Our story Our purpose Our Board and Leadership Team
Health and safety Sustainability Systems Accreditations
Our projects
Project locations Our awards
Undergraduate and graduate opportunities Careers
Lake Mannus Dam Restoration
Restoration of a dam after it was destroyed by flood

Background

Lake Mannus is a popular location for recreational fishing, boating, walking and bird watching and brings tourism and economic benefits to the local area. On 15 October 2010 a large flood event caused the dam to overtop, resulting in the failure of the dam and loss of the majority of the right half of the embankment.

Scope

Works included:

  • Drilling and blasting
  • Bulk earthworks
  • Reconstruction of the main embankment with a higher dam crest level
  • Primary and auxiliary spillways including reinforced concrete training walls and hydraulic control structure
  • Inlet/outlet MSCL pipework, including trunnion and valve block
  • Electrical and telemetry works
  • Commissioning

The project resulted in an increase in the capacity of the dam to 2350 ML.

Outcomes

  • The project was delivered on time and under budget and with an exemplary safety record despite a redesign of the embankment being necessary due to an unexpected lack of suitable rock from excavations on site.
  • A carefully designed program protected the site from flood—in late June the dam survived the biggest flood since the October 2010 event that destroyed the old dam.
  • The project was undertaken in a cooperative manner led to Leed being awarded another water infrastructure project by council.

The project has restored the recreational amenity of Mannus Lake and increased water storage capacity for the township of Tumbarumba.

Related projects

Project Quipolly Dam Safety Upgrade $10m Quipolly, NSW Project Porters Creek Dam Safety Upgrade $10m Porters Creek, NSW Project Lake Manchester Dam Safety Upgrade $20m Regional Queensland