01.12.12
The role of infrastructure investment in preparing for floods and water scarcity in a changing climate
Source: Public Sector Executive Nov/Dec 2012
Dr Sebastian Catovsky, head of adaptation for the UK Committee on Climate Change (CCC), discusses the challenges of two major environmental threats, and how infrastructure investment can counter this.
Investment in a modern effi cient infrastructure system is a key pillar of the Government’s economic strategy. The £250bn of investment in the nation’s critical infrastructure planned over the next decade will be an important driver of economic growth. Ensuring that this infrastructure is resilient to the inevitable impacts of climate change will support sustained growth and competitiveness over the longer term.
Infrastructure plays an important role in managing two of the most signifi cant risks from climate change facing the country: fl ooding and water scarcity. In its 2012 report, the Adaptation Sub-Committee analysed how well the country is preparing for future fl ooding and water scarcity.
Flood protection
Climate change is likely to make fl ooding more frequent through increases in rainfall intensity, high river fl ows and sea level rise. Currently one in seven homes and businesses (3.6 million properties) face some form of fl ood risk in England. Of these, 330,000 are located in areas that have a signifi cant chance of flooding. Around 10% of the country’s critical infrastructure and emergency services are located in the fl oodplain. Capital investment of £1bn in new flood defences over the last spending review (2008/09 to 2010/11) reduced the chance of river and coastal flooding for 182,000 households in England. One-third of these households had been at signifi cant risk of flooding.
Funding constraints have meant that spending on fl ood defences from both public and private sources is decreasing. It is 12% lower for the current spending period compared with the previous period after infl ation. The Environment Agency estimates that funding needs to increase by £20m a year on top of infl ation to keep pace with climate change. This level of investment could lead to a four-fold reduction in risk over the next 20 years when compared to a scenario with no additional action.
At the same time, the Committee found that the country has become more exposed to future fl ood risk through continued development in the floodplain and paving over of front gardens. Development in the fl oodplain in England increased by 12% over the past ten years compared with a 7% increase outside the floodplain.
While much of this development took place in locations well protected from flooding with defences, one in fi ve properties built in the floodplain were in poorly protected areas that face a signifi cant risk of flooding.
Water scarcity
Over recent decades England has been affected by a drought every seven years on average. Security of supply has improved through continued investment by water companies. As a result, signifi cant interruptions to public water supply from drought, such as those requiring the use of standpipes, are rare. Restrictions such as hosepipe bans and constraining the level of abstraction are more common.
Current levels of abstraction are putting undue stress on the natural environment; 11% of rivers are under investigation by the Environment Agency for potentially failing ecological standards due to over-abstraction. Water companies estimate that without action to prepare, nearly half of water resource zones could be at risk of supply-demand defi cit during a drought by the 2020s, due to the combined effect of climate change and population growth. The supply-demand defi cit for England and Wales in the 2020s could range from negligible to 3 billion litres per day, with a central estimate of 1.2 billion litres per day (7% of existing supply).
In their latest long-term plans water companies have proposed measures to deal with around 1.4 billion litres of defi cit in the 2020s. Just over half of this effort focused on investment in infrastructure to improve supply, with the remainder of their effort split between reducing consumer demand or limiting leakage.
Household use of water per person has declined since 2000. However, average water consumption in England, at 145 litres per day per person, remains one of the highest in north-western Europe. If the current trend were to continue, water use would be reduced to 130 litres per day per person by 2035.
This could save around 700 million litres of water per day, dealing with around half the projected defi cit at the time. In comparison, the latest water company plans deliver savings of 440 million litres of water per day from reductions in water use.
The Committee has identifi ed scope for greater action to manage demand of water by households through sustained rollout of water metering, uptake of water effi ciency measures and information campaigns.
In summary, climate change will increase the risks facing the country from extreme weather.
Early action to limit the consequences of climate change will be important – both through infrastructure investment and other win-win measures, such as reducing inappropriate development in the fl oodplain and accelerating the pace of water use reductions.
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