The Darent and Cray are groundwater fed chalk rivers located in north-west Kent and south-east London. Chalk rivers are characterised by clear water, abundant aquatic plants, low banks and comparatively stable flows, but the Darent and Cray like most rivers within the UK they are not as healthy as they should be.
The Darent has suffered from over-abstraction in the past and has on a number of occasions virtually dried up on many sections. Both the Darent and Cray have been heavily modified to provide power for milling and current problems include pollution, non-native invasive species and physical modifications.
As a result two Catchment Improvement Groups have been set-up, representing each of the rivers. These groups consist of organisations who represent the different interests on the Cray and Darent and who are working towards improving the quality of these unique water bodies.