Sewer service diagrams: where to get the plan of your pipes

It's a drawing of the private sewer pipes on a block, from the house to the connection with the utility's sewer, with the buildings shown. Sydney Water's diagrams don't show pools, and older ones may also show the connection point and easements. Pipes missing from a diagram may not have been inspected.

Plumbers use sewer diagrams to find and fix pipes. Builders and designers need them for knockdown-rebuilds, extensions and granny flats. Buyers and conveyancers use them when a property changes hands.

No. A title lists only registered interests, such as a sewerage easement in favour of a water authority. Many sewer mains cross private land without any easement on the title, because the utility's rights come from legislation. To see the pipes you need the diagram, and to see the utility's mains you can use the free Before You Dig Australia service.

• Sydney Water area: buy it through Sydney Water Tap in for A$33.67 (2026-27), or through a Property Link broker for A$18.75 plus the broker's own fee. Sydney Water can supply diagrams for most properties, but not all. Call 13 20 92 if you're unsure.
• Hunter Water area: ask Hunter Water.
• Elsewhere in NSW: usually your local council, which is often the water and sewer authority in regional areas.
• Victoria: your water corporation. South East Water, for example, charges A$36.60 for a property sewerage plan in 2026-27.
• Queensland: usually your council. Brisbane City Council sells copies of existing house drainage plans, and the City of Gold Coast charges A$63 for a residential drainage plan in 2026-27.
• Western Australia: drainage plumbing diagrams are sold online through the state building regulator's DPD search. You need the street address.
• SA, Tasmania, ACT and NT: start with your water utility (SA Water, TasWater, Icon Water or Power and Water) or your council.

Where the house drain runs and where the sewer main sits decide where you can put an extension, a granny flat or a new house. Building over or near a utility's sewer usually needs its approval: in Sydney that's a building plan approval through Tap in (A$24.15 in 2026-27).

Diagrams can be missing or out of date, especially for older houses. If there isn't one, a plumber can locate the pipes with a camera before you design anything.

Not yet. Go to your water utility or council directly, as above. If you buy through a third party, check what happens if the utility has no diagram on file.

What we sell at launch is the title search, which lists registered easements, including sewer and drainage easements, and the Title + Full Report, which explains each entry (not available for WA, or for Queensland yet). Together with the diagram, that covers what's registered and what's in the ground.