Flood risk across Buckinghamshire
The Thames runs along Buckinghamshire's southern edge at Marlow, and the Great Ouse crosses the north near Buckingham and Milton Keynes. In the Chilterns, groundwater can rise in the chalk valleys after wet winters, and surface water affects towns such as High Wycombe and Aylesbury.
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 Buckinghamshire Council and landowners.
River Thames – Marlow and the southern boundary
River Great Ouse – Buckingham, Newport Pagnell and Olney
River Wye – High Wycombe and Bourne End
River Thame – Aylesbury Vale
River Ouzel – Milton Keynes
Who manages flood risk here
Buckinghamshire Council and Milton Keynes 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. The same councils also decide 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.
