A flood warning and several flood alerts have been issued in Sussex.
In the worst tidal surge in 60 years the Environment Agency has warned of coastal flooding in the early hours of Friday morning in Sussex and again early on Friday afternoon.
On Thursday afternoon new flood warnings were issued for the coast of Sussex.
A warning has been issued in Shoreham, where waterfront properties particularly around the A259 near the old Parcelforce site and the Houseboats could be affected by the overnight high tide.
Tidal areas of Shoreham Harbour including Shoreham Airport, Shoreham high street, areas of Riverside Road and Shoreham Harbour East arm are also at risk of flooding.
Flood alerts - the next warning level down - have been issued for Newhaven, Littlehampton, Seaford and Hastings seafront.
Alison Baptiste, Regional Flood & Coastal Risk Manager for the South East, said: "We are working closely with the Met Office, emergency services and our local authority partners to monitor the forecast and continue to warn people of the risks and prepare our response.
"In order to help protect properties, the Environment Agency is closing tidal gates throughout the South Coast.
"There is the risk that up to 3,000 properties could be affected and we advise people to keep a close eye on our website for the latest information.
"We want to alert people to the risk of possibly serious flooding early to allow them time to prepare."
The Environment Agency and Met Office are forecasting that there is a significant risk to people and property as spring tides combine with a coastal surge and significant waves.
Emergency Planners from the police, councils, Environment Agency and Fire and Rescue Service are currently meeting and will be issuing updates.
People living in the affected areas should call Floodline on 0845 988 1188 for the latest flood warnings in their area.
For advice on how to prepare for flooding, tune into local radio and TV stations and keep an eye on local weather conditions.