Weemala at the Lake

Project Summary:

Construction of a 154-lot subdivision including bulk earthworks and lead-in infrastructure

Project Scope:

Bulk Earthworks

The first phase of the project involves 300,000m³ of bulk earthworks under level 1 geotechnical supervision. Complex water management to handle a 40ML catchment above site, whilst maintaining a 10.5ML catchment and the bottom of site. Construction of a coffer dam using material from a borrow pit above site prior to construction of the subdivision.

154 Lot Subdivision

Construction of road pavements, gravity sewer, complex large-scale stormwater, water reticulation, gas, electrical and communications services. Construction of 150m² of sandstone retaining walls, and 4,324m² of post and panel retaining walls. All construction whilst managing the large volumes of water detailed above.

 PRV Construction

Construction of a complex Pressure Reducing Valve to provide water reticulation to the development.

 Lead-In Sewer

Construction of lead-in sewer for the Weemala development to connect in to. Involves the underbore of Main Road using micro-tunnelling techniques to bore directly into an existing manhole. Constructed under Hunter Water Complex Works.

Key Challenges:

History of Contamination

The Weemala development is the site of the old Pasminco lead smelter. Given the history of the site, and the contamination remediation undertaken prior to Daracon establishing on site, high levels of caution were taken throughout the bulk earthworks phase. Contamination management, tracking and disposal required for the lead-in sewer underbore. Comprehensive preparation undertaken prior to commencement to ensure worker safety when dealing with contaminants.

Highly Involved Local Community

Continuing from the above, there is a well-known and detailed history of contamination at the Weemala site. This has resulted in a highly involved and vocal local community. Daracon have been extremely proud to be involved in transitioning the public view of this land from contaminated, to somewhere families can grow and thrive.

Inclement Weather

From commencement on site in September 2021, to March 2023, Daracon has been impacted by over 130 days of rain delay due to an accumulated rainfall exceeding 1300mm. The resulted in the need for intricate and innovative thinking and planning in order to construct in a productive and program-friendly manner.

 Environmentally Sensitive Project

At any given time, the Weemala site can be handling in excess of 50ML. The outlet for the site flows directly into Cockle Creek, a river inlet to Lake Macquarie. This creek is regularly used by local residents for recreational activities and has a biodiverse ecosystem. Daracon site team has taken a lot of care in ensuring environmental controls and basins are suitable and effective to mitigate impacts on the community and environment.  

Multiple Designers

This project involves different designers for civil, stormwater, and sewer and water. Comprehensive tracking of RFIs along with updating drawings that are being regularly revised required to ensure site team are constructing based on the most up-to-date drawing sets.

 Material Procurement

The construction industry began experiencing ballooned lead-times for concrete products and pavement and construction materials. Daracon site team needed to be prepared through detailed forecasting of materials, and ordering of concrete products almost a year in advance. Labour shortages meant the same had to be done for labour resources such as plumbers, concreters, etc. To reduce the strain on pavement material procurement and promote innovation and environmental consciousness, Daracon crushed site won rock generated through bulk earthworks to make a suitable NGS20 sub base that was approved by LMCC for use on local roads within the development.