This dataset contains Cycle 1 Water Framework Directive (WFD) unchanged class status at water body level, for England only, for the year 2013, for quality elements. This dataset also contains the statistical confidence and derived certainty that a change in class has not occurred. This is assessed by detecting unchanged class status in 2013 against the baseline status of 2009, and estimating the confidence that a class has actually not occurred. Attribution statement: Environment Agency copyright and/or database right 2016. All rights reserved.