Residential Sewer Systems

A working residential sewer system is critical to health, environment and life style. Whether you’re building a new house, intending on buying an existing property or needing a repair Drainage NZ is your solutions partner!New Residential Sewer Systems

Are you a developer? Please visit our commercial drainage profile page.

If your building a new home Drainage NZ can help you from concept stage. Considerations for sewer drainage systems need to be taken if your building site is unusual or demands the use of specialised drainage applications which will contribute to the increase of your all-round building cost

Drainage scenarios which could increase your building costs:

  • Sewer pumps used to pump lower level sewage upstream to a point of gravitational fall.
  • In many Auckland suburbs stormwater and sewer are still on a combined system, new homes will need to provide a backflow of detention solution to satisfy councils.
  • Does the site have a public drain running through it? If yes, considerations need to be made to possibly divert or bridge depending on building design.

If you’re unsure about how your sewer drainage will affect your build of have any questions please don’t hesitate to call us on 0800 Drainlayers or email

Are you looking for a drainage quote? Drainage NZ has very quick turnaround time for residential drainage. Our experienced QS will quantify and make appropriate recommendations to enable you savings with the drainage installation. You can upload your plans through our contact page or call us on 0800 Drainlayers for an obligation free consultation.


Existing Residential Property Sewer Drainage

If you are purchasing an existing property or doing a renovation it’s important to consider the following with your sewer drainage:

  • Before you purchase a house, make sure you get CCTV inspection done to ensure all existing sewer lines are in good working order. Repairing an existing sewer line can be very expensive and you want to make sure you don’t get caught out.
  • With older houses your sewer line could be made of Verified clay or “earthenware pipe”. Due to age such sewer system are degraded and prone to damage by tree roots, ground settlement or simply collapse. Before committing to a renovation or purchasing a new home make sure you have all your bases covered by knowing the costs involved to replace or repair such pipes.
  • If you intend on adding more sanitary fixtures as part of your renovation, ensure your discharge units do not exceed the required maximum. Also check to make sure you have enough falls from your fixtures to the designated sewer line. In New Zealand building under a house is very common which very often leads to the use of sewer pump.


If you have committed to a drainage installation then it’s good to know that drains must:

Be laid to an even grade, straight and with smooth interior, have as few changes in direction as possible, have a minimum gradient as shown in the relevant standards, have a diameter and gradient appropriate to the fixture loading given in the correct standard. Reduced grades are permissible where those gradients specified in the standards cannot be obtained. For more information on this please consult your certifying drainlayer.

damaged_accesspointResidential Sewer Repairs

With sewer repairs one of the most important factors to our clients is cost. In some instances the repair is not optional and must be done, this can certainly sting especially when it comes unexpected. Experience is KEY to saving you money. The more experience a drainlayer has the less time he will need to do the job. Having the right tools is also important, if machinery has to be hired a higher cost will be generated which you will have to cover.

With Drainage NZ you can be assured that you are employing a team with over 25 years of drainage experience! All our employees are directly employed, ensured, and fully qualified to tackle any repair at hand. With all our in-house machinery you can confident that you are getting the best market place price possible.

Please visit our sewer repairs page for more information

Additionally Drainage NZ also offer the following residential services:

  • CCTV surveys and inspections
  • Sewer relining work and drilling services
  • Pump station design specifications, supply and installation
  • Swimming Pool drainage
  • External shower drainage
  • Subsoil drainage under and around building envelope (basement and garage flooding)
  • Residential Cesspits and channels
  • Overflow relief gully installation and repair (gully traps)
  • Under-slab Drainage
  • Residential Septic tank design and installation

House drainage with onsite sewage disposal systems (septic tanks)Onsite disposal is where the liquid and solid waste generated by a household passes into a drain and is conveyed to a septic tank. Separation of the liquid / solids mix takes place inside the tank before the liquid (effluent) passes through an outlet into a disposal field. Bacteria present in the disposal field treat the effluent and render it safe, before discharges to ground water or surface waterways.The septic tank onsite sewage disposal system consist of three parts:

  • 1. House drainage
  • 2. Pre-treatment, and
  • 3. Effluent disposal

Provided there is sufficient ground available for disposal of effluent, all the domestic waste can be treated using a septic tank system. Sometimes there are restrictions on what goes into a septic tank because of local soil conditions or awkward terrain. It may be better to separate the waste water from toilet wastes and treat is differently.

For more information on septic tank design and installation please call 0800 Drainlayer or email us on