Water

Goulburn Weir showcased in Canberra museum

By Country News

Australia’s oldest irrigation structure, Goulburn Weir, will be showcased in an upcoming exhibition at the National Museum in Canberra.

A delegation from the museum met with Goulburn-Murray Water staff at the weir just outside Nagambie on Friday to learn more about the structure and the significant role it plays for irrigation districts.

Heralded as an engineering marvel of its time, construction began on the weir in the 1880s and it was later rebuilt to modern standards after close to a century of use.

One of the weir’s original gates, two pier supports and a complete set of lifting gear were donated to the museum eight years ago and will be housed in a new environmental history gallery set to open in 2020.

‘‘It is a very culturally, historically and economically significant piece of infrastructure as the first major intervention in the Murray-Darling Basin system for irrigation purposes,’’ Gallery Development Project lead curator George Main said.

‘‘We will be trying to give visitors a sense of what the weir is like and was like when it was first built and throughout its working life.’’

The structure was completed in 1891, and under the management of Goulburn-Murray Water it continues to supply properties in the Shepparton and Central Goulburn irrigation districts as well as filling the Waranga Basin storage and forming Lake Nagambie.

The original elements of the weir will be installed in the National Museum to replicate exactly how they once worked, and will remain on display for 15 years.

G-MW’s dams operations manager Scott Wikman said the weir was refurbished in 1988 after it was discovered the original structure had sustained a significant amount of damage.

‘‘They did some investigation and found the original gates deteriorated to such a state they could not longer be maintained,’’ he said.

‘‘When they drained the weir to have a look at the damage there was a large cavity and they were concerned over time the whole structure could just fall forward.’’

The upgrade project saw the removal of the original iron gates which were replaced with mild steel replicas constructed according to the original plans.

The newly grafted gates were installed in front of the remaining ones, which where then cut and lifted from their position and transported away to be stored.

With each gate and accompanying cast iron piers weighing close to eight tonnes, Mr Main said a lot of preparation had to be done to ensure the museum could hold a structure of that size.

‘‘Installing such a big object inside the museum, we’re not quite sure how it will all work just yet,’’ he said.

‘‘We have had an engineer do some assessments on the floor loadings and he identified two locations where the entire set of components could be assembled ... if we can install it, it will be the largest object in the exhibition.’’

Goulburn Weir was the first major diversion structure built for irrigation in Australia, and in October last year was awarded international heritage status.

With an embankment 127m long and 15m high, the weir has a capacity of 25500Ml and covers a submerged area of 1130ha when full.

Much more than concrete and cast iron, Goulburn Weir quickly proved critical to the prosperity of central Victorian communities and incorporated one of the first hydro-electric turbines in the Southern Hemisphere.

G-MW’s managing director Pat Lennon said the weir was highly recognised for its advanced engineering, and appeared on the Australian half-sovereign and 10-shilling banknotes in the early 20th century.

‘‘It is an iconic structure and really important, not just for Victoria and our irrigation but it is recognised globally,’’ he said.

‘‘The weir services more than a quarter of our customers and about half the water we delivered to customers in the last year came through this infrastructure.

‘‘It is an impressive place and very important for us.’’

—Liz Mellino