The Tempe Town Lake is contained by an inflatable dam system consisting of eight bladders, four in a row at the east end (located between Rural and McClintock roads), and four in a row at the west end (located between Mill Avenue and Hardy Drive). The rubber dams are made of 3 elements: a strong, flexible, rubber coated fabric tube which is fixed securely to a concrete base slab by clamping bars and anchor bolts; an operating system which controls inflation and deflation of the tube; and an automatic safety device which ensures tube deflation in flood situations.
Each section of dam, or bladder, is about 240 feet long, weighs 40 tons and is more than one inch thick. At times, a small amount of water can be seen flowing over the top of the west dams, creating a 19-foot waterfall. This water can be recaptured by a recirculation system and pumped back into the lake.
The dams were shipped across the ocean from Japan, arriving on large spools, that were transported by truck to Tempe. These spools were stored until construction of the lake was ready for installation of the bladders. The spools were then moved by crane into the river bottom, and unrolled into place.