The US Army Corps of Engineers exploded a large section of a Mississippi River levee on Monday in a desperate attempt to protect an Illinois town from rising floodwaters.
The corps said the break in the Birds Point levee would help tiny Cairo, Illinois, by diverting up to 1.2m of water off the river. Just before Monday night’s explosions, river levels at Cairo were at historic highs and creating pressure on the floodwall protecting the town.
Questions remain about whether breaking open the levee would provide the relief needed, and how much water the blast would divert from the Mississippi River as more rain was forecast to fall on the region yesterday.
Flooding concerns also were widespread on Monday in western Tennessee, where tributaries were backed up due to heavy rains and the bulging Mississippi River. Streets in suburban Memphis were blocked, and about 175 people filled a church gymnasium to brace for potential record flooding.
The break at Birds Point was expected to do little to ease the flood dangers there, Tennessee officials said.
The Ohio River at Cairo had climbed to more than 18.6m as of Monday, a day after eclipsing the 1937 record of 18.1m.
The river is expected to crest late today or early tomorrow at 19.2m — just 30cm below the level that Cairo’s floodwall is built to hold back — before starting a slow decline by Friday.
The high water has raised concerns about the strain on the floodwalls in Cairo and other cities. The agency has been weighing for days whether to blow open the Birds Point levee, which would inundate 52,600 hectares of Missouri farmland.
Carlin Bennett, the presiding Mississippi County commissioner, said he was told a 3m to 4.5m wall of water would come pouring through the breach. The demolition was expected to cover about 3,350m of the levee.
“Tell me what that’s going to do to this area?” he said. “It’s a mini-tsunami.”
Major General Michael Walsh — the man ultimately responsible for the decision to go through with the plan — has indicated that he may not stop there if blasting open the levee doesn’t do the trick. In recent days, Walsh has said he might also make use of other downstream “floodways” — basins surrounded by levees that can intentionally be blown open to divert floodwaters.