Irish Water has published details of its preferred route for a new 170km pipeline to take water from the River Shannon to supply the eastern and midlands regions.

The preferred route emerged after nine different potential pipeline options, as well a water desalination plant in Fingal, were examined in detail.

It will run from the Parteen Basin in the lower Shannon region to a termination point at Peamount in Dublin.

The pipeline, which is expected to cost between €700 million and €900 million to build, is scheduled to be completed by 2024.

Irish Water expects that about 1,000 jobs will be created during the three to four year construction phase.

The project envisages 330 million litres of the water being diverted each day from the Parteen Basin to supply the midlands, eastern, and Dublin region.

That is about 2% of the water flowing through the Shannon.

The fact that the water is to be extracted so close to the mouth of the river, and after it has flowed through Lough Derg, minimises the environmental impact of the scheme.

The extraction of the water will reduce the flow available for the ESB's hydroelectric station at Ardnacrusha by a marginal amount but Irish Water will compensate ESB for that loss.

The proposed pipeline is the first major new water upgrade for the eastern and midlands region in over 60 years.

The route envisages that the water will be piped the short distance from the Parteen Basin to a new water treatment plant to be built at Birdhill in Co Tipperary.

From there it will be pumped to a new break pressure tank to be located near Cloughjordan, also in Co Tipperary.

The water will then be transported by gravity from Cloughjordan along a route close to the Laois-Offaly border and on to Peamount in Dublin with the supplies also being made available to midland communities and towns close to the route.

Irish water said that 40% of the population of the country - over two million people - will benefit from the new water supplies including the towns of Athlone, Tullamore, Mullingar, Portaloise, Athy, Carlow, Navan , Drogheda, Arklow as well as Dublin.

It used computer and other detailed analysis, including consideration of one-off housing and other obstacles, to identify the "least constrained" 2km pipeline corridor between the lower Shannon and the Dublin region.

Within that corridor it has identified a preferred 200m wide "Preferred Pipeline Corridor", and within that again a 50m temporary pipeline corridor has been identified, pending public consultation and negotiations with landowners for permissions and necessary wayleave agreements, to lay the pipeline.

Irish Water is publishing its 'Final Options Appraisal' report which identifies the preferred route and also an 'Environmental Statement Impact Scoping Report' which considers the nature and likely scale of potential environmental impacts that may arise from the Preferred Scheme.

It is also embarking on a public consultation programme over the next 14 weeks to seek feedback and views about what should be considered in the Environmental Impact Statement, which will accompany its planning application for the scheme that it expects to submit to An Bord Pleanála this time next year.

However, with the scheme potentially costing up to €900m to construct, a final decision by Government will be needed to enable Irish Water to access the funding required to build the pipeline.

This permission would not have been required if Irish Water's original financial model had not been suspended by the Government as a result of opposition to water charges.

Irish Water's Managing Director Jerry Grant said there is an urgent need for the new pipeline, adding "we are very close to the limit" in the greater Dublin area and in many schemes across the midlands.

Speaking on RTÉ's Morning Ireland, he said the scheme must be in place by 2020.