The first of a billion gallons of water began whooshing into Tempe Town Lake Friday as city leaders just couldn’t resist making a final crack over the burst bladder that emptied the lake.
“We had lots of comic relief with the dam jokes,” Mayor Hugh Hallman chuckled.
While Tempe has kept a sense of humor, it’s also worked frantically to restore a very serious tourist attraction. The lake draws 3.2 million to 3.6 million visitors a year, second only to the Grand Canyon as an Arizona destination and a source of $415 million of economic activity since 1999.
The flow of water should fill the lake by Oct. 25, or perhaps sooner based on how well things went Friday morning.
As city officials gathered in the lake bottom at 7 a.m. to see the first water arrive, it gushed in at 50 cubic feet per second. Salt River Project officials were unsure how much water their canals could handle, but within an hour deemed it safe to boost the flow to 75 cfs. The flow could top out at 100 cfs by Saturday.
While it would take about 21 days to fill the lake at the lower flow rate, it could take just 14 days at the faster rate, said Tom Sands, a water engineer with SRP.
Water is arriving through a pipe on the lake’s north shore, immediately underneath the Metro light-rail bridge. Gawkers hung out Friday morning to witness the flow – but that view will disappear soon as the pipe becomes submerged.
“If they want to see the water come out, they need to come out in the next few days,” Sands said.
The water comes from Roosevelt Lake, which will drop about 1 inch to supply the water. Fish will flow in with the water, but grates will prevent fish wider than two inches from entering, Sand said. Fish that arrive will be 12-14 inches long at the most.
One of the lake’s fathers was on hand Friday to watch it fill for the second time since its opening in 1999. Chuck Pedri was the project manager for engineering firm CH2M Hill, which designed key features – including the inflatable rubber bladders that burst on July 20.
Pedri lives in Tucson now and made his first trip to the empty lake Friday.
“I purposely avoided it,” Pedri said. “I didn’t want to see it in the state that it was in.”
Pedri now works for URS Corporation, which did a study about a year ago on types of dams for Tempe to consider. The inflatable dams were supposed to last 30 years but Tempe discovered in 2007 that Arizona’s intense heat and sun were causing the material to break down.
The replacement dams, manufactured by Bridgestone, can only be used for five years under an agreement between the company and the city to replace the aging bladders.
Tempe is considering inflatable bladders from another manufacturer or a metal gate that can be lowered to accommodate water that occasionally flows in the Salt River.
“More studies need to be done to determine which one is the best for the city to choose,” Pedri said.