Insight User Guide: Hydrology

Water network (OS MasterMap)

Detailed water network data showing the flow and precise course of every river, stream, lake and canal. This dataset provides a detailed centre line following the curve of the waterway precisely.

Surface water features

Covering rivers, streams and lakes (some overlap with OS MasterMap Water Network data in previous section) but additionally covers smaller features such as ponds. Rivers and streams narrower than 5m are represented as a single line. Lakes, ponds and rivers or streams wider than 5m are represented as polygons.

WFD Surface water body catchments

The Water Framework Directive is an EU-led framework for the protection of inland surface waters, estuaries, coastal waters and groundwater through river basin-level management planning. In terms of surface water, these basins are broken down into smaller units known as management, operational and waterbody catchments. This dataset provides the latest water quality assessments under the Water Framework Directive (WFD) for the site. Catchment information, water body assessments and links to the relevant page on the EA catchment explorer.

WFD Surface water bodies

Surface water bodies under the Directive may be rivers, lakes, estuary or coastal. To achieve the purpose of the Directive, environmental objectives have been set and are reported on for each water body. The progress towards delivery of the objectives is then reported on by the relevant competent authorities at the end of each six-year cycle. The river or coastal water bodies directly associated with the catchments listed in the WFD Surface water body catchments section are detailed, along with any lake, canal or artificial water body within 250m of the site. For surface water bodies, ecological/biological and chemical status is reported on. A link is provided on the water body ID within the data table which takes you to the EA Catchment Explorer, where further information can be obtained on each surface water body listed, including the objectives. Further explanatory information is provided on the Environment Agency website: environment.data.gov.uk/catchment-planning/help#help-catchment-data-explorer.

WFD Groundwater bodies

Groundwater bodies are also covered by the Directive and the same regime of objectives and reporting detailed in the previous section is in place. For groundwater bodies, quantitative and chemical status are reported on. A link is provided on the water body ID within the data table which takes you to the EA Catchment Explorer, where further information can be obtained on each groundwater body listed, including the objectives. Further explanatory information is provided on the Environment Agency website: environment.data.gov.uk/catchment-planning/ help#help-catchment-data-explorer