River Itchen Flood Alleviation SchemeFlood wall

The River Itchen Flood Alleviation Scheme is a proposed Flood Defence Scheme that has been developed from the Southampton Coastal Flood and Erosion Risk Management Strategy, with the main objective of protecting hundreds of homes and businesses located on the West Bank of the River Itchen, including areas such as Northam, St Marys and Chapel, from present and future tidal flood risk. Presently there are no formal flood defences in place and the existing quay walls, structures and land levels are not high enough to prevent more frequent and severe flooding that threatens these areas with the increase of climate change and sea level rise.

Why is the scheme needed?

There are currently approximately 400 residential properties, along with many businesses, on the west bank of the River Itchen, which are at risk from a 1 in 200 year flood. As a result of climate change and sea level rise, flooding will because more frequent and severe, and if no action is taken to address the tidal flooding, the number of residential properties at risk in this area will increase to over 1400 by 2110.

Key points

  • The proposed flood wall will follow a front line route from Mount Pleasant Industrial Estate, North-West of Northam Bridge, along the frontage towards Ocean Village, South of the Itchen Bridge, as shown in the image
  • The proposed wall will vary in height depending on local ground levels along the route, generally varying between 0.8m to a maximum of 1.7m with an average height of 1.2m
  • The scheme will cost approximately £45 million to complete, with funding coming from several sources
  • Main benefits of the scheme include a reduction of flood risk over the lifetime of the scheme
  • Development of the scheme has taken place over several years

For further details on the scheme please see the following documents