This dataset is a subset of "WFD Classification Status Cycle 2" and contains classification data for hydrological regime. A river can only hold a healthy biological population if there is sufficient water and natural structures to support biological processes. Rivers with sufficient flows can also support human activities such as farming, drinking water supply and industrial processes. The hydrology assessment tool uses data on freshwater flows, physical modification and water abstraction to assess the health of a water body. The tool works by assessing a water body’s compliance category (freshwater inputs less abstraction amounts) against a score for flow compliance.
A water body cannot score high status if it is considered to be ‘heavily modified’ which refers to a river being modified from its natural state for human use. If a water body considered heavily modified scored high in the compliance and flow tests it would be automatically downgraded to ‘Supports Good’ status.
Flow, abstraction and physical structure data are used in combination to produce scores known as Ecological Quality Ratios (EQR). EQRs are used to produce a Hydrology classification (High, Supports Good, Good, Moderate, Poor, Bad) of the water body for Water Framework Directive (WFD) purposes. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.