Skip to main content
Go to search page
Published: 26 May 2010   •   Media release

The Mildura weir pool is to be fully drawn down over July to allow upgrade works and the construction of a fishway.

The water level of the Wentworth weir pool down river of Mildura may also need to be lowered.

The Murray–Darling Basin Authority and Goulburn-Murray Water said today that the lock at Mildura would also be closed while the weir pool is drawn down.

Upgrades will include installation of a new prototype trestle with mechanised gates to significantly improve flow regulation. The existing method requires manual adjustment of wooden drop bars.

The works will also include construction of a ‘Denil’ fishway on the Victorian side of the river. The fishway is part of the MDBA’s ‘Sea to Hume Fishway Program’ which is restoring fish passage along the River Murray all the way from the sea to Hume Dam, a distance of about 2,200 km.

The drawdown of Mildura Weir pool (to about 3.6 m below full supply level) will start in mid July.

After the modifications are completed and all trestles have been placed back in the river, the weir pool will be raised back to full supply level by early August 2010.

The prototype trestle will be trialled over the next year. It is expected that further trestle upgrades will be undertaken in future years based on the knowledge gained from this trial.

Construction of the fishway is expected to start in June and will take about three months. To assist with construction, the water level of the Wentworth weir pool may need to be lowered slightly (by up to 20 cm) to reduce the water level on the downstream side of Mildura Weir. Such lowering, if needed, would occur late July.

The proposed schedule for works is:

Proposed date
Action
Early June Commence construction of the fishway at Mildura Weir.
Early July Wentworth Weir pool at full supply level for the 'Junction Rally'.
Early July Mildura Lock closed.
Mid to late July Mildura Weir pool lowered and trestles removed from river. Modification to two existing trestles and arrival on-site of new trestle.
Late July Lowering of Wentworth weir pool, if needed.
Late July / early August Trestles placed back in river, including the new mechanised trestle, and the gradual refilling of Mildura Weir pool commences.
Early August Mildura Weir pool raised back to full supply level and Mildura Lock reopened.

Water quality measurements will be taken during the drawdown at Mildura Weir, so that any salinity impacts in the weir pool or downstream can be carefully assessed.

Any higher salinity water will be diverted into Lake Victoria to minimise impacts on the river and to water users in South Australia.

During the drawdown of Mildura Weir, interference with any habitat, including removal of trees, stumps and fallen logs and aquatic plants is prohibited.

Boat operators, stock owners, river pumpers and other river users are advised to take these changed water levels into account and make any necessary adjustments to their activities.

Over the coming weeks, the Murray-Darling Basin Authority and Goulburn-Murray Water will issue further advice with more specific dates and details.

Media contact: Sam Leone, phone (02) 6279 0141

Photo: Arthur Mostead

Get in touch with the MDBA media team

Media releases

Sign me up to receive media releases:

Journalists can contact the MDBA media team by calling 02 6279 0141 or emailing media@mdba.gov.au.

We are a small media team and do not monitor emails after hours (including weekends). For urgent issues please call 0407 054 234.

Follow us on social media

Follow @MD_Basin_Auth on Twitter
Find MDBAuth on Facebook