Thursday, August 27, 2009

Tiger Dams Fail on Indian Creek - Cedar Rapids, Iowa

After 7.07 inches of rain fell in a 36-hour period, 42N country's Indian Creek flooded southeast side neighborhoods in Cedar Rapids, Iowa. This event occurred only 14 months after the historic 2008 flood of the Cedar River and Indian Creek in Cedar Rapids. Today's flash flood was significant for a couple of reasons. For the first time the city deployed Tiger Dams, a removable bladder-like series of tubes that fill with water, tether together and stack to form a barrier. These dams were assembled the day before as part of a training exercise (see video). The other reason this flood was significant was that the muddy colored waters crept a bit closer to the 42N command center than in years' previous.

Today's rainfall sent the creek rising much faster and higher than anticipated. The swollen creek circumvented the 200 feet run of the temporary dam and began to back fill behind the structure. City crews raced to the scene and positioned sandbags in an attempt to shore up the Tiger Dams. Due to several factors (water pressure, positioning, join strength, current velocity, debris and who knows what), the Tiger Dams failed around 7:30 pm. Upon their collapse water was sent up the streets and into homes. The crew quickly approached the sewer lines and began pumping to relieve the water pressure. When the first location failed the crew went a half block up the street to repeat the pressure fix. This time their actions were successful. Waters began to slowly recede around 9:10 pm and by morning the creek was near its banks again.

Local ABC-TV affiliate KCRG (Channel 9) arrived around 8 pm and interviewed the residents about the Tiger Dams' effectiveness. Station reporter and producer Alyson Hunt conducted the interview. Her report was actually the lead story for the 10 pm news. Know that.