The smallest Lake in Ireland is in the Burren.

Sitting on top of Slieve Elva at an elevation of almost 330m is a tiny pond of water called Lough Garrig. Only a couple of metres across, it is barely noticeable in the broad bog that covers the highest upland in the Burren. The lake has been marked un-named on maps since the acclaimed 1842 Ordnance Survey 6 inch maps. The name Lough Garrig first appears on the 25 inch Ordnance Survey maps (1888-1913). I have not been able to discover yet why it was named, why this insignificant pool of water warranted a name, title, recognition on a map.

And yet, it is significant.

Bogs have been very useful to us in Ireland over the last few hundred years, primarily as a local source of fuel and more recently as a source of organic soil for our gardens and potted plants. Before that the iron (bog iron) beneath the bog was used for the forging of iron tools.

Today our bogs are universally recognized as carbon ‘sinks’ or reservoirs, that is, places where carbon is stored on the Earth’s surface so it doesn’t end up as carbon dioxide in the atmosphere. This is important, but bogs can only act as carbon sinks if they can continue to store water. The noted and notable presence of Lough Garrig on top of Slieve Elva from over 150 years ago to today indicates a hydrological stability, it means the bog is consistently able to store water and it acts as a not just a carbon reservoir but an important water reservoir as well.

When rain falls in the Burren some of it falls on the limestone and it quickly disappears underground. When rain falls on the bog a lot of it is held there by the bog. The rain is held by the bog acting like a huge sponge. If it is full, then water will flow off the surface very quickly, however once the rain stops the bog will release the water it is holding very slowly over many months, supplying numerous streams that in turn flow into rivers or caves.

If it wasn’t for the bog on top of Slieve Elva than all of the streams that flow off the hill, the streams that supply water to local houses and farms, the streams that provide water to the Aille river and the sea and the invertebrates and fish that live there, would be dry in a matter of days in summer or any dry period. The bog is an important reservoir and the diminutive Lough Garrig may be the smallest lake in Ireland, but rather than celebrating it for its size, we should celebrate it as an important part of that water reservoir and the hydrology of the Burren. I hope it is still on maps in another 150 years.

Dr. Eamon Doyle, geologist for the Burren and Cliffs of Moher UNESCO Global Geopark, Clare County Council.