Wednesday 13 March 2013

Case Study: Coastal Management in Dawlish Warren

Dawlish Warren in South Devon is one of Britain’s best loved spits and beaches but is under threat as it is being eroded at an alarming rate. However the beach on the other side of the River Exe Estuary, Exmouth, is growing.

Its problems include:

  • Less erosion of the cliffs at Langstone rock headland means less sediment for the beach
  • Longshore drift restricted by the construction of a large breakwater designed to protect part of the headland
  • Less constructive wave action than in the past


Protection: The spits at Dawlish Warren are protected by revetments, gabions and groynes, with its natural dunes and saltmarshes act as a soft defence structure both behind the Warren and on the seaward side.


Reasons for Protecting Dawlish Warren:

1.       It is a valuable habitat for birds and plants eg a wide array of wading birds like the avocet

2.       Highly popular with tourists - 20,00 people on the spit at peak times (the Environment Agency concluded that between 18th August and the 12th December 2004, 487,624 visitors visited Dawlish Warren equating to a spend of £3,787,463)

1.       Tourism brings revenue to the area such as the car park charges of £1.75 an hour

2.       There are over 40 local businesses on the spit that provide goods for tourists and jobs for local people (122 full time jobs)

3.       The Spit protects other low lying areas of the Exe Estuary from waves and flooding

4.       This could result in damage to valuable infrastructure, such as the railway line, and increased flooding for the whole the Exe Estuary

5.       It’s a traditional bucket and spade resort serviced by approximately 11,260 bed spaces, 10,560 of which are holiday park units and touring pitches compared to Exmouth’s 8300


Hard Engineering in Dawlish Warren:

In 1992 the National Rivers Authority (part of the Environment Agency) began work to reconstruct the rock armoured revetment; landward of the timber piles, a 300m line of steel sheet piles were sunk to offer further stability; 35,000 tonnes of Norwegian granite boulder were imported to face the new sea wall. The cost was around £1.5 million.


Sustainable Development:

The existing Exmouth seawall frontage, owned and maintained by East Devon District Council, has arrested beach movement that would otherwise have taken place on that shoreline. Recent storms and associated damage to defences have highlighted the need for a long-term, sustainable coastal management.


SMP Suggests… Due to the dynamic nature of the distal end of the spit it would be preferable to allow it to evolve as naturally as possible. The protection that the spit affords must be continued. The short term policy is to Hold the Line along the seaward face of Dawlish Warren. The estuary-facing side of the spit would be left undefended and allowed to continue to evolve naturally during this period with No Active Intervention during this period. Beach management techniques such as recycling and/or recharging could also be considered in the short term. It is anticipated that the policy determined by more detailed study in the short term will result in either Hold the Line or Managed Realignment being adopted for Dawlish Warren.

5 comments:

  1. Thanks so much for this, I really needed to learn this for GCSE Geography

    ReplyDelete
  2. Is Dawlish Warren a discordant or concordant coastline?

    ReplyDelete