The Environment Agency, in partnership with Lewes District Council, is developing a scheme to reduce flood risk from the sea and the river along the Ouse valley.
The scheme will reduce the risk of flooding to 431 homes and 387 businesses in and around the East Sussex town of Newhaven.
The Newhaven flood alleviation project will be designed to provide at least a 1-in-100-year standard of protection, taking into account the effects of climate change.
The scheme covers both banks of Newhaven, including the commercial areas near the port.
This flood protection program is estimated to cost around £17 million, with the majority of funding coming from the Environment Agency in the form of central government Flood & Coastal Risk Management Grant in Aid.
Construction of the scheme is planned to start in autumn 2016 and is scheduled to be complete by 2019.