Millicent Swimming Lake Reconstruction

After the 2022/23 summer it was discovered that excessive amounts of water had been used to maintain the levels of Millicent Swimming Lake and on investigation it was determined that the 50-year-old lake floor had been compromised in multiple locations.
The condition of the lake floor could not be fully assessed until the lake was drained and dry after winter.
Aquatic engineering advice has recommended that the best long-term solution would be to remove the existing bitumen seal, reshape the limestone base and concrete the entire floor. This work can only be done during dry weather.
Upgrades to the filtration system and improved disability access are also being designed to enable all to enjoy the renewed facility and this infrastructure upgrade will transform this important asset, extending its life for many decades to come.
Key points:
- The Millicent Swimming Lake is over 50 years old.
- The Naracoorte Swimming Lake is similar in design and age and went through the exact same process several years ago.
- The deteriorated lake floor is currently made up of a bitumen seal over a limestone base - just like a sealed road.
- Just like a road, this bitumen seal needs to be periodically reapplied.
- Just like filling potholes, we have been undertaking routine maintenance on the lake every year.
- After 50 years, the limestone base has failed and needs to be fully reconstructed.
- A concrete liner is a superior long-term solution to bitumen, as it will prolong its life and reduce future maintenance costs and disruptions.
- We also want to make use of this 1 in 50-year opportunity and replace the underground filtration pipes to improve water quality.
- This work can only be done when the lake is completely dry.
After the 2022/23 summer it was discovered that excessive amounts of water had been used to maintain the levels of Millicent Swimming Lake and on investigation it was determined that the 50-year-old lake floor had been compromised in multiple locations.
The condition of the lake floor could not be fully assessed until the lake was drained and dry after winter.
Aquatic engineering advice has recommended that the best long-term solution would be to remove the existing bitumen seal, reshape the limestone base and concrete the entire floor. This work can only be done during dry weather.
Upgrades to the filtration system and improved disability access are also being designed to enable all to enjoy the renewed facility and this infrastructure upgrade will transform this important asset, extending its life for many decades to come.
Key points:
- The Millicent Swimming Lake is over 50 years old.
- The Naracoorte Swimming Lake is similar in design and age and went through the exact same process several years ago.
- The deteriorated lake floor is currently made up of a bitumen seal over a limestone base - just like a sealed road.
- Just like a road, this bitumen seal needs to be periodically reapplied.
- Just like filling potholes, we have been undertaking routine maintenance on the lake every year.
- After 50 years, the limestone base has failed and needs to be fully reconstructed.
- A concrete liner is a superior long-term solution to bitumen, as it will prolong its life and reduce future maintenance costs and disruptions.
- We also want to make use of this 1 in 50-year opportunity and replace the underground filtration pipes to improve water quality.
- This work can only be done when the lake is completely dry.
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Council endorse staged approach to Lake reconstruction
Share Council endorse staged approach to Lake reconstruction on Facebook Share Council endorse staged approach to Lake reconstruction on Twitter Share Council endorse staged approach to Lake reconstruction on Linkedin Email Council endorse staged approach to Lake reconstruction linkAt the May 2024 meeting Council resolved to endorse a staged approach to the renewal of the Millicent Swimming Lake, commencing with Stage 1, being a temporary bitumen reseal to ready the facility for the 2024/25 Swim Season.
The remaining three stages would require Council to make application for grant funding through both State and Federal Governments, to support the reconstruction.
- Stage 2 - reconstruct the Swimming Lake (including demolition, preparation and construction of the lake walls, floor, underfloor circulation lines and drains and concrete works as per the detailed design (Estimated cost $4,46M).
- Stage 3 - Upgrade the filtration and chlorination systems and construct new pump shed. Connect all pipe work and fully commission upon filling the lake for the coming season (Estimated cost $1,28M).
- Stage 4 - Complete additional value add items such as the proposed splash park elements (Yet to be costed).
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Improvements included in plans for Lake reconstruction
Share Improvements included in plans for Lake reconstruction on Facebook Share Improvements included in plans for Lake reconstruction on Twitter Share Improvements included in plans for Lake reconstruction on Linkedin Email Improvements included in plans for Lake reconstruction linkThe upcoming reconstruction of the Millicent Swimming Lake presents an opportunity to not only improve water quality through upgrades to the filtration system but also undertake improvements to the entire complex. This will make the facility more attractive to users and provide a safer environment for swimmers.
Planned improvements include:
A new concrete floor and piping system - The concrete floor will consist of 49 separate concrete pours, ranging in size up to 15 x 15 m, each with a specialized joining system. All filtered water from the pump shed will be returned through an under-floor system to improve the consistent delivery across all areas of the lake.
Improved drainage - The floor of the lake will be designed for more controlled drainage, the deep end of the lake will have slight differentials in slope creating six low points. These points will have drainage vents fitted and the lake can then be drained much more effectively.
Removal of the old diving board/platform - The existing diving platform will be removed to enable the floor and piping works to be carried out. Two new filter islands will act as new diving platforms for swimmers to enjoy.
Installation of two new filter islands - The improved filtration system will use the existing 12 skimmer boxes located on the perimeter of the lake, combined with two new large standing surface suction islands. These two islands are designed to increase the return water flow to the filter shed and improve water quality but will second as new diving platforms within the lake.
Change to swimming lanes with new touch platform - The swimming lanes will be improved by reshaping the existing lake wall and incorporating a new touch platform. This will allow for easier access both ends of the swimming lanes and brings the swimming lanes closer to the edge of the lake, which will be easier to manage for lifeguard line of sight, which improves safety.
Disability access - Access at each end of the lake will be improved with handrails and flooring allowing entrance to the correct water depth. Approach pathways will be upgraded to vastly improving accessibility of the complex to the wider community.
Replacement of shade sail and flooring in children’s area - The shade sail within the lake will be removed to enable floor work to be carried out. The floor angle will be changed to meet the required standard for children and disability access. The children’s area will then be reconstructed with improved slip resistant underfloor treatment. The shade sails will be replaced with improved footings and a new fence constructed beneath.
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Lake to open for Summer school holidays
Share Lake to open for Summer school holidays on Facebook Share Lake to open for Summer school holidays on Twitter Share Lake to open for Summer school holidays on Linkedin Email Lake to open for Summer school holidays linkThe Millicent Swimming Lake will now open for a shortened period over the 2023/24 swim season following a decision made at the November Council meeting.
Prior to consideration of a report presented by staff, Elected Members heard a deputation from Millicent resident Tamara Cockrum and her son Chad, who pleaded the importance of the facility to the wider community. A letter from the Millicent Business Community Association reinforcing its economic benefits, was also tabled as correspondence. Community sentiment had also been heard by the members through online consultation and a stall held at the Millicent Show.
Following deliberation, including consideration of the estimated costs associated with preparing the asset for limited season opening ($100K), it was resolved that Council would open the Millicent Swimming Lake to the public between the 16 December 2023 and 29 January 2024.
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Visit the Millicent Show Indoor Trade Hall to chat with Council
Share Visit the Millicent Show Indoor Trade Hall to chat with Council on Facebook Share Visit the Millicent Show Indoor Trade Hall to chat with Council on Twitter Share Visit the Millicent Show Indoor Trade Hall to chat with Council on Linkedin Email Visit the Millicent Show Indoor Trade Hall to chat with Council linkDon’t forget, if you are heading to the Millicent Show this weekend (November 3 & 4) you can pop in and chat with us about the Millicent Swimming Lake Reconstruction Project.You will find your Elected Members in the indoor trade hall, ready to answer any questions you might have. -
Geotechnical investigations commence at Lake
Share Geotechnical investigations commence at Lake on Facebook Share Geotechnical investigations commence at Lake on Twitter Share Geotechnical investigations commence at Lake on Linkedin Email Geotechnical investigations commence at Lake link13 bore holes and 4 test pits were dug at the Millicent Swimming Lake earlier this week as the aquatic engineers conducted geotechnical investigations to assist with the design of the planned reconstruction.Council staff assisted as the engineers gathered soil samples and measured the existing footings. This data is needed to help define the extent of the work required.
Estimated Project Timeline (Subject to change)
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November 2022
Millicent Swimming Lake Reconstruction has finished this stageExcessive water use was identified in topping up the lake.
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Early February 2023
Millicent Swimming Lake Reconstruction has finished this stageA Council diver undertook an inspection of the lake to determine the extent and location of any significant leaks. The dive confirmed 4 locations of concern.
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April 2023
Millicent Swimming Lake Reconstruction has finished this stageThe swimming lake was drained at the end of the swim season, allowed to dry out and then cleaned. This takes approximately one month to complete.
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May 2023
Millicent Swimming Lake Reconstruction has finished this stageA report was presented to Council detailing the findings of the inspection, possible solutions and estimated funds required to address the various issues. This resulted in a significant allocation of funds to the 2023/24 budget.
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July/August 2023
Millicent Swimming Lake Reconstruction has finished this stageMultiple site inspections were made with various specialists in the field of aquatic engineering. Council also obtained advice from various civil contractors on possible solutions in attempting to understand the best options in fixing this asset.
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September 2023
Millicent Swimming Lake Reconstruction has finished this stageA further Council report was tabled, detailing the findings of the various advice and recommending that the best long-term solution was for the full reconstruction of the filtration system and lake floor. Council resolved that we proceed to tender for these works.
Council Agenda - 12 Sept 2023 | Council Minutes - 12 Sept 2023
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September 2023
Millicent Swimming Lake Reconstruction has finished this stageCouncil engaged the services of an Aquatic Engineer to undertake a detailed technical design and provide a specification and scope for the reconstruction works.
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October 2023
Millicent Swimming Lake Reconstruction has finished this stageSurveying and geotechnical assessment will be undertaken by Aquatic Engineers to guide the scope and specification.
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November 2023
Millicent Swimming Lake Reconstruction has finished this stageFollowing deliberation, including consideration of community sentiment and the estimated costs associated with preparing the asset for limited season opening ($100K), it was resolved at the November meeting that Council would open the Millicent Swimming Lake to the public between the 16 December 2023 and 29 January 2024.
Council Agenda - 14 November 2023 | Council Minutes - 14 November 2023
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16 December 2023 to 29 January 2024
Millicent Swimming Lake Reconstruction has finished this stageMillicent Swimming Lake open to the public for a limited swim season.
Note: The works involved in opening the lake include completing repairs to the lake floor, filling the lake, commissioning the existing filtration system and ensuring chlorine levels are safe. Although there will still be a water leak, it is anticipated that only being open for a month should not result in water allocations being exceeded.
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January 2024
Millicent Swimming Lake Reconstruction has finished this stageDelays in the development of the detailed design by the Aquatic Engineers resulted in the tender period being rescheduled. This provides the opportunity for Council to make the decision to postpone the closure of the lake until such time as a contractor has been appointed or the water allocation has been exceeded.
Council Agenda - 5 February 2024 | Council Minutes - 5 February 2024
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Beginning of February 2024
Millicent Swimming Lake Reconstruction has finished this stageAquatic Engineer to supply detail design drawings to inform tender process.
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February/March 2024
Millicent Swimming Lake Reconstruction has finished this stageCouncil will seek tenders for the reconstruction works from suitably qualified contractors, to install new filtration pipe work and for new concrete floor.
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May 2024
Millicent Swimming Lake Reconstruction is currently at this stageOn consideration of a report detailing the project scope and cost estimate summary Council resolved to endorse a staged approach to the reconstruction, with stage 1 being a temporary bitumen reseal ready for the 2024/25 swim season.
Council Agenda - 14 May 2024 | Council Minutes - 14 May 2024
Who's Listening
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Phone 0887330900 Email council@wattlerange.sa.gov.au -
Phone 0887330901 Email engineering@wattlerange.sa.gov.au