Why Do Chalk Streams Matter?

There are 260 chalk streams in the world, and the majority of them – 85% – are in the UK, mostly in southern and eastern England. They only exist when chalk bedrock meets the surface, which is why they’re so rare.

Chalk streams are pure, clear water that originate in underground chalk aquifers and springs. They provide such an effective, oxygen-rich environment, they’re teeming with wildlife, supporting some of the UK’s most iconic aquatic and terrestrial species, for example kingfishers, swans, water voles, damselflies, otters, trout and salmon. In fact, the chalk streams support such a high number of species, they’ve been described as ‘Britain’s rainforests’.

Chalk streams are an essential part of the food chain

Chalk streams are fed by water that’s been filtered through chalk. It is nutrient-rich and clear which means it supports an abundance of wildlife and oxygenating plants. The minerals in the water feed microorganisms that in turn become the food needed for the incredible variety of insects, fish, birds and mammals that live in chalk streams.

Chalk streams benefit people too. They’re not only beloved by anglers looking to catch wild brown trout or salmon, they are also beneficial to mental health and wellbeing. People have a deep emotional connection with nature and a walk next to a chalk stream can enhance mood as well as physical health.

How human activity affects chalk streams

Whilst many people enjoy chalk streams, human activity is having a negative effect on water quality and quantity. Many of these precious waterways have been affected by run-off pollution, sediments and sewage discharges. We are also draining them of too much water, reducing some streams to a trickle with devastating consequences to the local wildlife. As a result the majority of the UK’s chalk streams are now in a poor state of health, and many are at risk of dying out completely.

Restoring England’s chalk streams

In October 2021, a group of environmental and government organisations launched the Chalk Stream Restoration Strategy. The strategy set out what needs to be done to protect what it termed the ‘trinity of ecological health’: water quantity, quality and the physical habitats of chalk streams, and recommended granting enhanced status for chalk streams as a way of preventing pollution and over-abstraction.

Following the Strategy, in November last year, the Chalk Stream Restoration Group launched its Implementation Plan. The Plan recommends an “overarching level of protection and priority status for chalk streams and their catchments.” The good news is that some of the recommendations made in the Strategy have already been implemented, and many others are in the process of being implemented. For example, chalk catchments are now defined as water stressed with the recommendation that water companies install compulsory metering in these areas; the government is now treating chalk streams as ‘high-priority sites’ in its storm water reduction plan; ‘principles for chalk stream restoration’ have been agreed upon by all the partners; areas for restoration have been identified and water companies are supporting the delivery of these projects.