Understanding and assessing flood risk

1) Use the Environment Agency flood map¹ to find if the development is:

• in flood zone 1, 2 or 3
• within 20 metres of a main river or a flood defence
• in a water storage area

2) Find out whether the development is in an area with critical drainage problems². 
   Please note that areas with critical drainage problems are currently only designated in Devon and Cornwall.

3) Check your LPA’s strategic flood risk assessment (SFRA) to find out if the development is:

• in flood zone 1 now but will be at risk of flooding from rivers or the sea during its lifetime
• at risk from any other source of flooding or it will be during its lifetime
• in flood zone 3b (functional floodplain)

4) Establish the site area and check the development class

5) Find out the vulnerability classification³

6) Check table 2 of the planning practice guidance⁴ to find out if the proposed vulnerability classification is compatible with the flood zone.

1. https://flood-map-for-planning.service.gov.uk/
2. https://data.gov.uk/dataset/d10fb8e5-f3af-48c1-a489-8c975b0165de/areas-with-critical-drainage-problems
3. https://www.gov.uk/guidance/national-planning-policy-framework/annex-3-flood-risk-vulnerability-classification
4. https://www.gov.uk/guidance/flood-risk-and-coastal-change#table2