Flooding 7 River Tees Case StudyPresentation Transcript
River Tees case study Key idea: River use and management Examples of hard engineering solutions on a major UK river Need photocopy of R. Tees case study sheet BP93
To study a UK river from source to mouth
To know the uses made of the river
To recognise how the river is managed
The River Tees
The River Tees is located in north-east England.
Its source area is high in the Pennines in the west and the river flows eastwards into the North Sea.
The source of the River Tees lies on Cross Fell in the Pennines, 893m above sea level, where rainfall is over 2000mm a year.
Run-off is high because of the impermeable rocks and the steep slopes.
The valley cross-section is steep sided and V-shaped and the long profile has a steep gradient.
In the Tees Valley the water quality is very high which makes it suitable for use as a water supply for homes and industry.
The high rainfall also gives a reliable water supply.
There are several reservoirs in the river basin, the highest of these is Cow Green reservoir. -The reservoirs also help in flood control.
The River Tees is 'flashy', meaning that water levels can rise very quickly following a rain storm, storing water in the reservoir helps to reduce flooding in the lower course
Cow Green Reservoir
Cow Green, a two mile long reservoir was built between 1967 and 1971 to supply the industries of Teesside The dam is about 1/4 mile long, took three years to build and holds back 40,000 million litres of water
Downstream the valley begins to widen and the river starts to meander .
There are more bridging points and larger villages and towns, such as Yarm.
Nearing the river mouth the river meanders in large loops across its flat tood plain (it is 30km as the crow flies from Darlington to Teesmouth but the river travels 75km)
It used to be longer but several of the meanders were cut off in the nineteenth century to shorten the journey for boats navigating the river up to Stockton and Yarm.
The river flows into an estuary where there are huge areas of mud flats such as Seal Sands. These are important wildlife habitats The lower course is much more urbanized and industrialized than the upper sections, with large towns such as Stockton and Middlesbrough and the vast port of Teesside. Industries such as chemicals, ships, steel-making and engineering
Teesside is a major centre for the ICl petrochemicals industry based at Billingham and Wilton. Oil and gas are brought ashore from the fields in the North Sea. Shipbuilding has been replaced by oil platform construction and there is a huge modern integrated steelworks (raw materials are converted to finished goods in one factory) at Redcar. The heavy industries (bulky/large raw materials and finished products have taken advantage of the flat and relatively cheap expanses of mud flats in the estuary. The land is easily reclaimed and there is a nearby labour supply and good transport: networks. The port also provides a sheltered harbour for the import of raw materials and the export of finished goods.
River basin management
The River Tees has a long history of flooding.
The Tees valley is also home to a large population and many industries, all requiring a reliable water supply.
The river is managed to provide a water supply and to control flooding.
In recent years there have also been developments to increase its potential for recreation and tourism.
Cow Green reservoir was built in 1970 to provide water for the growing industries on Teesside.
It is a regulating reservoir, storing water in times of plenty and releasing enough for the needs of industry in times of low flow.
In times of severe summer droughts water can be added to the River Tees via a tunnel which connects it to the River Tyne and Kielder reservoir.
Yarm's flood defence scheme
Yarm, a historic market town and once an inland port, is located on the inside bend of a large meander.
Yarm is particularly prone to flooding. The most recent serious flood was in January 1995.
Since then a new flood defence scheme costing £2.1 million has been built The scheme also incorporates features designed to reduce the visual impact of the walls and to enhance the environment.
Improved flood warning systems. These have better liaison with the Meteorological Office, police and other emergency services.
New development discouraged building on low-lying and flood-prone land is discouraged - an example of land-use zonation (land is used for activities not damaged by inundation e.g. playing fields, parks, urban forests/walks etc)
Yarm flood defences
Reinforced concrete walls with metal flood gates for access by people and vehicles
Gabions to protect walls and embankments from erosion
Fishing platforms, street lighting and replanting to improve the environment
Building materials approved by English Heritage to remain in keeping with existing architecture
Management in the Lower Tees Valley
The Tees Barrage (a man made barrier across a river) -The aim of the Tees Barrage was to improve the water quality and recreational value of 22km of the lower Tees. The barrage was completed in 1995 and cost £54 million.
The 22km stretch of river between Yarm and Stockton is now kept permanently at high tide.
The water is fresher and cleaner as it does not mix with the tidal salt water in the lower estuary.
The barrage also reduces the risk of flooding at very high tides or during a storm surge.
The barrage has acted as a catalyst for £500 million of investment in offices, housing, educational, leisure and shopping facilities.
Dredging The lower stretches of the Tees estuary are dredged (sediment is extracted) periodically to improve navigation by maintaining a deep-water channel. There has also been some dredging in the upper parts of the estuary to reduce the flood risk - it increased the capacity of the channel
Flood Control on The River Tees
1. Produce a brief fact file:
Amount of precipitation
Nature of rocks
How river is managed in upper course
Uses of river
Nature of flood defences around Yarm
Other engineering strategies –straightening and dredging
Reasons for building Tees Barrage
2. Overall which type of engineering strategy dominates – hard or soft engineering?