Australian Water Management Review Vol. 1 2014 | Page 33

Sharks, poor visibility and a
broken underwater main:
How Queensland Urban Utilities rose to the challenge

Q

ueensland Urban Utilities is responsible
for almost nine thousand kilometres
of water mains across south-east
Queensland. Maintaining them is a core
part of our business.

But like most things in life – there are easy jobs and
difficult ones. Repairing the water main under the
Brisbane River at Jindalee was not easy.
The Jindalee River Crossing Water Main plays a
pivotal role in supplying water to more than 5000
Brisbane residents but suffered major damage during
the severe wet weather events of 2011 and 2013.
In 2011, the flood eroded huge parts of the river
bed, fully exposing the cross-river pipeline,
normally buried 2-3 metres beneath.
“So much soil had been washed away, and over
time, the timber cradles pinning the pipeline into
place had rotted, causing it to shift and leak,” Acting
Manager of Civil Maintenance Delivery Daniel
Faccio said.
Queensland Urban Utilities’ repair crews faced a
combination of difficult conditions –contending with
strong river currents, poor visibility and the constant
threat of sharks, known to inhabit that particular
reach of the Brisbane River.
“Temporary repairs were done largely by touch and
feel. The divers couldn’t see,” Faccio said.
A more permanent repair was planned to ensure
reliability of supply.
But this time, the pipe had been re-buried 2-3
metres beneath the river bed due to constant river
silting. Fixing it required significant dredging,
including the removal of a thick layer of clay. This
delayed the repair job, pushing works into the wet
season and subsequent flood event of 2013.
A solution required innovative thinking. Queensland
Urban Utilities engineers were instrumental in this
process.
Kerry Peters from Queensland Urban Utilities and
David Underwood from Marine Engineering, a
diving and underwater welding contractor, designed
and built a safe, temporary underwater habitat that
protected the divers while they worked on the pipe.

“Fresh water was continuously pumped into the
modified tank to improve visibility and enable
underwater welding repair work to be done at a
higher standard,” Daniel Faccio said.
“Once again, we were up against poor visibility
which created problems for both CCTV and welding.
But on top of that, we were plagued by constant rain
into the Brisbane River which re-filled the trench
with silt and caused the original underwater habitat
to fail,” Faccio said.
“It was crucial to create another controlled
underwater environment to improve visibility and
enable the welding to be done to a high standard.
This time, we used a shipping container.
“The work was further complicated when the
barge from which the divers were working lost its
moorings and floated off downstream during the
2013 flood event.
“To avoid a budget blow-out, we brainstormed with the
contractor to build an innovative, fully-welded pipe.”
To build the custom pipe, the diver was required
to measure between the displaced pipes at predetermined points on the pipe. These measurements
were used to calculate the horizontal (120mm) and
vertical displacement (150mm) from which a scale
drawing was developed for the pipework. The pipe
was built on land at Rochdale and transported to the
drive barge.
The custom-built pipe had a kink in it to avoid
dredging the heavy clay-based soil and further
damage re-positioning the pipe. It fit perfectly and
the welding process was finished within two weeks.
Queensland Urban Utilities’ water truck crews then
completed the disinfection process.
The success of the repairs were thanks to a huge
team effort from Ethan Bartier and Queensland Urban
Utilities’ Nick Ambrosini, Cherrie-Kee Krautz and
Kerry Peters as well as all the Queensland Urban
Utilities trunk water crews who worked with Greg
Quinn from Harcore Welding and Dulce de Abreu
from Reliability Asset Maintenance and Planning.
The original feed is now reinstated to ensure a
critical means of water supply to residents in the
Jindalee area.

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