What's different about drainlaying in Wellington
Connections go through the council
A new water, wastewater or stormwater connection is applied for and paid through Wellington City Council, then processed by Tiaki Wai, even if you already hold a building or resource consent. It usually takes up to 3 weeks, and approval comes with conditions such as inspections and as-built drawings.
The 3 metre rule near public pipes
Public pipes can run through private sections. Tiaki Wai says work within 3 metres of one generally needs its approval, and piles within 10 metres may too. It won't approve building over service connections, water supply pipes or sewer pressure pipes.
Drain inspections and letters
Tiaki Wai tests for pollution with smoke, dye, cameras and pressure tests, on private drains as well as public ones. If it finds faults on your side it writes asking for repairs, allows 90 days, and follows up. The letter goes on the property file and comes out with a LIM.
Gas pipes under the ground
Powerco's gas network runs under Wellington. It asks anyone digging, drainage work included, to get plans through beforeUdig first, allowing 48 hours, and to hand dig to expose pipes. Digging within 2m of its pipes or cables needs its consent.
Before you build on a Wellington section
Tiaki Wai's application needs the consent number, your drainlayer's or plumber's name and contact details, and a site plan. Alterations and new drainage usually need a building consent before work starts, and before the connection application goes in.
Some parts of the network have capacity limits. Where that's the case, Tiaki Wai may require wastewater control before it lets a new connection in, so raise it early.
Flooding matters on a hillside city too. Some stormwater pipes only cope with smaller storms, minimum floor levels can apply, and overland flow paths mustn't be blocked. Tiaki Wai's regional app has flood information for parts of Wellington City, Johnsonville, Karori and Tawa.
Downpipes in the gully trap
Tiaki Wai calls cross connections a common mistake in home drainage work: wastewater piped into stormwater, or the reverse. The classic case is a downpipe diverted into the gully trap. Keeping the two systems apart is the owner's job, so on an extension or new build, make sure your drainlayer knows exactly where every pipe ends up.
A lateral can also be damaged by roots, land movement or building work, and usually only shows it by leaking up or backing up at the gully trap. Sewer and drain repairs and pipe relining cover the fixes.
Licences, supervision and sign-off
Laying, altering or repairing a drain is restricted work. Certifying drainlayers can work alone and certify; the Drainlayer and restricted classes work under a named certifying supervisor. Look up both the drainlayer and their supervisor on the PGDB register and confirm each licence is current.
Since 7 September 2026, certifying drainlayers have been able to apply for a self-certification endorsement. With that endorsement, a drainlayer signs off eligible consented jobs themselves instead of waiting for council inspectors. You still need the consent, and if they weren't named on your application, you must tell the council in writing who they are. Our certificates guide sorts out the different certificates.
Questions for a Wellington drainlayer
- Is there a public pipe within 3 metres of what we're planning?
- Who lodges the connection application with the council, and what will Tiaki Wai inspect?
- Have you checked beforeUdig plans for gas and power?
- Will you certify this yourself, or will the council inspect?
What we would do
Find the public pipes before you draw anything. An extension, retaining wall or extra fill near one can need Tiaki Wai's approval, and some won't be approved at all, so it's cheaper to know at the design stage. If you've had a letter about drain faults, get a drainlayer to read the footage and log sheet with you, then fix the serious items inside the 90 days. Tell us the job and we'll pass it to a drainlayer who works in Wellington.