An introduction to Flood Risk Management and Cost-Benefit Analysis
How do you start to calculate flood damages and benefits?
- You need to assess the impact of all the floods that might occur in your locality, not just a single event, as a scheme will defend against more than one flood.
- This means you calculating what are called the ‘annual average damages’ (i.e. the average of all floods that can occur there)
- You need to proceed step-by-step and Figure 1 gives a flow chart of the steps that need to be followed.
There are some key official ‘decision rules’
- The Environment Agency provides a logical decision making approach to guide you about the ‘best’ scheme to tackle your flood problem.
- The options open to you should be assessed using these rules, so as to seek the best value for public money.
- That appraisal will almost always be done for you by the authorities, but you will need at some time or another to understand what it means.
Who else do you need to think about?
- You should not assume that everyone necessarily wants the same scheme you identify as ‘the best’ in benefit-cost terms.
- Early engagement with all stakeholders and working towards a common goal is very important.
- It’s good to talk about whether all ‘stakeholders’ agree with what a scheme is, what it looks like and how much flood damage it will avoid.
- Authorities can help you to find the right data to start thinking about your own risk and benefits.
- Approach the Environment Agency for main rivers and local authorities for ordinary watercourses to seek application for funding and advice, which can only be done through the Risk Management Authority.
