June 12, 1980 — The Arizona Groundwater Management Act | Scottsdale History

What happened

After a 1976 Arizona Supreme Court decision on groundwater transport triggered a study commission, and after Interior Secretary Cecil Andrus — privately urged on by Governor Bruce Babbitt — threatened to withhold Central Arizona Project funding unless Arizona reformed its groundwater law, the Legislature passed a 200-page bill unamended in a seven-hour special session. Babbitt signed the Groundwater Management Act on June 12, 1980. It created the Arizona Department of Water Resources and four Active Management Areas, including the Phoenix AMA that contains Scottsdale, with a goal of 'safe yield' by 2025.

Why it matters

Before 1980 Scottsdale drank groundwater and almost nothing else. The Act's Assured Water Supply rules (in force from 1995) required every new subdivision to prove a hundred-year supply, which sent the city to the Colorado River through the CAP plant of 1987, to the Water Campus of 1998 with its reverse-osmosis plant and recharge wells, and to safe yield in 2006, nineteen years early. Groundwater is now under ten percent of the city's supply. The Act is also why Rio Verde Foothills, outside any provider, was cut off in 2023.

The threat

Arizona in 1980 was mining its aquifers. Farms and cities pumped far more than the rains put back, the water table under the Valley was dropping, and the law treated groundwater as the property of whoever owned the land above it. A 1976 Arizona Supreme Court decision on moving groundwater from one basin to another had set off a study commission, and the commission had produced a bill so contentious that nobody expected it to pass — until the federal government made it a condition of the Central Arizona Project. Interior Secretary Cecil Andrus told the state that the CAP, the $4-billion canal that would carry Colorado River water across north Scottsdale to the Valley, would not be finished without groundwater reform. It later emerged that Governor Bruce Babbitt had privately asked him to say so. “The whole structure was ready to collapse,” Babbitt recalled.

On June 12, 1980, after the Legislature passed the 200-page bill unamended in a special session lasting seven hours, Babbitt signed the Groundwater Management Act.

What it did

The Act created the Arizona Department of Water Resources and drew four Active Management Areas around the state’s most overdrawn basins — Phoenix, Tucson, Pinal and Prescott — with the Phoenix AMA, Scottsdale inside it, given a goal of safe yield by 2025: no more pumping than recharge. New wells were regulated, water duties were set for farms, and, most consequentially for a city that would double in the next decade, the Assured Water Supply rules that took effect in 1995 required every new subdivision to prove a hundred-year supply before it could sell a lot.

What it did to Scottsdale

Scottsdale answered by leaving the aquifer. Its CAP water treatment plant opened in 1987, the year after Colorado River water reached the Valley; its 1995 CAP exchanges added 17,800 acre-feet; the Water Campus of 1998 in the far north added a reverse-osmosis plant, aquifer recharge wells and reclaimed water for the golf courses; and in 2006 the city reached safe yield for its service area, nineteen years ahead of the deadline. Groundwater fell from all of Scottsdale’s supply to under ten percent, and in 2014 the city put more than 29,000 acre-feet back into the ground.

The Act’s other legacy is the line it drew around the people outside any provider. The Rio Verde Foothills, unincorporated county land northeast of the city, had no assured supply and hauled water from a Scottsdale standpipe until the city, citing the Colorado River shortages, closed it on January 1, 2023. The water guide explains the portfolio the Act produced; the 1980s chapter has the decade the city spent building it.