Previously developed sites – why not go for “betterment”
Steve Wilson, Technical Director, Environmental Protection Group.
Allowable surface water discharges from previously developed sites are often based on maintaining the status quo. This means that new surface water systems discharge water at the same rate as the existing site. Adopting this approach means we are missing a vital opportunity to maximise the impact and benefit of SuDS on flood risk management.
For SuDS to have any effect on reducing current flood risk then retrofitting SuDS into a catchment is vital and a critical mass of sites is necessary before any significant gains will be made in reducing current surface water flows into rivers and sewers. The quickest and easiest way to retrofit SuDS is to include them in redevelop of existing sites. If all sites were attenuated to Greenfield runoff rates then we will begin to see the real impact of SuDS much sooner.
It is time local authorities and the Environment Agency were allowed to adopt this approach.