Introduction

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.

Otter

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.

Current or recent activity

Otter holt construction has been a feature of riparian work by many agencies including the Durham Wildlife Trust, the Environment Agency and Northumbrian Water Ltd.

Working on the Wear (2003-2008) – is a Mineral Valleys Project based within the Wear Catchment implementing habitat improvements along the Wear and its tributaries.

The Team Revival Project (2001-2006) was a partnership between the Environment Agency and public and private sector organizations which developed a programme of environmental improvement to the Team Valley, including

•  8 ha of reedbed were created at Lamesley as part of the joint treatment system for Northumbrian Water's Birtley Sewage Works and the Coal Authority Kibblesworth Pumped Minewater discharge.

•  500m of river Team bankside habitat through the Team Valley Trading Estate were improved by installing berms to increase marginal vegetational and flow .

Catchment Flood Management Plans (CFMPs) are being developed by the Environment Agency  for sustainable flood risk management on a catchment scale.

NWL Fish Study - expand

A project was initiated in 2002 to attempt to control Giant Hogweed in the Wear Catchment. By combining the resources previously invested by local authorities and other relevant bodies it was hoped that a more strategic approach could be adopted. Unfortunately a lack of long-term funding resulted in this project being unable to implement control over the time period required to eliminate Giant Hogweed from the catchment.

Through the North Pennines Peatscapes project improved land management in the uplands will improve water quality and reduce flood risk in the downstream catchments.

Fish passes etc. – EA? - expand

Dipper Box project by Durham Bird Club (2001-2004) erected 28 boxes under bridges in the Wear catchment with 60% take-up in year one.

Threats

• 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.

Objectives To promote the multi-functional role of rivers and their importance for biodiversity, recreation and sustainable flood risk management. To undertake river restoration to restore natural habitat features and reconnect rivers to their floodplain. To support sustainable erosion control where erosion is resulting from poor land management – e.g over stocking. To ensure that riparian land management practices are not facilitating the spread of invasive plant species, and where possible are controlling these species. To reduce run-off and improve water colour from upland peatland through projects such as Peatscapes. Using Northumbria Area Wetland Feasibility Study, identify suitable areas for the restoration and creation of wetland habitats. To improve water quality and undertake habitat improvement and management in the Skerne and Team catchments to support otter colonisation. To establish natal areas for otters in all catchments. To improve our understanding of the distribution and dynamics of good quality ERS and ensure appropriate management. To raise awareness of the importance of the ERS resource. To draw up a programme of measures to achieve good ecological status (as part of the Water Framework Directive). To continue the refocusing of the work of the Environment Agency away from protection of agricultural land to the establishment of more natural morpho-hydrological regimes, for example the removal of floodbanks. Ensure improved riparian habitat management, wetland creation and greater interaction between the river and its floodplain are targeted through Environmental Stewardship schemes.