End Mandate for Century-Long Water Supply Demand

Arizona Considers Scrapping 100-Year Water Supply Rule for Developers

Arizona’s Senate president, Senator Warren Petersen, aims to remove the requirement for residential developers in urban areas to prove a 100-year water supply availability. Petersen, a Republican from Gilbert, finds the 100-year rule “arbitrary” and seeks a more relaxed alternative.

Petersen’s criticism comes in the wake of the Arizona Department of Water Resources (ADWR) declaring unwillingness to permit new subdivisions in parts of Phoenix, due to groundwater modeling data revealing inadequate water for the 100-year supply. This move led to national headlines portraying Arizona as a state running out of water, a narrative Petersen attributes to ADWR.

Petersen argues the 100-year requirement, central to Arizona’s 1980 Groundwater Management Act, has been randomly picked. He highlights that the state with the second-highest requirement, California, mandates a 25-year supply, and suggests a more reasonable figure would far exceed any national precedent.

“Frightening to me”

Kathleen Ferris, the main contributor to the 1980 Groundwater Act, expressed concern over Petersen’s proposal. She believes the 100-year rule is not arbitrary but deeply ingrained in Arizona’s history and state law due to past land frauds and water supply issues. She maintains the requirement is vital until Arizona determines an alternative to groundwater-dependent development.

“We have enough”

Petersen disputes the necessity of the 100-year rule, comparing it to absurdly stocking up on a century’s supply of gas or food. He insists that current water supplies, backed by proper modeling and regulation, can support housing development.

However, Ferris contends that cutting the 100-year requirement would be shortsighted. She argues for a longer-term plan, questioning if we plan to just abandon Arizona after a century. She also points out that other states’ practices cannot be directly compared to Arizona’s unique circumstances as a desert state with a history of land fraud.

“Created an image of Arizona”

Petersen’s proposal stems from ADWR’s decision to halt new development around the Phoenix metro area due to a slight water shortage. Petersen argues this decision, based on a mere 4% gap in the 100-year supply, has unfairly stigmatized Arizona as a water-scarce region.

Amid housing affordability crisis

The ADWR’s decision has also frustrated Spencer Kamps, executive director of the Home Builders Association of Central Arizona, considering it neglects homebuilders’ substantial conservation efforts. Kamps argues the decision exacerbates the housing supply and affordability crisis, and proposes changes to the 1980 Groundwater Act, such as recognizing groundwater replenishment. However, he does not support Petersen’s move to eliminate the 100-year rule entirely.

Petersen believes that there are compelling reasons to reconsider the 100-year rule, pointing to homes that have a net zero impact on water as potential game-changers. Ferris agrees that the 100-year rule could be reviewed in the future, but maintains it is essential for the time being until a significant shift to alternative water supplies occurs.