Older suburbs such as Linwood and Woolston, riverside streets in Burwood, 1960s and later homes in Parklands, and beachside homes in New Brighton and Sumner, many repaired or rebuilt after the earthquakes. Drainage is the part of a build nobody sees once the trench is filled, and the most expensive part to get wrong. A fall that is too flat blocks, a joint that is badly bedded cracks, and a connection in the wrong place fails inspection. In Christchurch there is an extra layer: the ground itself, which ranges from liquefaction-prone land with high groundwater in the east to Port Hills rock in the south.
Drainlaying in the east: liquefaction land, pressure tanks and coastal ground
Drainlaying in East and Coastal Christchurch starts with the land. Burwood, New Brighton, Linwood and Woolston all took earthquake damage in 2010 and 2011, and the technical category on a property's LIM tells us how the ground is expected to behave in future. Where the land is TC2 or TC3, rebuilt homes sit on enhanced or engineered foundations, and the drains have to be designed alongside them, with flexible joints and connections that cope with movement and high groundwater.
The other difference is the sewer itself. Before the earthquakes Christchurch used gravity sewers almost everywhere, but since then the council has installed pressure and vacuum systems in some areas, including the vacuum network in Shirley, Aranui and Prestons. A new house or extension on a pressure system drains to an on site tank and pump, and the owner supplies the power to that pump. On a vacuum system, private laterals feed a collection chamber. We confirm which system serves your street before drawing the plan.
Near the coast, the sandy ground in New Brighton and along the spit is easy to dig but needs trench support, and groundwater can rise into an open trench quickly. Woolston and Linwood have older housing among factories and the Heathcote River, where flood management areas may also set minimum floor levels for new work. Every job here is consented through Christchurch City Council and inspected before the trench is filled. We also look closely at where new drains meet older private lines that survived the quakes. A camera run through the existing lateral before we connect tells us whether that section can stay or should be replaced at the same time, which is usually cheaper than coming back later with the lawn already reinstated.
Local tip: Before planning an extension in the east, find out whether your property drains by gravity, pressure or vacuum, because it changes the whole drainage design.
For anything else, see our plumbers in East and Coastal Christchurch.
Pricing: quotes are free, and every job gets a fixed price before we start, so there are no surprises on the invoice.
Drainlaying Jobs We Do in East and Coastal Christchurch
- Subdivision drainage
- Drain layer
Drainlaying East and Coastal Christchurch FAQs
Our New Brighton section is TC3 land. Does that change how the drains are laid?
Yes. TC3 land needs site specific engineering, and the drains are designed to suit the foundation and the expected ground movement. We work from the engineer's plans and the consent.
Do I need a building consent for new drainage in Christchurch?
Most new drainlaying, including new connections and alterations to existing drains, needs a building consent from the council for your address. We prepare the drainage plans and the application.
My street has a pressure sewer. Can I still add a minor dwelling?
Often, but the connection has to suit the system. We confirm what is on your street and what the council will accept before design.