OFA is pleased to note the approach being taken in the Flood Risk Assessment which forms part of the OXWED planning application. At the insistence of the Environment Agency the developers have adopted a ‘level for level’ approach to flood compensation, meaning that any reduction in floodplain capacity at a given level has to be compensated for by an increase in capacity at that same level. This is the standard we would expect to see applied.
The development will also allow flood water to enter voids beneath some of the built structures.
Up to date flood modelling has been used in the assessment, and allowance has been included for the proposed new bridge over the Thames (which will be part of a separate planning application).
Calculations in the FRA show an overall net gain in flood plain capacity for all levels of flooding. This will help to reduce flood risk in the city. The EA is now reviewing these proposals and will provide its comments to the planning authority. OFA welcomes the robust approach being taken.
During 2021 OFA took part in several meetings between the OXWED developers and members of St Ebbe’s New Development Residents Association (SENDRA) where flood risk was being discussed. Community members highlighted concerns about continuing erosion of the riverbank at Oxpens Meadow. These concerns are acknowledged in the planning documents with provisions included to address them.
Some SENDRA members were also interested in the potential to improve the biodiversity of the meadow, an interest OFA shares. The planning application includes proposals for a net gain in biodiversity which is assessed to be in excess of 10%. This is achieved through additions to hedgerows, numbers of ecologically valuable trees, and sowing of the meadow with a richer mix of grasses.
Going forward we expect to see similarly robust approaches on flood risk being applied to other planned development in this area, especially Osney Mead. We also want to see areas set aside for biodiversity being linked so that green corridors continue to serve wildlife in the area. Protecting and enhancing the diverse habitat provided by the main river and its margins will be critical.
The extension to Seacourt Park & Ride reopened on Wednesday 8 February after being closed on 5 January due to flooding. The City Council acted promptly to prevent access to the extension once flooding became likely. The facility, which is designed to flood, was closed for a total of 35 days. In the planning application the City Council estimated that the car park would be out of use because of flooding for an average of 10 days a year. We argued at the time that this was an under-estimation. Construction of the facility, which OFA opposed, resulted in a net loss of floodplain capacity.
River levels are now falling in Oxford and we expect to see floodwater begin to drain away over the coming weeks. The flood peaked yesterday, 18 January, when the Thames south of Osney Lock reached 3.58m, the Bulstake at New Botley recorded 2.64m, and the Seacourt at Minns estate was at 2.68m.
These levels are below those recorded two years ago, on 3 February 2021, when the Thames at Osney reached 3.73m, the Bulstake 2.80m and the Seacourt 2.90m.
The 2021 event was the most serious flooding since the floods of January and February 2014. On 9 January that year the Thames downstream of Osney lock recorded 3.93m, the Bulstake 3.02m and the Seacourt 3.08m. Some properties were affected by the 2014 flooding. A second wave of flooding in February reached similar levels, though not quite as high.
We’ve been pleased with the level of preparedness and response from the various agencies involved this year. We have been sharing photographs of this year’s flooding with the Environment Agency to assist them in checking assumptions in the flood model used to manage response to high rainfall and river levels.
Willow Walk will be closed for the next three months to enable replacement of the existing bridge over the Bulstake Stream, repair of a small culvert next to the bridge, and the resurfacing of the track. This work is being undertaken by the County Council, and is not part of the Oxford Flood Alleviation Scheme. Information on the planned work can be found here.
As there has been limited information about the work being undertaken OFA checked with the County Council and the Environment Agency to make sure that no increase in flood risk would result from the work. We have been assured that the planned work does not pose an issue and we’re satisfied that the work has received appropriate scrutiny.
Following heavy rain last week, river levels in west Oxford have risen sharply and water has spilled out across the floodplain. Fields, parks, playgrounds, allotments and some paths are now under water, but properties and streets have so far stayed dry. Levels have not yet reached those seen in early February 2021 but are still going up.
Well-rehearsed responses from the Environment Agency and the local authorities have kicked in. Demountable barriers were transported to South Hinksey on Sunday 15 January and are ready to be deployed. Sandbag defences were put in place this afternoon at Bulstake Close off Botley Rd. Barriers are not currently expected on Osney Island but are available if required.
Seacourt Park and Ride extension was closed by the City Council on 5 January when groundwater began to appear there. The car park is now completely flooded.
River levels upstream in the Thames catchment and on the Cherwell are starting to fall, and we hope levels in Oxford will soon peak. Environment Agency staff are monitoring the situation closely and are ready to ramp up the response if needed. OFA steering group members are also keeping a close eye on the situation and are in contact with the EA.
These pictures, all taken on 16 January, show the extent of the current flooding.
Botley ParkBack of Bulstake CloseOsney allotmentsSeacourt Park and Ride extensionSeacourt stream near Richer SoundsOatlands ParkFields near South HinkseyField next to South Hinksey where barriers will be erected if needed
Don’t get caught out – flooding can happen to you.
Recent polling suggests nearly two in three households at risk from flooding do not believe their homes could flood[i]. But just because flooding hasn’t happened to you in the past, it doesn’t mean it won’t happen in the future.
In England there are over 5 million properties at risk of flooding[ii]. The research shows that people who haven’t taken action to prepare for flooding are in the clear minority (30%), but this still means that as many as 1.5 million households who are at risk are yet to prepare. With climate change already causing more frequent, intense flooding and sea level rise, we all need to know what to do, should the worst happen.
The risks of not taking action
According to the Environment Agency, the average cost of flooding to a home is around £30,000. Flooding also brings a significant risk to life. The mental health impacts of flooding can last for 2 years or more after flooding has happened. Depression, anxiety and PTSD can affect up to a third of people who have been flooded.
But, crucially, taking steps to prepare for flooding, and knowing what to do in a flood can significantly reduce the damages to a home and possessions (by around 40%)[iii], reduce risk to life, and reduce the likelihood of suffering from mental health impacts in the future.
Know how to Prepare. Act. Survive.
The good news is that there are some simple things you can do to prepare for flooding, which could help keep you and your family safe, and save you thousands of pounds in damages and disruption. The below infographic sets out the steps you can take.
Caroline Douglass, Executive Director Flood and Coastal Risk Management at the Environment Agency, said, “Climate change is happening now. We’re seeing more extreme weather – in this year alone with three named storms in a week, record-breaking temperatures and drought declared across large parts of the country.
“That is why it is vital that people take the necessary preparations as early as possible to prepare for the worst. Our recent investment programme has better protected 314,000 homes from flooding and we’re investing millions into keeping communities safe, but we can’t stop all flooding.
“The message is clear – households risk ignoring the danger of flooding at their own peril. Anyone can go online to check if they are at risk, sign up for Environment Agency warnings, and, most importantly, know what you need to do if flooding hits.”
Oxfordshire County Council has published details of the replacement bridge on the southern bypass near Kennington. The existing bridge needs to be replaced because of structural weaknesses. The new bridge has been designed in partnership with the Oxford Flood Alleviation Scheme and will increase capacity of the Hinskey streams to help reduce flood risk. The new design also includes improved traffic layouts. Anyone wishing to comment can do so using the form provide
The local environmental charity Earth Trust is one of several organisations providing advice to the Environment Agency about the biodiversity aspects of the Oxford Flood Alleviation Scheme. Their experience of introducing new wetland habitat on the Thames is an invaluable source of learning. This recent post on their website gives details of some of the early progress in their River of Life initiative, including data about carbon emissions.
This earlier post, from June, describes an innovative remote monitoring station (see photo below) which enables the Trust to gather data about the presence of various species in the project area – bats, water voles, birds, moths. Lessons from this initiative will be beneficial to the implementation of the Oxford Flood Alleviation Scheme and may help inform the way biodiversity gain is monitored.
The Environment Agency has circulated its latest newsletter with updates about the Oxford Flood Alleviation Scheme. The text of the newsletter is reproduced below:
Scheme update
Since our last newsletter we have submitted the planning application for the Oxford Flood Alleviation Scheme to Oxfordshire County Council and they have held a consultation on the proposals. We have received a request for further information from them, which is quite normal for a project of this size. Once we have submitted this additional information the council will run a 30-day consultation on the newly submitted information, before considering it alongside the rest of the application.
We expect to make a Compulsory Purchase Order (CPO) for the land needed to build the scheme later this year.
Movement of material by rail
Construction of the scheme requires removing material from the floodplain offsite. We will reuse as much material as possible on site, for example to create earth embankments. Excess material will be taken to sites which already have planning permission for environmental restoration, such as former quarry sites.
We are looking to transport some of the excavated material by rail. We will be submitting a planning application to construct a temporary access track to the Hinksey Rail Sidings. Use of rail will depend on gaining planning permission to access the sidings, their availability and trains at the time of construction, and agreements with the operator of the sidings.
Once the work is finished, the temporary access track, alongside a temporary bridge crossing Hinksey Stream and pedestrian diversion, will all be removed and reinstated to their current use.
Maintaining the scheme for decades to come
We have a detailed programme in place to maintain the scheme operationally and to establish and manage habitats for at least the next 100 years.
In order to secure the potential benefits the scheme can bring for future generations, once we have all the necessary approvals and are nearing construction of the scheme, we will appoint an environmental partner who will be responsible for looking after the wildlife and landscapes of the scheme area in the long-term.
They will work alongside our operational team to bring additional environmental enhancements, involve local people and community groups, establish opportunities for scientific research and visit schools to teach children about the work we do to protect and enhance the environment.
Earth Trust is helping us set the foundations for this approach. They are advising us on the development of plans for how the eventual land management of the completed scheme could/should function to deliver the long term environmental, climate and human health and wellbeing benefits of the scheme.
Scheme design
We have received lots of helpful feedback on the design of the scheme during our consultations and conversations with local communities over many years. The planning application we have submitted will ensure that the scheme provides Oxford with robust and reliable flood protection, that will also enhance the local environment.
The new stream with lowered floodplain is integral to the working of the flood scheme so that flood risk is reduced adequately and not transferred elsewhere. The lowered ground alongside the new stream does not store static water but provides additional space and a defined route for it to flow through the floodplain, away from communities, properties and businesses. Absence of a defined route for the water could lead to an unintended increase in flood risk elsewhere.
Crucially, the design will also enable us to create valuable new environmental features within and around the whole area of the scheme. This will include wetland habitat, new floodplain meadow, and backwaters and ponds.
Next steps
Before we can start building the scheme, we need to have all approvals, including planning permission and our compulsory purchase order, in place. Subject to approvals, we currently anticipate construction to begin in 2024.
Construction projects are currently experiencing cost increases due to wider inflation and the price and availability of materials and labour. The scheme’s budget takes inflation into consideration and its costs are reviewed regularly.
Until the scheme is completed, the Environment Agency has well tested flood-protection plans in place for Oxford, working with others, including the fire service and county council, to help those at greatest risk in the city. We encourage people to check their own flood risk and sign up for Environment Agency flood alerts.
In our previous post we highlighted a concern about the Supplementary Planning Documents for Osney Mead, which envisages ‘activating’ the riverbank south of Osney Lock and down to Grandpont nature reserve. The illustrations of what this might look like show a heavily urbanised and landscaped river frontage with paths and building all at the same level. We don’t believe this is consistent with the Thames towpath clearly being in flood zone 3b – functional floodplain.
The image below is taken from the Flood Risk Assessment: Appendix B Modelling Report which forms part of the 2022 planning application for the Oxford Flood Alleviation Scheme. This figure shows flood risk for a 1 in 5 year scale event. Areas which flood when the scheme is in place are shown in blue. Areas protected from flooding by the scheme are shaded pink. The Osney Mead area is just south of the word ‘Osney’ (partly obscured by white squares) on the map. Note the wide blue area east of Osney Mead. This is the Thames south of Osney Lock, The river corridor floods even in these frequent, low-level events.
Flood risk for a 1 in 5 year event – OFAS planning documents
Any development proposal for Osney Mead will need to allow for a 1 in 100 year event, i.e. for much more severe flooding than shown above. The image below shows the extent of flooding expected in such an event. Significant areas of Osney Mead will be flooded. One of the challenges developers will have to overcome is ensuring safe exit routes for residents and people working in a redeveloped Osney Mead. Exit via the proposed new cycle bridge just south of the railway on the Thames will not be accessible as the towpath under the railway will be flooded. The streets at the southern end of Osney Island are likely to flood in such an event so will not provide a safe escape route either. The only way out by road, along Ferry Hinksey Rd, will also flood, as it does currently. The need to erect temporary flood barriers – the white squares on the map – also presents a challenge for any proposal to create new pedestrian and cycle routes through Osney Island. These issues have not been addressed in the Supplementary Planning Document.
Flood risk for a 1 in 100 event – OFAS planning documents
oxford flood alliance 