|Ó Dochartaigh, B É, MacDonald, A M, Fitzsimons, V, and Ward, R. 2015. Scotland’s aquifers and groundwater bodies . British Geological Survey Internal Report, OR/15/028.|
Scotland’s groundwater is a hugely valuable resource, which among other things underpins much of Scotland’s private drinking water supplies and the bottled water and whisky industries. Groundwater bodies are the fundamental management units for Scotland’s groundwater under the Water Framework Directive (2000/60/EC) and in a River Basin Management framework, providing a risk-based framework for preventing new problems and the prioritisation of action to address existing problems. Groundwater bodies were first defined for Scotland in 2007 (SEPA, 2009b). This report describes how the delineation of groundwater bodies has been reviewed and revised during the second River Basin Management cycle, using the latest geological, hydrogeological, hydrological and pressures information, and experience gained from the first River Basin Management cycle.
This has been a collaborative project by the British Geological Survey and the Scottish Environment Protection Agency. This report includes both a record of the groundwater body review and revision process, and a summary of the physical and chemical hydrogeology of Scotland’s main aquifers for use by technical specialists.
The key features of Scotland’s groundwater bodies are:
- Groundwater bodies define areas of groundwater that behave in a similar way, both naturally and in response to pressures from human activity.
- Groundwater bodies have been divided into two layers: a shallow layer of superficial aquifers, and a deeper layer of bedrock aquifers. This helps to target action, as shallow bodies are more at risk from activities such as agriculture, while deeper bodies are more at risk from activities such as mining.
- Groundwater bodies are primarily delineated on the basis of geological differences, which are the fundamental control on aquifer hydrogeology. This was based on the best available geological mapping at 1:50 000 scale.
- Superficial groundwater bodies are defined as permeable superficial deposit aquifers with a minimum area of 1 km2. They are subdivided by large surface water catchments, with a minimum total outcrop area in any one river catchment of 10 km2, unless they are clearly linked to a groundwater dependent feature such as a wetland or large drinking water abstraction. Where necessary to maintain a relationship between bedrock and their overlying superficial groundwater bodies, they are also subdivided by bedrock groundwater body boundaries.
- Bedrock groundwater bodies are defined primarily by bedrock aquifer type, which reflects key characteristics such as aquifer properties, groundwater flow characteristics and groundwater chemistry. Bedrock aquifer groups have been subdivided into smaller groundwater bodies or amalgamated into larger bodies where necessary, according to known pressures from human activity — mostly from mining and agriculture — and management requirements. Subdivision was done on hydraulic criteria, either based on surface water catchment boundaries, or on geological and structural features, such as faults. The minimum bedrock groundwater body size is 10 km2.
- SEPA. 2009a. The river basin management plan for the Scotland river basin district 2009–2015. http://www.sepa.org.uk/water/river_basin_planning/scotland.aspx Accessed 13 August 2014.