Australian Water Management Review Vol 1 2010 | Page 22

Mitchell Water
The ongoing drought facing Victoria
has seen the State Government invest
in a range of major water infrastructure
projects to secure water supplies.
One of the first major water projects was
the $688 million Wimmera Mallee Pipeline
Project – an ambitious scheme to replace
the many thousands of kilometres of open
earthen channels used to reticulate water
to farmers and towns throughout the vast
region with a pressurised pipeline.
The scope of the project is massive and
so too the benefits. More than 100,000
megalitres was lost every time the
earthen channels were filled. The new
pressurised pipeline will deliver 100 per
cent efficiency with every drop released
from the Grampians reservoirs now
reaching end users.
The Government and local water
management authority, Grampians
Wimmera Mallee Water, elected to tender
the pipeline construction task in a staged
construction approach with an initial
construction estimate of 10 years.
Leading Victorian based pipeline
construction company Mitchell Water
successfully won six of the seven
construction stages and is on-track
to commission the final stage in early
2010 – little more than three years since
construction began in 2006.
While Mitchell Water’s fast tracked
construction program assisted in
delivering much needed clean water to
users across the network in record time,
a comprehensive stakeholder relations,
environmental and cultural heritage
management program smoothed the
project’s pathway.
Addressing the concerns of the thousands
of farmers whose land the pipeline
traversed and the many challenges
presented in a region noted for its rich
bio-diversity, agricultural and cultural
heritage, Mitchell Water’s environmental
and stakeholder management program
was broad and detailed in scope.
All information, including landholder
contact details, ecological, soil,
vegetation and cultural heritage
information, together with a detailed
aerial survey and contour information,
as well as pipeline design and
specification (including ‘as constructed
data’) information was combined

Water Management Review 2010

in a comprehensive Geographical
Information System.
The landholder liaison process provided
the basis for managing the interface
between Mitchell Water, landowners and
customers – and involved contact with
more than 4,000 landholders.
The process was considered extremely
important during the three year
construction phase and the company
experienced no construction stoppages
due to landowner issu es or concerns.
Mitchell Water was also extremely
sensitive to bio-security issues to prevent
cross contamination in the important
agricultural region. Staff also undertook
a compulsory environmental care course
including training in environmentally
sustainable work practices.
Conducted by the Department of
Sustainability and Environment, the
course provided Mitchell Water and GWM
Water staff with an understanding of the
key environmental issues relating to the
project, as well as practical training and an
understanding of the required actions.
To ensure ongoing environmental
consideration over the course of the
project regular toolbox meetings provided
refresher information on key issues, with
participation by client staff as required.
Reinstatement of the pipeline route was
carefully managed. “We’ve been very
mindful of environmental considerations
and have reinstated the route to the
complete satisfaction of the Department
of Sustainability and Environment who
are now using our work practice as a
benchmark,” Mitchell Water General
Manager, Rob Shelton said.
The construction specification called for
topsoil stripped from the right of way
to be replaced within just three days.
This called for efficient construction
management on large diameter pipe
sections and saw utilisation of a range of
proprietary developed equipment such as
the Swiftpipe vibratory plough, to speed
construction and minimise soil disturbance
on the smaller diameter pipeline routes.
During the four-year construction phase
there was also an imperative to maintain
water supply to customers.
This proved difficult due to severe water
restrictions, low storage capacities,

extremely low rainfall and the need to
maintain dual supply arrangements - annual
channel supply and emergency pipeline
supply combinations across the region.
Furthermore, a cooperative approach by
Mitchell Water and the client saw the
industry standard practice varied to
allow water to customers prior to full
commissioning and handover of the
system.
By aligning construction priorities with
practical requirements, emergency water
supplies were made available to customers
well before the contract completion.
For example, in Supply System 1 (Yaapeet)
rural and urban customers were supplied
with water within just 12 months of the
award of the contract for construction of
the 1,200 kilometre pipeline stage.