"The era of relatively inexpensive water is past for our community," Modeer announced when he unveiled the public utility's new water plan, which includes a proposal to recharge treated sewage water at city's Avra Valley facilities before pumping it back up and into your taps.
Chalk it up as another example--along with bulldozed desert, increased traffic and higher taxes--of how unrestrained growth continues to erode our quality of life.
Exactly how much water bills will increase has yet to be determined. The new plan--developed during the last two years--lays out a variety of options for the City Council to consider. But no matter which route the city takes, costs are guaranteed to rise, and quality is sure to sink, says Modeer.
Using projections developed by the Pima Association of Governments, Tucson Water anticipates serving somewhere around 1.3 million customers by 2050. Most of that growth will come on the city's southeast side, in the so-called 1,083-square-mile Southlands area, where city officials foresee a quarter of million residents in the next quarter-century.
Assuming those new customers use the average 177 gallons per day that current residents do, the city will need to be delivering 253,000 acre-feet of water annually. Since the city expects to have access to only 144,000 acre feet of CAP water every year, that leaves a shortfall of somewhere around 109,000 acre-feet, says Modeer.
To make up some of that, officials hope to change state law so they can continue to indefinitely pump between 45,000 to 50,000 acre-feet of groundwater annually, which is roughly the amount recharged in the Tucson basin through natural recharge.
The gap would be closed by recharging effluent for future use, which would require the construction of a new plant to treat effluent before adding the water to the CAP recharge basins.
Without the use of effluent, Modeer estimates that a shortfall in sustainable supply could occur as soon as 2020.
As use of CAP water increases, so will the mineral content in Tucson's water supply, making the water harder. Currently, as CAP water is blended with groundwater, the average concentration of total dissolved solids, or TDS, that customers receive is about 280 milligrams per liter. As less groundwater is used in the mix, the TDS concentration is likely to rise close to CAP water's level of 650 milligrams per liter.
The increased hardness will decrease the life of appliances such as hot-water heaters and increase scaling on swamp coolers, as well as affect the taste of tap water. In Tucson Water's "At the Tap" survey, customers preferred a blend of water with a TDS of less than 450 milligrams per liter.
Modeer estimates the proposal will mean the cost of running Tucson Water will increase by 66 percent. His staff has yet to calculate how much of that increase will be passed on to customers, because the utility is also recommending the city adopt a water impact fee that will place a portion of the bill on new development.
The proposal is not yet a done deal. Tucson Water officials offer a number of alternatives that they will present to the public during the next nine months before asking the council to approve a final plan.
The city could, for example, work out a deal with Native American tribes to purchase a portion of their CAP allotment. But such a plan would probably prove to be more expensive and less reliable than recharging the effluent.
"There's no cheap water out there," Modeer says.
The controversy over whether the city will agree to serve developments that refuse to agree to annexation remains unresolved.
That issue floated to the surface earlier this year when developers complained that city officials were refusing to provide water service unless they signed agreements that stripped future residents of the right to refuse future annexation efforts by the city.
The Tucson City Council voted unanimously earlier this year to revisit the annexation issue after reviewing the city's new water plan.