Where the soil map comes from
ISIS was produced between 2007 and 2013 by Teagasc with EPA funding. It builds on An Foras Talúntais's national soil survey (1950s to 1990s), which described soil profiles by hand across about 44% of the country. ISIS added 246 newly dug and sampled soil pits and digital soil mapping to complete national coverage, at 1:250,000 scale, with 213 named soil series.
What each soil record tells you
- Soil type and series: for example Brown Earth, Grey Brown Podzolic, Gley, Podzol, peat, or alluvium near rivers.
- Drainage class: well drained, moderately drained or poorly drained. Poorly drained soils (gleys) stay wet for much of the year.
- Texture: the balance of sand, silt and clay. Clay holds water; sand lets it through.
- Depth: how deep the soil is before subsoil or rock.
- Soil organic carbon: how much carbon the soil stores. High in peaty soils.
Urban areas are often recorded simply as built over, with no soil attributes.
Why it matters for a site
- Wet ground: a poorly drained soil is an early warning for septic tank percolation, soggy gardens and the need for land drainage.
- Peaty soils are soft and hold a lot of carbon; they need care in construction.
- Growing: drainage and texture largely decide what grows well.
Soil isn't subsoil
Geological Survey Ireland's "subsoil" map describes the deeper glacial deposits between the soil and the rock. The two are related but different: see the geology guide.
What it can't tell you
- At 1:250,000 scale, the map shows the dominant soil of an area. The soil in one field can differ.
- It's not a percolation test. For a septic tank, the site assessment's trial hole decides.
Sources
- Irish Soil Information System (ISIS), Teagasc and EPA, published on the EPA's map service under CC BY 4.0
Last reviewed 2026-10-02.