By Caitlin Ryan

1. The River Gade By Caitlin Ryan

3. The River Gade • The River Gade is a chalk stream that rises from a spring in the Chiltern Hills. • It’s a shallow river. • It’s named after the village of Great Gaddesden (where it begins).

4. Chalk Streams and Aquifer • The River Gade is a chalk stream with very clear water. Chalk streams are globally rare, which makes the River Gade even more special. • Chalk streams are fed from groundwater. This water is stored in an aquifer. • An aquifer contains layers of chalk that soak up rainwater like a sponge. At various points the water emerges as springs, which feed the streams.

5. Aquifer process • This process through the chalk allows the water to gather nutrients (useful for plant life) and is cooled by it’s journey through the chalk to emerge at a constant temperature regardless of summer or winter.

6. Map of River Gade

7. The River’s Journey • The River Gade travels almost entirely through Hertfordshire. • The river begins it’s journey from the springs in Great Gaddesden. • It travels through Hemel Hempstead, Kings Langley and Croxley Green to Rickmansworth. • Finally it joins the River Colne and The Grand Union Canal. • Later joining the River Thames.

8. Pressures on the River • In the past couple of years many chalk streams have been on the verge of extinction due to a lack of rain. Thankfully the recent wet weather has saved chalk streams.

9. Building • The River Gade suffered problems during the building of Hemel Hempstead’s new town after World War 2. • The demand for water increased. • High levels of water were drawn. • The natural water table level dropped causing a drop in the river depth.

10. Features of the River Gade

11. Upper Course • Source - Spring at Great Gaddesden • Small stream • V-shaped Valley - “High Gade Valley” • Waterfalls - Rocky ridges in the riverbed cause little waterfalls.

12. Middle Course • Floodplain - “Hemel Hempstead” • Erosion - Meander about to meet to make an oxbow lake near Croxley Green

13. Lower course • Large floodplain - near Rickmansworth • Wide smooth channel

14. Wildlife • The River Gade is very important to wildlife. Including many species that are rare and come from different countries. A little egret was seen here on one especially bleak winter. • The meadows support a diverse community of birds. Such as finches, thrushes, waders and a wildfowl during winter and other birds breed on the meadows in the summer.

15. History • The River Gade has attracted people for centuries to live, work and enjoy the countryside in it’s beautiful valley. • The Romans created a settlement in the area now occupied by Gadebridge Park. • The River provided a source of power for a corn mill at Water End. • Watercress used to be grown for the London market. Traces of the old watercress beds can still be seen from Google Earth.

16. Quiz? • What’s the name of the village where the River Gade begins? • Answer: Great Gaddesden • Where does an aquifer collect it’s water from? • Answer: The Rain • Name all four of the towns and villages the River Gade travels through? • Answer: Kings Langley, Hemel Hempstead, Croxley Green and Rickmansworth. • What’s the name of the rare bird spotted by the River Gade? • Answer: Little Egret