Tempe Town Lake reopening delayed up to 2 weeks

Ongoing tests of a new hydraulic dam at Tempe Town Lake will delay the lake's reopening longer than the city had hoped.

Tempe had set April 30  as the approximate date for reopening the lake after it closed to water activities Feb. 10, but it could take up to two more weeks, said Kris Baxter, a Tempe spokeswoman.

"Basically, we need to do water-bearing testing,'' she said, adding the lake could reopen sooner than two weeks if testing is completed.

That testing involves opening and closing the dam's eight steel gates in various combinations to allow water to spill through. The tests can only be completed when the lake is filled with its 880 million gallons of water, a process completed on Wednesday, Baxter said.

Baxter said a minimal amount of water will be released downstream during testing. She said Saturday was an estimated opening date and the construction contract for the work extends beyond April 30, to include completion of all testing.

"It's making sure all of the components of the dam work with the weight and pressure of water on it. So far, everything is performing as we expect,'' Baxter said. "(The contractor and city) always knew they'd have to do this testing, and would have to wait until the lake was full to start doing that.''

The city, working with Salt River Project, emptied the lake in February by moving water into SRP's canal system. Workers then removed a temporary rubber dam and completed work on the new dam. The lake was refilled over the past two weeks.

The structure is the nation's largest hydraulically operated steel-gate dam, according to the city and its contractor, PCL Construction. Each of the eight gates is 106 feet long and 17 feet tall.

“So far, everything looks great, but we need to finish our testing before we can open the lake for boating,'' said Tempe Public Works Director Don Bessler, in a prepared statement. He could not be reached for additional comment. Officials for PCL Construction did not return calls seeking comment.

Work to replace the temporary, inflatable rubber dam began in 2014.  An original rubber dam on the west end installed in 1999 failed in 2010, causing an estimated 1 billion gallons of water to rush downstream.

The new steel dam cost about $46 million. Voter-approved bonds cover $33 million of that, while the rest is from the city's general fund, Tempe officials said. The dam spans about 950 feet across the river and is projected to last at least 50 years.

Although the lake is closed to on-water activities, anglers can fish from the shore or from paths around the lake, Baxter said. Bass, catfish, carp and sunfish stored in a marina holding area at the east end of the lake swam downstream as the water level rose, she said.

In addition, more than 1 million small goldfish and minnows eat insects and help keep the mosquito population under control. Additional fish will be stocked in coming weeks.

Larissa Gaias, co-president of Team Arizona Outrigger Canoe Club, which trains on Tempe Town Lake for competitions, said her group planned to resume training this Saturday at the lake. The group has about 30 full-time members and 20 recreational paddlers who participate in training. She said they had not been notified of the delay.

"We'll probably wait to hear from (the city) before making decisions on where we'll practice this weekend,'' she said.