Protecting our precious chalk streams – Our Award Winning Success Story
The Bulbourne River is a key feature of the Moors and is one of only 210 chalk streams in the world, 160 of which are in England. It flows through the Chiltern Hills, part of a system of chalk down lands throughout eastern and southern England, which formed between 84 and 100 million years ago in the Cretaceous Period when the area was a chalk-depositing marine environment.
Our chalk streams have characteristic features that support special wildlife habitats and species, thanks to a combination of geology and climate. They are fed from groundwater aquifers, meaning that the water is of high clarity and good chemical quality. It is the quality of the waters as well as the gravels of the river bed that make chalk streams so precious for invertebrates, such as dragonflies and damselflies.
The abundance of insects in a pristine chalk stream provides food for fish species, and the well vegetated banks and channels provide fish with shelter from predators. Chalk streams are important habitats for fish such as brown trout, brook lamprey and bullhead. Chalk streams also have characteristic plant communities, many of which can be seen in the river, for example water crowfoot and starworts, with plants such as watercress and lesser water parsnip along the margins. These plants and the crystal clear waters make chalk streams the most beautiful and iconic of all our rivers.
Restoring the Bulbourne back to its natural beauty
Over the years the Bulbourne River has been heavily compromised by historical changes. The construction of the Grand Union Canal, activities such as milling, fisheries, watercress production, groundwater abstraction and urban development have all contributed to its modifications. These have affected the condition and volume of the flow and consequently, under the Natural Environment and Rural Communities Act 2006, the Bulbourne was listed as a priority habitat for restoration.
In 2013, in conjunction with the Environment Agency and other interested parties, The Box Moor Trust embarked on a restoration project for the Bulbourne which included:
- Re-grading the banks to narrow the channel, in order to create more sinuosity and increase flow velocity.
- Altering the banks to make them shallower to encourage vegetation growth and improve ecological value.
- Installation of woody debris to help create fast and slack flows, providing habitat diversity and helping to clean and sort gravels.
- Stabilisation and narrowing of river crossing points.
- Reconnecting the floodplain and creation of floodplain scrapes (also known as seasonal ponds) to restore more natural chalk stream hydro-morphology.
- Bed-raising where the channel has been over-deepened to speed up flow, thereby creating cleaner water. This encourages fish and other wildlife to thrive.
The Bulbourne today
What we now have is a river that has returned to its natural, healthier state, a chalk stream that has been restored to its former, meandering flow. Its wetlands attract an abundance of habitats for all wildlife, including fish, invertebrates and plants. If you look closely you may see otters, herons, egrets, caddisflies, dragonflies, damselflies, toads, frogs, grass snakes, graylings, bullheads, chub, roach and much more.
Double Award Winning Project
The River Bulbourne Restoration scheme has won:
- “Best medium-scale habitat enhancement scheme”, recognised by the Wild Trout Trust Conservation Awards and
- “Best Practice Award for Small Scale Practical Nature Conservation” recognised by The Chartered Institute for Ecology & Environmental Management.
Special thanks go to our partners, volunteers and staff who all made this project possible.