Whether you're planning a knockdown rebuild, an extension, or simply trying to understand your property's drainage layout, obtaining accurate drainage plans is an essential early step. In Melbourne, drainage records are held by several different authorities, and knowing which one to approach can save you significant time.
Why Drainage Plans Matter
Your property's drainage diagram shows the location and depth of sewer and stormwater pipes, inspection openings, and connection points. This information is critical for:
- Positioning a new home to avoid conflicts with existing infrastructure
- Understanding where proposed excavation and footings may interact with buried services
- Planning for new connections to the municipal drainage system
- Identifying whether existing drainage complies with current standards
- Informing engineers designing retaining walls and below-ground structures
Sewer Plans: Your Retailer Water Authority
In metropolitan Melbourne, sewer infrastructure is managed by one of three retail water authorities depending on your location: Yarra Valley Water (north and east), South East Water (south and east), and City West Water (west). Each authority maintains a plan archive and allows property owners to purchase a property service diagram (PSD), commonly called a sewer plan.
- Yarra Valley Water: Plans can be ordered online via their property services portal. Cost is typically around $25–$40 per plan.
- South East Water: Available through their digital portal or by phone. Similar cost.
- City West Water: Via their online services platform.
The plan will show the sewer drain location, depth, gradient, pipe size, and the position of any pits or inspection openings on your property.
Stormwater Plans: Your Local Council
Stormwater drainage (roofwater and surface water) is typically managed by your local council rather than the retail water authorities. Council drainage plans show the location of council drains in and around your property, easements for drainage, and connection points to the public system.
Most Melbourne councils maintain a drainage plan archive. Contact your council's engineering or infrastructure department, many now offer online plan requests. Plans are usually available within a few business days for a modest fee.
Melbourne Water: Waterway and Major Drain Catchments
For properties near waterways, major drains, or in flood-prone areas, Melbourne Water is the relevant authority. They manage the region's major drainage infrastructure and can provide flood level information and drainage catchment data relevant to your property.
Dial Before You Dig
Before any excavation, including for footings, trenching, or earthworks, contractors are legally required to submit a referral through Dial Before You Dig (1100 or dialectfordug.com.au). This service notifies all relevant utilities and provides plans showing the location of underground assets near your works. It's free and takes minutes to submit online.
Building Permit History
Drainage plans submitted with previous building permits may also be accessible through your local council's permit archives. If the previous home was built or extended with a permit, the drainage design submitted at that time may provide useful as-built information, though it should be verified against current conditions.
When You Can't Find Plans
For older properties, particularly those built before 1960, drainage records may be incomplete or unavailable. In these cases, a licensed plumber can conduct a CCTV drain inspection to map the actual drainage layout on site. This is often the most reliable approach and provides current, accurate information rather than potentially outdated archival records.
Varcon's project managers routinely assist clients in sourcing drainage information as part of our pre-construction planning process. If you're preparing to build and need guidance on where to start, we're happy to point you in the right direction.
