The Issue: Should we go ahead with plans for a £123m Oxford flood relief channel?

Simon Collings and Peter Rawcliffe. Oxford has flooded six times since 2000, particularly severely in 2007 and 2013-14.

Our community-based alliance was formed in 2007, to give a voice to people directly affected by flooding.

We have campaigned successfully for a series of small scale measures which have reduced the number of properties flooding.

Our emergency services are well organised. The simple, low-cost measures have been taken. Now more is needed. As the floods earlier this year showed, even with the new measures in place a number of homes still come perilously close to flooding. 

Another few centimetres of water in the flood plain and the interim measures put in place would not cope.

Flood water needs to move through the city more quickly. The local pinch-point stopping this is the railway line to London, which forms a dam. 

Simon Collings

The damaging effects extend well beyond the flooding of properties. Businesses are affected. Roads are closed, journeys into Oxford that usually take 30 minutes take three hours.

During flooding the water on the west of the line at Kennington is 60cm higher than on the east. Relieving this pinch-point is the top priority.

There is an opportunity to improve flow at Sandford. There may also be a need for extra carrying capacity under the Botley Road. The proposed scheme is centred round these. 

The connecting waterways will probably need augmentation: indications are that this will be with a natural-looking two-stage channel – a small central channel with wide, gradually sloping, banks that will fill only during a flood.

The natural environment should be enhanced. The flood plain will still flood, just not as deeply. Water will be kept moving, not allowed to build up.

Importantly, no more water would leave Oxford than before, merely earlier, so unlikely to cause any adverse impact downstream. The Environment Agency is carrying out detailed modelling to check this. Comparisons with the Jubilee River are wide of the mark.

Dr Peter Rawcliffe

Technical, economic and environmental appraisals have to be carried out. While the scheme is supported by a wide range of partners it is not yet a done deal.
If climate change makes things worse, other, upstream, measures may be needed too. 

Considering these is an integral part of the EA’s long-term strategy. Oxford is the meeting point for seven rivers, the total catchment area about 2,500 km-squared – 1cm of rain over that area represents 10,000 Olympic swimming pools – it all has to come past us.

The Environment Agency looked at the potential for upstream storage in its original study for a relief scheme in 2008 and concluded that on its own, storage was not the answer and that a relief channel would have to be provided. That’s the solution we believe the city needs now.

NO:

Dr Kate Prendergast, Green Party Parliamentary Candidate for Wantage and convener of the Sustainable Flood Plan Group

Floods are an environmental problem and they need an environmental solution. Oxford lies in the Cotswolds catchment and several thousand properties have been built on the flood plain.

At times of heavy rainfall excess water runs off the hills, overwhelming the rivers, and floods those properties in its path. Moreover, the Met Office has confirmed global warming is affecting the likelihood and severity of flooding.

So although we cannot say the 2013-14 floods – the most severe for 200 years – were caused by global warming, we can say it increased their impact. This scenario is only going to worsen in the years ahead.

Dr Kate Prendergast

It is envisaged the proposed Western Conveyance Channel will divert water away from at-risk properties. It has not yet been designed or costed in any detail, but estimates suggest capital build and maintenance costs could be around £240 million over a 100 year lifecycle.

This huge spending commitment will only get higher if, as the Government proposes, the Oxford channel is developed as one of many to divert water away from urban areas into the tidal Thames. Combined costs could spiral into billions.

At a time of ongoing cuts to flood protection budgets we must assess all proposals for cost effectiveness and maximise our options rather than commit vast amounts of public money upfront to a scheme that may not work and we cannot reverse.

A relief channel may move water more quickly away from Oxford – but where would it go?

What are the alternatives? Projects such as the River of Life in Wittenham, run by the Earth Trust, show how working with the flood plain can hold back water from human settlements – and help to cut carbon and save wildlife too. Re-foresting our uplands can also hold back water.

Investing in targeted local solutions must be a top priority, including sustainable drainage, temporary and permanent bunds, pumps and other measures which are low cost, proven to work and have minimal environmental impact.

The Environment Agency could maintain existing waterways and relieve pinch points before digging up the remaining flood plain – and robbing us forever of implementing the environmentally friendly solution we so desperately need.