Recycling waste water, desalination plants and piping water from the North may all be considered as Irish Water looks ahead to how it will meet growing demand in the coming years.
The options are among many referred to in the company's first draft National Water Resource Plan which sets out to examine how Irish Water will source, treat and supply water over the next 25 years.
The task is likely to become more tricky and expensive as it grapples with a legacy of poor infrastructure, an expected 1.2 million surge in population, continuing climate change and associated droughts and floods, and new sources of chemical contamination and pollution.
It will also need to be able to support the construction of 34,000 houses a year for the next decade and a net increase of 660,000 new jobs over the full period of the plan, many in water-intensive industries such as pharmaceuticals and manufacturing.
"Our infrastructure is under increasing pressure to meet the current demand," said Sean Laffey, head of asset management with Irish Water.
"How we choose to plan our water resources today will determine the water supply we can provide now and into the future."
Over the next 10 weeks, finishing on February 16, members of the public can submit comments on the plan.
After that, Irish Water will publish four regional plans and invite public submissions on them before compiling the documents in one master plan.
All 749 individual water treatment plants will be assessed and options for additional, replacement or amalgamated plants, as well as ways to connect up some of the many very small supplies, and other infrastructural investment will be considered.
On the demand side, the aim is to find ways to avoid simply taking all the extra water that will be needed from existing sources.
For example, where there is a demand for 10 million extra litres a day, Irish Water says the plan would aim to supply six million litres, cut leaks by three million and save one million through conservation.
The company is calling this its 'lose less, use less, supply smarter' code.
Among the 'smarter supply' ideas are recycling waste water for use in industry, agriculture and horticulture; desalination plans that would use sea water for non-drinking purposes, and 'water transfers' which would involve linking with Northern Ireland Water.