Managing water levels at Lake Eppalock

Wednesday 11 December, 2024

Lake Eppalock’s current state

Lake Eppalock is currently at 77.2 per cent as of 2pm, 11 December 2024.

Supply level update - Lake Eppalock - 11 December 2024
A graph showing changes to Lake Eppalock's volume over the past four months. The dark blue line shows Lake Eppalock's full supply level. The light blue line shows the changes to storage volume of Lake Eppalock. The orange line shows the inflows into the lake, and the grey line shows the outflows.

Updates to daily release plans can be found under the Lake Eppalock drop down on the  Managing Water Storages webpage

How Eppalock is managed

The spillway at Lake Eppalock is a fixed crest spillway, which means GMW is unable to release more water than the capacity of outlet valve of 1,600 ML/d. During spill events, downstream flows are governed by how high the storage level exceeds the full supply level.

While GMW storages are not specifically for flood mitigation, Lake Eppalock does still partially mitigate downstream flows by storing water above the full supply level and water passing over the spillway.

Lake Eppalock operating arrangements assessment

Following the October 2022 floods, the Department of Energy, Environment and Climate Action (DEECA) commissioned a technical assessment into the operating arrangements at Lake Eppalock.

A summary of this assessment can be found on the DEECA website

GMW’s responsibilities

The requirements for GMW to manage its storages are set out in the Victorian Water Act.

More information

For more information visit www.gmwater.com.au/managing-storagesor phone GMW on 1800 013 357. 

The release from Lake Eppalock is 60 ML/d to deliver IVT flows down the Campaspe River to the Murray system.

While GMW storages are not specifically for flood mitigation, Lake Eppalock does provide some flood mitigation by storing water above the full supply level and water passing over the spillway.

For more information on how the October 2022 floods occurred across the Campaspe River, visit Floods in Focus: Campaspe River System 

Flow and release rates for the Campaspe River system

GMW has created a simple dashboard overview of flow and release rates for the Campaspe River system from Lake Eppalock to Rochester since October 2022.

The inflow rate at the storage includes flows from tributaries upstream of Lake Eppalock, such as the Coliban and Upper Campaspe rivers and McIvor and Wild Duck creeks.

As well as releases from Lake Eppalock, inflows from Mount Pleasant, Forest and Axe creeks contribute to flow rates along the Campaspe River downstream of the storage and Rochester. 

Click the button below to be taken to the dashboard.

Campaspe River system flow and release rates dashboard

The spillway at Lake Eppalock is a fixed crest spillway, which means GMW is unable to release more water than the capacity of outlet valve of 1,600 ML/d. During spill events, downstream flows are governed by how high the storage level exceeds the full supply level.