Freshwater - State and impacts (United Kingdom)

Water quality

River water quality has historically been measured using the General Quality Assessment (GQA) classification in England, Wales and Northern Ireland, giving long term, separate measures of biological and chemical quality. In Scotland, results were based on the Digitised River Network (DRN), giving one overall measure. Results and further information are published as one of the UK’s 68 indicators of sustainable development, and are presented below.

Figure 1: Biological river water quality, United Kingdom, 1990 - 2009

Figure 2: Chemical river water quality, United Kingdom, 1990 - 2009

The Water Framework Directive has brought about a new method of assessment which requires the classification of all water bodies as part of the River Basin Management Planning process, and resources have been diverted to this away from the GQA monitoring networks. 

In December 2009, River Basin Management Plans were published for river basin districts in England, Wales, Scotland and Northern Ireland. Classification results for each country are provided below:

Water abstraction and use

The UK receives an average of 265 billion cubic metres of precipitation each year, of which around 60 per cent runs off to rivers and groundwater where it is available for public supply or direct abstraction (Figure 3). UK rainfall varies geographically – the Anglian region, for example, receives on average less than half that of either Scotland or Wales.

Figure 3: Long term average rainfall (left-hand scale) and runoff (right-hand scale)

Each year more than 14 billion cubic metres of water are abstracted from UK freshwater sources, of which 12.4 billion are abstracted in England and Wales. About half of all abstraction is taken by the public water supply and the remainder by agriculture (including spray irrigation), fish farming, industry and electricity generation. Approximately one third of the public supply is abstracted for non-household use.

Overall the Water Exploitation Index for the UK is 5 per cent.

Flooding

In England, around 5.2 million properties, or one in six, are at risk of flooding. Of these, 2.4 million properties are at risk of flooding from rivers or the sea and a further 2.8 million properties from surface water.

In Scotland, around 100,000 properties, or one in 25, are at risk of flooding from rivers or the sea. There are no reliable figures for the number of properties at risk from surface water.

In Wales around 375,000 properties, around one in six, are at risk to flooding. Of these, 220,000 properties are at risk of flooding from rivers and the sea in Wales, with around 97,000 of these properties also susceptible to surface water, and a further 137,000 properties susceptible to surface water flooding alone.

In Northern Ireland approximately 46,000 properties, around one in eighteen, are at risk of flooding from rivers and the sea. There are no reliable figures for the number of properties at risk from surface water.

There is also significant risk to national energy, water, communications and transport infrastructure and basic public services such as schools and hospitals (Figures 4 and 5).

Figure 4: National transport and utilities infrastructure assets in flood risk areas

Source: Flooding in England (2009), Environment Agency

Figure 5: National transport and utilities infrastructure assets in flood risk areas

Source: Flooding in Wales (2009), Environment Agency

Human health can also be extremely affected both in the short term with diseases spread by contaminated floodwater, and in the long term with victims experiencing mental illnesses such as depression and anxiety. Finally biodiversity can be impacted through frequent inundation.

The EU Floods Directive, which has been transposed into national legislation, provides a framework for the assessment and management of flood risk from all sources of flooding and aims to reduce the adverse consequences on human health, the environment, economic activity and cultural heritage.

·        In depth analysis of the risks that flooding presents in England, Scotland, Wales and Northern Ireland

·        More information on water in England, Scotland, Wales and Northern Ireland