Backed by a regional investment pipeline worth more than AUD $16 billion, civil construction firms and independent civil contractors based in Geelong, a fast-growing city about an hour southwest of Melbourne, Australia, are in the midst of overhauling essential water and sewer networks to help the city cope with rapid population growth.
However, these contractors are facing severe challenges as they navigate uncharted territory, with issues ranging from reactive clay soils to volatile material inflation, coupled with complex underground urban plumbing networks.
The current wave of population growth in the Greater Geelong region demands not just expansions of public infrastructure, but also refurbishment of existing systems, which is squeezing the civil sector to its core. Some of the more complex initiatives being undertaken by civil construction firms for Barwon Water, the region’s government-owned water corporation, include regional water security enhancements linked to recycled water main extensions, and local drainage and sewer system upgrades.
Examples include a 6.2-kilometre recycled water pipeline to Deakin University’s Waurn Ponds campus and upgrades to sewer pipelines running through the Geelong CBD. All of these projects fall into the sphere of civil plumbing which, unknown to most, is among the most complicated and challenging components of urban construction, especially in rapidly developing regions such as Geelong. The scope of civil plumbing starts with the deployment of qualified and certified civil contractors who carry out wide-scale pressure management before any asset renewals or new installations are approved by the water authority, to safeguard long-term supply.
These civil contractors are also tasked with organising, planning and scheduling extensive trenching, high-density polyethylene (HDPE) welding and trenchless directional boring, all needed to lay kilometres of new water, sewer and stormwater mains beneath a rapidly expanding region.
Among the more serious challenges these civil construction firms currently face are reactive clay soils. The region is notorious for its soil type; Geelong’s reactive clay ground profiles are known for shifting below the surface, and these movements often exert immense stress on laid pipelines. For this reason, civil contractors often lay specialised bedding and use various stabilisation techniques to prevent pipe joints from fracturing.
Coupled with material price volatility, these firms are more often than not facing increasing costs for vital civil components, including PVC, polyethylene (PE) fittings, ductile iron, copper and other metals. The situation is made worse by material suppliers becoming reluctant to lock in pricing for more than 30 days, which complicates civil contracts that are mostly fixed-price.
To keep overheads in check, many contractors partner with a Geelong excavator hire company for trenching machinery rather than tying up capital in their own fleets, giving them flexibility as project demands shift. Other complications include locating and identifying legacy infrastructure in need of repair.
This means civil contractors working in Central Geelong have to navigate a dense matrix of hidden, older utilities beneath existing structures. This requires contractors to use non-destructive digging (NDD) and hydro excavation tools to avoid accidentally striking live power and gas lines, which would significantly increase project costs.
