Leave it to an Arizona-desert environment, where precipitation of any kind is but a stranger passing through, to be the mother of invention for a globally unprecedented dam project.
For those who haven’t visited the normally tranquil shores of Tempe Town Lake for a brisk run, stroll or simple people-watching since the mercury started its yearly ascent, 250 feet of fencing has dominated the southern-shore scenery since mid-June. The Temporary Green Monster has blocked passersby from a “superstructure” steel dam’s eventual construction site.
The city’s $40.8-million project began with clearing animals and brush from the Salt River bed feeding the lake before construction begins on the 950-foot structure that PCL Construction’s Adam Gordon claims will be “the world’s largest hydraulically controlled, crest-gate dam.” The clearing of the riverbed makes way for 15 feet of desert-dirt excavation in September that paves the way to relocate a storm-drainage pipe west of where the new dam will go up.
Here’s a peek at the resources being poured into this ambitious undertaking by the City of Tempe in the 18 months between the June start and the goal December 28, 2015 completion:
- A 61,100-ton concrete foundation poured between two abutments and seven concrete piers in the dry Salt River bed
- A total of eight 106-feet-long, 17-feet-high, 232,000-pound steel gates
- An array of 16 hydraulic cylinders measuring 27 feet long each
- Support from seven 9-feet-wide, 45-feet-long, 30-feet-high concrete piers
The City of Tempe chose to go all-in on the project four years after a rubber bladder in the lake’s former dam exploded in 2010. The catastrophic breakage sent about 1 billion gallons of Tempe Town Lake water running into the Salt River with a disgusting-smelling bog behind it. The Tempe City Council had been warned as far back as four years earlier that the existing rubber dam wouldn’t stand up to the desert sun’s beating forever. All things considered, its 10-year warranty was probably never devised to stand up to a decade of desert temperatures.
Here’s where we’re anxious to hear from you, the citizens of Tempe: is it worth it? On the one hand, Tempe Mayor Mark Mitchell has publicly emphasized the importance of an estimated $1.5 billion annual revenue stream that lakeside activities, development, recreation, events and tourism brings to the local economy’s table. Opponents balk at the city piling another $40.8 million tab onto the millions already spent annually to maintain the lake, not to mention the various consequences of the previous dam’s premature failure.
Let us know in the comments below!