House Drainage Plan and Sewer Search for Melbourne Buyers

By the Pearson Chambers Conveyancing.
Published 29th April 2026

The plumbing paperwork can look quiet in a contract pack, but it can turn into a very expensive surprise if nobody checks it before settlement.

The short answer: A Melbourne buyer should check both the water authority asset information and the house drainage plan before settlement. The asset information shows water and sewer infrastructure, easements and authority interests on or near the land, while the house drainage plan shows how the dwelling’s private plumbing connects to those assets. The Section 32 should disclose easements under section 32C of the Sale of Land Act 1962 and services not connected under section 32H, but buyers often need separate searches to understand the real drainage risk.

What is a house drainage plan in Melbourne?

A house drainage plan is a map of the property’s private sanitary drainage. It usually shows the pipes within the boundary, inspection openings, gully traps, boundary trap if there is one, vent stacks and the point where the private drain connects to the sewer main.

Think of it as the close up view. It tells you what the dwelling itself is doing with waste water once it leaves the bathroom, kitchen, laundry or ensuite.

It is not a building inspection and it does not prove every pipe is in good condition. It also may not tell the whole story if past works were done without proper records. That is why the plan should be read with the title, plan of subdivision, Section 32, water authority material and anything visible at the inspection.

For a buyer looking at a renovated single fronted house in Richmond or a townhouse in Preston, the drainage plan can explain whether that shiny second bathroom connects cleanly, or whether the plumbing route looks older and more awkward than the renovation photos suggest.

Is a sewer property report the same as a house drainage plan?

No. A sewer property report, water information statement or asset plan looks outward; the house drainage plan looks inward.

The authority report may show sewer mains, water mains, easements, recycled water assets, charges, notices or other property information held by the relevant water authority. The house drainage plan focuses on the dwelling’s private sewerage layout.

You need both because they answer different questions:

Does an authority sewer, water or drainage asset affect the land?
Is there an easement on title?
Does the private drain cross a neighbour’s land?
Has a deck, shed, garage or extension been built over a sewer line?
Do the Section 32 disclosures match the authority records?
Is there any sign of unapproved or poorly documented plumbing work?

This is where first home buyer conveyancing in Melbourne matters. A good pre purchase review does not just skim the headline price and settlement date. It checks whether the property you fell for on Saturday morning is hiding a drainage problem behind the back fence.

Which water authority do I need to check?

The right authority depends on the property’s location and the asset involved. Most Melbourne homes sit within the service area of Yarra Valley Water, South East Water or Greater Western Water. Melbourne Water may also matter where the land is near larger drains, waterways, trunk sewerage assets, floodways, retarding basins or regional infrastructure.

In practical terms:

Yarra Valley Water commonly appears for homes across Melbourne’s north and east.
South East Water commonly appears for bayside, south eastern and Mornington Peninsula properties.
Greater Western Water commonly appears for western and north western suburbs and growth areas.
Melbourne Water may need separate attention if the property is near one of its larger assets or easements.

For borderline suburbs, do not guess. A property in Coburg, Glen Waverley, Mentone or Werribee may all raise drainage questions, but the records and approval path can differ.

What does your conveyancer check in the drainage paperwork?

Your conveyancer reads the water material against the title plan, contract and Section 32 vendor statement. The aim is to spot mismatches before you are locked into a problem.

The main checks are:

Sewer and drainage easements
An easement is someone else’s legal right to use part of your land for a set purpose, such as sewerage, drainage or access. A sewer easement across the rear yard may not stop you buying, but it can affect a future extension, pool, garage, studio or landscaping plan. This is one of the property encumbrances buyers miss when they focus only on the floorplan.
Build over risk
Section 148 of the Water Act 1989 is the key warning sign for buyers. In plain language, certain building works over or near authority assets and easements need consent from the relevant water authority. If a previous owner built a deck, shed, pergola or brick extension without consent, the buyer may inherit the practical headache after settlement. We see this most often when sales photos show a lovely new deck sitting exactly where the sewer easement appears on the plan. That is when a buyer should ask about approval before signing, not after moving in. For more on this issue, see our guide to build over a sewer easement.
Common or shared drains
Older terraces and cottages in inner Melbourne may share a private drain with neighbouring properties. A drain can run through several backyards before reaching the authority sewer. If it blocks or collapses, repair costs and access rights can become messy, especially where the arrangement is old, implied or poorly recorded.
Stormwater and roof drainage
Sewerage is not the only issue. Stormwater problems can affect paving, garages, retaining walls, extensions and lower lying yards. A buyer should know where roof water discharges, whether there is a legal point of discharge and whether any authority or council drain affects the block.
Plumbing compliance certificates
In Victoria, plumbing compliance certificates matter for many types of plumbing work, including work valued at $750 or more and certain below ground sanitary drainage work. If a renovation added a second bathroom or moved plumbing, missing certificates do not always mean disaster, but they do justify more questions.

Why are older Melbourne terraces more exposed?

Older terraces and weatherboards are more exposed because their drainage lines were often laid long before modern renovations. The original house may have connected through a rear lane, side path or neighbouring property, then later owners added lean tos, bathrooms, decks and kitchens around those old pipes.

In our practice, we’ve seen this come up most often in inner north and inner west homes: Brunswick, Carlton, Fitzroy, North Melbourne, Richmond, Yarraville and Footscray. A buyer falls in love with the high ceilings and courtyard, then the documents show a sewer easement running diagonally across the exact spot planned for a studio or outdoor room.

Growth corridors carry a different risk. In places such as Tarneit, Mickleham, Mernda, Cranbourne and Officer, the issue may be a drainage reserve, future infrastructure corridor or newer easement that limits later works. The land can look clean and open at inspection, but the plan tells a different story.

How does the drainage search connect with the Section 32?

The drainage search checks whether the Section 32 tells the same story as the property records. Section 32C of the Sale of Land Act 1962 deals with easements, covenants and other restrictions. Section 32H deals with services not connected in a Section 32, including sewerage.

A few examples make this easier:

If the title shows a sewer easement and the Section 32 discloses it clearly, the buyer can assess the risk.
If the authority material suggests a sewerage issue but the services disclosure is silent, your conveyancer should ask questions.
If a structure appears to sit over a sewer easement but the Section 32 does not mention any compliance problem, the buyer may need urgent advice before settlement.
If the property is not connected to reticulated sewerage, the Section 32H disclosure needs careful review.

A drainage plan is not always a required Section 32 attachment. That is why buyers should not rely only on what the vendor gives them. The buyer’s side should order and check searches where the property type, location or renovation history calls for it.

What can you do if a drainage defect is found before settlement?

Before settlement, you may still have options. Your conveyancer may ask the vendor for missing approvals, request plumber’s certificates, seek a price adjustment, negotiate a special condition, extend time for further enquiries or advise on rescission rights where the Section 32 appears defective.

The right path depends on the defect. A minor record gap is not the same as a permanent structure sitting over an authority sewer with no consent. A shared drain in a row of terraces is not the same as an unconnected sewerage service.

After settlement, the position is harder. You may still have legal rights if the vendor or agent gave false or incomplete information, but the cleanest time to deal with drainage paperwork is before you accept the title and take possession. Once the keys are in your hand, the authority will usually be dealing with you as the current owner.

Practical drainage checklist before you sign

Before signing a contract, ask your conveyancer to check:

the title search and plan of subdivision
any sewerage, drainage or water easements
the water authority information statement or asset plan
the house drainage plan or property sewerage plan, where available
any visible structures over easement areas
whether plumbing works have compliance certificates
whether the Section 32 services disclosure matches the search material
whether a common or shared private drain affects the property
whether future plans, such as a pool, second bathroom, extension or studio, may be restricted

Do this early if you are buying at auction. A successful auction bidder in Victoria does not get the standard three business day cooling off period, so the quiet drainage search can become very loud once the hammer falls.

Frequently asked questions

What is a house drainage plan in Melbourne?

A house drainage plan, also called a drainage diagram or property sewerage plan, is a map showing how a property’s private sanitary plumbing connects to the sewer system. It may show pipes, inspection openings, gully traps, a boundary trap and the connection point to the sewer main. Melbourne buyers use it to check whether the home’s plumbing matches the title, Section 32 and water authority records.

How does a drainage diagram differ from a sewer property report?

A drainage diagram shows the private plumbing layout for the dwelling. A sewer property report or water authority information statement is broader and may show authority assets, easements, charges, notices and infrastructure near the land. Buyers should check both because one shows how the house drains and the other shows what authority interests may affect the block.

Who pays for the house drainage plan when I’m buying a home?

The buyer usually pays for extra searches ordered by their conveyancer, including a house drainage plan or sewer property report. The cost is commonly treated as a search disbursement and may appear on the settlement or invoice paperwork. Fees and availability vary by authority and product.

What if the house drainage plan shows a build over violation?

If the plan suggests a structure has been built over or near a sewer asset without consent, the buyer should get advice before settlement. Possible steps include asking the vendor for approvals, negotiating a price adjustment, seeking a special condition or considering Section 32 rights where the disclosure appears defective. Do not assume a long standing deck, shed or extension is approved just because it is already there.

Does the vendor have to give me a drainage diagram in the Section 32?

Not always. The Sale of Land Act 1962 requires key disclosures, including easements and services not connected, but a house drainage plan is not always included as a mandatory attachment. That is why the buyer’s conveyancer may order the drainage plan or sewer property report separately.

Can a common drain through the neighbour’s yard make me liable for their plumbing?

Sometimes, yes. Older Melbourne properties can share a private drain that crosses several lots before reaching the sewer main. If your property uses that shared drain, repair costs and access issues may involve more than one owner, so the arrangement should be checked before you sign.

How long does it take to get a sewer property report and drainage plan in Melbourne?

Timing depends on the authority, the product and the property. Some online asset information can be fast, while older records, complex assets or extra authority reviews can take longer. If you are buying under auction pressure or during a short cooling off period, ask your conveyancer to order searches as early as possible.

About the Pearson Chambers Conveyancing team

Pearson Chambers Conveyancing is a Melbourne focused conveyancing team helping first home buyers, investors and homeowners review contracts before they commit. We deal with Section 32 statements, title checks, easements, water authority material and settlement questions every day. Drainage searches are part of that work because a small line on a plan can change what a buyer can build, repair or afford later.

Sources we consulted

Need a complimentary Section 32 contract review?

If you are buying in Melbourne and the drainage paperwork feels unclear, send the contract and Section 32 to Pearson Chambers Conveyancing before you sign. We can review the title, water authority material, easements and services disclosures, then explain the practical risk in plain English.

For a complimentary Section 32 contract review, contact Pearson Chambers Conveyancing:

Email: contact@pearsonchambers.com.au

General information only, current as at the date of publication. Victorian conveyancing rules and legislation change frequently. Please contact the Pearson Chambers Conveyancing team for advice on your specific contract.