5.1 Approach
This section provides guidance on the systematic process of choosing systems best suited to
particular flood protection scenarios. This selection process is the follow up to the initial
decision process outlined in Figure 3.1 and presupposes the decision to consider the use of
temporary and demountable defences was the chosen option.
The approach to the selection of an appropriate system is a risk-based one, which
systematically removes systems that cannot be safely deployed within the available time by
the available resources. Once closure is achieved, the ability to effectively protect the area at
risk is then considered by ensuring the appropriate protection levels and integrity of the
protection system. Other relevant economic, environmental and/or whole life management
issues would then assist in making the final decision.
Due to an increasing number of available systems and a large range of potential situations
where protection systems would be required, the selection involves a process of elimination of
unsuitable systems.
This elimination process is simplified by the gradual progression from principal types of
defences to generic types, and then onto specific systems. Through each of the stages there is
a constant review of the ability of the available systems or groups of systems to effectively
provide the required protection at the required location, with the required resources and within
the available time. All these requirements need to be satisfied for a system(s) to be suitable.
This process is illustrated in Figure 5.1.