River Case Study - Carding Mill Valley

Where is Carding Mill Valley?

Shropshire, UK

How long is Carding Mill Valley?

2.8km

What is the source and mouth of Carding Mill Valley?

Source - A natural spring on the mountain at 460m

Mouth - Feeds into River Severn at Shrewsbury at 70m elavation

What is the geology of Carding Mill Valley?

Permeable sedimentary rock

Mountain acts as an aquifier (stream never dries even in summer with 8+ week no rain)

What is the % land usage of Carding Mill Valley?

95% Agriculture

5% Recreation & Tourism (National Trust Takeover in 1960s, path and stream have flood defence installation)

What is the flood history of Carding Mill Valley?

1970s - Debris built up in stream so water couldn't flow freely

Flood defences installed in 1930s (dams) updated in 1960s

What are the flooding implications of Carding Mill Valley?

October 2017 saw a heavy downpour in the area

100s of tonnes of rock, earth and obstructions picked up by water and deposited along the valley

Large section of stream bank next to car park threatened roads

Area was cornered off

How have humans impacted Carding Mill Valley?

Farming - Victorian times woodland deforested for sheep farming

Tourism - 5% of land use

Flood defence - Dams and stone trap built to prevent floods

What is the hard engineering of Carding Mill Valley?

Stone trap - A concrete base that catches stream debris (rocks/pebbles), costing £1,000 per 18 months

Dams - Built to control level of stream, ineffective

What is the soft engineering of Carding Mill Valley?

Flood warnings - Flood warning system measures and tracks discharge to warn residents of risk

Flood plain zoning - Council aware of issues building on flood plain and consider when building houses

Tree planting - Planted to increase interception and slow surface runoff