The Town of Oro Valley will add 500 acre-feet of Central Arizona Project (CAP) water to its potable water system after the completion of a blending facility at Calle Buena Vista, near Hardy Road.
Water Utility Director Philip Saletta said at $332,000, the facility was relatively inexpensive to complete since it didn’t involve the installation of a significant amount of pipeline to connect into the Tucson water system, which provides the town with its CAP water.
The installation also included valves to control pressure and flow, a flow meter, a solar panel for power, and a security wall.
The process of water blending is becoming more common these days, and as explained by Saletta, “is accomplished through a simple, in-line device called a static mixer. It is a three-foot length of pipe that has baffles, so the water from our well and the Tucson Water system is evenly mixed as they enter the pipeline in the water distribution system. This is done to maintain consistent water quality for our customers.”
Blending CAP water with groundwater will also reduce the town’s groundwater pumping, meeting the town’s goal to pump only 5,500 acre feet of groundwater each year. That is significantly less than in years past, such as in 2005 when the town was pumping more than 10,000 acre feet. Last year, the town pumped 6,000 acre-feet of groundwater.
The blending facility will help the town not only now, but looking ahead, Saletta said.
“Projects such as this protect and preserve the groundwater in our big aquifer,” he said. “This is a current benefit for our community and customers. It also puts us in a good position with a diverse and reliable water supply for the future.”
There will not be a change in water rates for Oro Valley customers, since the costs were already figured into existing rates to pay for the capital expenses of the project, Saletta said, adding that changes to delivery routes will be very minor, but will actually provide better system reliability.
Currently, 42 percent of Oro Valley’s water supply comes from renewable water resources – 22 percent of which comes from reclaimed water from irrigation of golf courses and athletic fields, and 20 percent of which comes from CAP water. The remaining 58 percent of the town’s water comes from groundwater pumped from wells.
The addition of 500 acre-feet will bring the town’s total annual CAP water supply from 1,500 acre-feet per year to 2,000 acre-feet per year.