Seacourt car park extension flooding

The recent flooding of the extension to Seacourt Park & Ride is further evidence that the City Council seriously underestimated the vulnerability of the site to flooding. The area flooded rapidly during the night of Christmas Eve, and as of today is still partly inundated though water is now being pumped out.

View of the extension down the main access ramp on Christmas Day

The Flood Risk Assessment (FRA) submitted with the Planning Application stated: ‘An analysis of historic flooding incidents relevant to the site suggests that the site will currently flood roughly once in every 1.7 years and will remain out of operation for around 10 days during an average flood event.’ That’s just under 6 days a year average.

Over the course of last winter (2019/20) the site was inundated four times and for prolonged periods. This latest incident represents a further 12 days of flooding. In our opposition to the planning application we argued that the Council had grossly underestimated the likely extent of flooding at the site. Events seem to be proving us right.

Sewer flooding in South Hinksey

It is not uncommon for residents of Kennington, North Hinksey and South Hinksey to suffer from sewer flooding problems and these continued over the Christmas period with surcharges occurring on both the 24th and 27th December. Both dates coincided with the heavy rainfall events and result from Littlemore Pumping Station being unable to cope with the high volume of water.

The second surcharge was particularly challenging for South Hinksey residents as the EA flood barrier prevented the sewage from leaving the village. Thankfully the pumps the EA had already provided prevented houses from being flooded, but they couldn’t stop a pollution incident as the sewage discharged into the local water courses.

Several residents reported the incident to Thames Water, but their response time was well short of their two-hour target. We know of one call which was responded to eleven hours after being reported, and another which took a whole three days. We’d be interested in other readers’ experiences.

OFA Steering Group member Adrian Porter has once again raised the poor level of service with the Thames Water customer liaison team.

Christmas 2020 flooding

Residents in Wolvercote, West Oxford, North and South Hinksey and Grandpont witnessed significant localised flooding on Christmas day after a rapid rise in river levels over the preceding days. Between the 17 and 22 December, more than 25mm of rain fell across the upper parts of the Thames catchment resulting in high river levels on the Thames and the three main tributaries feeding the Thames – the Evenlode, Windrush and Cherwell. An additional 20-60mm of rainfall fell between the 22 December and the 24 December on the already saturated Upper Thames catchment causing a rapid rise in river levels on the Thames in Oxford. The large volume of water discharging from the Cherwell to the west of Christchurch Meadows, is thought to have caused flood water further upstream in Oxford to back up, contributing to a faster rise in levels than we typically experience in the city.

After peaking on Christmas day levels fell, but further rainfall on Saturday night nudged levels back up. The rivers seem to have stabilised since and levels are expected to fall in the coming days. The peak level of the recent flooding was significantly higher than those seen during last winter’s flood events. The Environment Agency has been actively monitoring the situation and flood barriers were erected in South Hinksey as a precaution. Flood Warnings were issued for Wolvercote, and for the New Botley – North/South Hinksey – Grandpont areas. There have been no reports of properties in the city flooding.

The speed at which river levels rose on Christmas eve is particularly concerning, as this limited the amount of time available to deploy defenses. This has potential implications for future flood management planning.

Peter Rawcliffe

It is with great sadness that we report the death of Peter Rawcliffe on 14 December 2020. Peter was a founding member of the Oxford Flood Alliance and he played a pivotal role in the organisation throughout its history. He did a great deal to advance the interests of flood affected communities in Oxford. Peter was a thoughtful and courteous individual, always willing to listen to others’ views. But also a forceful and determined advocate for what he believed to be right. We owe him a great deal. He will be greatly missed.

Photo: Kirsty Edmonds/Oxford Mail

A new fish pass at Godstow

The Environment Agency is replacing the weir on the River Thames, located next to the Trout Inn at Godstow, in Oxfordshire. They say (our bold emphasis):

“We will remove the old weir structure and build a new weir, two metres downstream. This will allow for better debris clearance. For the last year we have been working on the detailed design of the new weir and applying for funding.

The weir will look largely the same, as we will be using the same design of gates. There will be an additional structure to the left (looking upstream) which will allow fish and eels to make their way up river.

The full briefing is here.

Maintenance and meadow management

We understand that an update on the search for an environmental partner for the Oxford Flood Alleviation Scheme (the Scheme) is likely to come soon. 

We have all along pressed to see the best possible done environmentally: having an expert partner to help manage the environmental aspects of the Scheme, while at the same time maintaining it for its purpose of flood relief, over the decades ahead, seems the ideal way.

Floodplains, with their meadows and wetland areas, are a valuable, and increasingly less common, habitat, demanding expertise to manage them well. So we’re waiting expectantly to learn what’s been happening.

Barrier at South Hinksey

A red letter day for South Hinksey village, with temporary barriers deployed (in a trial exercise) for the first time!

The exercise went well with the EA teams getting the barriers up in 3-4 hours from delivery to site. In a real flood event in the wet it might take longer and pumps would have to be deployed too but even so this would represent a good time. The residents will now feel very much more secure as winter approaches. Let’s hope the barrier isn’t needed but if it is it will be there. A big thank you to all involved.

Flood exercise today

The flood exercise mentioned in the last post, testing and demonstrating readiness to deploy defences, is under way today. In South Hinksey temporary barriers are being set up by the Environment Agency (EA). At Bullstake Close on the Botley Road the barriers there, which have been used before in a flood, will be erected; and fire crews are showing how the pipe which has been installed under the Botley Road can be used to deal with flood water and reduce the flooding of the road.

For South Hinksey this is a very reassuring demonstration of the ability to now defend the village from flooding. Such barriers have never been used here before.

Of course Oxford still needs a bigger, more permanent scheme – in the form of the Oxford Flood Alleviation Scheme. The OFA update in the previous post summarises the present position – the Scheme is under way, albeit delayed. In the meantime today’s activities show that we will not be without  protection in the interim.

Emma Howard-Boyd, Chair of the EA, and Sir James Bevan, Chief Executive, are in South Hinksey today to see what’s being done and meet the teams and there is no doubt that protecting Oxford in both the short and long term is being taken very seriously.

Our thanks to everyone who is working hard on behalf of the many local residents, businesses and other organisations affected by flooding.

OFA Update / OFAS & Flood Exercise

This update has recently been sent to those on our mailing list.

Dear OFA contact,

We last sent out an update in Oct 2019, just after the news about the problems with the A423 bridge (southern bypass) and likely delays to the Oxford Flood Alleviation Scheme (OFAS). OFA is still active and has been participating in meetings of the Sponsoring Group for the OFAS scheme and has also held separate meetings with the Environment Agency team about water course maintenance since our last update.

Despite the A423 issues, and the challenges presented by coronavirus, the OFAS scheme continues to progress. The EA and the County Council have agreed a collaborative approach to replacing the A423 bridge and constructing the OFAS scheme. This should save on costs for OFAS, and reduce the level of maintenance required in future.

The EA withdrew the original planning application earlier in the year and is currently revising this to incorporate the new A423 arrangements, and to update the documents on some other aspects of the scheme. Once these are resubmitted to the planning authority the public will have a fresh opportunity to comment on the plans. The EA is continuing to meet with objectors to the scheme with a view to trying to address outstanding areas of public concern.

Because OFAS is now expected to be delivered two years later than originally expected it is important that effective flood response procedures are in place in case a major flood event happens in the next few years. The EA, Fire Brigade and the local Council officials will be holding a practice response on 20 August to test aspects of current procedures. Because of coronavirus these will not involve the pubic.

The text of a recent update from the Environment Agency is pasted below which provides some additional information on OFAS and other matters,

OFA Steering Group

Oxford Scheme update

A423 bridge replacement

Oxfordshire County Council began the propping work on the A423 Kennington Railway Bridge in July.

Replacement of the A423 Bridge has provided an opportunity to design and build the bridge and the flood scheme together. This allows us to reduce disruption during construction and ensure the best use of public money. The updated design will use open channels instead of culverts to allow the flow of floodwater under the bridge. This will provide a better environment for wildlife and requires less maintenance.

The bridge is at the southern end of the scheme and during a flood, water would need to pass underneath it to re-join the River Thames. This capacity needs to be in place before the scheme is constructed to avoid increasing flood risk elsewhere. We also need to have all approvals, including planning permission and our Compulsory Purchase Order secured.

South Hinksey Archaeology

If you’ve been walking near South Hinksey, you may have spotted our contractors on site. We are carrying out archaeology surveys in a field near South Hinksey village to check whether the area is suitable for us to use as the main compound for when we construct the scheme. The archaeology surveys will determine whether there are any historical artefacts in the field. We want to ensure there’s no risk of us damaging any artefacts or remains. Once we have finished the investigations, we will remove our equipment from the site and reinstate the fields.

Kendall Copse Ground Investigations

To complement the new A423 bridge replacement, we are reviewing the design of the scheme around Kendall Copse, near Kennington.

From 10 August, we will be digging trial pits and drilling boreholes to understand the ground conditions beneath the site in order to finalise these designs.

Oxford Flood Incident Exercise

To ensure our flood protection plans are well-tested, the Oxford Flood Alleviation Scheme partners and emergency responders will be practicing their incident response plans on 20 August 2020.

The flood response exercise will consist of:

 •temporary flood barriers in South Hinksey and Bullstake Close

•pumps to remove flood water along Botley Road

Due to the current Government guidance on public gatherings, we won’t be able to invite members of the community to attend. We will be sharing updates on Twitter and Facebook as the exercise progresses. We will also share video footage of the temporary barriers and pumps so you can see our field teams in action.

Managing your flood risk

During the summer months, flood risk might be low on your list of priorities, but Environment Agency officers are thinking about it year-round. Throughout the year our operations staff carry out inspections and clear debris to keep main rivers moving. To report a blockage that could cause flooding call our 24 incident hotline: 0800 80 70 60.

You can also find out what maintenance is planned in your area: environment.data.gov.uk/asset-management/index.html

Stay prepared by signing up for flood alerts and preparing a flood plan: https://flood-warning-information.service.gov.uk

  

Want to know more?

If you have any questions or want to be added to our mailing list, please contact us at: OxfordScheme@environment-agency.gov.uk