Irish Water has published a report that sets out the urgent need for a new water supply for the eastern and midlands region.
It shows demand for water in Dublin is expected to increase by over 50% by 2050.
Irish Water will begin a consultation process to discuss the report's findings with stakeholders.
The report relied on independent studies that focused on population projections, economic forecasting and water demand.
It also examined the maximum capacity of existing sources of water supply in the Eastern and Midlands Region.
It estimates an additional 215m litres per day will be needed in Dublin by 2050.
The findings show not implementing a new water supply carries a risk of disruption and shortages.
While the report acknowledges ambitious goals to address water leakage and conservation, it states significant amounts of water are still required.
It recommends the new water supply system should be in place ideally in around six or seven years.
Irish Water is to assess the report's findings over the next eight weeks with stakeholders, before deciding on the best Shannon-based supply option.