On this World Water Day, we want to focus our attention on the importance of chalk streams and advocate for the sustainable management of these unique and vulnerable freshwater resources.
Chalk streams are a quintessential part of the English landscape and are home to an incredibly special array of fauna and flora. These rivers are also a crucial freshwater resource, providing millions of people in the UK with water. However, over-abstraction, abuse, and climate change is placing huge pressure on these unique and vulnerable ecosystems.
What are chalk streams and how are they under threat?
Chalk streams are some of the planet’s rarest habitats and 85% of them are found in Southern and Eastern England. Chalk streams in their natural condition are home to a profusion of wildlife. Botanically they are the most biodiverse of all English rivers. For invertebrates, fish, birds and mammals, they offer a vast range of habitats.
However, chalk streams are under immense pressure. There are a host of reasons why our chalk streams are at risk. This includes pollution, a decline in native species, development and population growth in the South East of England, and the fact that we simply waste too much water.
The most pressing of all is the low flows and chronic over-abstraction. We have become dependent on chalk streams for water supply and, in recent years, we have simply not had enough rain to support the level of abstraction still taking place. Our chalk streams are, quite simply, dying from a lack of water.
First of all, chalk streams are being drained of water by companies trying to meet the nation’s increasing thirst. This process began in the 1970s as more and more homes were being built and fitted out with dishwashers, showers, washing machines and other domestic appliances. These devices have helped to cause a 70% increase in household water use in the UK and, as a result, abstraction rates have soared across the country. This has only been exacerbated by the lack of investment water companies have put into water storage infrastructure. No new reservoirs have been built for decades, so now water companies are taking more and more water out of rivers as a result, particularly in drought conditions when rivers are at their most vulnerable.
Agricultural irrigation also has a large impact on chalk streams. More than 1,000 agri-businesses depend on irrigation to produce fruit and vegetables for the nation’s wholesalers, supermarkets, and food service sectors. However, irrigation water use is concentrated in the months and years when resources are most constrained. As a result, in some dry summers, irrigation of food crops can be the largest abstractor in some chalk streams.
Abstraction is not the only problem. There is also the impact of global warming, which is triggering more and more heatwaves that in turn are helping to dry out streams and rivers.
Whilst we typically associate water security as an issue for drier climates, hotter drier summers and less predictable rainfall has led to increased drought risk and possible water shortages in the UK.
This threat is now becoming a major concern after the Met Office warned recently that over the next five years, there is now a 40% chance that global temperatures will reach 1.5°C above pre-industrial levels, the upper limit that climate scientists want to set for the warming of our planet.
In recent years, rising numbers of heatwaves have led to increasing numbers of chalk streams being drained dry in many places: some have stopped flowing in the headwaters or dried up in low rainfall years. Some have stopped flowing at all. Most have been reduced to shadows of what they once were.
There is no doubt that we are on the verge of a water shortage crisis in the UK, which is already impacting our chalk streams and other rivers. With growing pressure from climate change, population growth and pollution, ensuring no further deterioration will be challenging without a step change in management.
At River Action, we want to see greater protection for these iconic and globally important rivers. Government, regulators and water companies must collectively acknowledge the conservation value of the chalk streams if we are to make considerable progress towards protecting these precious habitats for wildlife and for future generations.