Community members get a rare tour inside the historic Somerset Dam wall

Somerset Dam Improvement Project

Somerset Dam is one of several dams identified to be upgraded as part of Seqwater’s Dam Improvement Program. The dam plays an important role in the SEQ Water Grid and its continued performance and safety is critical to the residents and visitors of South East Queensland.

The project will improve the dam’s ability to withstand extreme weather events.

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About the project

Dams are long-life assets which require continual assessment, monitoring and maintenance. South East Queensland dams were built to high safety standards, but most were built some decades ago. Methodologies and data used to estimate extreme rainfall events continue to improve and industry engineering standards and understanding of risks can progress over time. 

Across Queensland and Australia, there are multiple dam upgrades occurring to meet modern engineering standards. 

Seqwater’s Dam Improvement Program is ensuring its dams comply with the latest safety standards and continue to function safely during extreme weather events in line with regulatory requirements.  

Seqwater is finalising the Detailed Business Case for the Somerset Dam Improvement Project, which will inform the design for the main dam upgrade.

The project will reduce risks associated with extreme weather events, achieve regulatory compliance, and ensure the continued reliability of this water source for the South East Queensland region for years to come.

Contact the team

Email [email protected]
Online feedback form
Phone 3432 7000 (Monday to Friday, 9am to 5pm)

News and updates
Media gallery
FAQs

Somerset Dam Improvement Project - update

19 Jun 2024

As part of our Dam Improvement Program, Seqwater is planning a range of early and enabling works at Somerset Dam to support future construction on the major dam upgrade set for this site.

Early and Enabling Works

While detailed planning for the business case continues, Seqwater has identified an opportunity to undertake Early and Enabling Works, as announced here.

The Early and Enabling Works are required to be completed irrespective of the final design configuration and will involve a range of preliminary activities that support the main dam upgrade.

Early and Enabling Works in and around Somerset Dam are expected to progressively commence and are likely to include:

Broad scale geotechnical investigations including the installation of dam surveillance instrumentation.
Removal of existing spillway (radial) gates as these no longer form part of Seqwater’s operation of the dam.
Replacement of the sluice gates (gates at the bottom of the dam wall) and outlets that are reaching the end of their serviceable life.
Construction of a temporary coffer dam that will help to maintain a dry work site downstream when investigations and construction commences in areas currently submerged.
Relocation of the existing operations facilities to allow construction of the future main dam upgrade.
Temporary and permanent access road works including a permanent realignment of Esk-Kilcoy Road and a new access to the dam wall from Wivenhoe-Somerset Road.
A range of investigations, studies and assessments to support finalisation of the Detailed Business Case for the main dam upgrade.

Main Dam Upgrade

Seqwater is developing a Detailed Business Case for the Somerset Dam Improvement Project. As part of this work, extensive technical investigations have been undertaken to inform design options, including geotechnical investigations, hydraulic modelling of the spillway and dissipator basin using a scale laboratory model, 3D scanning of the dam wall, downstream bathymetry and lidar aerial surveys.

While a final design configuration for the Somerset Dam Improvement Project will be determined through the Detailed Business Case process, current design elements are likely to include:

Raising the height of the dam wall to improve dam function during very extreme floods
Extending and reinforcing the dissipator basin and training walls, plus adding a new control structure, downstream of the spillway to reduce energy from the spillway flow in very extreme weather events
Adding concrete to the downstream face of the dam wall to help strengthen the wall.

For More Information

To sign up for project updates and receive updates on upcoming community engagement opportunities, fill out the newsletter subscription request at the bottom of the web page, or email us requesting to be added to the Somerset Dam Improvement Project update list.

For more information on the project, contact the project team via:

07 3432 7000 (during business hours)
[email protected]

Non-English speakers call 131 450 and ask for Seqwater on 07 3035 5500.

If you have a hearing or speech impairment, contact us through the National Relay Service and give the number 07 3035 5500 a call or visit www.relayservice.gov.au for more information.

Enabling works commencing on Somerset Dam, ahead of major upgrade

19 Jun 2024

Enabling works will commence, ahead of major upgrades to Somerset Dam.

Early and enabling works will commence onsite in 2025 upon contract award and approvals, as part of the first stage of the Somerset Dam Improvement Project.

Somerset Dam continues to operate safely, and the Dam Improvement Project will ensure the dam meets modern engineering and design standards to provide ongoing safety and water security for years to come.

More information is available in this Ministerial Media Statement.

An aerial shot of the upstream side Somerset dam wall a long concrete wall holding back deep green coloured water

Dam Improvement Program Market Briefings coming soon

26 Apr 2024

Seqwater is conducting a market briefing for engineering services providers regarding the Dam Improvement Program, ahead of an Expression of Interest / Request for Proposal being released.

The briefing will introduce Seqwater and the program, and provide high level detail around project timing and delivery, as well as outline the approach to partnering throughout the program.

Event details:

Date: Friday 10 May 2024
Time: Arrival at 2.15pm (AEST) to register for a 2:30pm start (allow approx. 60 mins).
Location: Seqwater Office, Level 2, 200 Creek Street, Spring Hill.
Online meeting option also available.

To register for an event, please click https://www.eventbrite.com/cc/dam-improvement-program-market-briefings-3303699. Spaces for those attending in-person may be limited and Seqwater requests a maximum of two persons per company attend each event.

Participation in the market briefing is not a prerequisite for Expression of Interest submissions. For further procurement information, email [email protected].

Somerset Dam upgrade - Technical Surveys - Notification

17 May 2021

The Somerset Dam Improvement Project involves improving the current design to meet the Queensland Dam Safety Guidelines. Over the coming months Seqwater will have technical teams doing surveys for the upgrade project. For more information, please read the works notification here.

The grandchldren of H.P. Somerset (l-r) Charles Somerset, Sue Rice, Bill Somerset, Bob Somerset and Arthur Somerset stand on the Somerset Dam wall (3).jpg

Poster explaining Somerset Dam Hydro electricity plant

Queensland State Archives (4604) photo of Somerset Dam August in 1947 of Rigging No 1 Tail tower

Poster explaining the beginning of Somerset Dam

Why does Somerset Dam need to be upgraded?

Somerset Dam is one of several dams to be upgraded as part of Seqwater’s Dam Improvement Program. Like all major infrastructure, dams are regularly assessed and upgraded to comply with improvements to engineering standards and guidelines. Seqwater is required to comply with the Queensland Dam Safety Guidelines under the Water Supply (Safety and Reliability) Act 2008.

Somerset Dam was built between 1935 and 1959. Since then, there have been significant changes including:

population growth downstream 
advances in dam design 
improved estimation of extreme rainfall and flood events 
improved understanding of earthquake probabilities and loads.

Will the upgrade work impact recreation at Lake Somerset?

The main construction site for the dam upgrade will be at the Somerset Dam wall. We do not expect any changes to recreation activities on the lake or at ‘The Spit’ or other popular recreation areas. There will be increased traffic on the road during construction which may impact recreation users travelling to Lake Somerset.

Will the upgrade to Somerset Dam impact recreation at Wivenhoe Dam?

Construction of the Somerset Dam Improvement Project is not expected to impact recreation at Lake Wivenhoe.

Will the water level of the dam increase?

While the Dam Improvement Program is underway, Somerset Dam is operating with a lowered full supply level. This is an industry-accepted practice to manage dam safety.

There will be no changes to the full supply level of the dam, which will be restored back to 100% post construction.

South East Queensland has a safe, reliable and resilient water supply system, stemming from careful and ongoing water security planning and a diverse asset base which allows Seqwater to supplement supply in a timely way when needed.

The lowered level does not significantly impact the long-term water supply security for the region. Periodic reviews will continue until the dam is upgraded to ensure dam safety, water supply and long-term water security are appropriately managed.

When will the main dam upgrade occur?

Seqwater recognises this project has had a long planning phase. Major dam upgrades have complex design and approval requirements and can take years to plan, and it is prudent that Seqwater takes the time to get it right to ensure the best options are selected to meet project objectives, regulatory requirements and deliver value for money.

Seqwater is completing a Detailed Business Case for the Somerset Dam Improvement Project, to carefully assess the preferred option for upgrading the dam. More information on project timing will be confirmed once the business case is approved.

How will you manage the construction impacts on residents and businesses?

A Social Impact Management Plan will be adopted to reduce and manage the impact on the Somerset community. More information on this will be shared as the project progresses, with opportunities for the community to provide feedback.

Will the dam upgrade project include improvements to the local area for long term benefit (legacy projects)?

Seqwater is committed to addressing the impacts of the Somerset Dam Improvement Project on the community. As part of the current Detailed Business Case process, a Community Reference Group was formed to partner with Seqwater in developing a Social Impact Management Plan. This plan will include legacy projects with long-term benefits that meet the needs and priorities of the local community as well as mitigating potential short-term project impacts.

For more information about proposed legacy projects see https://www.seqwater.com.au/news/legacy-projects-shortlisted-part-somerset-dam-upgrade

Will the project provide opportunities for local jobs or for local businesses?

Seqwater supports local employment and local procurement on all its capital works projects. We strongly encourage small and medium sized businesses in the Somerset region to tender for work packages and sub-contracts associated with the construction phase of this project.

We are identifying ways to maximise local opportunities/benefits during the construction period. These may include local apprenticeships and traineeships, a local procurement register and targets for local employment and procurement.

How can my business tender for work on the upgrade?

The contract for construction of the Somerset Dam Improvement Project will be listed on the QTenders website. 

Seqwater supports local procurement on all its capital works projects. We strongly encourage small and medium sized businesses in the Somerset region to tender for work packages and sub-contracts associated with this project.