Flooding
Immediately below the development the Great Ouse floodplain has regularly flooded on average at least once a year. With climate change, this is now occurring several times a year and predicted to worsen, leading to increased flooding in Stony Stratford as well as Newport Pagnell, downstream of the site. The site itself is prone to flooding as can be seen from
our recent images, as it lies within the Dogsmouth Brook flood zone. The image below shows the flood-zone across the site (with the site outlined in red).
Flood-zone crossing proposed site (site outlined in red)
Button
The developer wants to increase the size of this little culvert at the Buckingham Arm (shown above). The Environment Agency say the culvert cannot be scaled up – it holds back water from escaping too fast into the River Great Ouse. If it is increased in size that would exacerbate the flooding in Stony Stratford and downstream in Newport Pagnell.
This image shows flooding in the centre of the built site, September 2024
The unpassable underpass in the corner of the built site
“...the site may be at risk of great depths of flooding with vehicles being potentially lifted in deep flood water. The northern site could potentially be cut off if flood water submerges the Spine Road with Old Cosgrove Road and Stratford Road already submerged..”
The Environment Agency
The Environment Agency, along with others, have raised objections to the first four proposals from the developer, and are concerned about loss of soakaway with so much area under tarmac and concrete.
The developers are now on their fifth flood mitigation scheme despite initially claiming that the site doesn’t flood. The 2025 flood scheme tries to revert to a much earlier version of the planning documents, where the culvert under the canal is enlarged to allow water to leave the built site more quickly. The fourth proposal (August ‘23) had water held in attenuation lakes and an earth dam, holding up to 44,000m³ of water. (about the size of 20 Olympic-sized swimming pools!) This is a major engineering project, and its size will require stringent regulation including a supervising engineer to monitor it during construction and every year after that.
We pointed out that this scheme constituted a high-risk reservoir and the Environment Agency agreed, maintaining their objection to the development. This option remains on the table but only if the first option, simply allowing flood water through an enlarged culvert to drain into the Ouse via a ‘wetland’ area within the park, is not viable. We, along with Old Stratford Parish Council, commissioned our Hydrology consultants to review the latest planning documents. This report concludes that 'the Flood Response Plan is poor and is missing key information specific to the type of activities likely to be undertaken at the site. The Plan does not adequately address the flood risk over the wider area and as such presents an inaccurate assessment of the flood risk. Therefore it should be rejected by the EA and LPA'. A full copy of the report can be found here.
The developers desperately want to have the site plan approved without the reservoir element, as they now accept that the site owner will be responsible for its maintenance for the next 100 years. With the significant loss of soakaway due to buildings, roads, etc., the Environment Agency is working through the implications of both schemes. We firmly anticipate that their conclusion will be the same: continued objection!
The new reservoir also means losing a huge area of the Country Park!
Large, raised reservoirs may be classed as high-risk when human life would be endangered if the dam fails, causing an uncontrolled release of water. If this dam fails it would cause a potential loss of life as well as calamitous flooding upstream in Stony and downstream in Newport Pagnell.
“We note the compensatory Flood Storage Area (FSA) is proposed to hold a large volume of flood water and that it will fall under the ambit of the Reservoirs Act 1975.....and it will be most likely considered a ‘high’ risk reservoir due to its location.”
The Environment Agency
Ouse Valley flooded, downsteam from site with site behind, 2021
Stony Stratford High Street flooded, Dec 2020
Stony Stratford High Street flooded, Dec 2020
The Dogsmouth Brook flooding Stratford Road, Cosgrove, 1970's
“...we still are unable to give acceptance to the application as the proposal has not demonstrated that there will be no off-site impacts and there will be no increased flood risk elsewhere.”
The Environment Agency
- Major loss of soakaway in a WNC Flood Zone, leading to the risk of increased flooding in Stony Stratford and downstream in Newport Pagnell
- Developers propose enlarging the culvert under the canal, disregarding the Environment Agency’s warning that this would worsen flooding risks by accelerating water flow to the Ouse
- The developer's plan to create a massive reservoir is a major engineering project and was not part of the original scheme. If it breaches, it could cause extensive flooding and potential loss of life.
- The reservoir will be filled with effluent-rich water during periods of high rainfall. Logic dictates that if the outflow is slower than the inflow, the reservoir will fill up. In that case, where will the floodwater go?
- Developers have ignored their own consultants' predictions that parts of the site are still at risk of flooding up to 2 meters in depth, making the site unusable and, as with the South Milton Keynes warehouses, unsalable
- Any flood storage scheme will function as a reservoir, requiring ongoing regulation and maintenance by site owners. The ‘reservoir’ will still be an earth bund with “engineering fill.”
- Developers boldly claim the development will “reduce” flood likelihood. We await with interest to see what the Environment Agency's review makes of this
