Flood risk across Hampshire
Hampshire's chalk rivers — the Test, the Itchen and the Meon — mean groundwater flooding is a real risk after long wet winters, as it was in 2000–01 and 2013–14. Southampton, Portsmouth and the Solent coast are exposed to tidal flooding, and the Avon and Blackwater bring river flooding to the west and north of the county.
Flood zones only show river and sea flooding, and they ignore flood defences. Surface water and reservoir risk aren’t part of the zones – check them on the Environment Agency’s long-term flood risk service, or get the full report, which covers every source.
Rivers that shape local flood risk
Main rivers are managed by the Environment Agency. Smaller watercourses and drainage are the responsibility of Hampshire County Council and landowners.
River Test – Andover, Stockbridge and Romsey
River Itchen – Winchester and Southampton
River Meon – The Meon Valley to Titchfield
River Avon – Fordingbridge and Ringwood
River Blackwater – Farnborough and the Surrey border
Solent coast – Southampton, Portsmouth and Lymington
Who manages flood risk here
Hampshire County Council, Southampton City Council and Portsmouth City Council are the Lead Local Flood Authorities, responsible for surface water, groundwater and ordinary watercourses. The Environment Agency manages main rivers and the sea, and issues flood warnings. Your district or borough council decides planning applications – and asks for a flood risk assessment in Flood Zones 2 and 3.
Getting a written answer for an address
The free check describes the area around your postcode. For a specific property, the full report checks your exact address against every flood dataset and gives you a dated PDF to share with your surveyor, conveyancer or insurer.
For planning decisions, your local council has the final say.
