TEMPE, Ariz. — A man-made lake near Phoenix will likely lose
two-thirds to three-fourths of its water after a rubberized dam burst
and sent thousands of gallons of water gushing downstream into a dry
river bed, authorities said.
The 16-foot-high section of the dam
on Tempe Town Lake near Arizona State University's campus broke open at
about 10 p.m. Tuesday. There were no immediate reports of any injuries
and authorities said no structures were in immediate danger.
"All
of a sudden, we heard this ka-boom and the ground started shaking,"
said 13-year-old Lukas Henderson, who was biking on the northside of
the lake with his sister and father.
Witnesses said the dry Salt
River filled as far as the eye could see within seconds, and small
animals could seen scrambling away from the floodwaters.
Warning
sirens began wailing within minutes, and officers rushed along the
riverbed to warn anyone — particularly transients known to camp on the
river bottom during the summer — of the approaching water.
Water
was flowing at 15,000 cubic feet per second, equivalent to the amount
released during heavy storm flows, Tempe Mayor Hugh Hallman said. The
lake was expected to continue draining into Wednesday morning.
Tempe
spokeswoman Kris Baxter-Ging said its unclear how the rubber dam burst,
but she said workers were speeding up an already under way effort to
replace the dam's bladders. The project had been delayed earlier this
year by winter flooding, she said.
The lake has four inflatable dams on both ends and the dam sections were supposed to last for 25 to 30 years.
However,
Tempe officials determined in 2007 that Arizona's harsh sun and dry
climate was taking a toll on the rubber dams and might have to be
replaced in a few years. The city inspects the dams about once a month
and repaired two tears in 2002.
Tempe officials said in April
2009 they intended to ignore a safety recommendation from the makers of
the rubber dams because sufficient safeguards were already in place to
prevent the dams from deflating.
The lake can hold up to 1 billion gallons of water, Baxter-Ging said.