ordered and how much is pumped into underground storage, so treat any single number you see with caution.
What matters here is the ratio, not the precise count. In a state that lifts so much of its water uphill, saving water saves power and saving power saves water. A gallon not pumped is a watt not spent, and a kilowatt-hour not burned is a little less strain on a grid that already strains when the afternoon hits 115 degrees.
Shade on the canal
Canal-top solar means putting solar panels on racks over open water. The idea claims two payoffs: the panels make power, and the shade cuts evaporation off the canal. In Arizona the most concrete example is the Gila River Indian Community, which has been building canal-top solar on its irrigation system with federal support, described by the community and the Bureau of Reclamation as among the first such projects in the country. Schedules on projects like this slip, so check the dates before you count on them.
SRP and others have looked at similar concepts across the Valley. The honest caveat is cost: covering a canal is more expensive per panel than open desert land, of which Arizona has plenty, so canal solar competes on evaporation savings and on not disturbing new ground, not on raw price. Whether that trade works depends on local water values and the specific canal, which is a real answer even if it is not a tidy one.
Who plans the two systems together
Responsibility for the water-energy link is split across desks. The Arizona Department of Water Resources handles state water planning; the Arizona Corporation Commission regulates APS and the other investor-owned utilities, though not SRP, which answers to its own elected board; the Central Arizona Water Conservation District's elected board sets CAP's water rates and buys its pumping power; and the Bureau of Reclamation operates the Colorado River itself.
That split means the question, what does our water cost in kilowatts and carbon, lands on several agencies at once and sometimes on none of them cleanly. If you want to follow the full loop, you end up reading water filings and power filings side by side. This desk does exactly that, and we will flag when the two actually meet in the same room.
Worth watching this month
1. Reclamation's Colorado River operating projections, the 24 month study, update through the fall, and a deeper Lake Mead shortage tier would raise Arizona's cuts and reshuffle what CAP pumps; this one actually matters.
2. CAWCD board meetings, usually monthly, post power-purchase and rate items worth a quick scan, most of them routine.
3. The Gila River Indian Community canal-top solar schedule is worth a look, but treat any announced in-service date as a target, not a promise.
4. ACC dockets on APS resource planning, the integrated resource plan, show how much new solar and storage is lined up for the summer peak.
5. The close of monsoon season, which officially runs roughly June 15 to September 30, marks the point each year when peak cooling demand and pumping pressure both ease.