The Commonwealth spent $47 million last year buying back water entitlements from irrigators throughout the Basin.

In May Water Minister Penny Wong trumpeted the program, saying it would return 34 gigalitres to the system.

But as FarmOnline reported at the time, the headline figure did not reflect the fact that the drought and reduced water allocations had decimated the actual amount of water currently available under the bought-back licences.

The full 34GL claimed by the buybacks would only be realised in a flood year, with a Government report indicating that in an average year 23GL would be returned to the river.

And today there are newspaper reports that in this year, when most water entitlements have been severely cut due to the drought, just 10ML of actual water will be returned to the environment.

"All the $50 million has bought is a promise in the future of water, it has bought air space, it will not put any water in the Murray River at this time," Opposition water spokesman John Cobb said on radio this morning.

"When you speak to those who have been charged with buying the water they concede there was no plan, they just bought the cheapest water they could, which was buying air space in dams, it did not actually buy water at this time."

The Department of Water's report into the water buyback shows that the Government bought only the cheapest licences on offer (see graph).

However, it also shows that about 25pc of the licences purchased by the Government were high-security licences.

The departmental report shows the Government paid an average of $2124/ML for high security water and $1131/ML for NSW general security and Victorian low reliability licences.

* For more details visit the Department of Water website.