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Inland water

Key trends

  • Biological river water quality has been consistently good in the South West, in 2008 88% of the biology network was classified in the top two quality bands.
  • Chemical river water quality has also been high since 1990 with the percentage of river stretches classed as very good or good reaching a peak of 91% in 2000.  In 2008 this now stands at 89%.
  • Stretches of rivers in the South West recording high phosphate concentrations have reduced from 54% in 1990 to 41% in 2008.

  • Stretches with high nitrate concentrations have remained around 26% for the last few years, however in 2008 this fell to 24%.

  • A total of 3,636 Million litres a day (Ml/d) of water was abstracted from all non-tidal surface and groundwater in the South West in 2006, in order to meet the needs of public water supply and industry. This was 19% lower than 1995 (4,486 Ml/d).

  • The number of households in the South West that now pay for their water by metered supply has risen from 28% in 2003 to 45% in 2008. 

  • Drinking water quality was generally of good quality in 2008 -   99.96% of the 599,041 tests on our drinking water passed drinking water standards.

Background to theme

The Environment Agency assess river quality using a range of monitoring networks and different aspects of water quality such as biology and chemical parameters including nutrients. However, the way that water quality is monitored is changing and we are currently in a transitional period of reporting. For twenty years, the Environment Agency have been using a general quality assessment (GQA) scheme to assess river water quality in terms of chemistry, biology and nutrients. GQA has helped drive environmental improvements by dealing with many of the major point sources of pollutants, such as discharges from sewage treatment works or other industry. GQA will continue to be used by the Government as a national headline indicator until 2010 and will overlap with Water Framework Directive reporting. The Environment Agency website has more information on how river water quality is measured.

The Water Framework Directive (WFD) is the most substantial piece of EC water legislation to date and is designed to improve and integrate the way water bodies are managed throughout Europe. It came into force on 22 December 2000, and was put into UK law (transposed) in 2003. It applies to all surface freshwater bodies (including lakes, streams and rivers), groundwaters, groundwater dependant ecosystems, estuaries and coastal waters out to one mile from low-water. WFD monitoring is risk-based, focussed where there is likely to be a problem, and classification is based on a far wider range of assessments than GQA. WFD is based on water bodies, not just river stretches and uses a principle of where the poorest individual result drives the overall classification. These differences to the way we measure water quality mean that WFD results will appear poorer than GQA results as it is a different assessment using different parameters and standards. It is the same improving water environment, just a different way of measuring it. WFD will give us a better understanding of the whole water environment, this will help us direct action where it is most needed. More information about the Water Framework Directive is available on the Environment Agency website.

GQA will continue to be used by the Government as a national headline indicator until 2010 and will overlap with WFD reporting. In England it is now based on fewer monitoring sites.. The chemistry GQA indicator has been recalculated with the remaining GQA sites and has been back calculated to 1990 (nitrate to 1995). These new statistics are not directly compatible with the old ones and due to lack of statistical confidence it cannot be summarised below government region boundaries with the exception of individual stretches.

The South West is one of the wettest regions, with the combined influences of the hydrological cycle and human activity contributing to the diverse character of the water environment.  However, some areas in the region currently face a lack of water available for new abstractions. Unsustainable abstractions and low river flows could be exacerbated by future pressures of increased demand for water due to projected population growth.

The Government has set legal standards for drinking water in the Water Quality Regulations (based on World Health Organisation guidelines). The UK also has additional standards to safeguard the already high quality of water in England and Wales. These standards cover bacteria, chemicals such as nitrates and pesticides, metals such as lead as well as look and taste. In the South West, drinking water is supplied by Bournemouth & West Hampshire Water, Bristol Water, South West Water, Wessex Water and some parts by Thames Water and Severn Trent Water.