The line chart illustrates the percentage of river water classified as having good chemical quality in four regions of the UK—Wales, Scotland, Northern Ireland, and England—between 1990 and 2002.
Overall, the majority of rivers in all four regions maintained a high level of quality, with figures consistently above 80% throughout the period. Scotland experienced steady improvement and became the region with the best river quality by 2002, while Wales saw a slight decline. Northern Ireland’s figures fluctuated but ultimately increased, whereas England showed consistent improvement.
In 1990, Wales had the highest proportion of good-quality river water at 97%, slightly ahead of Scotland at 95%. However, Wales experienced a gradual decline over the period, falling to 94% by 2002. In contrast, Scotland’s river quality improved consistently, peaking at 98% in 2002 and overtaking Wales to become the leader.
Northern Ireland’s river quality was unstable, dropping sharply from 93% in 1990 to 84% in 1996. Despite this, it rebounded to 95% by 1999 before declining slightly again. By 2002, it recovered to reach 95%, equal to Scotland’s figure in earlier years. England, which started with the lowest proportion of good-quality rivers at 82%, demonstrated steady progress, climbing to 91% by 2002, the most significant improvement among the four regions.