Flood Management Options

Flood Management Polices
Four flood management policies were considered for each flood management compartment within the Strategy study area: No Active Intervention, Hold the Line, Managed Realignment and Advance the Line, and a brief description of each is given below:

No Active Intervention
There would be no further active intervention by the Environment Agency. Without intervention the defences would eventually fail and areas currently protected from flooding would no longer be protected. This would happen gradually over a long period of time.

Hold the line
This would involve maintaining the existing flood defences and control structures in their present positions and increasing the standard of protection against flooding in some areas.

Managed Realignment
The policy of Managed Realignment involves the placement of a new Managed Realignment flood defence landward of the existing flood defences or realignment to higher ground. This policy would be achieved through the partial or complete removal of the existing flood defences or through regulated tidal exchange. This policy would be gradually implemented and regularly monitored in order to study any potential effects on the overall estuary shape.

Advance the line
This policy involves the construction of a new flood management scheme in front of existing flood defences.

These policies were assessed to determine which one or more policy would enable the primary strategic objectives to be achieved in each flood compartment.

The next stage involved identifying the flood management option(s) that would implement the preferred policies.

Flood Management Options
Six strategic flood management options have been considered for all flood compartments within the Roach and Crouch study area. This approach has provided an indication of the relative costs and benefits of each generic approach to flood management, and has demonstrated that the preferred overall Strategy should be formed from a combination of different flood management options.

The strategic flood management options are:

1. No Active Intervention - abandonment of all flood defences in the study area, allowing them to fail over time with rapidly increasing risk of flooding to the hinterland;
2. Maintain - whilst all defences would be maintained and repaired as necessary, the risk of flooding will steadily increase in response to climate change and, in many areas erosion will increase as well);
3. Sustain - continued regular maintenance, but with defences being raised to sustain the standard of protection currently being provided i.e. in line with the effects of climate change and sea level rise;
4. Improve - improve the existing defences to achieve a higher standard of protection throughout the study area;
5. Cease Environment Agency maintenance of all uneconomic flood defences . This option would involve abandonment of the uneconomic flood defences (i.e. where the costs of maintaining the flood defence are greater than the value of the assets that it protects over the lifetime of the strategy) irrespective of the potential impacts on neighbouring frontages, the potential for harm to environmental sites, and the potential for loss of inter-tidal habitat; and
6. Achieve the strategic objectives , where possible, through the implementation of one or more of the above options in each flood compartment. In addition, managed realignment may be considered in those flood compartments where the estuary