Trickle-Down Theory

How the government learnt absolutely nothing from the recent floods.

By George Monbiot, published on the Guardian’s website, 7th January 2016

Those of you with memories longer than a week will be aware that Britain experienced a degree of hydrological inconvenience in December. You know: 16,000 homes inundated, £5bn of damage, that kind of thing. I vaguely recall that it made the news once or twice.

You may also remember that, for the first time in Britain, there was a wide-ranging discussion on the causes of the floods. Connections that have been familiar to geographers, hydrologists and fluvial geomorphologists for two centuries finally broke through the media dam and into public debate. We began, at last, to discuss the second component of freshwater flooding.

The first component is of course heavy rainfall (or snow melt). The second is the way the land and rivers respond to this deluge. If land and rivers are managed to enable them to hold back the water, slow the flow to the lowlands (where almost everyone lives) and reduce the height of the flood peak, flood defences at the bottom of the catchment are less likely to be overwhelmed. If, instead, the water flashes off the land and rushes down the rivers as quickly as possible, the chances of disaster downstream are significantly raised.

So reducing the likelihood of devastating floods means considering a river’s catchment as a whole, rather than treating different sections of it as isolated components. It means retaining water in the hills (where most of the rain falls) for as long as possible, by allowing trees to grow and bogs to form.

It means leaving obstructions in rivers and the streams and ditches that feed them, to impede the water that flows through them. This means letting the main channels meander and braid, developing islands, gravel banks, riffle runs and pools. It means allowing wood and other vegetation to accumulate in the feeder streams and ditches, to act as leaky dams, restraining the flow of water (beavers, by the way, can greatly enhance this process). It means reconnecting rivers to their floodplains where it is safe to do so, holding the water back on farmland, rather than allowing it to balter down to the nearest town.

When very high rainfall hits a country, not all the water can be retained at the top of the catchment. Some parts of the floodplain must flood. Either fields take the water, or the river is rushed past them with the help of embankments, canalisation and dredging, so that the homes, schools, sub-stations, roads and railways downstream cop it instead. The obvious way of resolving this choice is to pay farmers to store the water in their fields until the flood peak passes. Yes, it’s inconvenient for the farmers, but it causes hundreds of times less damage, expense and misery than the alternative.

There’s nothing exotic or esoteric about this knowledge; it’s common currency among scientists, insurers and government officials. In fact everyone involved in seeking to prevent homes and infrastructure from being flooded seems to be aware of it – except the person in charge: the secretary of state for the environment, Liz Truss.

That, at least, is the charitable interpretation. For if she possesses even the vaguest flicker of awareness of basic hydrology, the policies she announced this week must be ascribed to something worse. Something like this: the appeasement of special interests at the expense of the rest of the population. Is she really as blitheringly ignorant of a central aspect of her brief as her announcement suggests, or is she placing the demands of one sector above the well-being of the nation?

At the Oxford Farming Conference on Wednesday, as if nothing had happened in the preceding month, Liz Truss revealed that she intends to go ahead with her long-standing plan to allow farmers to dredge and clear the water courses passing through their land, without oversight, regulation, or consideration of the impacts downstream, in order to prevent their fields from flooding.

She also intends “to give internal drainage boards and other groups more power to maintain local watercourses.” The autonomy of internal drainage boards has long been recognised as part of the problem: dominated by local landowners, they tend to be narrowly focused on getting water off farmland as quickly as possible. They are responsible for much of the embankment, canalisation and dredging that speeds rivers into people’s homes.

She capped this madness by announcing that the government “will be protecting an additional million acres” of farmland from flooding by 2021. I repeat: when extreme rainfall strikes, you can’t protect both farmland and homes; a choice has to be made. And the secretary of state for the environment has chosen to use public money to make the flooding of the built environment more likely.

Why do I suspect that Liz Truss cannot be as ignorant as the charitable interpretation would suggest? Because advice to the contrary by her own officials continues to be not only ignored but purged.

I’ve mentioned in previous articles how reports by Natural England and the Environment Agency on rational catchment management have been deleted and pulped. Now, thanks to the Angling Trust, we discover that another, crucial Environment Agency document has been removed from public view. Titled “Evidence: Impacts of dredging”, and first published in 2013, it has now been deleted from all government websites. The trust has republished it.

Here is some of the advice this document contains:

“Increasing risk downstream: Dredging could in theory speed up flow and potentially increase the risk of flooding downstream. This is fully covered by the existing research.”

“Channels which have been artificially deepened by dredging silt-up more frequently as they return to their pre-dredged state. In these situations dredging will be an unsustainable activity since it needs to be repeated regularly. The best approach is to identify the sediment source and address the issue at source rather than treat the impact.”

“Dredging can damage ecology by directly affecting its physical habitat, disrupting riverine processes and reduced connectivity with the floodplain.”

“Dredging may also make a channel more vulnerable to exploitation by invasive non-native species such as signal crayfish and Himalayan balsam.”

So, if the advice conflicts with the policy, what do you do? Change the policy? Not on your life. Get rid of the advice. And if that’s the kind of censorship you might expect in Uzbekistan, not the United Kingdom, who cares?

Why is this happening? The National Farmers’ Union gives us a clue. Its president, Meurig Raymond, told the BBC: “The NFU has pressed Defra [the environment department] and the Environment Agency to enable farmers to undertake minor works for many years.” At the Oxford Farming Conference, he got what he wanted. And to hell with everyone else.

That wall between 17 Smith Square, London SW1, where Truss’s department is based, and 16 Smith Square, London SW1, occupied by the National Farmers’ Union, is looking thinner than ever. Under Liz Truss, Defra – which claims to be the Department for Environment, Food and Rural Affairs, but really stands for Doing Everything Farmers’ Representatives Ask – appears to be even more susceptible to lobbying and regulatory capture than it was under her predecessor, Owen Paterson.

As for the people who live downstream of the orgy of dredging, channel clearing and field protection that Truss has just licensed – and have just been condemned by her to even greater misery when the next storms break – sorry, who are you again?