Somerset Levels Flooding 2014 Flashcards
(11 cards)
What are the Somerset Levels and Moors?
Extensive area of low lying farmlands and wetlands which used to be covered by the sea but is not wetlands and a landscape of rivers.
What rivers drain the area?
Tone and Parrett, whrich flows to the Severn Estuary via Bridgewater. Flooding has occured naturally here for centuries.
Why are areas like the Severn Estuary at risk even though they’ve been flooded naturally before?
The area has been developed for farming and settlement, so many people are at risk of these extreme flooding events.
Why is it so prone to flooding?
Claimed to be one of the lowest areas of the UK, which lies below the high water mark of spring tides. It’s maximum altitude is 8m ASL.
Social impacts of the flood
- 600+ houses flooded
- 6880 hectares of agricultural land flooded, cutting off villagers
- Crimes- 900 litres of fuel stolen from a pumping station in Westonzoyland + bikes were stolen
- Main roads were closed including A361, and train services were distrupted.
- 16 farms evacuated
- Some residents evacuated to temporary accommodation for several months.
Economic Impacts of the flood
- 2015- Economic Impact Assessment estimated that winter floods cost Somerset up to £147.5 million, including emergency resposes, railway and residential.
- Over 14,000 hectares of agricultural land under water up to 4 weeks affecting food supply and income from it.
- 1,000 + livestock evacuated
- 80+ roads closed at cost of £15 million to economy
- Bristol and Taunton railway lines closed
Environmental Impacts
- Heavily contaminated floodwaters with sewage, oil, chemicals etc.
- Lots of debris had to be cleared
- Stagnant water that had been collected for months had to be reoxygenated before being pumped back into rivers.
Physical Causes
- Quick succession of depressions (areas of low pressure) by Atlantic storms caused prolonged rainfall, and gale force winds. Roughly 350mm of rain fell in January and February (100mm above average). The river couldn’t cope with the volume of water in it causing the river to burst its banks.
- High tides in Bristol Channel and narrowing created tidal surges, blocking floodwater trying to escape Somerset Levels into the sea.
- Coastal defences coped with tidal surges
Human Causes
- River wasn’t dredged for 20 years, so sediment raised channels and redyced the rivers capacity.
- Changes in farming practices. Much of land converted from grassland to grow Maize. Intensive use of land prevented infiltration, because it’s less capable of holding water causing increased surface runoff.
Immediate Responses
- Villagers cut off by floods used boats to go shopping or to school
- Local community groups and volunteers gave invaluable support.
Longer-term Responses
- Somerset Rivers Authority (SRA) launched in January 2015 to implement flood protection and resilience strategies identified in Somerset’s £100 million Flood Action plan.
- March 2014- 8km of Tone and Parrett dredged for £6 million to increase capacity of river channel. They are now dredged annually.
- Road levels have been raised (e.g. Muchelney) to maintain communications and enable businesses to continue during flood events.
- New flood alleviation schemes constructed at Westonzoyland and Aller
- Old diesel pumping stations replaced with effective electric pumps.
- River Banks repaired and raised to increase channel capacity.
- The Environment Agency plans to construct a tidal barrier at Bridgewater by 2024 to reduce the threat of tidal flooding. Estimated to cost £65-80 million, it will protect 11,500 homes and 1500 local businesses.
