Arizona's ag-to-urban water swap saves resources | Opinion

Arizona's Ag-to-Urban Program: A New Approach to Water Conservation

Arizona has managed to use less water today than it did in the 1950s, even though its population has grown significantly—from about a million people to 7.5 million. This reduction in water usage is largely due to the fact that municipal uses typically consume three to six times less water compared to agricultural practices. Over time, Central and southern Arizona have supported growing populations by shifting from farming to more efficient municipal water uses.

However, this trend changed in 2023 when Governor Katie Hobbs and the Arizona Department of Water Resources (ADWR) decided that no new Assured Water Supply determinations could be approved in much of Maricopa County if they relied on groundwater. This decision immediately halted new growth on farmland, forcing landowners to continue pumping fossil groundwater to sustain their crops.

Introducing the Ag-to-Urban Program

To address these challenges, the Arizona Legislature passed and the governor signed Senate Bill 1611, which marks one of the most significant changes to groundwater management since the Groundwater Management Act of 1980. The bill introduced an ag-to-urban program designed to reverse the disincentive for retiring farmland while offering voluntary incentives to convert that land into highly water-efficient homes.

This program allows the use of fossil groundwater for growing alfalfa and cotton to be replaced by municipal uses that consume far less water, recycle most of their water, and bring in alternative water supplies to replenish aquifers. ADWR estimates that the ag-to-urban program could save nearly 10 million acre-feet of water over its lifetime.

Requirements for Participation

For a subdivision to participate in the ag-to-urban program, its projected water demand must meet a strictly limited "conversion rate." This means the volume of groundwater available if an acre of irrigated land is retired. To achieve this, new developments must follow high water efficiency standards both indoors and outdoors.

Additionally, the program prohibits cities and homeowner associations from requiring minimum amounts of grass or using water for non-functional turf or water features in common areas. These measures are expected to set new development standards and promote an ethic of desert living that will become the norm for all new homes and subdivisions.

Guardrails to Protect CAGRD

Since the 1990s, many new subdivisions relying on groundwater have been required to replenish the same volume of groundwater they pump using alternative water supplies such as effluent or Central Arizona Project water. The Central Arizona Groundwater Replenishment District (CAGRD) was created to implement this program.

Critics of the ag-to-urban program argue that an incentive to build more houses could increase CAGRD’s replenishment obligations. Given the impending reductions in Colorado River supplies and political opposition to importing or transferring water to central Arizona, these concerns are not unfounded.

Balancing Growth and Conservation

Despite these concerns, the ag-to-urban program includes several guardrails to limit its impact on CAGRD. These include:

• A time limit on the program, which serves as a cap on the amount of land that can be converted and the volume of water that will need to be replenished.
• Strict eligibility criteria, ensuring only actively irrigated farmland can be retired. Land must have been irrigated in three of the last five years to qualify.
• Narrowly tailored withdrawal and use limits, so that new groundwater withdrawals and uses remain near the farmland. Landowners must demonstrate that pumping for the new use will not exceed the depth limit for the applicable active management area over 100 years using the Department of Water Resources’ most recent model projections.

A Win-Win for Arizona

The ag-to-urban program represents a balanced approach to responsible urban growth. Housing projects that were previously stalled due to the Assured Water Supply moratorium can now develop in a way that conserves groundwater and provides economic benefits.

After two years of negotiation and compromise, Arizonans came together to enact good water policy. While everyone had to give up a little bit, the result is a sustainable solution that benefits the state's future.