Our partners at the Environment Agency have contacted us again to ask for help in spreading the word that the Wandle’s rarely-seen headwaters at Caterham may be about to start flowing again.
Because so much water is usually pumped out of the Wandle’s chalk aquifer for drinking water and other purposes, the river’s historic springs and headwaters are often dry (and the upper river is sometimes only kept flowing by a unique system that takes water out of the river at Goat Bridge and recirculates it back upstream to Carshalton Ponds!)
However, following several weeks of rain, many local residents in the Carshalton area have recently noticed spring water flowing from the Grotto and Hogpit in Carshalton Park, as well as the springs in St Philomena’s lake.
And even the Caterham Bourne, which as a true winterbourne only flows out of the chalk downs above Croydon during exceptionally wet years, may be on the point of reappearing.
Groundwater levels have risen rapidly in the upper Wandle catchment in response to recent sustained and intense rainfall. As a consequence groundwater levels, as measured at the Environment Agency’s monitoring boreholes, indicate the potential for sustained flow within the Caterham Bourne. The rapid rate of groundwater level recovery within the Chalk aquifer allows us to conclude with a high level of confidence that initially low lying roads and properties will be susceptible to flooding.
The Caterham Bourne joins the Wandle at Croydon, so we may also see slightly elevated water levels on the Croydon arm of the Wandle through Beddington Park to Hackbridge.
If you live in Caterham, Whyteleafe, Kenley, Purley, South Croydon or along the upper Wandle, please take care and feel free to keep us updated by adding messages or pictures below this post.