The reservoir was first constructed in between 1959 and 1961 and has the capacity of 8,600 megalitres (ML).
In 2002 major works were undertaken to bring the reservoir up to modern day standards, including anchoring the dam wall to the foundation bedrock and strengthening the four gates.
The dam is an essential part of providing water for cooling the power stations generators in the Latrobe Valley. This supply is supplemented from Blue Rock Lake approximately 15 km upstream on the Tanjil River.
|Dead storage||53 ML|
|Surface area||281 ha|
|Full supply level||47.7 m AHD|
|Catchment area||1,942 km²|
|Maximum height||23 m approx.|
|Crest length||64 m approx|
|Discharge capacity *||268,000 ML per day|
* Narracan Reservoir has been designed to withstand overtopping following anchor installation in 2003.
A Bulk Entitlement Order is a set of operating rules for a reservoir.
At Southern Rural Water (SRW) we deal with the following Bulk Entitlement Orders:
- Yallourn Energy
Because more than one organisation or group can have shares (or entitlement) in the water being held in a reservoir, each shareholder must follow rules about:
- the volumes that can be taken from the reservoir, system or waterway
- costs of managing the system, and how they are shared
At a number of reservoirs, SRW acts as the storage manager on behalf of all shareholders.
As a storage manager, we:
- allocate water (both increases and decreases) according to the inflow and capacity shares held by shareholders
- ensure that we meet the rules for passing flows downstream for environmental purposes
- release water to meet a shareholder’s request
Passing flows are a vital part of our Bulk Entitlement Orders and are met before allocation requests are supplied.
Environmental Entitlement Orders spell out a whole pattern of environmental flows that are required downstream of a reservoir – from how long they last, to how frequently they flow and how large they are.
Environmental flows are designed to mimic the natural conditions of rivers. It is not just about the amount of water but also the timing and quality. In each order, environmental flow requirements are low during the summer and autumn, and are much higher during winter and spring.
Environmental flows are vital to supporting the river’s ecological processes. High flows provide triggers for fish breeding and supply water for fish passage, so that they are able to move up and down rivers to appropriate habitat. They also keep estuaries open and provide recreational opportunities. Low flows in summer maintain fish refuges and connect habitats. Spring floods regenerate wetlands and floodplains and replenish the river channel.
To make sure that we comply with the rules about passing environmental flows, we:
- perform random checks at points along rivers, to ensure that customers are taking only the amount of waterthey have ordered
- maintain a number of gauging stations with alarms that alert us of unusual changes in water levels.
For more information contact us on 1300 139 510 or visit www.srw.com.au.
Lake Narracan is located on the Latrobe River in Gippsland.
Please check the water levels before planning a day out at the lake!