The number of license holders wanting to sell Murray-Darling Basin water entitlements in the latest government buyback far exceeded that needed to hit target volumes in some catchments, according to newly-released data.
The data also illustrated a significant difference between what the government was prepared to pay for water in the various catchments, with an average across all water entitlement types of $4,980 per megalitre.
The buybacks were part of the strategic water rights purchasing program - Bridging the Gaps - to divert 44.3 gigalitres per year (GL/y) in six basin catchments to environmental flows.
The federal government announced on Thursday that once all contracts had been settled it would have paid farmers, irrigators and water traders around $205 million for 26.35 GL/y - or $0.007 a litre.
Figures since posted to the Department of Climate Change Energy and Environment website shows license holders had offered 137.65 GL across all six catchments towards that 44.3 GL target between when tenders opened in March and closed in May last year.
Despite this the overall buyback target was not reached in the tender round.
About 250 offers were received overall.
The NSW Murray catchment saw the most competitive tender process, with the target purchase volume of 10 GL being met with a thumping 71.5 GL being offered up by license holders.
The government purchased 13.8 GL.
Offers from the Namoi catchment of 48.6 GL also far-exceeded the target volume of 9.5 GL, with 19 GL purchased.
Likewise, Lachlan catchment tenders of 5.7 GL exceeded the 0.9 GL sought by authorities, who bought 2.3 GL.
Meanwhile, the 2.8 GL volume offered by entitlement holders in the NSW Border Rivers catchment did not meet the target volume of 5.1 GL - with the government buying only 0.01 GL.
The Condamine Balonne (surface water) target of 14 GL received tenders of only 7.6 GL - 5.2 GL purchased.
The data also revealed that no offers were received for Condamine-Balonne groundwater in an area home to Cubbie Station, Australia's biggest cotton farm.
CCEEW water recovery branch head Malcolm Southwell told Senate estimates on Friday that "we will need to do another process of some sort to recover" the remainder of the target.
"Where we have fallen short (of targets) there were either insufficient bids or they did not represent value for money," he said.
"We have active conversations continuing with the NSW and Queensland governments and we have started conversations with groundwater users in Queensland as well to understand the opportunities to recover that water."
He said the volumes received in excess of the tender were weighted to the southern basin.
Offers were assessed by the department on value for money, ability to contribute towards 'bridging the gap', environmental utility and cost and "other financial factors."
A mix of buybacks, water offsets and improving efficiency through subsidised on and off farm irrigation infrastructure will likely be used to reclaim the additional water needed to hit the 'bridging the gap' target.
Nationals deputy leader and shadow water minister Perin Davey pointed out that as the table does not include more specific details, such as whether the water purchased was general or high security, it could not be ascertained if the Commonwealth had paid a premium.
However, estimates was told that information may be added at a later date.
While the average price paid across all catchments and water entitlement types was $4,980 per ML
The highest value was surface water in the Condamine Balonne catchment that went for $7,692 ML. Next was the Namoi catchment at $6,447 ML.
Meanwhile, Barwon Darling catchment holdings sold for $3,314 ML, NSW Murray licences for $2,400 ML, Lachlan at $2,190 ML and NSW Border Rivers the lowest at $774 ML.
The individual licence holders nominating to sell their stake belies the strong opposition to the buybacks from community, irrigator and farmer representative groups.
The data also shows an "incidental" over-recovery of 0.4 GL mainly due to the size of the parcels offered.
The government has not revealed its full budget to complete the MDBP, stamping it "not for publication" and cabinet in-confidence.
Assistant Climate Change and Energy Minister Jenny McAllister told estimates that revealing the figure would show the government's hand and be counterintuitive to securing value for money for the transactions.
While the purchases are a fraction of the 700GL still needed to reach sustainability targets under the Murray-Darling Basin Plan, they illustrate the mountainous task the government faces.
Environment and Water Minister Tanya Plibersek said the tender process showed the direct purchasing of water - the first in the basin since 2020 - "can be effective" as one tool to reclaim water rights.
"Through these willing sellers we will return water that is desperately needed to restore our rivers and support the plants, animals and communities that rely on it," she said.
"We are determined to deliver the Murray-Darling Basin Plan in full."
An MDBP audit found it would fall 750 gigalitres short of its total of 3,200GL by the deadline of June 2024.
To cover the shortfall, the plan was extended last August in a new agreement reached between the Commonwealth and the states, although Victoria has refused to sign up to buy entitlements.
The Greens and Labor then reached a "breakthrough" deal in November to amend the plan to mandate an additional 450GL of environmental flows into the southern basin specifically to increase flows into South Australia.
The states have until the end of 2026 to deliver their 605GL of water-saving infrastructure projects. The full recovery of the 450GL of environmental water has been set for the end of 2027.
Ms Plibersek is expected to announce the progress of discussions on the "Bridge the Gap" program with the ACT in coming days.