Severn Barrage - Coastal Developement Case Study

Question 1

What are the potential benefits of a Severn barrage?

Answer 1

• The government must reduce its CO2 emissions by 80% by 2050.
• A tidal barrage, which could generate up to 5% of the UK’s energy, would help the government meet that target.
• The Severn Barrage would create many local jobs; it’s estimated such a huge project could increase employment in the Severn Estuary region by up to 50%.

-The barrage would act as a flood defence, protecting the estuary from storm surges.
A reduction in the tidal range of the estuary could potentially make swimming safer. This could be a boost to tourism.

-Bristol and the South West could become hubs for renewable technology. This could create lots of specialised employment and business opportunities (e.g. science roles in research and development).

Question 2

What are the potential costs of a Severn barrage?

Answer 2

• 85,000 birds are dependent on feeding grounds within the Severn Estuary.
• The barrage would generate coastal squeeze, causing a loss of vital mudflat habitats that these birds need to survive.
• Salmon use the estuary as a migration route. If a barrage is constructed, that migration route may be obstructed.
• The barrage would prevent water movement, causing it to become more turbid (contains lots of still sediment). This would be issue for many fish, as only specialised species can survive in highly turbid water.
• The ports of Avonmouth and Cardiff handle 3% of UK shipping and are supporting approximately 15,000 jobs. A barrage would make using such ports extremely difficult, putting a significant amount of trade and jobs at risk.
• The barrage could increase the risk of flooding in the Severn Estuary, as a barrage would mean increased water levels.
• The lifespan of a potential barrage is estimated to be only 120 years. Is this enough time to fully recoup the costs of construction?

Question 3

What is the proposed coastal development?

Answer 3

-In 1989, £4.2m study into building a tidal barrage across the Severn Estuary.

-The Severn Estuary has the second highest tidal range in the world, meaning a barrage could potentially generate enough energy to meet 5% of the UK’s annual consumption.
The size of the barrage would depend on its location in the estuary.

-To achieve maximum energy output, the barrage would have to be approximately 16km.
The barrage would take 6-9 years to construct.
The construction of the barrage would likely be over £13bn.