Severe water shortages in the Midlands and east will get even worse unless progress is made on sourcing water from the Shannon.
That is the view of Engineers Ireland, which has given Ireland's water system a 'C' grade in its latest report on our infrastructure.
It says our water system is unable to meet peak demand and needs major investment.
The report is based on input from a panel of 40 engineering experts.
Peter Quinn, President of Engineers Ireland, said: “Today, our report sets out two- and five- year priority actions which are necessary to improve the performance of our infrastructure networks.
These priority recommendations need to be delivered if we are to meet current environmental, social and economic challenges.
"And only sustained action in these areas will enable us to mitigate and adapt to the effects of climate change.”
Mr Quinn said: “Over the next 20 years, our population is set to increase by one million people. Regional development is vital but we must prepare for the majority of this population and jobs growth to be focused in urban centres.
"This will mean putting in place strategic systems of sustainable infrastructure to support growth, including water and wastewater services and flood defences.
“Delivering Project Ireland 2040, including our priority actions, will be impossible without expanded industry and a larger engineering workforce. We face challenges posed by skills shortages, particularly in the Civil and Building Engineering field."