By Ruth Slavid
The town of Pickering worked out its own approach to tackling and preventing flooding, with some help from outside experts – and even medieval monks.
When floods hit the north of England at the end of last year, one town that was relatively unscathed was the old market town of Pickering in the North Yorkshire district of Ryedale. Although water came into the town it was not enough to flood any properties – in contrast for example with the catastrophic floods of 2000. This was largely thanks (although one national newspaper blogger was sceptical) to the efforts taken by the town and particularly by the civic society, and especially by one man, Mike Potter.
He describes himself as ‘non expert and non qualified’ but by the end of the project he knew enough to be asked to talk at several conferences. Phrases such as ‘leaky dam’, ‘bund’ and ‘catchment area’ trip off his tongue – and that is not surprising. We hear a lot about the rise in and necessity for volunteering, but to most people that means a couple of hours a month. In Mike Potter’s case it was (‘conservatively’ he says) a matter of 10 hours a week for five years.
But it was not just one man’s passion that made Pickering a success. It was also that he and others in the town brought together local knowledge, and that there was excellent cooperation between the agencies involved. This was made easier by the fact that the catchment area for Pickering is relatively small and local, so the number of organisations involved was restricted. In addition the project benefitted from some research funding, and intelligent use of grants.
Nevertheless, although the solution Pickering adopted, which was largely of natural flood management, would not translate directly to another location, the approach and the lessons learned are worth disseminating more widely.
The story begins after the floods of 2000 that hit much of the north of England, including Pickering. There were hastily designed flood defences for several towns in the region again, including Pickering. But in the case of Pickering, there was considerable opposition. This is partly to do with position. The Pickering Beck, which feeds into the River Derwent, is in a deep gorge and is near to the catchment area. As a result it is, says Mike Potter ‘very flashy’. That is, it rises fast and falls equally fast, often within a day.
To defend the town it would have been necessary to build very high walls, which would have virtually destroyed its links with the river and would also have caused problems both upstream and downstream. In any case, after a large report from the Environment Agency and considerable amendments, a revised scheme was produced that was costed at £7 million – far more than could be justified on a cost-benefit basis.
It was at this point, with the town at continued risk of flooding and no obvious solution, that Pickering & District Civic Society became involved, and with it Mike Potter, a relative newcomer to the area, having moved there in 1998.
The first move was to look back – a long way back. ‘The monks at the nearby Byland Abbey had built leaking dams across the valley,’ Mike said. ‘We thought this could be done above us.’ There were two other, unrelated events. Really serious floods hit the town in 2007 – so serious that they would have overtopped the earlier planned defences, had they been built. At much the same time, academics working on a joint project involving Oxford, Durham and Newcastle universities approached the town to take part. A mix of physical scientists and social scientists, they were looking at how a community in which there was quite a lot of conflict could come together to solve problems. Led by Dr Sarah Whatmore in Oxford’s school of geography, the project was called ‘Slowing the flow in Pickering’.
‘We worked with them for a year and learnt about flooding,’ Mike said. ‘I don’t like bullshitters. This was an ideal opportunity to work with experts.’ A flood modeller worked on the proposed solutions. The result was a mix of natural flood management, largely funded by the Forestry Commission, and the construction of a bund about one and a half miles upstream of the town. These were designed to resist a one in 25 year flood. This was as far as the money would stretch and means the town is still vulnerable to the worst flooding. But, Mike said, ‘an affordable 1:25 scheme will protect from numerous small events – still vital for the more vulnerable properties.’
The natural flood management was mostly on Forestry Commission land. It consisted of building debris dams, mostly from tree branches, that would slow the flow of water through without holding it back so completely that they would be overtopped violently or ripped away. A lot of the moorland drainage has been reversed, either by ripping out drains or by blocking drainage channels with heather bales. There has been replanting of heather wherever possible. And in some of the valleys trees have been planted. These, Mike said, have been shown to slow down flow. The difficult is finding land in the right ownership that will allow the planting to take place.
The overall aim of all this work was to increase the storage capacity of the ground by reducing drainage, increasing plant cover, preventing peat drying out, holding back some water and preventing it rushing down slopes and gouging channels. In some areas, for example around Hebden Bridge, establishing this kind of regime is difficult, Mike said, because the land is used to raise sheep and grouse, both of which benefit from good drainage.
These natural flood management measures probably provided around 10 per cent of the storage that was needed to prevent a one in 25 year flood. The rest of it came from the bund. This is effectively a dam with a culvert cut through it. In normal times the water flows through the culvert, but when the flow is extra heavy the water backs up behind the dam and floods the adjacent fields rather than rushing down into the town.
The cost of all this was around £2.1 to £2.5 million with the funding coming from a variety of sources, including the local council, Defra and the ‘slowing the flow’ project. The Forestry Commission paid for most of the natural flood management work. Mike Potter pointed out that for a town like Pickering, with a population of 7,000 not all of whom would be affected by flooding, the Environment Agency’s cost benefit analysis would never work without some special funding from elsewhere.
He is full of praise for the people within agencies who really ‘got it’ and made working together not only possible but pleasurable. There was also work to do in the town itself and below the town, clearing channels including some dredging to ensure that the water can flow fast out of the town – before of course being slowed again in advance of the next town.
One potential problem with this approach is that there may be some flooding of outlying properties, actually built on the floodplain, but Mike has little sympathy in the longer term. ‘The flood plain is part of the river,’ he says. We have got to list the cost benefits of building on the flood plain. Those benefits are all up front – and the costs are all downstream. The benefits are private and the costs are social. Any property newly built within the footprint of a 1:200 flood event should be built to be flood resilient (solid floors, high electrics etc). I have suggested to my MP that this should be a national standard and included in building regs. I’m not holding my breath. Owners of existing properties within the 1:200 year flood event zone should be made aware of this fact and should seriously consider flood resilience measures, particularly during any renovation work. Perhaps this could be partially grant funded?’
Jeremy Biggs wrote in the Guardian on 7 January that ‘Working with nature didn’t save Pickering from the floods – it just didn’t rain much.’ His point was that the rainfall in December overall was low for the area. But Mike Potter argues that because the river is so flashy, a brief storm raised the levels significantly. He saw this on a gauge, and he saw some additional water get into the town. Without the flood measures, he is confident that there would have been significant flooding, as there had been several times over the past decade.
I think I would rather trust a local, especially an ‘amateur’ with as much knowledge, dedication and fighting spirit as Mike Potter has.