PHOENIX — After six weeks of having parts of the Central Arizona Project canal being dry in order to do $6 million in repairs, Colorado River water will be flowing again this week.
The Arizona Republic reports that repairs were done to the canal where it tunnels beneath the Salt River in north Mesa.
Water was still delivered to customers west of that point, but about 75% of CAP water is normally delivered beyond there.
Several cities, tribes and irrigation districts rely on CAP water deliveries to supplement water supplies they get from the Salt and Verde rivers and from groundwater pumping.
CAP general manager Ted Cook told the newspaper that plans for the repairs took about three years so that all of the customers who would have to go without Colorado River water for the duration could prepare.
The repairs were needed to the 1.6-mile-long tunnel, or siphon, where the CAP water uses a 21-foot diameter steel tunnel deep below the Salt River.
The inside of the pipe needed recoating to protect against rust, officials said. The last such repairs were made almost a decade ago.
It is one of 10 siphons on the CAP that carries water under natural waterways including the Agua Fria, New, Gila and Santa Cruz rivers.
Once CAP water emerges from the siphon under the Salt River, it arrives at a pumping station where it is lifted 75 feet uphill, and the canal heads south toward Pinal County and beyond.
The CAP lifts water about 2,900 feet on its 336-mile journey from the Colorado River to its endpoint south of Tucson with 14 pumping stations.
Until recently, the CAP got much of the power to run those pumps from the Navajo Generating Station coal plant near Page.
With that plant’s closure last month, Cook said the CAP has relied on a variety of natural-gas plant contracts and market purchases.