This dataset contains Cycle 1 Water Framework Directive (WFD) class deteriorations at water body level, for England only, for the year 2015, for quality elements. This dataset also contains the statistical confidence and derived certainty that a real deterioration in class has occurred. Deteriorations are assessed by detecting downgrades in class status in 2015 against the baseline status of 2009, and estimating the confidence that a real deterioration in class has occurred. Attribution statement: Environment Agency copyright and/or database right 2016. All rights reserved.