River Bourne, Chertsey

The land either side of the River Bourne below the Lake and west of Virginia Water railway station is owned by Runnymede Borough Council as trustees of the Cabrera Trust, named after Spanish noble Ramòn Cabrera who owned and developed a wide landscape at Wentworth.

The colony is probably the largest in the United Kingdom and is of international significance due to the rapid decline of mandarin ducks in its native Asia.

The river creates access for small motorboats and canoes for the c. 20 properties in its lowest reach at Hamm Court.

Only the lower section below a weir is canalised, the remainder is natural bank, forming a minor habitat for the European water vole.

[3] It is a small river, once past Virginia Water lake about 3–5 m wide and flows over land which is geologically between the Bagshot and London Formations, where sands and gravel overlie chalk with limited clay, described as "loamy soils with naturally high groundwater".

Approximately 130 properties were flooded and public buildings, including St Anne's County Primary School, were cut off by floodwater.

[6] Local concerns that this flood was exacerbated by the building of the Jubilee River are false as this scheme protects the Windsor and Maidenhead area, however, the Environment Agency is introducing plans for a new flood alleviation scheme which will create additional capacity to help other affected reaches of the Thames, at Staines upon Thames and Chertsey.