Long-term trends in water quality reflect the increasing eutrophication of rivers in East Anglia. DO decreased in eight rivers over periods of up to 40 years. TON and SRP generally increased upto the mid to late 1980s, then declined, reflecting new legislation for water treatment. In 1997, several rivers in the region, including the Brett, Colne, Chelmer and Deben, had problems with stagnated flow, minimal DO and fish kills, most
likely due to a combination of drought