The following example focuses on water utilities in England and Wales, and their experiences with planning for climate change in the context of recurring drought and flood episodes. The government privatized the major water utilities in 1989 and organized them according to the boundaries of the former Water Authority units. The duties of these privatized utilities are defined by statute and include cost-effective provision of clean water, treatment of wastewater, and environmental responsibilities. These broadly defined duties, and the fact that the utilities are organized on the basis of catchment basins, makes integrated water resource assessment and management both easier and more necessary for these utilities than may be the case for utilities in other settings. That, in turn, has facilitated the process of assessing climate change impacts and response options. 

Water utilities in England and Wales face heavy regulation with respect to both pricing and performance of their statutory duties.  Regulation involves a regular cycle of planning that is subject to intense public scrutiny. The government now encourages a “twin-track” approach to supply planning that simultaneously considers both resource development and demand management options. The government also has actively encouraged utilities to consider climate change when formulating their long-range water resource plans. In doing so, the utilities work closely with regulatory agencies such as the Environment Agency.  One of the methods that they use to deal with uncertainties in demand and supply projections is to calculate a “headroom” factor that would be needed to meet supply security targets.  The headroom calculations incorporate allowances for the possible impacts of climate change.

Assessment efforts have also been helped by the coordination of industry and government-funded research efforts through UKWIR (UK Water Industry Research), which is a water industry research group funded by the utilities.  The UK government has invested a considerable amount of money in climate change research and supports a number of research centers across the country.  The water utility industry has formed successful research partnerships with these centers to evaluate the risks that climate change may pose for the utilities.

Longer dry spells are one of the likely consequences of global climate change. In fact, droughts have played a significant role in shaping changes in water planning and management in England during the past quarter-century, and in focusing the attention of UK water utilities on planning for climate change (Subak 2000). There have been four major droughts during this period: the first occurred in 1976 through 1977, the second in 1984, followed by a three-year drought beginning in 1989, and finally a single-year drought in 1995. 

The 1995 drought prompted the national government to mandate that all major water supply companies begin to examine climate change scenarios when calculating demand and supply balances.  At the request of the Department of the Environment, English and Welsh utilities began to prepare detailed plans for adapting to global climate change following the 1995 drought.  They have based these planning efforts on global climate change scenarios derived from various climate model projections and on climatic trends that utilities have observed in recent years.  The model projections tend to suggest wetter winter conditions and hotter summers, with an increased likelihood of extended dry spells. Recent climate observations vary from one region to the next, but many of England’s utilities reported drier summers or more intense but less frequent periods of precipitation in comparison to the historical record.  While these scenarios do not provide a clear picture of the likely magnitude of future changes in hydrology, the utilities are using them to explore and assess the types of problems that climate change could pose.

An interesting aspect of the recent drought experiences is that despite similar hydrological characteristics, each drought evoked different responses by water resource managers. Expansion of water storage capacity was the main response to the 1976–1977 drought.  While the resulting infrastructure projects did not solve all problems during later droughts, they greatly increased the ability of many utilities to respond to the subsequent drought events.   After 1977, five of England’s ten major water regions built new reservoirs, and the utility managers in these districts observed that they would not have been capable of supplying sufficient water during the 1995 drought without these infrastructure investments. The droughts during the 1980s also resulted in several supply infrastructure projects, but demand management began to play a role in some regions with the introduction of water use restrictions.  The drought episodes demonstrated that dealing with peaks in demand presented the biggest challenges for most of England’s utilities. Such demand spikes are intensified and therefore most obvious during droughts.

Responses to the 1995 drought focused much more on demand management than in previous years.  Since 1995, utilities have worked in earnest to implement a number of projects to reduce consumption, including metering water and reducing system leakage. Other infrastructure development has followed these droughts, with most construction projects focused on developing redistribution capacity.

In the context of future planning, utilities are considering adaptation strategies that they have applied following past droughts.  Some utilities, for example Essex and Suffolk, are vulnerable to increased runoff variability because their storage volume is insufficient to capture enough runoff during high flow periods to supply longer dry periods.  As a result, these utilities have developed plans for reservoir addition or expansion.  The Thames Water Utility is considering storage expansion to prepare for future summer droughts, but also has invested in regional distribution changes to cope with peak demands.  In addition to enhanced regional distribution systems, several regions are planning to increase transfers from one region to another; for example, Severn Trent negotiated arrangements to import water from the Anglian region.

Wetter winters and episodes of intense precipitation are some of the possible consequences of climate change that climate model projections suggest for the UK.  In that context, UKWIR has funded research on the implications of heavy rainfall events for the design of sewerage systems.  The potential water quality impacts of inadequate sewerage design in the event of heavy runoff is a significant concern for the industry.  Utilities have dealt with the uncertainties associated with projections of wetter winters and hotter summers by exploring the merits of various options for storing winter runoff for later use under a wide range of climate scenarios.  In summary, forward-looking planning for climate change has become a standard practice for water utilities in England and Wales.