The EA has released a range of revised allowances relating to various components of climate change such as ‘peak river flow allowances, peak rainfall intensity allowance and offshore wind speed ‘ among others.

The EA has looked at every river basin catchment and coastal area and has adopted more onerous climate change allowances. Amongst other matters, this has significant implications for development proposals within river flood zones 2 and 3. For example, looking at the Thames river basin, the extended allowances may very well lead to the sterilisation of development potential in locations where previously, flood risk assessment, sequential analysis and mitigation suggest development might take place.

In the case of the Thames river basin, the more onerous allowances are as follows:

• For ‘more vulnerable’ land use classification, which includes residential, care homes and hotels etc., peak river flows within flood zone 2 have been increased by 15% – 25% and for zone 3 by 25%
• For ‘less vulnerable’ uses such as shops, offices and industry, peak river Thames flows have increased by 10% in zone 2 and 10% – 15% in zone 3.

Of course in flood zone 3b, the revised guidance reconfirms planning permission should not be granted for any land use considered to fall within the more vulnerable or less vulnerable classifications.

Transitional rules will be applied to flood assessments submitted in support of current planning applications yet to be determined.
This is a very complex subject of crucial importance to development proposals and land holdings, and developers ignore the implications at their peril where land holdings are already within sensitive locations from a flood perspective.

For more information contact John Foddy, Managing Director, FoddyConsult