1. Increase awareness, understanding and appreciation of the value of rivers and streams, their conservation needs and their sustainable use.
2. Undertake river restoration to enhance degraded river channels and restore natural habitat features
3. Identify suitable areas for the restoration and creation of wetland habitats.
4. Protect the habitats and associated species of rivers and streams from loss or degradation through appropriate management
5. Maintain and enhance the quality of existing natural channels, and flood plain features preserving the ecological value of these watercourses.
Rivers and Streams Targets
Vision Statement: To improve the water quality and physical structure of degraded watercourses. Where possible to ensure that watercourses remain, or are allowed to become, dynamic features linked to their floodplains
|1. Increase the number of rivers with good ecological quality||expand||rivers||30|
Floodplain Grazing Marsh Targets
Vision Statement: For large scale creation of floodplain grazing marsh on agricultural land, in line with changing priorities for flood defense.
|1. To increase the area of floodplain grazing marsh in the Durham BAP area.||expand||ha||10|
Exposed Riverine Sediment Targets
Vision Statement: To improve understanding in the distribution of suitable habitats. To establish 3 key reaches at the sub-catchment scale where management is sympathetic to needs of the associated invertebrates.
|1. To maintain ersqi (ERS quality index) scores over a number of selected reaches of rivers in the Durham BAP area.||maintain||average ersqi score||356|
Vision Statement: To increase the population to the carrying capacity in all rivers systems.
|1. To expand the current range of otter to 22 five kilometre squares.||expand||5km2||22|
Rivers and streams are naturally dynamic habitats with a constant or seasonal flow of water. As dynamic systems they provide a wide range of ecological niches supporting a diverse flora and fauna. They also play a vital role as wildlife corridors.
The constant movement of water causes a scouring motion which, alone or in combination with changes in rainfall and run-off, can alter the course of the waterway. The associated features such as sand and shingle habitats, and marginal and bankside vegetation form an integral part of the stream or river and contribute to the associated wildlife that they can support.
Watercourses fulfil a range of important socio-economic functions such as water supply, pollution dispersal, provision of amenity and acting as a biodiversity resource.
Rivers can also have an impact on adjacent land through flooding and erosion. For these reasons rivers have been heavily managed in both rural and urban settings. It is essential that future management takes account of the importance of the dynamic nature of rivers and streams, and the need to maintain and improve their contribution to biodiversity, locally, nationally and internationally.
The major rivers within Durham are the Wear, Tees and the Derwent, though smaller rivers, streams and ditches are widespread throughout the plan area.
There are currently no rivers or streams in the Durham area designated as SSSIs specifically for their biodiversity value, although the River Tees, within the Upper Teesdale NNR, is cited as an example of a good upland river. The biological water quality of the rivers and streams in the area is varied, although over half are considered to be of a high standard. The majority of the “good” rivers, classes A and B, are in the uplands whilst those classified as poor or bad are normally found in the lowland reaches flowing through urban and industrial areas. Many of the poorer quality rivers, however, are valuable biodiversity resources, for example they provide critical wildlife corridors and are able to support endangered species such as the water vole; the rivers Don and Skerne being two such examples.
The Wear and Tees catchments support important stocks of migratory Salmonids. In recent years the number of sea trout returning to spawn in these catchments has been increasing. Salmon also appear to be increasing in numbers. The Wear and Tees catchments also have diverse non-migratory fish communities including brown trout, grayling, lamprey and a range of coarse fish species including dace, chub, gudgeon, bream, eel, stone loach, minnow and bullhead. Improvements in water quality, the removal of obstructions, improvements to habitats and anti-poaching strategies have all contributed to the upsurge in fish stocks in local watercourses.
Rehabilitation work is being undertaken or investigated in several areas including the River Team and the middle to lower reaches of the River Wear. Restoration of a length of the River Skerne, is an example of what can be achieved in restoring natural hydrological features to a polluted and previously heavily managed watercourse.
Even the smallest watercourses often provide an important amenity resource and riverside access affords the possibility for a wide body of people to experience freshwater and its associated habitats.
Exposed Riverine Sediments
Exposed riverine sediments are the sands, gravels and shingles of active streams and rivers. These support a rich invertebrate fauna including many rare and specialist beetles. Limited survey work from four sites in Weardale suggests it is important within an English context. This feature is limited to the middle and upper reaches of the Wear and Tees Catchments, but it is not sufficiently well characterised or mapped within the Durham BAP area.
Floodplain grazing marsh
Floodplain grazing marsh is UK BAP priority habitat which would, historically, have been much more widespread. Agricultural drainage, built development and river flood management schemes have destroyed almost all grazing marsh. Some recent schemes are starting to reverse the trend. Floodplain grazing marsh is not necessarily species rich, but can be highly important feeding and breeding ground for many birds.
Since 1996 otters have successfully colonised the River Wear, and are now widespread on our three major rivers systems, the Derwent, Wear and Tees. The return of the otter to these watercourses is, in large part, due to better water quality and consequent availability of food. Two smaller river systems remain to be fully colonised by otters in the Durham BAP area, the Skerne and the Team.
Other Durham BAP priority species that will benefit from actions in this plan have their own action plans, namely Freshwater Fish (covering salmon, wild trout and eel), White -clawed Crayfish, Water Shrew, Water Vole & Pale Bristle Moss.
The primary threats to rivers and streams in the DBAP area are:
- Point source and diffuse pollution (including abandoned mine discharges, run-off, atmospheric deposition and nutrient enrichment) are a serious threat to many waterbodies.
- Land drainage and flood defence works. Historic works have shaped the rivers that we see today. Insensitive works can affect in-stream and riparian habitat and isolate watercourses from floodplains.
- Invasive plant and animal species including, mink, signal crayfish, giant hogweed, Japanese knotweed.
- Poor or inappropriate land management can result in exacerbated erosion rates, loss of riparian vegetation, sedimentation and nutrient enrichment.
- Urbanisation and road building within the floodplain.
- Upland drainage. The use of “grips” in the uplands to drain areas of moorland can alter the flood regime. A more “flashy” regime, results in rapid runoff, higher flood peaks, and increased erosional activity.
- Poor gravel management, including extraction, damages the dynamic character and quality of exposed riverine sediments
- A conflict between otters and the recreational course fishing industry can lead to otter persecution.