Chris Stuart shows a surprising lack of understanding of how water behaves if he believes that SUDS can make flooding worse (NCE 30 May).
If flooding occurs because of rises in groundwater in low lying areas then any drainage system will be ineffective. As the groundwater rises and flooding occurs, the levels in surrounding watercourses will rise and back up a conventional piped system and water will also inundate the system due to leakage.
It is recognised in both the UK and worldwide that SUDS are an important technique to help reduce the impact of urban development on the water environment. Correctly designed SUDS schemes do reduce the risk of flooding in surrounding water courses and are often more cost effective that traditional drainage schemes.
Steve Wilson (M), technical director, Environmental Protection Group.