Economic Considerations
The development of flood management options must meet the criteria set by the Treasury and the Department for Environment, Food and Rural Affairs (Defra). These criteria include:

• The cost of flood damage that would occur if the existing flood defences in the Essex Estuaries are left to fall into a state of disrepair must be defined (the Do Nothing Option);
• The most cost effective option, in relation to the benefits it provides and the assets that it protects, must be chosen as long as it meets the technical and environmental criteria; and
• Opportunities for partnerships must be sought to ensure that any potential for joint development is identified.

The justification for implementing a flood management option will partly be determined by the assets that it protects. Within the Roach and Crouch Estuary complex the assets include residential, commercial and industrial properties, farmland, recreational land and grass land.

The importance of agriculture to the local economy, and to the economic case for flood management, is such that a land agent was employed by the study team to evaluate flood damage to land and crops.

A numerical flood model has been used to predict how the Roach and Crouch estuary flood plain may flood under different storm and surge scenarios. The flood model output data has been used to assess and calculate the number of assets affected by flooding during each scenario and to develop an economic appraisal of flood damages and losses to property, land and infrastructure within the Roach and Crouch flood plain. A high level economic appraisal has been carried out in accordance with Government economic guidance. In some cases, it has been identified that the cost of maintaining a flood defence exceeds the value of the assets that it is protecting and therefore there may not be an economic case for the Environment Agency to continue maintaining the flood defence in the future.

Defra produced guidance (Defra, 2004, Maintenance of Uneconomic Sea Flood Defences: A Way Forward) on the approach that the Environment Agency should take regarding the future maintenance of uneconomic seawalls. The guidance stated that any defence that is no longer economic (i.e. the cost of maintaining a flood defence exceeds the cost of the assets that it protects) must be considered for 'withdrawal of maintenance' under the Environment Agency's permissive powers. The exceptions to this are where a flood defence currently protects internationally important habitat or where the collapse of the flood defence could have a significant negative impact on the wider estuary and neighboring flood defences due to changes in the estuary processes or the release of contaminated material. The Roach and Crouch Flood Management Strategy has applied this guidance throughout the decision-making process for selecting the preferred flood management options.