Film ID: NEFA 21984 DERWENT RESERVOIR 1969 Visitor TabsDescription An industrial film that shows the construction, opening and extended use of the Derwent Reservoir in County Durham. The film includes the opening of the reservoir by Princess Alexandra in July 1967 and then goes on to examine the reasons for building it and some of the technical innovations and difficulties that had to be developed or overcome. The film ends showing how the reservoir, as well as providing water for the region has also developed into a leisure facility with fishing and sailing now well established. Title: Derwent Reservoir A windswept view of Derwent Reservoir follows. Title: 18th July 1967 The opening ceremony of the reservoir shows Princess Alexandra arriving by limousine to officiate. She joins a number of dignitaries on a covered platform, decorated in blue and white. The princess announces over a microphone that the reservoir is open. A military band provides a fanfare, and the princess goes on to speak to some of the men on parade. An overhead view shows the princess accompanied by a dignitary walking across a concrete footway above the main reservoir structure. A general view shows the finished reservoir and its associated buildings and landscaped surroundings. The next section shows some of the internal structures such as tunnels through which pipelines run and chambers that house control valves. A view of an animated map of Great Britain follows which zooms in on the North East area of England. The rivers Derwent, Tyne and Wear are highlighted followed by the towns of Newcastle, South Shields, Sunderland and Durham. The map shows the location of the new earth dam and reservoir, as well as of the location, a few miles west of Durham city. The map also shows the extent of the lake which will be formed by the dam, which just falls short of the villages of Blanchland and Edmundbyers. General views follow of the Durham landscape that will be altered by the development, and the river Derwent. Views follow of some of the buildings, including three farms and other features that will be lost because of the building works. The map also shows location details of the dam, the whole project, according to the commentary taking six years to build. The construction will involve diverting the river Derwent and the animated map shows the route this will take. Construction techniques had to overcome geological problems, views follow showing the building of an outlet channel hampered by large geological deposits of sand and silt. A special pipe system was used for removing excessive groundwater, views follow showing the unusual pipework. Removal of the groundwater allowed heavy excavators to gain access to the channel, views show a number of excavators at work. General views show the excavation of shafts and tunnels. Still photographs show the inclusion of steel ribs in the tunnels that help support the tunnel structure. More photographs show the tunnels lined with concrete. The commentary states that by May 1962, the tunnels and channels were ready fro the diversion of the river. A bulldozer moves gravel and other material in the river, to block its normal route. General views show excavators and bulldozers moving earth and other material to alter the course of the river. An animated diagram shows how trial boring revealed an area of weak clay in the substrate. Excess water in the clay is to blame and has to be drained, so that the ground will take the weight of the new dam. Views show special drilling equipment being deployed to drill 4500 hundred ‘sand drains’ in the ground that will be filled with sand and gravel. The weight of the dam will squeeze the clay and the water will be dispersed into the drains. General views show sand and gravel being excavated locally for the concrete needed to build the dam. A screening plant washes and grades the excavated material, lorries deliver the sand and gravel to the plant. Closer views show the screening plant at work. Lorries then take the washed and graded material to the concrete plant. The concrete is distributed to various parts of the project site. The commentary states that 50,000 cubic yards of concrete was made for the project. An animated diagram shows how water is prevented from escaping under the dam. Clay is used to line a special cutting to resolve the problem. The cutting is shown under construction where half a million cubic yards of spoil wqs removed, and replaced with rolled clay and backfill General views follow of heavy earth moving equipment scouring the landscape. The clay water barrier is checked by test drilling at various stages during construction. A man operates a special apparatus to check a sample of the rolled clay. General views show heavy earth moving equipment at work shaping the landscape. At it’s peak the total vehicle fuel consumption on the site was a 1000 gallons a day. The machines at this stage were working into the night, a number of excavators are shown working in the gloom, with headlights on. General views show progress of the dam construction, broken stone is added to some parts of the construction to help water dispersement. Technicians deploy special test equipment to check on the stability of the dam during construction. One of the technicians places a measuring sensor in the fabric of the dam. Workmen lay nylon tubing in trenches which is connected to sensors. These tubes will be connected to gauges housed in a specially built chamber. A view shows a man checking an array of gauges and he also checks a piece of electrical apparatus. Bulldozers, prepare a section of the dam for landscaping, but by the end of 1965 the work of heavy earth moving equipment is finished, and a general view shows the dam and reservoir site nearing completion. Concrete blocks are used to prevent wave damage to the reservoir. Workmen make special moulds to make the blocks, then fill the moulds with concrete. A crane lifts one of the blocks after the mould is removed, men brush the block clean then put it to one side. General views show the blocks being put in position on the banks of the reservoir. Because of the colour of concrete used in the blocks, the visual effect of the finished area is of a sandy beach. An animated diagram shows how the diversion channel for the river will be plugged. The diagram also shows that after the plugging, the lake behind the dam will fill and extend. General views show work in progress to plug the diversion channel. Men work in hot and difficult conditions to get concrete to where it’s required. Water runs through the area they are working. Pipes that take water from the reservoir are laid, showing workers wading through water. General views show trenches dug into the landscape near the reservoir to take the same pipes to a water treatment plant at Mosswood a small hamlet nearby. General views show the construction of the treatment plant. General views show the finished buildings of the reservoir, dam and surrounding landscape. A man plants saplings in scrubland adjacent to the reservoir. A couple stop their car in one of the new lay-bys built on new roads that skirt the reservoir. The lay-bys are there to encourage people to stop and take in the views around the reservoir. The film cuts to a group of people walking across a field, they head towards the camera, in the background is the reservoir. A lorry parks with its load of farmed fish, mainly brown and rainbow trout that will stock the reservoir. Fishing will become one of the main pastimes that can be enjoyed at the reservoir. General views show a man fishing, while another man stops at a kiosk outside a small building where he applies for a fishing permit. A man ventures out in a small motor boat to fish. Sailing is also popular and members of the Derwent Reservoir Sailing Club sail small dinghies on the water. Aerial views and other more general views of the reservoir, end the film.