Turloughs (1) Definition: A topographical depression in karst, having intermittent inundation on an annual basis arising mainly from groundwater. A turlough will have a substrate characteristic of wetlands and/or ecological communities characteristic of this combination of inundation regime and substrate. Seasonal lake in karst areas mainly fed by groundwater
Turloughs (2) 13 SACs designated in the Shannon because they contain turloughs High degree of groundwater dependency Incorporated into the risk assessment as a GWDTE
River Basin Boundary Issues (1) Some cases of shared groundwater between river basins Mainly in areas of karst groundwater where the influence of topography is diminished Decision to assign groundwater to most appropriate river basin was based on: Surface water boundary Groundwater flow regime Tracer studies Bedrock/structural geology Modelled source protection areas Dependent ecosystems Source: Environmental Protection Agency
River Basin Boundary Issues (2)
Diffuse pressures – Shannon approach (1) Step 1 (pressure) Step 2 (pathway)
Diffuse pressures – Shannon approach (2) Step 3 (impact potential) 22% High impact potential 1.3% High impact potential
Groundwater Bodies at risk from diffuse phosphate pollution (Draft – Oct 2004) Four risk categories (UK-TAG) 22 GWBs at risk (1a+1b) from PO4 In at risk GWBs turloughs were examined further Source: Shannon River Basin District Project
Turlough – SACs in at risk GWBs from PO4 Focus on turlough catchment areas Identify main pressures impacting on turloughs Nutrients Drainage works Abstractions Assess sensitivity of turloughs, e.g. Ellenburg indices
Conclusions Groundwater and wetland management Risk assessment process Complex systems Requires multi-disclipinary approach Often data gaps Habitat surveys, hydrological connectivity Risk assessment process Allows us to prioritise further characterisation of GWBs and associated GWDTE (e.g. turloughs) Opportunity to link WFD and Natura 2000 sites Pressures and impact assessments Further characterisation work