THE NSW government has already costed more than a dozen water infrastructure projects for the Peel catchment, which range from dam upgrades to new pipelines.
Last year, NSW Water put out its "20 Year Infrastructure Options Study", which identified a raft of long-term security options for catchments across the state.
Within the Peel catchment, there are three options to upgrade the 6.3 gigalitre Dungowan Dam, which could be expanded to three times, six times or ten times its current size.
The federal government has already committed $75 million to its upgrade, but if NSW Water's costings are correct, that figure would barely make a dent.
The NSW government has investigated the smallest option of 22.5 gigalitres, but deemed the $484m price tag to be too much.
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However, the Leader understands the government will revisit it as an possibility in another study it is current undertaking, the Namoi Regional Water Study, which aims to identify which projects are the most cost effective.
The other Dungowan Dams options are a 40-gigalitre expansion ($526m) and a 60-gigalitre expansion ($569m).
Any upgrade of Dungowan would also need to include a new pipeline, which has been factored into the cost.
There are also options to connect Chaffey Dam to the upgraded Dungowan Dam's pipeline, which would add between $83m to $86m to the project, depending on the size of the expansion.
Chaffey Dam was augmented in 2016 from 60GL to 100GL, but the original design allows it be expanded by a further 20GL for $143m.
NSW Water has also costed another expansion to take Chaffey up to 180GL at $215m.
A number of pipeline options are being considered. A Split Rock Dam transfer pipeline would cost of $141m, while a pipeline from Keepit Dam to Tamworth is also an alternative ($128m).
Another possibility is a 10GL off-river storage upstream of Tamworth for $187m and an inter-basin transfer from the Barnard River to the Peel, upstream of Chaffey Dam, for $756m.