Although declaring the initial buyback delivered value for money for the Government and was efficiently run, Hyder Consulting said the only reason the lack of a specific target had had minimal impact in the first round was because the volume bought was so small.

"The evaluation of appropriateness of future purchases will be difficult without clarification of the goals and objectives of the water purchases plan," it found.

"It is essential that the objectives and targets are clarified."

It also advocates:

• greater co ordination of the multiple State and Federal purchase programmes to reduce conflict and competition;

• that the Government work more closely with irrigation communities on restructuring;

• investigation into buying specific environmental outcomes;

• purchase of unregulated entitlement;

• conversion of low security to high security entitlement; and

• purchase of allocated water to meet short term needs.

The call for clear goals echoes community criticism of the lack of transparency and ad hoc nature of the buyback process, which irrigation groups say creates uncertainty and threatens to undermine the viability of rural communities.

The release of a planned approach to the buyback is also one of the conditions set down by the Victorian Government as essential before it will consider lifting the 4pc annual limit on permanent trade out of a district which is hindering further Federal purchases of Victorian high security water.