Soft Engineering - Abbotts Hall Farm

Question 1

Where is Abbotts Hall Farm?

Answer 1

Abbotts Hall Farm is an area of farmland in Essex, South of Colchester

Question 2

Who owns Abbotts Hall?

Answer 2

Essex Wildlife Trust

Question 3

What is Abbotts Hall the site of?

Answer 3

Abbotts Hall is the site of a pioneering managed retreat scheme developed in 2002

Question 4

Why Managed Retreat at Abbotts Hall Farm?

Answer 4

• Essex’s saltmarshes were disappearing very rapidly (60% of marshes eroded by the rising sea levels in last 20 years)
• Due to drainage of marshes to create farmland and ‘coastal squeeze’
• So, conservation & restoration of habitats is main reason for managed retreat
• Salt marshes would combat the problems of sea level change

Sea Walls (Breached)
• The 3.5km sea wall was built 300-400 years ago along the southern edge of Abbotts Hall land
• Maintenance of sea wall was becoming expensive and needed repairing
• Cost-benefit analysis said breaching defence is best option

Question 5

Method of Managed Retreat at Abbotts Hall Farm

Answer 5

• Counter walls constructed in 2002 at each of Abbotts Hall to protect neighbouring land from flooding
• (Low value) agricultural land brought to let flood
• 5 breaches made in old sea wall to allow flooding in October 2002 (10m wide & one 100m wide)
• First big tide flooded 120 acres of Abbotts Hall in November 2002
• Land which floods creates a saltmarsh

Question 6

Economic Consequences of Abbotts Hall Farm Managed Retreat

Answer 6

• Expensive to replace old sea walls & not sustainable in area at risk of sea level rises
• Income from farmers is lost
  + Income can be generated by tourism as wildlife enthusiasts, bird watches visit area
  + Salt marshes cheap to create and maintain (average about £12000)

Question 7

Social Consequences of Abbotts Hall Farm Managed Retreat

Answer 7

+ Abbotts Hall Farm strategy could be used as a precedent (example) to other areas with same issues
+ Tourism creates jobs
- Farmers lose jobs due to farmland flooded
- Strategy not initially popular with some residents as they were concerned marshes would not offer same level of protection as improved sea walls

Question 8

Environmental Consequences of Abbotts Hall Farm Managed Retreat

Answer 8

• Agricultural land is lost so less can be produced
  + Marshes act as a natural sea defence
  Waves are slowed down as they cross the marshes (like waves slow on beaches)
  + They can absorb flood water
  + Adapt to gradual changed in sea level
  + New wildlife habitats are created in the marshes
  + Larger variety of wildlife e.g. large numbers of young bass, herring and 14 other types of fish

Question 9

Define Managed Retreat

Answer 9

Managed Retreat is allowing an area that was not previously exposed to flooding by the sea to become flooded by removing/breaching coastal protection

Question 10

Define Salt Marsh

Answer 10

Salt marsh is an area of coastal grassland that is regularly flooded by seawater