Salt River Project began sending about 20,000 cubic feet of water per second out of Bartlett and Stewart Mountain dams on Sunday, and roads that cross the normally dry Salt River bed in the East and West Valley are closing as that water moves through the metro.
The utility said the releases are needed to keep enough room in its reservoirs for safety after near-record runoff this fall. It expects October and November inflows on the Verde River to be the highest since 1972, roughly eight times the average, following three straight dry seasons.
"Water releases are one of the most important tools SRP uses to safely manage the reservoir system," Tim Skarupa, SRP's senior manager of atmospheric sciences and hydrology, said in the utility's announcement. The water will pass over Granite Reef Diversion Dam and down the riverbed, where SRP said it will also recharge the aquifer.
Cities and irrigation districts on the SRP system can take some of the extra water.
SRP did not list the individual crossings. It pointed drivers to AZ 511 for current closures and asked them to obey road signs, which matters for anyone heading toward Mesa, Tempe or the West Valley on Monday morning.
Upstream, the creek leaves its banks
Farther east, the creek that shares the town's name had its own bad day. Boyce Thompson Arboretum near Superior recorded 2.62 inches of rain by 1 p.m. Sunday, and Queen Creek, which runs through the garden's southwest side, rose over its banks around 11 a.m., the arboretum said. The Silver King Wash, which feeds the creek, was also at flood stage.
Water reached the Demonstration Garden, the picnic area and the Australian Pavilion. The arboretum closed for the rest of Sunday and plans to open Monday, Nov. 2, with the Wallace Garden, the Demonstration Garden and parts of the Australian Garden roped off for cleanup. Executive Director Kim Gray called the past 24 hours of rain "historic" and said staff would assess damage in the morning.
Downstream of the arboretum, Pinal County officials told residents of western Queen Valley to leave their homes Sunday because of flooding, according to Arizona's Family, which reported that a shelter was set up at the Old Texaco, 21880 E. U.S. 60, at Florence Junction.
The National Weather Service issued flash flood warnings for Queen Valley on Sunday morning, then flood warnings into the afternoon covering Superior, the arboretum, Queen Valley and Florence Junction.
