Plans for a £7.4m scheme to improve flood defences in North East Lincolnshire have been approved by the local authority.
Immingham was hit by major flooding caused by a tidal surge in 2013.
The council's cabinet has agreed to install new outer lock gates at the port, replace flood walls and extend the height of the existing defences.
Councillor Dave Watson said the work was "vital" and the risk of flooding would be "significantly reduced".
In a report, the council said replacing and raising the existing flood defences would "provide a flood defence level of 6.1m" (20ft) above sea level.
The Environment Agency was investing £4.5m in the project, the authority said.
Mr Watson said: "The Port of Immingham is a vital part of the UK's economic infrastructure, and is its largest port by tonnage, handling over 53m tonnes a year, and around 10% of all seaborne traffic.
"This work, once completed, will significantly reduce the risk of flooding to the port estate, and as such, it's absolutely vital that we support work to make this happen."
Hundreds of properties were flooded in December 2013 when a combination of high tides and strong winds caused a tidal surge, that breached flood defences along the east coast.