Rock stability works at Lake Eppalock’s main spillway in Victoria, Australia, wrapped earlier this month, with the project set to ensure that Goulburn-Murray Water’s (GMW) storage continues to operate safely and efficiently into the future.

The works, which started in June, involved excavating and stockpiling 16,000 cubic metres of rock from behind the spillway walls and “benching off” both cliff face walls.

GMW Infrastructure Delivery Services general manager Warren Jose said the works were an important part of maintaining the region’s water storage and delivery infrastructure. “The works will significantly reduce the risk of major rockfalls and erosion along the sides of the spillway,” he said, praising regional contractor Apex Earthworks for delivering a quality project on time and within budget.

“They have performed to GMW expectation and overcome many unique challenges including COVID-19 and rising water levels in the dam,” he said.

Apex Earthworks project manager Hugh Ellis highlighted the unique nature of the works, in particular the importance of protecting the spillway from damage from falling rocks during excavation near the spillway.

“Extensive controls such as 60-tonne props and 600 straw bales installed via crane were used to protect the spillway concrete structure during the works, where large rock columns were able to be removed without any damage to the walls,” he said. “Equipment as large as a 90-tonne excavator and rock breakers were used to carefully dismantle the 13m high columns, only a few metres away from the spillway.

“The team even managed to negate the need for blasting, which was a great outcome for the project as it eliminated a key risk to the dam structure.”