Groundwater is water that fills the spaces within and between soil particles and rock formations underground. It is primarily withdrawn through wells that pump groundwater from below the water table. Throughout most of Arizona, only about 2.5% of precipitation converts to groundwater. In many parts of the state, groundwater withdrawals exceed the natural rate of recharge.
The Colorado River Basin is experiencing diminished flows in its rivers and streams. This story map explains how satellite data can measure changes in total water storage, a new and efficient means of measuring groundwater changes.
Learn how to use the interactive map of groundwater level changes throughout Arizona's 51 basins.
Learn more about the "groundwater hotspots" within Arizona where there are significant concerns around underreported shrinking groundwater supplies.
Within Arizona's Active Management Areas (areas in which groundwater use is highly regulated) there is a cap and trade system for groundwater, and cities, Tribes and other entities can accrue and exchange long term storage credits for water that is stored in underground aquifers. This report explains how these credits are accrued and accounted for and how they have become an integral tool for water providers. It includes a dashboard of long term storage credit accounts in Arizona.
Learn the story of Arizona’s water, past and present: where it comes from, how it’s used and what challenges lie ahead.
To ensure long-term supplies, Arizona has imposed limitations on future housing developments in the Greater Phoenix area that rely on local groundwater. This report explains these limitations and explores whether and how these limits will impact housing affordability.
Four of Arizona's Active Mangagement Areas (AMAs) have a goal of "safe-yield" -- a long-term balance between groundwater withdrawals and recharge. And yet four decades after that goal was adopted there is little expectation that any AMA will achieve safe yield over the long-term. This critical analysis examines the barriers to achieving safe-yield and offers recommendations for strengthening groundwater management in the AMAs.
The Central Arizona Groundwater Replenishment District (CAGRD) was created to enable groundwater-reliant urban growth in areas that lacked access to renewable supplies. This critical analysis examines how CAGRD has shaped urban growth and water policy over the past 25 years, outlining reforms to strengthen the state's water future amidst CAGRD's long-term sustainability challenges.
Arizona's 2023 groundwater model for the Phoenix AMA concluded that the region had reached the limits of physically available groundwater. This report explains the implications of that finding and what it means for continued development.
For over three decades, rigorous groundwater management combined with regulations requiring renewable water supplies for growth have helped ensure water resilience for Greater Phoenix. As the region confronts new water supply challenges, continuing groundwater protection may require changes to the rules for managing groundwater in the Phoenix Active Management Area.