Monday 18 July 2011

Flood Plain Challenges - What's it all about - How do I change it

So your site is within Flood Zone 3 or 2; and it looks odd.  Your much higher than the river, it doesn't make sense.


 [Confused CLICK HERE for Frequently Asked Questions on flood risk].


Did you know that you can challenge the Environment Agency's flood map, it isn't always accurate.


The Environment Agency periodically update their flood maps, through new modelling, recent flood events, or site specific flood map challenges.


At Enzygo we often get asked to look at flooding for specific sites, and one recent example is below.


New Flood Map (post challenge)
Existing Flood Map (pre challenge)


Before we were instructed to challenge the flood map, most of the site was shown to be in flood zone 2 (1 in 1000yr/0.01% annual probability).


After a site walkover, it became clear that something was incorrect, discussions with the EA indicated that this was down to their year 2000 aerial photography flood mapping.


We created a numerical model of the river and ran the 100, 200, 1000 year flood flows, and amended the flood map.


The site is now being looked at for new development.


If you have a similar problem, we can help solve it, see Flood Modelling