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Coliban Water has been utilising trenchless technology for its major pipeline projects and routine main renewals program.

Trenchless methods have been used in the Bendigo Creek Sewer Duplication and Back Creek Siphon projects, and for the routine renewal of water and sewer mains.

The benefits of trenchless methods of pipeline construction and renewal include the prevention of damage to trees and root systems caused by excavation and the protection of local wildlife and fauna.

Less construction machinery is needed for excavation and reinstatement work, which means substantially less carbon emissions: on average 90 per cent fewer greenhouse gas emissions than open cut excavations.

Road closures and disruption to residents and businesses around construction sites are also reduced.

Some of our trenchless projects and methods for main renewal include:

Bendigo Creek Sewer Duplication
The construction of 6.1km of pipeline for Stage 2 of the Bendigo Creek Sewer Duplication project comprised of 30 per cent trenchless work.

The pipeline passed through environmentally sensitive areas, such as the Bendigo Creek, and through residential streets and high traffic areas.

Laser boring techniques were used to minimise the impact on wildlife and vegetation, customers’ properties and traffic flow, as well as avoiding damaging telecommunication and power cables.

About 1.3 km of the sewer main was located within Bendigo Creek, where heritage-listed features, such as the blue stone channel, were not disturbed.

Stage 2 of the project was completed four months ahead of schedule and under budget.

Back Creek Siphon
The 90-year-old Back Creek Siphon, located near Malmsbury, is an historic and important piece of infrastructure, connecting two sections of the Coliban Main Channel across a 37-metre deep valley and under the weir across Back Creek.

The pipeline had exceeded its useful life but it was important that the upgrade kept the historical integrity of the pipeline intact.

By installing  the new 1.3 metre diameter pipe inside the existing 1.5 metre diameter pipe, the historical integrity of the pipeline was retained and the excavation of the surrounding countryside was kept to a minimum.

Pipe bursting
Replacing water mains by pipe bursting is part of our routine renewal program and has an annual budget of around $1 million.

The process involves bursting the existing main by pulling a cone through the pipe with the new polyethylene pipe attached. A temporary service is put in place to ensure there is no disruption to customers.

Studies show that compared to open cut trenching, pipe bursting can cut the time it takes to replace a main by more than 50 per cent.

To see pipe bursting in action view the video below or > click here

Cured In Place Pipe (CIPP)
CIPP is a trenchless method for repairing sewer pipelines and has been used to reline a sewer close to Bendigo’s historic Sacred Heart Cathedral.

Existing sewer maintenance holes can be used as access points for this work so there is less excavation of footpaths and nature strip, and no damage to trees.

CIPP technology is based on the principle of a liner being inserted directly into the existing pipe and then thermally cured. Once hardened it can handle high loads under pressure even without the old pipe in place.

Rib-Loc relining
Another trenchless technology we currently use to renew sewer mains is Rib-Loc relining.

This technique involves spiral winding a continuous plastic strip directly into a deteriorated sewer pipe.

The edges of the strip interlock as it is spirally wound to form a continuous watertight liner inside the pipe restoring the structural integrity of the aging main.

For more information on other methods of trenchless techniques we use visit the Water and Sewer Main Renewal project page on our website.

Coliban Water wishes all our customers a happy and safe festive season.

We thought you might like to see some beautiful aerial photographs of our three major catchment storages near Kyneton: Malmsbury, Lauriston and Upper Coliban.

The photos were taken in December by our Board Director, Noel Harvey.

Our Catchment Storages on 23 December 2011 are at 95.6% (66,522 megalitres). For more information and to visit our Reservoir Levels page > click here

Birdlife at the Bendigo Water Reclamation Plant is booming.

The plant treats wastewater for Coliban Water’s 88,000 customers in Bendigo and includes the Bendigo Water Factory, which produces recycled water for use on public gardens, sporting facilities and irrigation in the Bendigo area.

The site’s 67 hectares of lagoons and treatment ponds makes excellent habitat for wildlife and attracts thousands of birds, with 112 species recorded at the site including threatened species such as the Freckled Duck, Blue-billed Duck and the Australasian Shoveler.

The plant is part of the ‘Land for Wildlife’ program, run by the Department of Sustainability and Environment to encourage landholders to provide habitat for wildlife even though the property may be managed for other purposes.

Land for Wildlife has been in operation since 1981. There are now more than 5,900 Victorian Land for Wildlife properties managing over 560,000 hectares as wildlife habitat.

For the past year the birds at the Bendigo plant have been monitored by bird watching enthusiast and photographer Ian Mayo.

Ian visits the plant on a monthly basis and has been able to record a pattern of the birdlife that passes through, visits for food or makes the site its home.

He spots around 35 species of birds on every visit and in his most recent visit with three other birders they spotted 62 species. 

Ian says that every time he visits the plant he sees something new.

“You see the full cycle of life. One time I witnessed a mass hatching of dragonflies, popping out of their cocoons, drying their wings and flying off. Suddenly a family of Rainbow Bee-eaters came swooping down and snapped up the dragonflies,” says Ian.

“I’m a fan of the raptors – Swamp Harriers, Whistling Kites and especially the Black-shouldered Kite. They’re big birds so they are easier to photograph.”

As well as birds, seven frog species have been found at the plant, including the Growling Grass Frog, which is endangered in Victoria.

The site also contains remnant Box Ironbark and Grassy Woodland vegetation.

For a list of birds spottted at the Bendigo Water Reclamation Plant on 5 December 2011 > click here

 To view some of Ian’s photos of birds at the Bendigo Water Reclamation Plant see the slide show below.

We began work to upgrade the Back Creek Siphon pipeline, located near Malmsbury, in June 2011, almost 90 years after the original concrete pipeline was built.

The original pipeline was constructed in 1921 and is an important piece of infrastructure, connecting two sections of the Coliban Main Channel across a 37-metre deep valley and under the weir across Back Creek.

The upgrade involved installing 600 metres of a new 1.3 metre diameter pipe inside the existing 1.5 metre diameter pipe to retain the historical significance of the pipeline and limit excavation.

After the new pipe was in place, grout was injected between the two pipes to fill the void and prevent movement.

Construction work is now coming to an end, with reinstatement work and preparation for pressure testing already underway, and we plan to have water flowing through the siphon this month.

We hope it will be at least another 90 years before it needs upgrading again.

Blog Co-ordinator

For photos of the original construction from 1921 and the construction work on the upgrade see the slide show below and for more information visit the Back Creek Siphon project page.

This Blog was launched in December 2009 as the Managing Director’s Blog with a post about our pricing proposal for the next three years.

Since then we’ve continued to post on pricing and a whole range of other subjects from storages and flooding to projects and pine trees.

It’s been encouraging to see our visitor numbers steadily increase but we value what our customers and communities have to say and want more of your comments, opinions and suggestions.

Our region faces many important challenges with a growing population and changing climate.

Our vision is to be a leader in sustainable water resource management and add to the prosperity of our region.

We will continue to publish our Blog with various contributors writing about a variety of topics.

We hope you will join the conversation.

Blog Co-ordinator

You can also find us on Twitter and Flickr.

Thanks to everyone who has read and contributed to the MD’s Blog.

I’m leaving Coliban Water to move to Goulburn-Murray Water.

I’m sure this Blog will live on in a new form.

Gavin