The steep upper reaches of the River Wandle exhibit many chalkstream characteristics despite being massively affected by abstraction from the river’s aquifer.
When the natural spring flows fall below 4.5 megalitres per day at Grove Park, the Carshalton arm is augmented by a recirculation system which abstracts water just below Goat Bridge and pumps it upstream to Carshalton Ponds. The Croydon arm is heavily influenced by urban runoff from Croydon.
Historic impoundments for milling have left the upper Wandle fragmented and difficult for many fish species to access. However, trout have been seen spawning for several years, and the Wandle Trust is working with the Environment Agency and Wild Trout Trust to improve many aspects of habitat, including water quality and silt control, with the aim of establishing self-sustaining populations of urban adapted wild brown trout and other species in the upper river.
Current and future projects:
- Hackbridge and Culvers Island: weir removal and river restoration (pdf download)
- Butter Hill: weir modification and river restoration (pdf download)
Recent and past projects:
- Butter Hill (phase 1)
- Butter Hill (phase 2)
- Hackbridge coir rolls