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Royal Canal, our little oasis of calm

Christine Moore - 19.03.2021

In a corner of Coolmine is a little oasis of calm. A place where kingfisher vie with otter for fish and where foxes build their dens. Where a 'Dawn Chorus' of birds starts the day and, at night, bats hunt for food. In the heart of the Deep Sinking, The Royal Canal at Coolmine is exceptional, with its steep canal banks, canopy of trees and unique ecosystem.

One of the great engineering projects of the early 1800s, the most challenging section of the Royal Canal was the creation of the Deep Sinking. This involved blasting a channel through sheer rock, using only gun powder and human effort. Those blasting marks are still evident on the bare rock face today. Replaced by the railway, the canal fell into disrepair and it wasn't until the 1990s, that the tourism and heritage potential of the canal network was realised. The Deep Sinking reopened in 1996, however, the Royal Canal at Coolmine is again under threat from the railway.

If Irish Rail's proposal, to build a flyover bridge from Stationcourt to Riverwood, succeeds, the negative impact on the Deep Sinking will be immeasurable. This section of the canal is unique in its structure and its biodiversity.

  • The canal is a narrow channel, which runs through a steep gorge of quarried rock.
  • It is shaded on both sides and from above by over-hanging trees, creating specific environmental conditions, different to the rest of the Royal Canal.
  • There is low boat traffic through the area and, without a formal towpath, there is reduced footfall.

These factors all contribute towards its unique ecosystem.

The Royal Canal is designated as a proposed Natural Heritage Area (pNHA) and a Water Framework Directive Register of Protected Areas site (WFDRPA), so is considered an area of national importance. The ecological value of the canal lies in the diversity of species along its linear habitats. So what wildlife is found in the Deep Sinking, at Coolmine?

  • Otters, a protected species, have been recorded along the canal between Clonsilla and Coolmine for many years.
  • Kingfisher, protected and on Ireland's Amber list for conservation, have also been recorded in this part of the Deep Sinking.
  • Foxes have been sighted numerous times, west of Kirkpatrick bridge, on the canal banks.
  • Two species of bat - the Common pipistrelle and the Soprano pipistrelle - have been recorded commuting through this area. Both bat species are protected under Irish law.
  • A multitude of songbirds have been observed nesting above and foraging through the flora on the canal banks.
  • The wildlife continues beneath the surface of the canal, with pike and perch sighted and recorded here, for many years.

Otters, kingfishers and bats are all protected species in Ireland, under both the Wildlife Acts and Habitats Directive. In addition to the wildlife listed above, there are numerous other birds, small mammals, insects and fish who depend on the Deep Sinking for survival. These species have been allowed to thrive here undisturbed for decades.

The disruption caused by construction, with noise and light pollution, together with the deterioration in water quality, would have a critical impact on them, potentially driving them away from the canal at Coolmine. This is not to mention the longer term impact of their unspoilt habitats being irreversibly destroyed. One has only to look at the banks of the canal, beneath the Diswellstown bridge to see the impact of constructing bridges.


Another exceptional feature of the Deep Sinking, is with regard to bryophytes (mosses and non-vascular land plants). The highest proportion of bryophytes - 38 of the 59 bryophyte species (64%), recorded along the Royal Canal from Blanchardstown to Maynooth - were reported in the Deep Sinking, between Kirkpatrick bridge (Coolmine) and Kennan bridge (Porterstown)1. Of these, 14 bryophytes are only found between Kirkpatrick and Kennan bridges2. The biodiversity of the canal at Coolmine is unmatched and we need to protect it.

Where the Deep Sinking is truly unique, however, is the Calcareous Spring, found west of Kirkpatrick bridge. Calcareous springs develop around permanent freshwater springs or areas of water seepage that are especially rich in calcium. They are a priority habitat (7220), under the Annex 1 EU Habitats Directive and are rare in Ireland. This Calcareous Spring, found in the canal at Coolmine, is the only one recorded along the Royal Canal, between Blanchardstown and Maynooth3.

Heritage and biodiversity, engineering brilliance and a tranquil space to enjoy. We cannot let it be destroyed. We need Irish Rail to look at other options. Take a virtual trip through the Deep Sinking below and see why it is so extraordinary and must be preserved.

Royal Canal - Coolmine area, thanks to Foley Digital for sharing video

*Notes 1,2&3 BEC Consultants Ecology Study of the Royal Canal between Talbot Bridge and Maynooth Train Station (2013)