Chalk rivers are one of the rarest environments in the world but they are under serious threat. They support some of our most iconic yet threatened wildlife, such as wild brown trout and water voles, but there are less than 250 chalk rivers in the entire world. We are lucky to find around 10% of these in Hertfordshire. Current threats include pollution, physical modification, over-abstraction, invasive non-native species and climate change.

We at Hertfordshire & Middlesex Wildlife Trust have a national and international responsibility for protecting its special chalk rivers. We will complete an ambitious programme of physical work and invasive species interventions that will deliver meaningful habitat improvements across the whole river catchment. These will be delivered by contractors overseen by our Project Team supported by volunteers.