Imagine the scene: tens of thousands of tonnes of sewage have backed up behind a jammed gate and a decision has to be made – to flood one of the world’s busiest airports or inundate a small river very few people know exist.
It is a stark version of the choices made daily around the planet between costly economic infrastructure and the natural world: inevitably, the River Crane, and its populations of perch, eels, kingfishers and dragonfly larvae, lost.
The Environment Agency, the UK’s official enforcement body, now reports almost the entire west London river has been “killed” by the huge influx of grey sludge washed down the toilets and drains of nearby Heathrow airport, starting last Saturday night. Experts, who estimate 3,000 fish are floating dead in and along the oxygen-starved Thames tributary, say it will take “months, probably years” to recover. Anglers and other people are being warned to stay out of the water in the seven mile stretch from the A4 to the River Thames at Twickenham, though the risk to the Thames itself is thought to be low.
Thames Water issued an apology in which the company said engineers battled for hours to free the jammed sluice gate and commandeered 20 trucks to haul sewage away by road before being:
“Faced with the unpalatable choice of letting the remaining sewage back up into the airport or spill to the River Crane, we were forced to opt for the latter.”
The company also stressed that rather than wait for a prosecution, it had volunteered to work with the Environment Agency on an immediate clean-up.
There will be many who support Thames Water’s decision: the closure of such a crucial piece of infrastructure would have caused chaos, for passengers around the world, and taken days to sort out. Others will feel that the ecology of a whole river, in an already built-up area, is more important than some temporary (and smelly) inconvenience to passengers. The Crane might not have the romance of a wild salmon stream or the majesty of one of the great rivers of the world, but in a heavily urbanised and industrial area it will be, literally, a lifeline for far more than fish: for plants, insects and birds and small mamals to live in and travel through, and a valuable green space for local people.
In this case, too, the comparison of choices is also made harder by conflicting stories about the scale of likely consequences. Thames told me its modelling showed that, had it not released the sewage into the Crane, it would have washed down into the road tunnel entering Heathrow, forcing the owners, BAA, to close the airport on Sunday afternoon, as thousands of people returned from half-term holidays. It could also have affected the airport’s fire brigade, said the company.
However a spokeswoman for Heathrow told me:
“There was a possible risk to terminals one and three but there were contingency plans in place to avoid disruption to passengers.”
Those plans included trucking in temporary loo blocks and trucking out the sewage. The EA said it was told after the sewage was released into the river.
Weighing on Thames Water’s corporate mind might also have been the likelihood of enormous negative publicity and millions of pounds of possible compensation claims from BAA, airlines, hotels and other local businesses.
In the event, almost nobody but local groups noticed the Crane dying, and the cost of a clean-up is more likely to be in the tens of thousands. Fish don’t sue.
Later Richard Aylard, the company’s director of external affairs and sustainability, contacted the Guardian to explain that the original statement might have been misleading. “There wasn’t a situation where there was a man with a lever in front of him saying ‘one way: flood Heathrow; the other way: flood the river’,” said Aylard. Instead, said Aylard, engineers had to decide whether to block the built-in sewage overflow into the Crane, without knowing where the raw sewage might end up if they did. “They took what they thought was the right decision at the time, which was not to over-ride a built in safety mechanism,” he added.
There is far more awareness of the value of nature’s “ecosystem services”, especially after the publication last year of a global assessment commissioned by the UN, and this year in the UK theNational Ecosystem Assessment and the attendent Natural Environment White Paper. All have generated a lot of interest in monetising nature, and some hope that within a few years planned decisions – in this case whether to make a river teeming with wildlife the default emergency sewage drain – will take better account of those values.
Creating an environment in which more immediate decisions are made which at least give the environment a fair chance against more obvious economic interests is harder to do, though, admits Ian Bateman, professor of environmental economics at the University of East Anglia.
“The big one will be when you make it in the interest of private companies to make profits out of the environment: then they’ll have an interest in the environmental quality,” he suggests.
Allowing companies to make profits from protecting the natural world will be very controversial with many of its most vocal protectors. But it needs to be considered if we are to reach a point where a sewage company would consider flooding a road before a river.