Group Scheme Preliminary Source Protection Areas Ireland (ROI) ITM

Category: Science
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Group Water Schemes (GWSs) are community-run water supply schemes. About 70% of GWSs take their water from a privately-sourced supply. The rest take their water from an Irish Water connection (DHPLG, 2017). 81% of the privately-sourced supplies affiliated to the National Federation of Group Water Schemes (NFGWS) take groundwater from boreholes, springs and dug wells. This is around 54% by volume (NFGWS, 2018).

The NFGWS is the representative for community-owned rural water services in Ireland. The NFGWS assists schemes in meeting the challenges of water quality legislation and promotes a ‘multi-barrier approach’ to source protection. The ‘multi-barrier approach’ includes delineation of the Zone of Contribution to a supply source.

A Zone of Contribution (ZOC) is the land area that contributes water to a well or spring (Misstear et al., 2006). It can be considered as the ‘catchment’ to the supply source. Like surface water bodies, springs have natural catchment areas, whereas catchment areas to boreholes depend on a number of hydrogeological and meteorological factors plus the abstraction rate. A ZOC accounts for the ‘horizontal’ movement of groundwater and any entrained contamination once it has reached the water table and is moving towards the abstraction point.

The aim of delineating ZOCs is to define the area that contributes water to an abstraction point. Knowledge of where the water is coming from is critical when trying to interpret water quality data at the groundwater source. The ZOC also provides an area in which to focus further investigation and is an area where protective measures can be introduced to maintain or improve the quality of groundwater.

Different methods can be used to map the ZOC to a spring, borehole or dug well, resulting in different degrees of confidence associated with the boundaries of the de-lineated area. The ZOCs and accompanying reports should be considered as preliminary source protection studies. The work was undertaken by consultants under supervision and review by GSI, and represents a partnership between the GWSs, the NFGWS and GSI. The work was funded through the Rural Water Programme funding initiative of grants towards specific source protection works on GWSs (DECLG Circular L5/13 and Explanatory Memorandum).

The ZOCs were delineated in the period 2011 to 2019. The maps produced are based largely on the readily available information in the area, a field walkover survey, and on mapping techniques which use inferences and judgements based on experience at other sites. As such, the maps cannot claim to be definitively accurate across the whole area covered and should not be used as the sole basis for site-specific decisions, which will usually require the collection of additional site-specific data.

This map shows the location of ZOCs which have been mapped around GWS supplies of groundwater in Ireland.

This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.

It is a vector dataset. Vector data portray the world using points, lines, and polygons (areas).

The data is shown as polygons. Each polygon holds information on name, year and consultant.

Data Resources (4)

SHP
ESRI Shapefile
ESRI REST
ESRI REST
DATA VIEWER
Data Viewer

Data Resource Preview - WMS

Theme Science
Date released 2012-01-12
Date updated 2021-10-22
Dataset conforms to these standards The INSPIRE Directive or INSPIRE lays down a general framework for a Spatial Data Infrastructure (SDI) for the purposes of European Community environmental policies and policies or activities which may have an impact on the environment.
Rights notes ['Creative Commons Attribution 4.0 International (CC BY 4.0)', 'Data that is produced directly by the Geological Survey Ireland (GSI) is free for use under the conditions of Creative Commons Attribution 4.0 International license.\n\nhttps://creativecommons.org/licenses/by/4.0/\n\nhttps://creativecommons.org/licenses/by/4.0/legalcode\n\nUnder the CC-BY Licence, users must acknowledge the source of the Information in their product or application.\n\nPlease use this specific attribution statement: "Contains Irish Public Sector Data (Geological Survey Ireland) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence".\n\nIn cases where it is not practical to use the statement users may include a URI or hyperlink to a resource that contains the required attribution statement.', 'license']
Update frequency Other
Language English
Landing page https://gsi.geodata.gov.ie/portal/apps/webappviewer/index.html?id=d333a8a9b6ab44378411fc0d973db4ef
Geographic coverage in GeoJSON format {"type":"Polygon","coordinates":[[[-10.47472, 51.44555],[-10.47472, 55.37999], [-6.01306, 55.37999], [-6.01306, 51.44555], [-10.47472, 51.44555]]]}
Spatial Reference Systems (SRS) Irish Transverse Mercator (ITM, EPSG:2157)
Vertical Extent {"verticalDomainName": "sea level", "minVerticalExtent": "0", "maxVerticalExtent": "0"}
Provenance information Originator - Groundwater Section, Geological Survey Ireland. Most of the Source Protection Areas were delineated as part of County Groundwater Protection Schemes (DELG/EPA/GSI, 1999). GSI delineated more than 125. As part of the WFD Grounwater monitoring network characterisation, EPA delineated more than 40. The methodology used to delineate the SPAs is summarised in Kelly (2010), and GSI/EPA/IGI, 2009. It includes: liaising with the Local Authorities (LAs) to identify key sources and facilitate data collection from key staff, a desk study, a site visit to inspect the supply, the local area, interview the caretaker and collect more data. Field work included short pumping tests, drilling in the potential ZOC to determine the thickness and permeability of the overlying protective subsoils, hydrogeological data collection (e.g. groundwater levels, spring or stream flows, karst feature mapping) and collation. The data were then analysed by hydrogeologists using hydrogeological knowledge and interpretation in order to delineate the SPA. The main digital data sources, coupled with data on use and abstraction from the local authority/Irish Water, include: (1) GSI bedrock geology maps at 1:100,000; (2) GSI bedrock aquifer maps at 1:100,000; (3) GSI sand and gravel aquifer maps at 1:40,000; (4) GSI groundwater vulnerability maps at 1:40,000; (5) GSI Quaternary sediments and geomorphology maps at 1: 50,000 scale; (6) Teagasc soils maps at 1:40,000; (7) OSI High resolution digitalglobe orthophotography dataset and national digital premium basemap map service cached from 1:4,000,000 to 1:1,000 scale; (8) EPA surface water body data at 1:50,000; Hydrogeological interpretation of the data allowed delineation of the SPAs by GSI staff, consultants working on behalf of EPA, and consultants working on behalf of Local Authorities/Irish Water. The SPAs for GSI and EPA underwent a review process within the Groundwater Programme, GSI. Other SPAs may not have been peer reviewed. Many groundwater specialists have undertaken Source Protection Area delineation with GSI (since 1995) and for the EPA (since 2009). The authors of the reports are listed on the front cover of individual reports. The methodology undertaken to delineate the ZOCs includes: liaising with the GWS and NFGWS to facilitate data collection, a desk study, a site visit to inspect the supply, the local area, and to record groundwater level(s). The data were then analysed by groundwater experts using hydrogeological knowledge and interpretation in order to delineate the ZOC. The main digital data sources, coupled with data on use and abstraction from the group schemes themselves, include: (1) GSI bedrock geology maps at 1:100,000; (2) GSI bedrock aquifer maps at 1:100,000; (3) GSI sand and gravel aquifer maps at 1:40,000; (4) GSI groundwater vulnerability maps at 1:40,000; (5) GSI Quaternary sediments and geomorphology maps at 1: 50,000 scale; (6) Teagasc soils maps at 1:40,000; (7) OSI High resolution digitalglobe orthophotography dataset and national digital premium basemap map service cached from 1:4,000,000 to 1:1,000 scale; (8) EPA surface water body data at 1:50,000; Hydrogeological interpretation of the data allowed delineation of the ZOC by consultants. The ZOCs underwent a review process by Groundwater Programme, GSI, to reach a consensus on the final version of the ZOC.
Period of time covered (begin) 2008-01-16
Period of time covered (end) 2011-07-14