RAB successfully challenge the Flood Map for Planning
Nov 3, 2017

Large parts of the village of Walkern were shown to be within Flood Zone 2 of the Flood Map for Planning.  Whilst working for a client in Walkern, our flood risk engineers recognised that Flood Zone 2 did not match up with more detailed hydraulic modelling of the River Beane.  On further investigation it was apparent that Flood Zone 2 was based on the 1968 flood outline. However, anecdotal and photographic evidence from residents who lived there during the 1968 floods contradicted the historic flood outline. RAB was then instructed to formally challenge the Environment Agency (EA) Flood Map.

Original Flood Map for Planning


There were other more obvious signs that the mapped 1968 flood outline was incorrect.  For example, an examination of the local topography showed that in 1968 the water level exceeded the 85m contour coming close to the 90m contour east of the River Beane, but did not come close to the 85m contour on the opposite river bank to the west. This is impossible due to the normal hydraulic response.

Using a combination of recorded 1968 flood levels provided by the EA, photographic evidence provided by residents and LiDAR survey of the village, RAB produced a revised 1968 flood outline and submitted it to the EA as a formal flood map challenge. The EA accepted the findings of our study and the revised Flood Map for Planningis now live and online.  



 Revised Flood Map v Original