Dewatering and relocation of pump infrastructure are among works taking place to reinstate the Dunkeld Arboretum Dam in Victoria, which was damaged by floods in 2016.
The flood caused significant water to flow over the wall outside of the spillway footprint. The spillway and discharge channel were significantly damaged, causing erosion and narrowing of the wall structure.
The Victorian Government made a budget allocation in the 2018/19 budget to reduce the risk rating on a number of regional dams, and the Dunkeld Arboretum Dam was part of this funding initiative. Inspection by Southern Rural Water found the dam to be in an unsatisfactory condition with some serious issues identified, most notably relating to failure from piping, stability and lack of flood capacity.
Following engineering design work completed by consultant SMEC, contractor LincRoads has been engaged to repair the wall and spillway to pre-flood condition. This includes adhering to current engineering standards for large dams, in order to reduce the risk associated with stability and potential dam failure, improving safety for Dunkeld residents.
The project is being delivered in partnership with the Department of Environment, Land, Water and Planning (DELWP) through National Disaster Relief Funding Arrangements.
Funding of $1 million has been released by DELWP to complete the project, with the Southern Grampians Shire Council to contribute the remaining approximately $400,000.
Major construction activities at the site include:
- Dewatering of the dam
- Construction of a new spillway
- Restrengthening of upstream embankment
- Removal of the trees along the upstream embankment
- Removal of the existing jetty
- Relocation of the existing pump infrastructure on the reservoir embankment
The project is due for completion by the end of April 2020.