The Murray-Darling Basin Commission is considering whether to raise the height of the Dartmouth Dam wall, but even if the project goes ahead it will not change the reservoir's capacity.

Commission chief executive Wendy Craik said as the dam wall was more than 30 years old some settling had occurred and they were now looking at the possibility of raising the height by between three to 4 m.

She said this would increase the capacity of the spillway to cope with bigger flood events upstream, but would not change the storage capacity.

Ms Craik said she expected more information would be released within a month about the options the commission was facing, but a decision might not be made until 2008-09.

She could not put a figure on the cost but expects it would be a multi-million dollar project.

Ms Craik said the proposals were part of the commission's asset improvement program which involved regular reviews of the state of the water storages.

Dartmouth Dam is operated by Goulburn-Murray Water on behalf of the MDBC.

It is the largest capacity dam in Victoria and the highest structure of its kind in Australia.

When full, the dam stores almost 4 000 000 Ml.

It is located downstream of the confluence of the Mitta Mitta and Dart Rivers, about 24 km east of Mitta Mitta in north-eastern Victoria.