Lake Macdonald (Six Mile Creek)

Although the official name is ‘Six Mile Creek Dam’, it is more well-known as Lake Macdonald. The dam is located in the Noosa hinterland and is part of South East Queensland’s drinking water supply.

It is an un-gated dam, meaning that when it reaches 100 per cent capacity, water flows over the spillway and safely out of the dam. If you would like to be notified when Lake Macdonald (Six Mile Creek) Dam begins to spill, sign up to our free dam release notification service or download our public safety mobile app.

Flood mitigation

All dams help mitigate flooding to some extent. The peak outflow from a gated or un-gated dam during a flood event is less than the peak outflow that would have occurred had the dam not been built, because some water is held in the dam while it is spilling. This means that water flow slows down as floods pass through the dam.

Current capacity

Full supply volume

8,018 ML

Current volume

8,690 ML

at 5:28pm 18/12/2024

Dam is spilling

It’s important neighbours and people downstream of dams know what to do in the unlikely event of an emergency. Each of our dams have an Emergency Action Plan (EAP) in place to enable us to respond quickly to potential incidents in partnership with the Bureau of Meteorology, relevant emergency services and local councils. For Lake Macdonald (Six Mile Creek Dam), this is Noosa Shire Council.

Lake lowering

Dams are life-long assets requiring continual assessment, monitoring and maintenance. While the dam continues to operate safely under normal conditions, Seqwater will take further precautionary action to enhance safety at Lake Macdonald ahead of the wet season by lowering the lake to manage large spill events and catchment inflows.

From mid-October 2024, Lake Macdonald will be gradually lowered to 42% of its total capacity, or by approximately 2.3 metres. Seqwater is aiming to achieve this desired lake level by the end of 2024, however this timeline may vary depending on rainfall, catchment inflows and other environmental conditions.

What to expect

A number of gravity siphons will operate continuously over the spillway until the desired lake level is reached. The noise will be minimal, comparable to the sound of water naturally spilling over the spillway during low flow events.
There will be minor vehicle movements along Lake Macdonald Drive entering the site.
As the lake level is lowered, some parts of the lake banks may become exposed. While certain areas of the lake will no longer contain water, the lower regions will still maintain a reduced water level. This is a normal and expected part of the lake lowering process.
The flow of water out of the dam into the creek will be similar to the levels experienced during a typical wet season. Neighbours living downstream should not notice any unusual waterway rises.
The lake lowering process will be carefully managed to reduce disturbance to aquatic environments ensuring that aquatic fauna experience minimal impacts.
Lake Macdonald is expected to remain open for on water recreational activities, including parks and facility use. This includes continued access to Lake Macdonald, Lake Macdonald Park (off Lake Macdonald Drive), and the Noosa Botanic Gardens. While temporary closures may be required for safety reasons, our priority is to maintain access for as long as conditions are safe and practical.

For more information

For any questions about the lake lowering, please contact us at [email protected] or call 3432 7000 (during business hours).

The lake level will be lower than usual but similar to what could be experienced during dry periods, and will remain lowered until the Lake Macdonald Dam Improvement Project is completed. Lowering the lake will not impact water supply to Sunshine Coast communities.

KEY INFORMATION
WATER SOURCE
LIVING NEAR DAMS

Key information

Name
Lake Macdonald (Six Mile Creek)

Watercourse
Six Mile Creek

Location
Approximately 4 km north-east of Cooroy

Catchment area
49.00km²

Length of dam wall
501.00m

Year completed
1965

Type of construction
Earth and rock fill dam
Lake Macdonald is located near Cooroy on the Sunshine Coast and is part of the SEQ Water Grid.

The lake has a catchment area of 49 km² and the dam holds 8,018 million litres of water at full supply.
Lake Macdonald Dam Emergency Action Plan
During a flood event, Seqwater monitors the safety of all dams, including Lake Macdonald Dam, 24 hours a day.

Dams cannot prevent flooding from occurring altogether and in an extreme flood, there are risks that the safety of the dam may become compromised.

All dams managed by Seqwater have an Emergency Action Plan (EAP). This is standard industry practice and a regulatory requirement of responsible dam infrastructure owners, to support a quick and coordinated approach in the event of an emergency.

While Lake Macdonald Dam continues to operate safely, severe weather can be unpredictable and it’s important residents living near or downstream of Lake Macdonald Dam and close to Six Mile Creek familiarise themselves with the Lake Macdonald Dam EAP and have an evacuation plan in place for the household.

What does this mean?

In the event of a potential or actual dam safety emergency at Lake Macdonald Dam, residents within the area will receive a text message or an automated voice message to the home phone via the Emergency Alert system.

Types of messages that could be used

WARNING LEVEL – Watch and Act
Prepare to leave

What you should do:

Prepare to leave so you can go quickly if the Pine River water levels start to rise. Get ready now.

Decide where you and the people you live with will go if the situation worsens. Find a safe and high place away from flooding such as an Evacuation Centre.

Warn friends, family and neighbours in the area of the possibility of flooding.

WARNING LEVEL: EMERGENCY WARNING
Move to higher ground – Dangerous flood levels

What you should do:

Stay where you are and get up as high as you safely can. This could be upstairs or the roof.

Help other people who are with you if you can.

Tell someone where you are.

Stay in place until you are rescued, or wait until the water goes down to safely leave.

Stay prepared & informed

In the event of a potential or actual flood emergency at Lake Macdonald Dam, it’s important neighbours and residents living nearby or downstream of this water source are aware of the flood risk and how to stay informed:

Register for updates from your local disaster management group (NoosaAlert)

Follow the Bureau of Meteorology for updates on weather, warnings and river levels

Understand your flood risk and familiarise yourself with the Lake Macdonald Dam Emergency Action Plan and ensure you have an emergency preparedness and evacuation plan in place for your household.

Follow @Seqwater on Facebook or X (formerly known as Twitter) for dam updates

Download the Seqwater app or sign up for Seqwater’s free dam notification service for text, email or landline.

Download the Living downstream of Lake Macdonald Dam flyer for easy reference.

THINGS TO DO

Electric boating at Lake Macdonald Park

Canoeing at Mary River Cod Park

Stand up paddling at Lake Macdonald

Electric boating from Mary River Cod Park

Kayaking at Mary River Cod Park

Rowing at Mary River Cod Park

Sailing at Mary River Cod Park

BBQs and picnic at Mary River Cod Park

Fishing at Mary River Cod Park

Horse riding at Lake Macdonald

Walking trails at Lake Macdonald Dam

Mountain biking at Lake Macdonald Dam

Kayaking at Jabiru Park

Bird watching at Lake Macdonald

Fishing at Jabiru Park

Canoeing at Jabiru Park

Stand up paddling at Jabiru Park, Lake Macdonald

PROJECTS NEARBY

Investigating a new South East Queensland Desalination Plant

Seqwater is investigating a second desalination plant to provide water security for South East Queensland.

Artist impression of the upgrades for the Lake Macdonald Dam Improvement Program - right side view

Lake Macdonald Dam Improvement Project

Seqwater is upgrading Noosa’s Lake Macdonald (Six Mile Creek) Dam as part of its Dam Improvement Program. Early works are underway.

ALERT

Information about Seqwater's flood releases