There is approximately 35km of tidal frontage in Southampton, including the lower reaches of the city’s two main rivers (the River Test and River Itchen) which join together to form Southampton Water. There are also a number of smaller rivers in Southampton, namely Tanners Brook, Holly Brook, Rolles Brook, Monks Brook, Jurds Lake and Blighmont Crescent Stream. At present, approximately 10% of the city is identified as being at high or medium risk of flooding from tidal and fluvial sources.
Due to the urban nature of Southampton, the city is also at risk from surface water flooding, which is far less predictable and can happen anywhere at any time following heavy rainfall. Other sources of flooding include groundwater and risk from artificial sources such as reservoirs; however these pose less of a risk to Southampton.
You can find out if your area is at risk of flooding from the sea, main rivers or surface water by viewing the flood risk maps available from the Environment Agency.