South East Rivers Trust

Considering Chalk Streams and Communities on World Rivers Day 2019


On World Rivers Day, we want to remind ourselves of the value of rivers to our society and the impact we have on them …

Local legend has it that the River Nailbourne, in Elham valley, is the result of an historic fight between St Augustine, who brought Christianity to Kent in the 6th century and became the first Bishop of Canterbury, and the pagan gods Wodan, the sky god, and Thunar, the god of thunder. When St Augustine arrived in Kent, the pagan villages in the Elham valley had not had rain for a long time and their crops were failing. He was so moved by their plight that he knelt down on the parched soils of the dry valley and asked God to send help – and out of the ground, from deep within the chalk rock, a spring of clear water emerged that made its way through the valley towards the Stour. Thus, the Nailbourne was born.

The Little Stour downstream from where the Nailbourne joins it in wet years. Photo: Kathi Bauer.

The people were so grateful for this miracle that they turned away from Wodan and Thunar to their new Christian saviour – perhaps forgetting that their former gods were not known for being forgiving. The displeased deities weren’t going to take this insult without showing their anger, sending misery and harm to the people of the valley and drying up the river again. Not to be overcome by the heathen gods, the angel of the bourne fought for the river to return – and so their fight continued for centuries. It is said that the river will run every 7 years, followed by bad luck and disaster brought by the “woe waters” as the old gods seek to subdue the river and its people over and over again.

We now know that the Nailbourne and other winterbournes like it only appear after very wet winters, when groundwater levels are high enough to press water stored in the chalk aquifer upwards through fissures and cracks to the surface. They are one unmistakeable sign of one of the most precious ecosystems we are lucky to have in South East England: chalk rivers.

The River Darent in North Kent flowing over a shallow gravel bed with willows and reeds shading the bank and macrophytes in the water providing habitat and refuge for fish and other animals. Photo: Chris Gardner.

Only about 200 of these unique features of chalk geology exist, in South and East England as well as some parts of France. About 80% of these are found in Southern England. Their source can migrate depending on the level of groundwater, flowing over gravel beds and providing clean and clear, alkaline water that is home to water voles, lampreys, mayflies and other rare species. But they are increasingly suffering because they don’t have enough water.

The River Dour is a beautiful example of a small chalk stream, with lush emergent vegetation and clean, bright gravels on the bed. Photo: Chris Gardner.

The clean water that feeds springs can take many years to filter through the chalk after it falls as rain. This is a process of filtration which facilitates a high quality of groundwater, which also makes it a great and reliable source of drinking water.

Between 50% and 100% of Kent’s public water supply is from groundwater. Additionally, businesses and farms can abstract through private boreholes for irrigation and other uses. Water, it is worth remembering, is a precious resource. Of all the water on earth, only 2.5% is freshwater, most of which is bound in ice, groundwater or soil moisture. Only 0.01% is surface water. That – to employ a much-used analogy – is the equivalent to about 2 table spoons of water out of a full bath tub.

Here in the UK, we’re lucky that we have access to clean drinking water so easily ­- 785 million people worldwide lacked a basic drinking water service in 2017. However, we are not the country of never-ending rain that some think we are, and the amount of water used in areas like the South East means that they are classified as “seriously water stressed” by the Environment Agency (based on how much water is abstracted annually compared to how much is available – per person, we have less water available in the South East of England than Morocco). We use an average of 149 litres of water per household per day (and this does not take into account the water that is needed to grow our food or manufacture our goods). Most of this water is taken from the same aquifers that feed our chalk streams, and with a growing population and climate change, the amount available will decrease further. This has economic and social impacts as groundwater becomes scarcer, but it also has repercussions on our rivers and their ecosystems.

Chalk rivers are famed for trout and salmon and popular for fly fishing, but at low flows, their clean gravels can become clogged with sediment and temperatures can rise beyond a point comfortable for many species. Pollution cannot be diluted easily, taking a toll on the wildlife and plants. Heavy rainfall events can wash nutrient- and sometimes pesticide-rich soil from fields into the watercourses, road runoff full of oils and heavy metals, or overwhelm drainage pipes resulting in sewage spills. Poorly sited manure heaps or pollutant spills can leak into the soil and groundwater, affecting the river and drinking water. Barriers such as weirs change the natural processes in the channel and stop fish from moving freely up- and downstream.

This is not only a problem in chalk streams but most of our rivers – however the unique status and rarity of chalk streams means we should pay special attention to their health. Although it is natural for so-called “winterbourne” sections of some chalk rivers to be dry for some periods, many of our chalk steams suffer from unnaturally low flows and over-abstraction, emphasised by a recent report on the crisis chalk streams are facing. They are also indicators of the state of our water resources overall – a healthy chalk stream can’t exist without a healthy aquifer. The urgency of addressing these issues was acknowledged in June when MPs debated it in parliament.

The Carshalton Arm of the River Wandle has run dry in the past.

A lot of responsibility for action lies with the government, regulators and water companies – but it also lies with each of us. We are all connected to and benefit from our rivers.  At the South East Rivers Trust, we work in partnership with local authorities, water companies, countryside partnerships, wildlife trusts and communities to address issues of too little water as well as too much, but we rely on the willingness of everyone to take action. Remember: the journey of a river already starts before it emerges from the ground. It’s in the raindrop that falls on our roof, our road or our field. It’s in the tap we turn on every morning to brush our teeth, and it runs down our drain when we empty that half-drunk cuppa. Today, we have acknowledged that it is not some ancient thunder-god that is responsible for our rivers and streams, but ourselves. Let’s not rely on an angel to come down from heaven to fix things for us – instead, here’s a few things you can do:

  • Learn about how you can save water and implement those recommendations. Be ambitious! If you don’t have a water meter, check with your water company if you can get one from them. They also provide water efficiency equipment that you can fit on your taps and that should help you save water without noticing it.
  • Respond to the government’s consultation on reducing water consumption: https://consult.defra.gov.uk/water/measures-to-reduce-personal-water-use/
  • If you garden, try to reduce water use, for example by choosing the right plants and watering at the right time of day.
  • Disconnect your downpipes and harvest rainwater for your plants, instead of using than mains water. Maybe you can even build a rain garden!
  • Don’t pour things down the sink that don’t belong there, like oils, fats and greases – they block drains and can cause spills.
  • Join a citizen science scheme like Riverfly or FreshWaterWatch and collect data on how healthy your rivers are that can help organisations like Rivers and Wildlife Trusts make the case for a change in management.
  • Ask your MP what she/he is doing to protect our rivers and water resources, and how she/he ensures water efficiency is maximised for businesses as well as households.

But first of all, make sure you get outside and just have a look! Have a wander along your river and marvel at the diversity of habitats and things you can see. And if you do see two Nordic gods who look like they’re up to no good, tell them to come back in 7 years…

The River Wandle.

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