The RE system does not appear to be a useful method of predicting the quality of lowland rivers in East Anglia, at least in terms of DO. Even in the clearest division of stretches, by DECORANA, there was no obvious grouping of those with the same RE classification. There was no evidence from this study that nutrient concentration was responsible for stretches failing DO targets. In many cases, failing stretches had higher
nutrient concentrations in the past, yet they still consistently fail RE targets. Targets for determinants other than DO are reached regularly.