Council undertakes sewerage maintenance in wake of record rainfall

22 March, 2012Posted in: Roads and Assets

You don’t have to be a weatherman to notice that we’ve had a bit of extra rain lately.

When stormwater finds its way into a sewerage network, it can play havoc with underground sewerage pipes resulting in an overloaded sewerage system.

An overloaded sewerage system means that the pipe network cannot function until flows subside to normal levels. Typical signs of an overloaded system include temporary lack of domestic service resulting in inability to flush the toilet.

“Typically, our sewerage network is designed to accommodate up to three times normal dry weather flow,” said Council’s Assets Manager, Selva Selvaratnam.

“However, over recent weeks we’ve experienced flows significantly above this figure resulting in our system becoming inundated with stormwater on a number of occasions,” he said.

Apart from stormwater inundation, other issues affecting service capability include groundwater infiltration, blockages and tree root intrusion.

“It’s important to remember if a tree root finds it’s way into our sewerage system, even one the width of a hair, it can grow into a major problem and eventually block and destroy an underground sewerage pipe,” Mr Selvaratnam said.

Within the Shire, pre-existing problems have been identified in some areas of Bowral, the northern villages and isolated areas in Bundanoon and Berrima.

Council is subsequently in the process of rolling out a scheduled program of works to address these issues.

Works to be undertaken include inspecting and refurbishing manholes; jet cleaning and locating defects in sewer mains using CCTV video equipment; repairing or replacing defective pipes, and conducting smoke testing and inspections to locate illegal downpipe connections, low lying gully traps and defects in service connections.

Where applicable, property owners will be notified of defects and any other issues which they are responsible for and will be asked to rectify them within a reasonable time frame.

This sewerage maintenance and upgrade project has already begun in areas of Bowral.

“Once we have moved through our initial areas in Bowral, Council will be extending this sewerage maintenance program to other areas within the Shire,” Mr Selvaratnam said.

Following the works, Council will carry out flow gauging and network hydraulic modelling to determine and action any upsizing of sewer mains.

“We would like to thank residents in advance for their patience and understanding while we undertake these investigations, repairs and upgrades.”