Rivers of good quality, United Kingdom, Percentages
About 95 per cent of UK rivers were of good or fair chemical quality in 2003. About 73 per cent were of good chemical quality.
Although there has been relatively little overall change in the proportion of rivers of good or fair quality in the UK since 2000, there has been an improvement since 1990.
In England, 93 per cent of river lengths were of good or fair chemical quality in 2003, compared with 84 per cent in 1990. In Wales, the proportion was 98 per cent in 2003 (similar to 1990). In Northern Ireland the proportion was 93 per cent in 2003, a fall in quality from 97 per cent in 2002. The proportion in Scotland was 97 per cent in 2003, using a different but predominantly chemical classification.
Improvements in water quality since 1990 are largely attributable to the impact of the investment programme of the water industry and pollution control measures which have dealt with many point sources of pollution such as sewage plants and industrial sites. It is thought that to achieve further improvements it will be necessary to tackle more diffuse sources of pollution such as agriculture and run-off from roads and urban areas.
The chemical quality of rivers is not only affected by human activity. Low rainfall and low river flows can have an adverse effect through reduced dilution of pollutants, while high rainfall can also increase pollution through greater leaching of pollutants from the soil into rivers, or overflows from the sewerage system.
River water quality is a headline indicator of sustainable development.
Comparisons between Scotland and the rest of the UK should be treated with caution as the data are on a different basis. The Scottish river classification network changed in 2000.
Northern Irelandís classified network was significantly expanded in 2002.
The conclusion of improvements since 1990 at the UK level is based on a comparison of the trends for individual countries. An exact percentage change cannot be given for the UK because of changes in monitoring methods and monitored river networks in constituent countries through the period.
Source: Defra, based on monitoring data from Environment Agency, Scottish Environment Protection Agency and Environment and Heritage Service.