Evaluating the Influence of Groundwater Pressures on Groundwater-Dependent Wetlands

Sarah Kimberley and Catherine Coxon

Summary: Environmental Supporting Conditions for Groundwater-Dependent Terrestrial Ecosystems

The chemical and quantitative status of groundwater bodies must be classified as either good or poor to meet the requirements of the EU Water Framework Directive.  The classification process involves a series of tests, one of which relates to groundwater-dependent terrestrial ecosystems (GWDTEs).  The EPA commissioned research in this area to  contribute to the development of chemical and quantitative status tests for GWDTEs. The published report recommends the following (some of which EPA have already started implementing on foot of this research).

• The key recommendation is that the EPA and NPWS agree on a priority list of GWDTE types for determining GW nutrient Threshold Values (TV) and GW level standard development for the next WFD River Basin Cycle. 
• The main conclusion of the research is that currently available data for GWDTEs are insufficient for determination of scientifically robust nutrient threshold values (TV) for calcareous fens.
• The main knowledge gaps hindering the development of chemical and quantitative tests for Irish GWDTEs are the lack of (a) reliable information on the spatial extent of some GWDTE types; (b) reliable information on the ecological condition of GWDTEs and (c) monitoring of GW Quality and GW level and/or flow within GWDTEs and their associated zones of contribution.
• Baseline surveys are also recommended to confirm the presence, extent and ecological condition of some GWDTE types designated for conservation. Groundwater nutrient data should be collated from the monitoring network, or collected from installed boreholes, for sites representative of good and poor ecological conditions in order to generate a reliable dataset for TV development.