Letter from Ewan Larcombe to Environment Agency in response to Thames CFMP Consultation
23/2/2007
Dear Sir
Third response to Thames CFMP Consultation (Summary document only)
Your consultation (Main messages for the region – Section 3 - page 6/7 of 22) states the following:-
3. The flood plain is our most important asset in managing flood risk.
Many flood plains in Thames Region have no flood defences and can serve their natural function of storing water during times of flood. We need to recognise the value of this flood plain in reducing the impacts of flooding. Improving the effectiveness of this flood plain can reduce flooding to properties, both locally and downstream.
The document then states;
Specific messages for the catchments - Undeveloped natural flood plain
• The flood plain is our most important asset in managing flood risk.
• Maximising the capacity of the flood plain to retain water in these areas can have many advantages for people and the natural environment.
• Managed flooding of some areas of the natural flood plain will reduce the risk to some communities.
• We will do all we can to prevent development that compromises the capacity of the flood plain to retain water.
Future maintenance work on river channels should aim to increase the capacity of the flood plain.
My response is as follows:
Your document states ‘The flood plain is our most important asset in managing flood risk.’
I believe that the watercourses, and in particular those designated Main River and the River Thames itself are the most important asset in managing flood risk, and that the flood plain is a bonus.
Your document states ‘Improving the effectiveness of this flood plain can reduce flooding to properties, both locally and downstream.
I believe this statement may be true (i.e. ‘can reduce flooding’ due to peak level attenuation) but only on the understanding that existing watercourses are properly maintained and therefore carrying flood water in an efficient and effective manner.
Your document states ‘Managed flooding of some areas of the natural flood plain will reduce the risk to some communities.’
I believe that ‘managed flooding’ i.e. transferring the problem from one area to another, is deliberately unfair and inequitable.
Your document states ‘Future maintenance work on river channels should aim to increase the capacity of the flood plain'.
I am not entirely sure how this is to be achieved, perhaps by installing and using water retaining weirs? I do believe that the watercourses, and in particular the River Thames, are suffering from long-term neglect of maintenance leading to reduced carrying capacity and ever-rising groundwater levels.
In a flood event, this can lead to floodwater ‘out-of-banks’ earlier, rising more quickly and finishing at higher peak levels. Apparently, although the EA are responsible for the important (Main River) watercourses, they are neither maintaining them, nor ensuring that riparian owners maintain the watercourses.
In addition there is evidence that the EA are refusing permission to re-grade watercourses suffering bed-rise due to sedimentation, which results in back-up problems in times of high flow, and water shortage in times of low flow.
Yours faithfully
Ewan Larcombe