A layperson’s guide
to the flood risk problem in Staines
… and how to lower the risk from new developments …
There are three sources of flood risk in and around Staines on both sides of the Thames: from the river; from surface water run-off; and from the ‘hidden’ groundwater flows through the thin gravel layer on which the town is built. A great deal is known about the first two of these, with the Environment Agency being the ‘statutory consultee’ in the planning process for flood risk from the river and Surrey County Council for the risk from surface water run-off. However, there is no statutory consultee for groundwater flood risk and, as a consequence, extremely little was known about it … until last year with the shock findings of scientific research by Royal Holloway, University of London. This revealed that flood risk from groundwater in Staines is greater than from the river or surface water run-off. The research also concluded that the River Thames Scheme, designed to lower the level of the river during a flood, will not reduce the flood risk from groundwater.
There are dramatic and localised fluctuations in the thickness of the gravel substrate under Staines adding to the powerful, wildly variable groundwater flows. When these bump into barriers in the gravel, such as the foundations and basements of large buildings, the water is displaced and pushed mostly upwards because of the resistance from what is around and beneath it. Such barriers from the foundations and basements of existing buildings have unquestionably altered and added to flood risks in Staines and have produced flood-risk ‘hot spots’. Indeed, even regulators have noted that “if we knew then what we know now, no-one would have built a town where Staines is!” New barriers, however shallow or deep, from new developments will add to the problem … and the problem will be made even worse the more there are of these new barriers both individually and as disturbed water-flows from them interact with each other.
Decisions and pronouncements by Spelthorne Borough Council on these issues to date have demonstrated a worrying ambiguity and at times disregard. Flood risk was a big enough issue before the Royal Holloway research. A really big factor has been the Council’s quite public disregarding of the research findings when they were released. This was at a time when the Council was finalising proposals in its Local Plan to add close to three-and-a-half thousand new homes in Staines, almost all in tower blocks of flats. The government Planning Inspector’s public examination of the Plan concluded in March this year, just before the Royal Holloway research acquired the validation of independent scientific peer review that makes its findings effectively beyond challenge. As things stand, there is a lack of clear and unequivocal safeguards in the Plan to protect against increased flood risk from new developments.
Perhaps the most alarming example of the Council’s attitude to increased flood risk from new developments is its agreement with a developer for a massive new hotel, to be by far the biggest building anywhere near it, in the riverside Conservation Area by Staines bridge. It was approved by the Council (with only one Councillor voting against) just days after telling the Planning Inspector the site should be removed from the Plan “for residential and hotel purposes” because of flood risk. The agreement places no demands on the developer to guarantee it will not increase flood risk for others in the area around it. In effect, the Council is saying “if you can get what you want through the planning process, that’ll be just fine with us.” As owner of the site the Council had a clear opportunity, and many think an obligation, to impose conditions on its use that would protect the community.
Highlighting the concerns of experts about the importance of flood risk is the recent conference on flooding hosted by New Civil Engineer with the following quotes from delegates: “The outcome is that we believe the exposure (to flood risk) is going to double by the end of the century, which provides perspective on how areas are impacted by flooding. This is not just due to climate change, it is also caused by urbanisation and changing population density” … “This concentration of assets in high-risk areas like floodplains is only going to make property and infrastructure much more exposed to flooding and storms” … “We rely on a lot of ageing flood risk infrastructure in this country, a lot of it post-war, with a large share of it coming towards the end of its design life. I don’t think we’re doing enough to understand what future hazards those assets could be facing” … “The lack of an integrated approach is what currently hold back flood resilience” … “There’s a human element to all this. Flood management is about saving lives and protecting communities”.
Highlighting the growing concerns in the legal profession are recent pronouncements from The Law Society to its members: “Climate risks may affect the ability to insure, sell, let, develop or finance property, which can adversely impact the property’s value or marketability … a property owner has ‘riparian obligations’ (responsibility of a land owner whose property is situated on the bank of a watercourse) and fails to take reasonable measures to manage the risk of flooding. As a result, that property owner could be found liable in negligence law for flood damage to neighbouring properties.” Perhaps Spelthorne Borough Council should note this as all of the sites for major development in Staines in the Local Plan are owned by the Council.
The Council must change its position, get off the fence, and ensure proper protection for residents in Staines and elsewhere in the borough under flood threat. Particularly now that the Royal Holloway research has independent scientific ‘peer review’ validation, the Council must seek amendments to its Local Plan. The Riverside Residents (Staines) Coalition has recommended the following in its submission to the Council’s Local Plan Modifications consultation, and has confirmed this to the Planning Inspector (who has in any event already told the Council unspecified aspects of its Local Plan need to be subject to “immediate review”):
* Major developments proposed for Staines should be subject to reconsideration as part of the “immediate review” of the Plan.
* As part of the immediate review, consideration should be given to strengthening and clarifying policies to ensure the risk of flooding from new developments to others in the area are removed (not just mitigated).
* Any and all proposed new developments in Staines must (not should as in the proposed revision to the Level 1 SFRA referred to in policy E3 on managing flood risk) be subject to a) an independent hydrogeological risk assessment and b) a contractual undertaking by the developer that they accept full legal responsibility for any increased flood risk created for others in the area.