Agenda item

To receive a resolution from the Audit and Risk Management Committee relative to flooding.

This item was considered immediately after Item 6B.

The Committee received a resolution from the Audit and Risk Management Committee which asked them to consider further the scope for engineering solutions to address surface water flooding risks in the Fleet Valley and behind the Thames river walls.  The Director of the Built Environment advised the Committee that existing underground drainage sewers were already very large (enough to accommodate a double decker bus) and could not be expanded except by major engineering works in the constrained locations to make a material difference to the surface water flood risk.  It was clear that no competitive economic case could be made for works of this scale. Therefore flood resistance and resilience measures would need to be prioritised in the areas at risk and elsewhere in inner and central London.  The Director also advised that the rainfall catchment area as shown on the maps in the Strategy that generated this risk covered much of north and west inner and central London including Hampstead Heath. 

As Hampstead Heath was just a small part of this large catchment area (and, because it was not paved, had a slower speed of runoff) it was not a major contributor to the surface water flood risk especially at this distance down the catchment area.  The Committee accepted the Director’s assessment.

RESOLVED – That a response to the resolution be submitted to the Audit and Risk Management Committee.