logoSouthwest Environmental Limited
Environmental Consultancy Services to Industry, Business and Individuals
02076 920 670
01392 927 961
01612 970 026 
01173 270 092 

Flood Risk Assessment - Example Report


Sometimes if it is discovered that you project lies within flood zone 2 or 3, it will be stipulated by you local planning authority that you may need a Flood Risk Assessment, although this is perceived by most as an annoyance, and its certainly can be that, a flood risk assessment can contain useful information such as finished floor levels, and material choices.

Flood risk maps that have been made by the environment agency and their consultant partners, are based on fluvial and marine flooding only, and do not take in to account surface water flooding (separate maps see below) and sewer flooding where large volumes of water can be transferred from one area to another through the sewer network.

So a flood risk assessment, based on available data is by no means fool proof, but more often than not will prove that your site is low risk (hopefully) or a bit of a nightmare.


 flood zonesDepending on what flood plains you are in will depend on what you can build as outlined by PPS 25.

However, chances are if you are building in the flood plan area, you will have taken advice from your LPA or the EA.

I you have a worry about anything give us a buzz and we will try to explain, you will get charged for a report but not for informal chit chat.

In the case of the project near the map area above, even though the site was situated within the flood zone 2, it was allowed to go ahead, for the following reasons:

1 - The type of project matched established uses for flood zone area 2 uses. That was good.

2 - There were questions over the resolution of the mapping, it appeared the site was on a raised area of ground not accounted for in the maps.

Historic Flooding

flood risk_historic_flooding

Historic Flood extent maps (left) and surface flooding maps are also used to compile data and flood risk for a site.

Key Parts of Flood Risk Assessment

1 - Exception Test

2 - Sequential Test

3 - Surface Water Management Plan

4 - Safe Refuge Designation

5 - Scoping or Screening

Surface Water Flooding


If you have any questions regarding discharge consents whether existing or proposed then please contact SWEL, and we will offer you (of course) a free of charge initial consultation.