One of the more interesting suggestions about the reasons for the impact of the floods in the UK in recent weeks has been the suggestion that land use may be a factor. George Monbiot has been sounding off on this subject although it's difficult to take him seriously because he keeps drifting off into class-warrior mode, linking the floods to grouse moors and the like.
Today his green colleague Geoffrey Lean takes up the baton, with an article in the Independent which claims that the North Yorkshire town of Pickering avoided being flooded because of preventative measures taken by the locals:
They built 167 leaky dams of logs and branches – which let normal flows through but restrict and slow down high ones – in the becks above the town; added 187 lesser obstructions, made of bales of heather and fulfilling the same purpose, in smaller drains and gullies; and planted 29 hectares of woodland. And, after much bureaucratic tangling, they built a bund, to store up to 120,000 cubic metres of floodwater, releasing it slowly through a culvert.
The result, claims Lean was that Pickering stayed dry while everyone else flooded.
Unfortunately, a North Yorks farmer has noted in the comments that this is grossly misleading.
The North York Moors area above Pickering received far less rain than the other flooded areas mainly in the Pennines. The rainfall through Christmas day and Boxing Day was rather gentle over a 48 hour period here and even over the high ground there was probably little more than 50mm.
The main installation which held back some water is a concrete dam with small outlet - that is a substantial engineering project. The implied success of blocking streams with logs in natural channels - let alone planting (still tiny) new trees is not vindicated by this one modest rain event. Debris washing down streams has blocked bridges and channels in other areas. Logs laid in streams will rot quickly and be easily broken loose.
Planting trees may be helpful in some situations but any benefit would take decades to materialise. Peaty moorland is itself a good water store and planting trees in some situations will dry out and destroy peat. There are already thousands of acres of woodland around the edges of the North York Moors and there is little evidence run off from these areas is less than moorland or farmland nearby.
You can see why the Telegraph might have felt Lean was surplus to requirements.