Cork Lower Harbour Main Drainage project to prevent daily discharge equivalent of 40,000 wheelie bins of raw sewage awarded Engineering Endeavour of 2021 accolade.

A wastewater drainage project which has ended the decades-long practice of discharging raw sewage directly into Cork lower harbour has been awarded the prestigious title of Engineering Endeavour of 2021 by Engineers Ireland.

Undertaken by Irish Water, the Cork Lower Harbour Main Drainage project was awarded the prestigious accolade having featured in Engineers Ireland’s Engineering Excellence Digital Series, held in association with ESB, and was chosen by the public and members of Engineers Ireland as the top engineering project of 2021 following an online vote. 

Seven years of extensive engineering works

Following seven years of extensive engineering works and completed in September 2021, the drainage scheme now prevents the equivalent of 40,000 wheelie bins of raw sewage from Ringaskiddy, Carrigaline, Crosshaven, Passage West, Monkstown and Cobh Town being discharged untreated each day into Cork Harbour, the second largest natural harbour in the world.

The project was completed in a number of phases by Irish Water, who invested €144 million to ensure that wastewater was collected and fully treated before its safe discharge into the harbour. In addition to constructing a state-of-the-art wastewater treatment plant in Shanbally, the project also involved two of the longest horizontal directional drills ever undertaken in Ireland to install sewer pipes more than 1km long, some 60m below the Lee Estuary. 

More than 20,000 businesses and homes are now connected to the new wastewater scheme, which will protect the environment and support the sustainable development and growth of local communities. 

“A high degree of engineering ingenuity and skill was required across all phases of this project, and we are incredibly proud to receive the Engineering Endeavour of 2021 title,” said Déaglán Healy, project manager at Irish Water. 

“We have come a long way since we started work on this project in 2014. Irish Water has eliminated 60% of raw sewage discharges across Ireland, and we are on track to remove 95% by 2025. This project brings huge benefits to communities around Cork lower harbour by protecting the environment and supporting the development of homes and businesses. 

“This scheme and its benefits have been delivered safely through a hugely collaborative effort between Irish Water and our delivery partners, Cork County Council, engineering representatives and contract supervisors Nicholas O’ Dwyer Limited and Long O’Donnell Limited, contractors Farrans Sorensen Joint Venture, O’Connor Utilities, Ward & Burke, EPS and Sisk and of course, all the communities and businesses whose cooperation and patience have allowed these works to succeed,” said Healy.

Professor Orla Feely, president of Engineers Ireland, said: “Engineers have a vital role to play to protect our environment and support our communities. The Cork Lower Harbour Main Drainage project is a fantastic example of how Ireland’s engineers develop creative and innovative solutions for society.

"By eliminating raw sewage discharge in these areas in Cork, this project has not only created a cleaner harbour for local communities, but it has also provided new opportunities for sustainable social and economic development.”


Caroline Spillane, director general of Engineers Ireland, added: “The challenges we face as a society all require and benefit from engineering innovation. Each of the shortlisted projects for this accolade demonstrate the creative ways in which Ireland’s engineers seek to support and transform the daily lives of individuals, families, and communities.

"I would like to offer my congratulations to Irish Water on achieving the prestigious title of Engineering Endeavour of 2021 and applaud each shortlisted finalist who appeared in our Engineering Excellence Digital Series.”

"I would also like to thank our title sponsors ESB and supporters, Accenture and Geoscience Ireland for their dedication and commitment to recognising engineering excellence in 2021 by supporting this year’s video series.” 

Paddy Hayes, CEO, ESB said: “The Engineers Ireland Engineering Excellence Digital Series shines a light on the outstanding and diverse achievements of engineers across Ireland. I would like to commend all of the project teams shortlisted and congratulate Irish Water on winning the prestigious Engineering Endeavour of 2021 Award, for the Cork Lower Harbour Main Drainage Project.” 

To find out more about the Cork Lower Harbour Main Drainage Project and to view the six-part Engineering Excellence Digital Series, held in association with ESB and supported by Accenture and Geoscience Ireland, visit: