The Allocation - Bryce Cristiano

Bryce Cristiano

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The Allocation<br>Phoenix isn't running out of water. It's running out of cheap water, and the cost is landing at the edge of the city

Bryce Cristiano<br>Jun 09, 2026

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This is the eighth essay in The Heat Ledger, a series about the physical systems Phoenix negotiates every day.

From behind the falls at Arizona Falls. Photo by the author.<br>Stand on the footbridge at Arizona Falls and the first thing is the sound.<br>Twenty feet of water going over a ledge, in a desert, in a city that catches eight inches of rain in a good year. The cool lifts off it even in July. You feel it before you decide to. Below, the canal runs flat and green-brown toward the next bridge, toward Indian School, where the cars do not slow down.<br>The falls look like they have always been here. They have not, and they are not natural. They are an accident of excavation. In the 1880s, crews digging the Arizona Canal hit a ledge of hard rock, a stubborn drop in the desert floor, and instead of blasting it level, they let the water fall.<br>The accident became a place. People came to picnic, to swim, to dance. A cool spot, back when coolness was something you went outside to find.<br>Phoenix stopped needing the falls the same way it stopped needing to think about where the water comes from.

The water in the canal is not “Phoenix water” in the simple local sense. And it is mostly not Colorado River water either.<br>For the City of Phoenix (the political city, plus about half of Paradise Valley), the tap water breaks down like this: roughly 60 percent originates as Salt and Verde River water, delivered through the Salt River Project. A little under 40 percent originates as Colorado River water. A very small amount is groundwater, pumped from local wells. That is the portfolio. The number that gets cited in most coverage (41 percent groundwater, 36 percent Colorado, the rest split) is the statewide figure, the whole of Arizona averaged together. It is not Phoenix. Phoenix is its own arrangement, and the arrangement is unusual.<br>Kathryn Sorensen ran Phoenix Water Services from 2013 to 2021, the utility that delivers tap water to well over a million people. She now directs research at the Kyl Center for Water Policy at ASU’s Morrison Institute. If Phoenix were running out of water, she is the person who would have known first. She put the spine of it plainly: the snowpack in central and eastern Arizona (the Mogollon Rim, the White Mountains) is what comes out of the tap in Phoenix. The Salt and the Verde, fed by that snow, are the river the city actually drinks. The Colorado is the supplement. Real, necessary, but not the center.<br>This runs against almost everything written about Phoenix from a distance. The national story points at the Colorado: at Lake Mead’s white bathtub ring, at the apocalyptic frame in which Phoenix is the city about to go dry. The frame is not invented. The Colorado is in trouble. But the camera is pointed at the supplement, not the spine.

The water is here because someone fought for it early, and the falls are where you can see the fighting start.

The Arizona Falls hydroelectric plant on the Arizona Canal, early 1900s. Photograph by Walter J. Lubken, U.S. Reclamation Service. Salt River Project / Arizona Memory Project; public domain.<br>Over the winter of 1901, Phoenix Light and Fuel Company built a hydroelectric plant at the falls. The company promised it would have “no equal between St. Louis and Los Angeles.” The Salt River Project rebuilt and took it over in 1913, and it ran until 1950. Then the site faded, not because the water left, but because the city’s cool places moved indoors. A power plant and one of the city’s earliest places to take a date both existed because nobody wanted to dynamite a rock.<br>A year after the plant, in 1903, valley farmers put their land up as collateral to the federal government to build a dam on the Salt River. They had been living at the mercy of the river, flooded out one year, dry the next. Pledging their land to finance Roosevelt Dam was the seed of the Salt River Project. The water security Phoenix now takes for granted began as a group of farmers betting everything they owned that engineering could outlast weather.<br>Then comes the part most people never learn, the part that makes Phoenix strange.<br>The Salt River system runs on prior appropriation, where the water belongs to the land. You cannot move it. And as the valley urbanized, as the cotton and alfalfa fields became subdivisions, something counterintuitive happened. It takes roughly six acre-feet of water a year to farm an acre of cotton in this sun. It takes about one to run a subdivision on the same acre. So as the farms became houses, total water use fell. But because the water belongs to the land, the “saved” water could not be picked up and sold to new development somewhere else. It stayed in the system. It sat in the reservoirs.<br>Sorensen called it a demand-capped,...