Payson residents last year used only about 60 percent of the water that seeped into its water table as per-person use dropped sharply.
Unfortunately, low water use averages probably reflected the impact of the recession and the plague of empty houses as much as residents’ thrifty water habits, according to the water department’s 2011 water status report.
The report headlines the Thursday night council meeting at 5:30 in the Payson Town Hall council chambers.
Payson in 2010 made big strides toward ensuring delivery of up to 3,500 acre-feet of Blue Ridge Reservoir water starting in 2015, the report concludes.
As a result, Payson by 2015 would have enough water to support a peak population of about 45,000, one of the few cities in Arizona with an assured long-term water supply.
“The town will have achieved its goal of long-term water supply sustainability, with a build-out population of 38,000 to 45,000. This fact is a rare occurrence in the desert Southwest and something for the community to be proud of,” the report concludes.
Average, per-person use declined last year to 79 gallons per day, less than half the per-person average in Phoenix and well below the town’s target of 89 gallons per day.
However, the water department report credited the downturn and the host of empty houses for much of the decline in average per capita use.
“It is believed that the economic downturn is responsible for the last few years of relatively ‘flat’ water consumption trends. This can be explained by increases in unoccupied houses and businesses and potentially fewer visitors and part-time residents staying in Payson in 2010.”
The watershed in 2010 got 19 inches of rain — about 14 percent less than normal. However, low per-capita use meant well levels remained stable.
As a result, the water department will leave the water conservation level at normal levels. That means residents still can’t hose down driveways and must water their landscaping on certain days of the week, but avoids the stringent limits and fines possible at higher water conservation levels reserved for droughts when well levels are falling.
The report concludes that on a long-term basis, 2,781 acre-feet of rain and snow each year seep into the underground water table from which the town’s network of 100 wells draws residents’ drinking water.
Last year, residents used just 1,620 acre-feet — about 60 percent of the “safe yield” of the watershed.
Back in 2005 when fears of a water shortage prompted Payson to adopt the state’s toughest growth restrictions, the town was using 93 percent of its “safe yield.”
But there’s less to that statistic than meets the eye.
In fact, Payson’s average annual water use has barely budged since 2000 as the town’s population first swelled and then declined. The census showed Payson’s population grew by 12 percent between 2000 and 2010.
However, in 2006 Payson acquired rights to the Tower Well in Star Valley, through a complicated swap of development credits for the well. The acquisition of that well increased the town’s watershed dramatically and increased the “safe yield” so much that the percentage use went from 93 percent to 63 percent with little change in total water consumption.
That calculation also stimulated the incorporation of neighboring Star Valley, where residents feared Payson would someday export much of their underground water.
The acquisition of up to 3,000 acre-feet from the Blue Ridge Reservoir dramatically altered the once contentious water politics in the region. The pipeline will also carry 500 acre-feet reserved for other northern Gila County communities, if they can strike a deal with SRP and chip in to the cost of operating the pipeline.
In its negotiations with the Salt River Project, Payson agreed to limit its groundwater pumping to 2,520 acre-feet annually as a condition of getting Blue Ridge water from the reservoir atop the Rim owned by SRP. That’s nearly 20 percent less than the average “safe yield” of the watershed.
However, the Blue Ridge water when combined with the safe yield of the town’s wells will give it a long-term, sustained water supply of 5,500 acre-feet.
The report estimated that even if the town tops out at 45,000 residents by 2050, it will need 4,000 acre-feet annually but have an assured supply of 5,500 acre-feet annually to serve as a cushion against drought.