Case Study: Residential Development, Milns Green, North Halswell, Canterbury

Johnston Civil is an award-winning civil construction company based in Selwyn District in the central South Island.

Paul Johnston from Johnston Civil, contacted BurrowTech, looking to hire a plug for a 1250mm pipe on a Christchurch land development project in Halswell.

Milns Green boasts picturesque views, and the tranquillity of a suburban lifestyle, just a short drive away from Christchurch’s city centre.

Though, there was a challenge. Water. Lots of it.

The low-lying land has a stream, multiple aquafers, and rainwater run-off from the hills nearby. As Johnston Civil’s Project Manager Manu De Silva put it, the water was coming from “all directions”.

Over-pumping had previously (and is continuing to be) used, but backflow into the work area was the major issue that could not be addressed using conventional plugging/damming means.

The solution settled on was a 1500mm Lampe sealing cushion, which solved the problem and helped work progress. Manu says the BurrowTech product sealed the pipe right away. “Before that, we were battling the water.

Without the sealing cushion we would’ve had to do a lot more pumping, and that would’ve meant more expenses and time on the project.”

The sewer sealing cushions (used overseas since the 1970s) are proven to be the industry’s safest, most economical pipe plugs. They don’t need additional bracing and fit a range of pipe profiles, very effectively stopping water flow.

Unlike conventional pipe plugs, sewer sealing cushions are extremely lightweight. Manu says the sealing cushion was amazingly easy to handle. “If I’d known this was available earlier, I would’ve used it from the start.”