Natural measures have their place. But throw a month’s worth of rain on a saturated catchment in one weekend and no nature-based solution is going to hold back the waterby Robert Wilby and Simon Dadson / February 24, 2020 / Leave a comment
As large swathes of the UK endure the worst floods in living memory, hearts and minds are rightly focused on protecting people and property. At one point the government’s Environment Agency had issued a record 594 flood warnings or alerts—its map of the country was a sea of orange and red symbols:
Once the floods recede, there will doubtless be a period of reflection on what could have been done better. It may be tempting to point the finger of blame or to promote a particular solution. But the hard truth is that there is no silver bullet for “preventing” floods.
There are common sense actions, like avoiding new development in places that are known to flood. Official statistics suggest that about 10 per cent of new residential addresses are created in these high risk areas (classified as National Flood Zone 3). It is also smart to protect critical infrastructure like bridges or power substations to high standards. Yet a 2016 government review of flood resilience revealed more than 500 assets vulnerable to flooding.
Other measures can help ensure that floods, when they do occur, are less devastating. These include paved floors, valves to shut off foul water, or raising electrical circuits. Who should pay for these is another matter.
However, we need to accept that the climate is changing, and with it the pattern and types of river flooding. For instance, the Met Office has charted a steady decline in the number and severity of substantial snowfall events since the 1960s. Less snow means subsequent spring melting is becoming rarer. Instead, the country is seeing more heavy rainfall, with winter records being broken on a regular basis.
Or consider how a warmer Atlantic boosted the intensity of Storm Desmond in December 2015 by 25 per cent. Desmond set the UK’s 24hr rainfall record and caused severe flooding across much of northern England.
These consequences are exactly what the climate models have been predicting for decades. The net result is more water flowing from the headwaters of rivers in shorter periods. We are also observing simultaneous flooding across many river basins on a regular basis—the period since the late 1990s has been especially flood-rich.
We aren’t going to halt or reverse climate change anytime soon. However there are…