THE proposal to extend the Seacourt Park-and-Ride has raised concerns about whether this might exacerbate flooding.

We believe it should be perfectly possible to design this scheme in such a way as to be ‘flood neutral’ or even to achieve a reduction in flood risk.

For example, should clay be found near the surface, its removal and replacement by more permeable and porous material would be beneficial.

Permeable surfaces can be used wherever practicable: even porous tarmac is now available.

The design team is of course well aware of such possibilities. We have suggested at a recent public consultation that the finished level might actually be set slightly lower than existing, so increasing the reservoir capacity over what exists at present.

If the extension were 1cm below existing, that would store about 150,000 litres of water (150 tons) of which much would be extra to what would have been in the soil anyway.

Thus it should be possible to offset the effect of the buildings and any areas which must be impermeable.

As far as flow goes, it should be straightforward to produce a design which allows flood water to flow freely over the car park.

Oxford City Council has worked hard to reduce flood risk for residents and we feel it is most improbable that they would let this development compromise what they have achieved.

Before a planning application is made, a flood risk assessment will be made and the Environment Agency consulted.

If permission is given we ask that it includes stringent stipulations on monitoring during construction to ensure that levels and surfaces are as specified, as even a small increase over the specified levels could lead to an increase rather than a reduction in flood risk.

ADRIAN PORTER AND PETER RAWCLIFFE
Oxford Flood Alliance