Geographical Association

Join the GA

The leading subject association for all teachers of geography

Wallasea Island Case Study: What is the coastal flooding hazard?

Wallasea Island is on the south side of the Crouch Estuary in Essex, which is also linked to the Roach Estuary. Like other estuaries in Essex, these are at risk of flooding because:

Tidal Flood Zone
  • reclamation of intertidal land has narrowed the estuary channels
  • flood embankments restrict the tidal flow, leading to erosion in the estuary channel and putting pressure on the flood defences
  • on low ebb tides mud is deposited in the channels, leading to a decrease in channel depth
  • sea levels are rising as a result of climate change, putting additional pressure on flood defences so that the chance of breaching and overtopping of defences is increased.

Together these mean there is a significant risk of flooding in South Essex from high tides and storm surges. It was a combination of these that caused the 1953 floods. In a 200-year annual probability flood, Foulness, Wallasea, Potton and Canvey Island would be inundated.

The threat of coastal flooding puts a wide range of assets in the coastal floodplain at risk, including 2,700 properties, 9,500 hectares of high-grade farmland, 168km of flood defences and a variety of natural habitats. Large areas of land are several metres lower than the normal high water in the estuary. As sea levels rise intertidal wetlands and saltmarshes in front of sea defences - internationally important wildlife habitats - are eroded by rising mean sea water levels. This process is known as coastal squeeze.

The Roach and Crouch Flood Management Strategy is used to identify the best way of managing flood defences to help counter the threat of flooding. It is part of the Essex Coast Shoreline Management Plan.

It is clear that that the estuaries cannot be maintained in their present form, and the Flood Management Strategy will ensure the flood defences in these estuaries are managed and improved in an integrated way. The solutions to the increased flood hazard include:

  • hard defences such as sea walls, which will continue to be important to protect towns and cities
  • soft defences such as the managed realignment of coasts, for example the Wallasea Island Project


View: Essex Estuarine Strategy

View: Coastal Futures

Download: 'Sea level is not level: the case for a new approach to predicting UK sea-level rise', Roland Gehrels & Anthony Long, Geography, Spring 2008

Next page >>> 

Comment on this page

Comments made by GA members appear instantly and don't require security words to be entered - make sure you're logged in!   Guest comments will be sent to a moderator for approval.

GA members can add a profile picture and their comments appear instantly

Join the GA

Please complete all fields

Journals - Free Access for GA Members

The Autumn 2014 issue of Primary Geography focuses on geography out of the classroom.

The Autumn 2014 Teaching Geography focuses on teaching about places.

The Autumn 2014 issue of Geography

Online Shop - Up to 30% Discount for all GA Members

KS3 Geography Teachers’ Toolkit. Introducing India: What ar..

£18.99 / £13.99 *

Add to basket

Global Energy Security (DVD)

£61.99 / £50.99 *

Add to basket

KS3 Geography Teachers’ Toolkit. The Role of Stones: How do ..

£18.99 / £13.99 *

Add to basket

Collins Junior World Atlas (Third edition)

£9.99 / £8.99 *

Add to basket

Debating Energy Futures: Coal, Gas and Nuclear (DVD)

£61.99 / £50.99 *

Add to basket
<-- -->

Your shopping basket is empty.

Items in basket 0

Basket Total £0.00

View/Edit Basket

* Applies to Full Personal, Group and
Concessionary members only

Resource Finder

Enter a keyword below or click 'advanced search' for more options

Advanced Search

Resources section
  • Visit the Discover the World website for geography resources
  • Find out more
  • Advertisement:
  • Visit the Fourth Global Conference on Economic Geography 2015 homepage

© Copyright The Geographical Association 2013

Charity No: 1135148 Company No: 07139068

Website design and development by Ledgard Jepson