SCOPE OF WORKS
Sunshine Cove (originally Wises Farm) is a multi-precinct residential, commercial and “Town Centre” area in Maroochydore. Originally a flood plain, this 100 hectare site has been transformed into what is slowly becoming the new Maroochydore town centre.
Over 1.5 million m3 of earthworks was completed in less than two years in a marine mud environment. During construction, over 3.4 metres rain fell on the site. This required us to develop some extremely complex construction methodology covering environment, safety and testing.
The project involved the construction of an 800+ lot residential subdivision and major commercial and high density residential site including:
- 16 civil stage packages
- Clearing and grubbing of 60 hectares
- 1,600,000m3 of bulk earthworks
- Over five kilometres of roadworks
- Major stormwater
- Over five kilometres of sewer and water
- Creation of a parklands and park
- Over 5,000m2 of retaining / revetment walls
- Creation of major lakes and the transformation of a flood plain into a river system
- Multiple major intersection upgrades
- Electrical works
- Landscape works
- Acid sulphate soil management
- Extensive and complex water quality testing and management
- Traffic management
- Sewerage pump station
STAGING OF WORKS
The property was originally a farm which consisted of small patches of remnant vegetation, grazing land, an orchard, and a few small creeks and open drains flowing through the site.
Early works were staged to achieve milestones set in the contract:
- Extending Cornmeal Creek to its final design to allow the Construction of a bridge for the future Maroochy Boulevard.
- Establishing building pads on the Eastern and Western side of Maroochy Boulevard to dispose of the fill from the excavation.
- We identified the existence of Acid Sulphate Soils (ASS) through test holes and soil testing so this needed to be addressed. We:
- Established multiple bunded treatment pads to place, dry and treat the highly acidic marine mud in 300mm layers.
- Once treated, we conducted validation testing before the placement of the next layer.
- Established a series of drains to deal with stormwater between treatment pads.
- Installed a permanent in-situ water quality monitoring station at the outlet weir to monitor water quality.
The lake construction provided some interesting challenges.
1. The lake system was divided into seven separate portions so we put bunds in place to control and manage stormwater run-off.
2. The site also managed the extensive upstream water catchment that flowed onto the site so we installed a seven metre deep stormwater pit and submersible pump. This diverted the water through the site via a clean water diversion drain.
3. It was located in the middle of Maroochydore with the outflow of the water flowing through the Sunshine Plaza, so it was absolutely paramount to maintain adequate control measures to attain good water quality.
We ensured water quality met the release criteria by the time it reached the discharge point through ongoing water treatment in each of the lakes and pumping over the bunds.
A 930 metre long, 600mm diameter poly pipe was installed to allow the pumping of water from the end of Cornmeal Creek to the start of the lake system to allow for recirculation and further aided water quality.
The project was a success, with water quality actually improving through the site; attributable to the control measures installed and managed.