The director of the Arizona Department of Water Resources says the state has to stop its denial when it comes to water.
“We’re spoiled by cheap, easily available water and have been for a long time,” Herb Guenther said. “We have a lot of water compared to other Western states. But we need to use it in a sustainable way.”
Otherwise, scarcer supplies could push rates up and create uncertainty about water availability, slowing economic growth, he said.
State lawmakers have adopted water protection laws, but excluded rural areas and allowed changes that let cities and subdivisions drill wells. The Legislature has rejected proposals to better link growth to water availability.
Some rural communities are drilling new wells without knowing how much water is needed or how much remains, and cities and towns are preparing to tap underground reserves set aside for the future.
Surface water from runoff from mountain snows – a renewable resource intended to replace groundwater – cannot meet demands of urban areas away from delivery canals.
An effort to allocate water rights and sift through competing claims in the Gila River system has been in court more than 30 years. The Central Arizona Project took decades to get through the approval and construction process for its 336-mile canal.
The Arizona Legislature in 1980 imposed rules on parts of Maricopa, Pinal, Pima and Santa Cruz counties and the Prescott area, restricting their groundwater use and requiring new homes to prove a 100-year supply of renewable water.
“It wasn’t the answer to all the problems, but it was intended to reduce reliance on groundwater. And it’s doing that,” said Sandra Fabritz, assistant director of the state Water Resources Department.
Communities in the areas rely on water from rivers, such as the Salt and Verde for Maricopa County; Colorado River water delivered through the Central Arizona Project; and a smaller mix of groundwater and treated effluent.
The supply rule forced cities to develop long-term water portfolios, but they’ve also been tapping aquifers.
The Central Arizona Groundwater Replenishment District was meant to help a few outlying communities and subdivisions meet the 100-year rule until pipelines or smaller canals could deliver renewable supplies.
Homes in the district use local groundwater and pay monthly charges to a water utility. Once a year, they also pay a replenishment fee that buys surface water equal to the groundwater used. That water goes into recharge basins.
Terri Sue Rossi, a Central Arizona Project analyst, said the district is a way for infrastructure and water to be paid for by users.
“To figure out how to do that is a major success story,” she said.
As of March 31, nearly 265,000 homes, about a third of which are already built, were eligible to use groundwater through the district.
But before 1995, those homes could not have been built because they would have lacked a renewable water source. And although their builders were required to prove groundwater reserves would last at least 100 years, the wells could lower water tables enough to cause sinkholes or subsidence.
While the district must offset groundwater use with surface water, there’s no requirement to replenish water near the wells. Most recharge basins sit far from developments.
The district “has taken the wind out of the sails of the groundwater management act,” said Robert Glennon, a University of Arizona law professor who has written two books on water management. “It’s clear it was a way to help satellite communities develop, but it really is a bastardization of the law.”
The Legislature established the Arizona Water Banking Authority in 1996, partly to help the state use its allocation from the Colorado River. Water is diverted to recharge basins and percolates into aquifers.
The bank holds about 880 billion gallons. A growing amount belongs to cities, which store excess water for use later. Storage has raised groundwater levels near the recharge basins and refilled aquifers.
However, the water bank operates like a network of ATMs. A customer can deposit water at the main recharge basin, then pump it out closer to home.
Legally, it’s counted as a renewable resource, but the withdrawals will drain local aquifers.
Banked water once was considered mostly for emergencies such as droughts, but cities struggling to meet growing demands have begun counting stored water as part of their 100-year supplies – in effect borrowing against the future.
State officials acknowledge they need to address where banked water can be pumped out since aquifers suffer just like they did before the groundwater act if wells are drilled miles from a recharge basin.
They also acknowledge cities will fail to meet the largest goal of the 1980 laws – that an equal amount of water replenishes water pumped out.
“‘How much water is there?’ is the wrong question,” said Patricia Gober, co-director of Arizona State University’s Decision Center for a Desert City. “We don’t know. More important for us, how do we restructure this place so we don’t have a crisis?”