Rehabilitation of Sewer Submain – Terrys Creek

Project Summary Sheet

Customer: Sydney Water

Location: Lane Cove, NSW

Delivered: 2016

The Challenge

Investigation showed that this section of 78-year-old reinforced concrete sewer was severely deteriorated by acid attack and considered to be at the end of its effective life.

A challenge of the project was the location of the sewer and its operating conditions. It was obviously constructed in an era when environmental considerations did not have the importance that they have today.

The route of the sewer in the National Park was largely along the banks of Terrys Creek. The 60 maintenance holes from which access could be gained could only be accessed by foot along tracks in the bushland.

Distances from these maintenance holes to the nearest possible vehicle locations ranged from 300 metres to 1 kilometre.

The Solution

Sewer renewal (as part of the Networks Facilities Renewals Program) was completed by installation of an SPR™ EX – Expanda Pipe spiral wound PVC liner. As well as sealing the sewer against leakage, infiltration or root intrusion it also restores the full external load carrying capacity. The internal smoothness of the installed liner means that flow capacity is increased.

Works also included repairs to the maintenance holes.

The Project

Planning for the works involved addressing construction issues caused by the remoteness of the location as well as environmental issues.

The works were carried out by applying modifications to typical installation procedures, adapting equipment so it could be more easily transported and paying close attention to environmental controls.

Temporary access was made by adapting existing walking tracks to allow materials and equipment to be carried up to a kilometre from the nearest vehicle access. All construction measures met the requirements of the National Parks and Wildlife Services, Sydney Water, Council, bushcare groups and Bird Life Australia.


The works were completed successfully with no environmental incidents. The National Parks and Wildlife Service were even able to use the temporary accesses to carry out bush regeneration and other improvements.

Interflow is committed to offering its customers optimum solutions of the highest value for pipeline rehabilitation.