Oxford Flood Alleviation Scheme. Thames RFCC. The Environment Agency and partners are working together to reduce flood risk in Oxford.

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1 Oxford Flood Alleviation Scheme Reducing flood risk Enabling a thriving economy Connecting people and the environment Thames RFCC Welcome The Environment Agency and partners are working together to reduce flood risk in Oxford. This exhibition will explain how the Flood Alleviation Scheme will help. Our early investigations have confirmed that a flood relief channel would significantly reduce flood risk in Oxford. We are in the early stages of development and the scheme requires approval from the Treasury to go ahead. We need your input at this early stage and we want to hear your views. This event is an opportunity for you to tell us your ideas, and include your local knowledge in the development of the proposed Oxford flood alleviation scheme.

2 Why does Oxford flood? Flooding in Oxford is not new. In the city, more than 1800 homes and businesses stand in the 1:100 year floodplain. Some are at greater risk than others of serious flooding. But the risk is always there. Flooding in Oxford 2014 Flooding in Oxford 1852 Oxford s history goes back to the 9th Century and the times of Alfred the Great, when people decided that this crossing point on the River Thames was the place to settle down and make a living. The centuries have brought fame, wealth, learning and the finest art and architecture to the city. But there is another legacy: flooding. It is a combination of the location, landscape, geology and long-term development in the floodplain that make Oxford so vulnerable to flooding. The millions of litres of water that flow down the River Thames from the Cotswolds have to pass through the city on the way downstream. Yet more water flows down the River Cherwell. When there is heavy rain, the river levels rise. And all that water has to make its way through the narrow gap between Sandford and Kennington, as it makes its way through the river and stream system towards London and eventually the North Sea. Flooding at Osney Island 2007 Railway flooding near Redbridge, 1875 Photo: Oxfordshire County Council 1800 properties are currently at risk in a 1:100 year flood (even with flood management we already do)

3 Current flood risk in Oxford This map shows the areas prone to flooding around Oxford

4 Flooding and Oxford s economy Businesses flooded along Botley Road Photo: Liz Smith The River Thames and its tributaries at Oxford have a large area of developed floodplain without flood defences. If nothing was done to manage flood risk over 4500 properties would be at risk in a flood with a 1 in 100 chance of occurring in any year, rising to over 6000 should climate change happen as currently predicted. Our current flood risk management work reduces this to Oxfordshire flooding in 2013/2014 saw 168 properties flooded 32 people evacuated 45 roads closed The main rail line from London closed One school closed Flooding can also impact on critical infrastructure such as roads, railways, communications, electricity and other services. Previous flooding in Oxford has closed transport routes such as Botley Road and the railway line. This creates disruption, delay and upheaval for businesses in Oxford, all contributing to a loss of revenues. When there is flooding, staff struggle to get into work, deliveries may be late and there are impacts on tourism as visitors cannot get into Oxford. Flooding also interrupts businesses operating well beyond the areas which have flooded. Mains sewers were affected so residents could not flush their toilets. Railway flooding Photo: Mark Gooding Travel around Oxford is severely interrupted Photo: Simon Li

5 How do we currently manage flood risk in Oxfordshire The role of Oxfordshire County Council In 2010 Oxfordshire County Council became Oxfordshire s lead local flood authority with responsibility for: Surface water Ground water Small rivers, streams and ditches. Main river flooding is still the responsibility of the Environment Agency. Oxfordshire s Fire and Rescue Service deploy quickly in times of need and employ the Oxford method. An effective course of action utilised during the flooding of Botley Road. It is the county council s responsibility to work in partnership with the City and district councils to manage local flooding. This includes long term planning, as well as reacting to emergencies. Recent Schemes Oxfordshire County Council s wider strategy draws together a number of schemes. There are small scale projects, such as Black Bourton and much larger on-going schemes across the county. Black Bourton before the works The sustainable drainage (SuDS) work at the construction of the new Bicester Park and Ride Black Bourton works completed

6 How do we currently manage flood risk in Oxfordshire Copyright Crown Copyright and database rights Reducing flood risk in Oxfordshire is a long term project with: 29 schemes scheduled over 2015/16, And a further 76 in the 3 years that follow. Some key schemes in the 2015/16 plan are: Flood Alleviation, Tackley Bridge End Flood Alleviation, Witney New culvert planned, South Moreton Twin mains under Botley Road As you can see Oxfordshire County Council takes its role as Lead Local Flood Authority seriously and is committed to long term flood risk reduction across Oxfordshire. Read the full strategy, go to,

7 Oxford Flood Risk Management Strategy In 2009 we completed a study of flood risk from rivers in Oxford. The resulting Oxford Flood Risk Management Strategy, set out how flooding can be managed over the next 100 years. We have looked for a way that respects the historic and natural heritage of the Oxford area, while: Reducing the risk to homes and people Cutting road and rail disruption in the main commercial and employment centre Protecting the wildlife and environment that enrich the lives of residents, workers and visitors to the city We looked at over 100 options to reduce the threat of flooding for homes, businesses and the city s essential transport infrastructure. We carried out a public consultation, gathering your views. All evidence we gathered showed that a new watercourse in West Oxford was likely to become the preferred option when climate change is taken in to account. Temporary flood defences in Osney Photo: Environment Agency The Strategy Recommends Local improvements to manage flood risk that can be implemented quickly. These short term measures are already completed. A flood relief channel in the West Oxford flood plain. An additional flood storage area upstream of Oxford. This would be implemented only if climate change makes it necessary. It would be used alongside the new watercourse. Short Term Measures 2.5 million has been spent on removing silts and gravels from the water channels, increasing the capacity of structures like culverts and providing temporary defences. This work helped to protect properties in the 2013/14 winter floods. Mitigation works near Abingdon Road Photo: Environment Agency

8 The flood alleviation scheme What is it? It would be a combination of a newly excavated river channel and enlarged sections of the existing stream system. It would run from Botley Road to just downstream of Sandford Lock. How would it work? A new channel would work with the natural processes of the local watercourses and the floodplain to help manage the movement of water through Oxford. The western floodplain would still be utilised in extreme weather as the channel would fill up and be overtopped, with flood water spilling into the surrounding floodplain. We will use river modelling techniques to assess the flows and flood levels to determine the most effective way of managing flood water. This will include assessing any changes in flow that the scheme may bring. The study area for the Alleviation Scheme The objectives of the Oxford flood alleviation scheme are to: Reduce flood damage to at least 1,000 homes and businesses in Oxford Reduce flood impacts on road, rail and utility infrastructure Safeguard Oxford s reputation as a thriving centre of commerce Create and maintain new recreational amenities, wildlife habitat, and natural watercourses accessible from the centre of Oxford.

9 What are the Constraints? Land use, structures and other factors which may affect the route and channel options In the area there are constraints, which will have an impact on the choice of route for any channel. Existing land uses, old landfill sites and the hydrology of the area all impact on this. There are also developments in the floodplain, such as electricity lines, roads and railway lines. They will all be considered in producing the options. When we assess potential routes for a channel we will consider the environmental effects to identify areas deserving special protection. We will also identify any historic and archaeological sites.

10 Opportunities for people and the environment The creation of a relief channel could enhance existing amenities and create new habitats and features. Our partnership team will be exploring ways to enhance the environment and the way people use the area. We will be working closely with all the existing landowners who will have an important say in any of these additional benefits of the scheme. The study area for the flood alleviation scheme includes a wide range of land uses. There may be possibilities for enhancing the use of some areas if a flood relief channel is built. For instance, we may be able to create, additional wildlife habitats, recreational spaces and additional walking or cycle routes. These could all be part of the resulting landscape once the work is completed, subject to agreement with landowners

11 Opportunities for people and the environment Enhanced wildlife areas Accessible areas for a variety of activities Improved pedestrian links Recreational areas for fishing and other activities Natural habitats can be enhanced Photo: Oxfordshire County Council

12 What happens next? The study area for the Alleviation Scheme Over the next few months we will be assessing the options available for the flood alleviation scheme. We will be assessing the options for the route and design over the next few months. You may see us out on site investigating these potential routes with our team. The construction work for the flood alleviation scheme would start during 2018 and, once planning permission for the final proposal has been obtained, construction will last for three years. Over the next three years we will continue to develop the business case and secure further funding.

13 How can you help? There are three main ways that you can share your ideas with us: Visit our map table to share your ideas, suggestions and concerns. Fill in your questionnaire and hand it back to the team before you leave. Speak to the partners and project team. Please tell us: Your ideas and suggestions about enhancing the recreational and community amenities of the study area About ideas or issues we should be considering for enhancing wildlife habitat within the flood scheme. If you have special knowledge or experience of a specific area or issue your knowledge could be useful to us. Your experiences of flooding and your suggestions about potential solutions How you currently use the area in the Western Floodplain What you think of the Flood Alleviation Scheme information in this exhibition. Thank you for coming. You can contact our team by OxfordScheme@environment-agency.gov.uk Keep up to date with developments on our website: Thames RFCC

14 Areas downstream from Oxford The Environment Agency work to reduce flood risk overall, not to transfer it from one community w another. As part of our detailed design of the Oxford Flood Alleviation Scheme (FAS) we will use our latest river modelling to assess any changes in flow that the scheme may bring. Before the final scheme is approved we will share this information with communities in Oxford and in downstream areas. We will include a detailed Flood Risk Assessment with any planning application we submit for the scheme. This assessment will contain information on any potential changes to downstream flood risk. It will also include details of any mitigation measures we will take, if required, to protect properties in the unlikely event that their flood risk is changed. Alongside the Oxford FAS we are also developing business cases to provide flood alleviation schemes for other communities at risk of flooding from the River Thames, as part of our six year plan of works. Together with our partners we take the management of flood risk very seriously.

15 Abingdon Flood Alleviation Scheme River Stert We are investigating solutions to reduce flooding upstream of the culverted section of the River Stert in this location. River Ock We will update the river models for the River Thames, from Sandford-on- Thames to south of Mapledurham, and the River Ock. We will then carry out an investigation into a potential flood storage area on the River Ock, upstream of the A34. St Helen s Mill We are investigating solutions to reduce the risk of flooding to both the access road and the properties at St Helens Mill from the River Ock. Alongside these investigations, we will undertake an initial assessment to explore whether there is a viable scheme for the Swift Ditch. What s next? If our initial investigations find there are technically and economically viable options for flood risk management schemes for the River Stert and St Helens Mill, we will carry out the detailed design and construction of these schemes over the next two years. We will need to carry out the river modelling projects for the River Thames and River Ock before we can complete our investigation into a flood storage area. This is because we will use the modelling information to assess and finalise whether a flood storage area is a viable option for reducing flood risk in Abingdon. These two modelling projects will take a considerable amount of time and therefore the earliest that we will know whether a storage area is viable will be in the middle of 2016.