Areas with heavy reliance on groundwater were identified and designated as Active Management Areas (AMAs). The AMAs were established to provide long-term management and conservation of their limited groundwater supplies. Within AMAs, the Arizona Department of Water Resources administers state laws, develops and implements groundwater management plans, explores ways of augmenting water supplies to meet future needs, and works to develop public policy in order to promote efficient use and an equitable allocation of available water supplies. Statutory management goals for each AMA guide the policies for managing water in these areas. Outside of AMAs, groundwater rights in Arizona are generally tied to ownership of the overlying surface land, meaning they cannot be bought or sold separately from the land. Learn more.

The 1980 Groundwater Management Act includes provisions to help prevent this scenario. Under the Act, there are two kinds of areas in which groundwater is regulated:

1. Irrigation Non-Expansion Areas (INAs) – wells larger than small residential wells are metered, and their groundwater use is reported annually. In addition, there is a prohibition on new irrigated agriculture (defined as two or more acres). 
2. Active Management Areas (AMAs) – metering and reporting of groundwater use; prohibition on new irrigated agriculture; developments of six or more homes cannot be platted without proof of a 100-year supply of water that is physically, financially, and legally available. Every ten years, ADWR develops a new management plan for each AMA, with increasingly rigorous conservation and efficiency requirements for all sectors. Agriculture tends to be the biggest water-using sector, and since 1980, new irrigated agriculture has been prohibited within the AMAs and Irrigation Non-Expansion Areas. (No such prohibition is in place outside the AMAs and INAs, which is why some parts of the state have seen an influx of industrial-scale, groundwater-dependent agriculture.) Farms with grandfathered wells are permitted to pump groundwater to irrigate their crops. Energy costs to pump groundwater are a consideration for farmers, particularly as the water table falls and more energy is required to pump it for use. At some point, the energy costs may render some types of irrigated agriculture unprofitable.

Usually, if municipal water is available it is much less expensive and far more reliable than water from an individual private well. Outside AMAs and INAs, there is virtually no regulation on the amount of water a well owner can pump.

Groundwater is water found under the surface of the earth between the pores and fractures of sand, gravel, and rock known as aquifers. We have access to a large groundwater resource and a large aquifer under the Phoenix region, and there are groundwater basins across the state of Arizona. Groundwater needs to be carefully managed because it is largely non-renewable on a human-time scale. Surface water from rivers is renewed by rain and snow, unlike groundwater, which is withdrawn much faster than it is replenished in Arizona. It can take decades, hundreds, or even thousands of years to replenish to the level that we have now. It's important to carefully manage it and look out over 100 years to ensure that groundwater is sustainable over that period. To explore changes in groundwater levels throughout Arizona, use the Arizona Water Blueprint tool created by the Kyl Center for Water Policy, one of the pillars of the Arizona Water Innovation Initiative.