An aquifer is an underground body of water bearing rock or unconsolidated materials (gravel or sand) from which groundwater can be extracted in useful amounts.

GSIs Aquifer classes are divided into three main groups based on their resource potential, and further subdivided based on the type of openings through which groundwater flows. There are nine aquifer categories in total. In the Groundwater Protection Schemes (GWPSs), these are also referred to as Resource Protection Zones.

1) Regionally Important Aquifers:

Regionally important aquifers are capable of supplying regionally important abstractions (e.g. large public water supplies), or excellent yields (>400 m3/d). Bedrock aquifer units generally have a continuous area of >25 km2 and groundwater predominantly flows through fractures, fissures, joints or conduits. Regionally important sand/gravel aquifers are >10 km2, and groundwater flows between the sand and gravel grains.

This group is subdivided into the following types:

Rk Regionally Important Karstified Bedrock Aquifer Rf Regionally Important Fissured Bedrock Aquifer Rg Regionally Important Sand/Gravel Aquifer

Regionally important karstified aquifers may be further subdivided based on the whether groundwater flows mainly through conduits (Rkc) or more diffusely through solutionally-enlarged fissures (Rkd).

2) Locally Important Aquifers:

Locally important aquifers are capable of supplying locally important abstractions (e.g. smaller public water supplies, group schemes), or good yields (100-400 m3/d). In the bedrock aquifers, groundwater predominantly flows through fractures, fissures, joints or conduits. Locally important sand/gravel aquifers are typically >1 km2, and groundwater flows between the sand and gravel grains.

This group is subdivided into the following types:

Lm Locally Important Bedrock Aquifer, Generally Moderately Productive Ll Locally Important Bedrock Aquifer, Moderately Productive only in Local Zones Lk Locally Important Karstified Bedrock Aquifer Lg Locally Important Sand/Gravel Aquifer

3) Poor Aquifers:

These bedrock aquifers are capable of supplying small abstractions (e.g. domestic supplies, small group schemes), or moderate to low yields (<100 m3/d). Groundwater predominantly flows through a limited and poorly-connected network of fractures, fissures and joints.

This group is subdivided into the following types:

Pl Poor Bedrock Aquifer, Generally Unproductive except in Local Zones Pu Poor Bedrock Aquifer, Generally Unproductive

Data Resources (3)

available as shp
available as data viewer
available as esri rest

Data Resource Preview - ESRI Shapefile

Theme Science
Date dataset released 2003-01-21
Date dataset updated 2019-05-30
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 license conditions apply', '', 'license', '', 'license']
Update frequency Irregular
Language English
Landing Page
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) TM75 / Irish Grid (EPSG:29903)
Vertical Extent {"maxVerticalExtent": "1041", "verticalDomainName": null, "minVerticalExtent": "0"}
Provenance information Application of the data: Local details are generalised to fit the original mapping and interpretation scale of 1:50,000. Evaluation of specific sites and circumstances will normally require further and more detailed assessments, and will often require site investigations. Sources of Information: Teagasc/EPA 1:40,000 Subsoil Map + Teagasc/EPA soils 1:40,000 GSI 1:50,000 Subsoil Permeability Map from county GWPSs and NDP-funded national mapping programme GSI 1:50,000 groundwater vulnerability map. GSI 1:100,000 Bedrock Aquifer map GSI 1:50,000 Sand and Gravel Aquifer map Met Eireann 1971-2000 Rainfall + AE Groundwater Recharge map creation technique: Created using tools built though ArcGIS model builder. On a county by county basis. In order for the Recharge map to be created, the recharge coefficient has to be calculated. This calculation depends on a large combination of conditions that are worked out from overlaying the following layers through a combination of unioning, intersecting, adding fields and calculating fields: 1. Teagasc Soils: For indicating areas of Peat and whether soil is wet or dry. 2. Teagasc Subsoils: For indicating sand and gravel soils. 3. Permeability 4. Vulnerability 5. Sand & Gravel Aquifers 6. National Aquifer dataset 7. Effective Rainfall (Met Eireann) The Recharge Map Creation tool goes through several different geoprocessing tasks. For each county: 1. Selecting the county: Union the Teagasc soil, sub-soil, Permeability and Vulnerability layers. 2. Unioning and intersecting with Fixed layers: -Intersecting Sand and Gravel Aquifer: This data will be included for analysis along with the Sand and Gravel soils from the Teagasc subsoils layer. -Intersecting National Aquifer: This layer will be used to calculate what cap (if any) will be applied to the potential recharge mm amount. -Aquifers of type LL, PU and PL will entail a capping on this final recharge figure. (100 or 200 mm/yr) 3. A hydrological Category is applied according to combination of values for each record. A recharge Coefficient is then calculated. 4.The final recharge value is calculated as Effective Rain amount x the %Recharge Coefficient. For further Information got to
Period of time covered (begin) 2005-01-07
Period of time covered (end) 2008-01-15