US ENGINEERS in New Jersey this week raced to install a 40m long temporary truss deck to replace a highway bridge swept away in floods. The extreme weather also caused the total or partial failure of 24 dams last week.
No lives were lost when freak weather dumped more than 300mm of rain in one night on Burlington County, but hundreds of residents had to flee homes when the dams failed.
In all 13 earth dams up to 7m high collapsed or were breached, and another 11 were partially breached or overtopped.
Abutments of the 10m span Route 70 crossing of Friendship Creek in Southampton collapsed after embankments were washed out, dropping the deck into the river. The bridge carried 17,000 cars a day.
Engineers from the state's department of transportation used two 550t cranes to install the 150t steel truss temporary bridge on Tuesday.
Most of the dams that collapsed this year dated from the first half of the 20th century or earlier and some had already been strengthened. Bad weather during 1999 and 2000 prompted the state to make $95M (£65M) available last year for testing and repairs to unsafe dams.
New Jersey Department of Environmental Protection (NJDEP) engineers estimated in its last survey that 317 of the state's 1,600 dams represented a Class 2 significant hazard - a risk of serious property damage if they fail, but no great risk to life, said a NJDEP spokesman. In total 51 dams in the state have collapsed in the last 15 years.
'We've doubled our dam inspectorate staff from eight to 16 since the last failures and all but three of the dams that failed this time had been inspected in the last three years.'