| Bulbourne | |
|---|---|
 | |
 | |
| Location | |
| Country | United Kingdom |
| Physical characteristics | |
| Source | |
| • location | Cow Roast/ Dudswell, Northchurch |
| • coordinates | 51°46′41″N 0°36′04″W / 51.778°N 0.601°W |
| • elevation | 120 m (390 ft) |
| Mouth | |
• location | Two Waters Apsley, Hemel Hempstead |
• coordinates | 51°44′20″N 0°28′16″W / 51.739°N 0.471°W |
• elevation | 90 m (300 ft) |
| Length | 11 km (6.8 mi) |
The River Bulbourne is a small river in Dacorum, Hertfordshire, England. The word bourne derives from the Anglo-Saxon word for a stream.[1] It is an unnavigable tributary of the River Gade, which flows into the River Colne, which in turn is a tributary of the River Thames. The Bulbourne is an example of a chalk stream, which is a watercourse that flows from chalk-fed groundwater. Chalk streams are a very rare habitat globally, with more than 85% of all the 210 chalk streams in the world are found in England.[2][3][4] The river is reduced in size, due to human activity, the main one being the building of the London to Birmingham Grand Union Canal through the narrow valley which takes most of the river's water.
- ^ One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Bourne (stream)". Encyclopædia Britannica (11th ed.). Cambridge University Press.
- ^ "River restoration project wins national conservation award". Environment Agency. 20 October 2017. Retrieved 10 December 2017.
- ^ "Herts chalk stream to be reprofiled". Landscape Institute. 16 January 2016. Retrieved 20 March 2016.
- ^ "The threat to chalk streams, our unique contribution to global ecology". The Guardian. 24 July 2014. Retrieved 25 March 2016.
