Noun
A water-tight inclosure, as of piles packed with clay, from which the water is pumped to expose the bottom (of a river, etc.) and permit the laying of foundations, building of piers, etc.
Source: Webster's dictionaryOther types Cofferdams main A cofferdam during the construction of locks at the Montgomery Point Lock and Dam A cofferdam is a barrier, usually temporary, constructed to exclude water from an area that is normally submerged. Source: Internet
The upper cofferdam was convert high, and convert thick at its base, thicker than the dam itself. Source: Internet
When the project is completed, the cofferdam will usually be demolished or removed unless the area requires continuous maintenance. Source: Internet
Work on the upper cofferdam began in September 1932, even though the river had not yet been diverted. Source: Internet
“On only a couple of occasions the ice built up very briefly (a few hours) just upstream of the spillway/temporary cofferdam area, but then flushed through the spillway,” O’Neill said in an email. Source: Internet
The circumstances of the incident are not known at this stage, but the man was said to have fallen between a cofferdam and a building under construction. Source: Internet