About this project


The Cork Lower Harbour Main Drainage Project aims to provide enhanced wastewater treatment through the development of a new wastewater treatment plant at Shanbally, Co. Cork. The project is important in terms of protecting the environment, facilitating economic development and providing for a growing population.

The plant will serve the areas of Cobh, Carrigaline, Crosshaven, Passage West/Monkstown (including Glenbrook) and Ringaskiddy (including Shanbally & Coolmore).

Co. Cork
In Progress
Aerial view of Cork Lower Harbour

What is involved?

The Cork Lower Harbour Main Drainage Project consists of: 

  • A new Wastewater Treatment Plant (WwTP). This plant has been completed and has been in operation since 2016.
  • 15 new pumping stations. 10 of these pumping stations have been completed.
  • Upgrading of 4 existing pumping stations. These pumping stations have been upgraded.
  • Approximately 30km of new sewers
  • A drilled crossing under the estuary. Find out more about what was involved in this longest-of-its-kind directional drill ever undertaken in Ireland in this video.

View the Cobh to Monkstown Estuary Crossing Information Sheet

View the Cobh Networks Information Sheet

We are now treating the equivalent of 30,000 wheelie bins of raw sewage daily from Passage West, Glenbrook, Monkstown, Carrigaline, Ringaskiddy, Crosshaven and Shanbally following the completion of the Shanbally Wastewater Treatment Plant and new pipelines and pumping stations on the south side of the harbour that redirect this sewage from the harbour to the new Wastewater Treatment Plant. The treated wastewater will then be safely discharged into the estuary via an existing pipeline near Dog Nose Point.

Irish Water completed the Cobh to Monkstown Estuary Crossing in 2020.  This landmark engineering feat involved two of the longest horizontal directional drills ever carried out in Ireland under the Lee Estuary. These drilled bores allowed the installation of sewer pipelines at a depth of 60m under the Lee Estuary – creating a vital connection between Cobh and Monkstown. This connection will allow the raw sewage from Cobh town to be transferred for treatment, once work on the Cobh Town Networks contract is complete in 2021.

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