Wastewater pipe relining set to get underway in parts of Westport and Reefton

Wastewater pipes in Westport below Adderley Street between Brougham and Wakefield Street and in Reefton underneath Buller Road will get a refresh soon.

Buller District Council will reline wastewater pipes in this area to strengthen sections in deep, difficult and time sensitive locations.

Manager infrastructure delivery Eric de Boer says: “We have chosen relining since it is significantly faster and removes the need for open trenching. In places where the wastewater pipes are very deep, open trenching becomes an expensive and slow process, due to requirements such as shoring and dewatering.” 

Shoring is the placement of barriers to prevent collapse of trenches more than 1.5m deep to protect workers. Dewatering involves pumping the groundwater out of trenches so that the level the pipe needs to be laid at is not submerged and to stabilise the sides of the trench .

Mr de Boer says: “Using this technique, only a small portion of the road around each manhole requires closing. What our contractors will do is clean the wastewater pipes then use a robotic camera to re check that the pipe is suitable for relining. This footage is also used to locate the position of household connections. The relining sleeve is then blown through the pipe and cured with UV. Lateral sections are cut out and relined or replaced with conventional pipe.”

The result is a pipe with an equivalent strength to the same PVC/PE pipe which would be used and installed through an open trench.

Mr de Boer says: “Relined wastewater pipes have a very similar diameter to the original wastewater pipe. The relining membrane is thin, and the wastewater pipe material is very smooth with few joints, the flow is essentially the same as the original pipe in new condition.”

The work is scheduled to start mid-June and will be carried out by RelineNZ, who are a division of HydroTech. There will be some road restrictions during the relining process to allow safe working around manholes.

The work is funded through rates as part of the planned wastewater infrastructure work.

Previous work was carried out on Peel, Cobden, Queen, Pakington and Romilly streets in Westport in 2021. It was carried out by RelineNZ, who are a division of HydroTech.

-ENDS-

further information please contact:

Manager Infrastructure Delivery
Eric de Boer
eric.deboer@bdc.govt.nz