14 July 2011
Water companies need to adapt to a changing climate
Water companies in England and Wales need to adapt their planning framework given the risk of droughts and disrupted water supplies over coming decades, warns research led by Oxford University. The research paper, published in the online version of the Water and Environment Journal, says that whilst the planning framework used by the water companies does factor in climate change, it is ‘not fully fit for purpose’ in the long term. The paper urges water companies to work with their regulators and stakeholders to develop approaches that assess the possible risks and management options for adapting to climate change in the 21st century through using simulation modelling of multiple future scenarios. This approach ‘explicitly considers the probability and consequences of harmful events, in this case water shortages for people or the environment’, says the research. The research was carried out by the Catchment Change Network, a consortium of universities, water companies, consultants and government regulators, who are working together with the aim of more sustainably managing the changes taking place in the UK’s river catchments.
Professor Jim Hall, Director of the Environmental Change Institute (ECI) at the University of Oxford, who led the research, said: "We need a more rigorous and open system to bring drought risk analysis into the 21st century. Although water companies are open about their planning, they need to work with the regulators and their stakeholders to do more to prepare for the long term. Possible patterns of water usage and water availability in coming decades need to be properly assessed: instead of basing decisions on past events, we need to look at the possible risks that lie ahead and test options for dealing with them. By using simulation modelling of future scenarios, it would be possible to test the effectiveness of adaptation and assess what levels of investment may be needed to deal with pressures like climate change."
The paper argues that in the past the water companies have benefited from publishing plans that are relatively simple to explain to the paying public. But it warns that assessments largely based on past events are no guide for the possible risks of the 21st century. Although water companies adjust projections in line with predictions about future climate change, the research paper suggests that scenarios, such as the durations of future droughts, are not factored in. Warmer climates and drier summers that are expected in future could bring longer droughts than water companies are currently planning for. New climate change scenarios from the Met Office that became available in 2009 are making it possible to test water supplies against a wide range of possible future scenarios. The paper argues that water companies should make full use of these scenarios.
The risk-based approach, advocated in this paper, is in line with Ofwat’s recent guidance to water companies requesting a ‘reasonable, risk-based, analysis consistent with the range of projected outcomes reflected in the application of a suitable analytical tool’. The paper also points out that other sectors, such as flood risk management and earthquake engineering, are already using risk-based methods.
In an earlier research paper (published in 2009), co-authored by Professor Jim Hall, it was revealed that the number of days on which water could be extracted from the River Thames is likely to reduce by a quarter by the 2050s. The research team used a wide range of combinations of climate model projections to produce what Professor Hall described as "a basis for decision making that was robust to model uncertainties".