Southern Arm Trunk Main

The project offers dual benefits, addressing both water quality and water security.

Water Security

Currently, water is extracted at Rosewood and pumped to the Port Macquarie Dam, prior to being delivered to the Southern townships via a network of trunk mains and reservoirs. Construction of the Southern Arm Trunk main Scheme will allow water to be fed directly from Cowarra Dam to Bonny Hills / Lake Cathie and down to Camden Haven along with the ability to feed the Port Macquarie reservoir network to the North. This additional link will provide the redundancy of a dual supply, improving our community's water security.

Water quality

This project will also reduce the distance that water must travel through the network to reach Lake Cathie, Bonny Hills, and those townships to the south of Port Macquarie, delivering an improvement to the overall water quality to these areas.

The first stage was completed in 2013 and involved the installation of over 4.5km of trunk main pipe connecting Abel Tasman Drive in Lake Cathie to the New Bonny Hills reservoir and the existing trunk main on Ocean Drive at Bonny Hills.

The second stage of the works was the construction of approximately 2.5km of trunk main pipe from Cowarra Balance Tank to the Pacific Highway. These works were completed in two parts in 2016 and 2018.

This stage of the project has completed the link between the Cowarra Balance tank and the New Bonny Hills reservoir.

Currently, there is one primary pump station for our LGA located in Port Macquarie. If that pump were to fail, water service delivery interruptions could be substantial. With the Cowarra Water Treatment Plant expected to be operational in the coming years, the Southern Trunk Arm Water main system will greatly bolster our community’s water supply. Furthermore, the project will exponentially reduce the distance that water currently must travel through the network to reach Lake Cathie and Bonny Hills, and as such will improve the overall water quality.

This project was designed to be delivered in a phased approach with the first phase delivered in 2013. This involved installing a large diameter trunk water main between Abel Tasman Drive Lake Cathie and the new Bonny Hills Water Reservoir off Panorama Drive Bonny Hills. Subsequent phases completed in 2016 and 2018 involved further mains installation between the Cowarra Balance Tank and The Pacific Highway. This final phase aims to link the trunk water main between the Pacific Highway and Ocean Drive along Houston Mitchell Drive, thus finalising the Cowarra dam to Bonny Hills secondary water supply feed.

It is expected that the final phase of this project will take approximately a year. With construction commencing in January 2024, we expect that this project will conclude in January 2025, weather permitting.

This final phase was originally intended to be built along a dedicated easement through National Parks and Forestry land, parallel to Houston Mitchell Drive. However, that plan has since been updated to run within the road corridor. This was deemed a better environmental option than installing the pipeline through virgin bushland as the road verge had already been partially cleared during the upgrade in 2017. This updated option also will provide better access to maintain the pipeline in future years.

While parts of the updated road will need to be altered to facilitate the new pipeline, much of the road will remain untouched with most of the work being conducted in the road verge.

During the construction phase of this project, traffic controls will be implemented as required throughout the worksite, with regular lane closures likely. This may cause minor delays to road user’s journeys and should be planned for accordingly. Wherever possible lane closures will be removed outside of the regular working hours of 8am-6pm Monday to Friday and 8am-1pm Saturday.

The final value for this stage of works is approximately $12 million and is being funded from Council reserves.

It should be noted that this project does not involve connecting residents who use private water supplies, such as those on Long Point Drive, to the town water network. The pipeline being installed is designed as a trunk main and is not suitable to supply directly to individual residences due to the high water pressure it carries.

We are happy to provide you with more information regarding this project, should you require it. You can contact us via email at council@pmhc.nsw.gov.au or by calling our customer service team at 6581 8111.