Severn Barrage tidal power scheme/economic benefits and environmental costs

Question 1

EIA negative impacts

Answer 1

• Loss of saltmarsh and mudflat habitats-important feeding grounds for waders and wildfowl. The estuary is a conservation wetland
• Migrating fish, such as salmon, shad and thwaite severely affected, with loss of spawning habitats
• Sediment flows in the estuary would be disrupted
• Severn Tidal bore would be reduced in size
• Problem with the dilution and dispersal of sewage waste in the absence of strong tidal currents

Question 2

EIA positive imapcts

Answer 2

• Generation of renewable energy and reduction of carbon emissions (1 million tonnes per year) meet international climate change obligations
• Dunlins benefit from stable water levels
• Studies of La Rance in Brittany suggested that they can increase biodiversity, improve water quality and oxygen levels

Question 3

CBA benefits

Answer 3

• Generate 5% of the UK’s electrical needs
• Renewable form of energy
• Fills the UK’s ‘Energy Gap’ as old nuclear power stations decommissioned over the next 5-10 years
• Life span of up to 150 years
• Creates 35,000 and 10,000 locally
• Provide leisure activities
• Strengthen flood defences around the Severn Estuary, act as a barrier.

Question 4

CBA costs

Answer 4

• Around £20 billion
• Disruption of shipping ports such as Avonmouth
• Weston-super-Mare beaches degrade affecting tourism
• Negative impact on local fishing and the extraction of aggregates from the estuary.