The UK’s network of canals and rivers provide homes for all kinds of plants and wildlife. Some waterways run through very rural areas, while others are hidden green spaces in towns and cities.
Canal and river habitats are surprisingly diverse - whether it is in the water or alongside it, nature thrives on the waterways.
The waterway network and its towpaths create valuable green corridors, connecting various wildlife sites and habitats. This allows animals to move freely, and brings the heart of the countryside into urban areas.
Though built for industrial and agricultural freight, our waterway channels are now our most obvious wildlife habitat. Other water features, such as rivers, side arms, winding holes and backwaters add to the diversity of aquatic habitats available.
Canals and navigable rivers were colonised by plants and animals soon after construction. Now, 200 years later, many are designated as important nature sites at local, national and international level. Their slow flows and managed water levels provide a unique habitat that has become a vital resource for wildlife.
Waterway banks, where land and water meet, are particularly valuable for biodiversity. Depending on the structure and vegetation cover, the waterway banks can provide habitat for a wide variety of wildlife including dragonflies, water birds, water voles, crayfish, and otters.
Towpath verges can extend many miles along waterways and support a very rich flora and fauna. Their wildlife value has developed over a period when meadows and field margins in the wider countryside have lost many species. Even narrow verges can support a range of animals and plants and be important oases for local wildlife in urban areas.
Flower-rich towpath verges have largely developed over the last 50 years as towing of boats declined. In more rural locations, the towpaths are managed to ensure flower-rich verges are maintained providing food and shelter for a variety of insects and larger animals.
Canal hedgerows were frequently planted by the original canal companies, and are therefore some of our oldest established habitats. Hedgerows are found along most of our canals and provide cover, shelter and food for many animals. They can also act as corridors between isolated habitats providing shelter for animals as they move between sites.
Cuttings and embankments are essential parts of canal and reservoir structures. The habitats on their slopes vary and can include rock exposures, grassland, woodland and scrub. Many have been designated as Wildlife Sites for their wildlife or geological interest and all add to the diversity of habitats on our network.
Grassy embankments are often particularly suitable for wildflowers, including cowslips and orchids, and there is usually a rich insect fauna associated with this kind of grassland vegetation.
Our many built structures play an important, but often overlooked, role in biodiversity. Bridges, tunnels, locks, weirs, cottages, warehouses and offices all provide valuable habitat for wildlife. In general it is the older structures, built of stone and with lime mortar, that have the greatest value.
Bats are probably the most well-known animals that use our structures. However, as they are beside the water, our structures support a very diverse range of other animals and plants, including white clawed crayfish, freshwater sponges, and nesting birds.
With over 100 reservoirs and many other lakes and ponds associated with our waterways, we have a significant ‘open water’ habitat. As with the rest of our network, many of the reservoirs are now over 200 years old, and plants and animals moved in soon after they were built. Today many are designated as Wildlife Sites at local, national and international level, often because of their importance for water birds.
One of the key features of these water bodies is the ‘draw-down zone’. As water is used throughout the summer large areas of mud are exposed providing valuable habitat for rare plants, mosses and invertebrates.
Last date edited: 17 May 2018