The water quality in the rivers of East Anglia fell to its lowest level in 10 years during 1988–90, due to a combination of drought conditions, a lack of investment in sewage treatment and agricultural pollution. The largest increase in nitrogen occurred during the drought years of 1980–1986, with more than 0.2 mg l1 yr1,coming mainly from land drains in agricultural areas and sewage effluent that was not sufficiently diluted due to low flows ([12,5,13], Environment Agency, pers.comm.). By 1995, river water quality across East Anglia had shown a general improvement of 37% over 1988–90 figures, but this was followed by another significant deterioration, attributed again to several years of
drought.