After a staggering journey across continents and through time, the 2,000-pound, stainless steel water wheel now spins furiously in its housing at the head of the East Verde River.
As a result, Rim Country visitors could frolic in a clear, cool East Verde River babbling along at several times its normal flow despite the past three rainless months.
The Pelton Wheel sitting at Washington Park generates a steady hum of power from Blue Ridge Reservoir water blasting through a long pipeline that ends at the head of the otherwise fitful, spring-fed East Verde.
The successful restoration of the Blue Ridge pipeline and generator to full design flows represents the latest victory in a good year for Salt River Project, which lays claim to the surface water flows throughout Rim Country to funnel water to its reservoirs on the Salt and Verde Rivers.
SRP’s Salt River reservoirs remain at more than 94-percent capacity, despite a bone-dry spring. Near-record rain and snowfall in January contributed to 1.4 million acre-feet of runoff — the 20th best year in 107 years of record keeping.
For Payson, the best news lies in the performance of the refurbished Blue Ridge system, for which the town footed about 27 percent of the repair bill. The Pelton Wheel alone represents one of the most impressive feats of engineering in a custom-designed system for moving water from a deep, astonishingly productive reservoir atop the Mogollon Rim all the way down to Payson.
The 75 square miles of steep, forested terrain that drains into the Blue Ridge Reservoir produces about 14,000 acre-feet of runoff in a normal year — the most productive reservoir for its size in the state. The ability of that watershed to capture storms before they can escape the mountains means that even when drought drains other lakes in the region, Blue Ridge has historically remained full.
The key to getting the water out of that deep reservoir is the precisely cast and polished wheel. It generates all the power needed to pump the water up out of the deep, narrow Blue Ridge Reservoir and into a newly refurbished pipeline that winds through the forest, sluices down the Rim and delivers some 11,000 acre-feet annually to the 3,000 horsepower electrical generating plant where Payson will eventually hook up its own, $30-million pipeline.
The wheel is a manufactured duplicate of a wheel constructed 20 years ago, but cracked in the course of its decades of spinning 12 times a second.
The Salt River Project acquired the one-of-a-kind Blue Ridge system in a water swap with the mining giant Phelps Dodge. SRP has spent the past two years bringing it up to the standards necessary for the pipeline to deliver 3,000 acre-feet of drinking water annually to Payson. The town’s future development plan now depends on the doubling of its water supply, which Blue Ridge makes possible.
“It’s been outstanding,” said SRP operations director Tom Sands of the chance to rebuild the hand-tooled system. “It’s a unique system — the only one like it in the United States, if not the world. It’s amazing how closely designed it was to operate.”
The Pelton Wheel is just one example, since SRP had to scour the world for a foundary that could copy the cracked wheel. They ended up casting the replacement and a backup at a foundary in Eastern Europe. They then shipped the 2,000-pound, two foot-wide, five-foot-across wheel to Canada for a first round of polishing and then to another plant in the American south for a final polishing.
Only then could SRP ship the wheel across the country to Payson.
Now, the wheel is humming away. The water blasts out of the pipeline under the pressure of its final descent off the Rim of nearly 1,000 feet, hitting the buckets and making the wheel spin. The wheel, in turn, sits on a 10-foot-long axle which drives the generator — the way the generator resting on a bike wheel spins to generate electricity to power a headlight.
The complex system has so far passed all its operating tests in the past two weeks, as SRP for the first time approximates what will become the normal flow on the East Verde.
Once Payson builds its pipeline, flows in the creek will drop off by about 20 percent, but that will still leave the East Verde brimming with many times its natural summer flow.
Of course, the creek will lose that augmented supply during the winter, when snow bars access to the pipeline atop the Rim. And this year, SRP will cut off the augmented flow in September, so engineers can replace the last six sections of leaking pipe in the existing line.
Getting the rebuilt Blue Ridge system running normally represents a happy footnote in a happy interruption of a decade-long drought that has taxed SRP’s deep plans and copious reservoirs.
The giant utility now has about 2.2 million acres in storage, according to Water Resource Operations Manager Charlie Ester.
The Salt and Verde watersheds received 13.4 inches of rain between December and May, the 10th wettest year on record. That includes 6.76 inches of rain that fell between Jan. 18 and Jan. 23. The record 3.76 inches that fell on Jan. 21 shattered the old, one-day rainfall record of 2.34 inches.
The deep snowpack produced so much runoff that SRP released some 668,000 acre-feet from Granite Reef Dam below Phoenix, bringing briefly to life the lower Gila River running all the way to Yuma.
The brimming reservoirs will provide the Valley with water enough to last several years, even if the drought returns.
“Is the drought over?” said Ester. “That’s a great question that we get asked all the time. Now, if we were to have another wet winter next year, I might say the drought is over locally. But when you look at the entire picture of the Southwest, with the Colorado River receiving below-normal runoff in an El Niño year like this, then I’m not ready to declare the drought over just yet.”