Flooding: a feature of the future

The problem is that flooding is a feature of the future that climate change is likely making worse. We need solutions and adaptations, some of which may need to be quite radical if we are to avoid things getting far worse before they get better. Even official bodies, such as the Environment Agency, are now starting to recognise this.

This article by Professor Dan Osborn was originally published in The Medium and is provided by UCL Public Policy. Continue reading below…

The increasing risks of flooding in the UK rise sharply over the century, as illustrated by the second UK climate risk assessment published in 2016. With the world heading for an average temperature rise of 3°C — or more given the current level of emissions — the expectation must be that the increase in risks is towards the upper end of those estimates, meaning millions more people in the UK could be at risk of flooding, although many already have flood defences in place. Of course, the UK is not alone in this, with 80% of the world’s population residing in flood-prone nations.

In the extreme, managing this risk could mean moving entire communities progressively away from locations prone to flooding, or simply not building on flood plains at all — measures that were unthinkable only a few years ago. An alternative, almost as extreme an approach perhaps, would be to calculate the true and full societal cost of flooding to include the impacts on people and the disruption to community life, so that more communities pass the test that would allow hard flood defences to be built; if only the money were available to do so. This might mean that as the concrete walls go up, some places lose their view of the river they value highly that also helps define their sense of place and their feelings of wellbeing. The affordability of such an approach would also be in question.

Why is all this so difficult?

Flooding is no simple matter, as it comes in various forms and can affect people in a multitude of ways — even those in unsuspecting places.

The type that catches public attention and that of the media most often is river flooding — but this can quickly be followed by extensive groundwater flooding that can be, in some ways, just as severe. This is because even a little water in a home or business can cause tens of thousands of pounds worth of damage, as well as having an emotional impact on residents and owners.

Before the river floods, there can also be surface water flooding, where the rise and fall of the land causes water to settle and drain into areas that are not always on a flood risk map. Most of us will be familiar with pictures of vehicles stranded under a road bridge surrounded by this type of flooding, which can disrupt transport systems across wide areas. Nowhere is immune, as surface water flooding is often accompanied by fast, if shallow, flows of water across ground. In some senses, even homes and business on hills can be affected, as water cascades downhill and into buildings on its way to a low point or the local streams and river.

Then, of course, there is coastal flooding and other impacts that cause problems for communities in these areas, resulting from a combination of rising sea levels, coastal erosion and wave action during storms. They can range from simple inconveniences — as when the beach shingle is thrown up across a road or footpaths (although even this can lead to damaging impacts for vehicles, cyclists or pedestrians) to more serious impacts such as houses collapsing into the sea, as has happened on the east coast of England in recent years.

In the future, whole communities may become entirely unsustainable in their current location, with residents facing relocation. At present, we have no legal or financial approaches for doing this at large scales. Fairbourne in Gwynedd, Wales, is one such coastal community that is already being affected by the risk of coastal flooding driven by sea-level rise, combined with the risks from the nearby river estuary and underlying groundwater situation.

Coastal flooding and erosion issues are also affecting some of the UK’s most iconic coastal areas, such as Cuckmere Haven in Sussex, where an area of high cultural heritage and amenity value could be lost to the sea in the coming years. Cuckmere is not the only place where rapid coastal change is happening even on coasts previously regarded as stable; for example, sea defences were breached at Climping, Sussex, during Storm Ciara and a new line further back from the sea has been established by emergency works, which fortunately held during Storm Dennis.

Coastal flooding could also worsen if the rate of sea-level rise picks up; currently, it is already two to three times what it was in pre-industrial times in parts of the world — partly due to the warmer ocean and partly to melting of ice caps that are now losing billions of tonnes more ice every year.

So how can we find a solution?

First, we need to face up to the risks of flooding and its true cost on whole communities, which should help to focus the minds of politicians and decision-makers. The Environment Agency has already undertaken some work on this kind of approach to costing, where health impacts and the disruption to the community are factored in more completely, unlike present models where property damage dominates cost calculations. A more realistic measure of impact is needed that includes monetary, human and societal costs.

Second, communities need to be engaged — and engaged early — with what they think needs to be done. There are flood risk options to be considered; in some areas there might be the choice between hard defences, temporary defences (of many different kinds) and some form of “natural flood risk management”. In some cases, a combination of approaches is necessary. The UK Government is currently not good at engaging communities in finding solutions to their problems; learning from other countries, like the Netherlands, who are further ahead is key.

There are plenty of community engagement methods available that would break open the necessary dialogue. They need to be used by lead flood authorities to help ensure flood impacts become less severe over time rather than more severe and extensive. This engagement needs to generate action within communities and needs to be based on successes achieved elsewhere, wherever possible. Actions should be incentivised by the Government and the private sector and can involve individual properties and business as well as groups working together.

Third, some hard decisions are needed on policy and its implementation. A complete overhaul is needed of the current exception test and tiered approach in the British planning system that can allow development on floodplains; the current approach is effectively encouraging such development. This option needs to be a key part of the upcoming review of the planning system. One idea could involve making planning authorities and developers carry some liability if new developments cause flooding elsewhere. Such a provision might help to drive innovation in community design and construction and create more thriving communities.

Finally, we all need to face up to the fact that it is the actions of humans over time that have caused the release of carbon dioxide and other greenhouse gases into the atmosphere and that, to a degree, at least some of the victims of flooding and coastal change are so because of the change in our climate resulting from our actions. Thus, rapidly reducing greenhouse gases emissions is crucial. 2020 is the year when emissions and levels of carbon dioxide in the atmosphere need to peak if, amongst much else, the impact from flooding and rising sea-levels is not to turn catastrophic. If we fail to limit emissions, we may not be able to afford to adapt at all. The UK may then lose communities or have to relocate them entirely. That sounds bad enough — but what of the countries that could be completely lost? Losing countries and communities really would make the world a poorer place. Radical action now is the only feasible option we have.

Professor Dan Osborn is Chair of Human Ecology, Department of Earth Sciences, UCL and Co-Chair of the UCL Environment Domain. He was a lead author, with his colleague Sari Kovats, on the chapter of the Evidence Report for the 2nd UK Climate Risk Assessment that dealt with flood risk.

Picture of flooding at Pulborough by Peter Burnage