The Torrumbarry Weir Complex incorporates the original lock (1924) and a concrete-reinforced rubble wall surviving from the former weir. The old trestles and original steam boiler and winch-house are visible beyond that on the original island created in the bend of the Murray.
The Torrumbarry Weir is one of the fourteen weirs and locks built to control the waters of the Murray following the 1915 formal River Murray Agreement. It was the culminating development which gave full effect to the Torrumbarry Irrigation System which was created in the later part of the nineteenth century and the early part of the twentieth century.
The harnessing of water assets in the region began on a small scale on local farms as early as the 1860s, diverting water from local streams and ephemeral lakes. Later local irrigation trusts were empowered to expand these earlier works, link them into larger networks and invest in large scale pumping facilities to take water from the River Murray. In 1886, following a Royal Commission, a new Act enabled concerted action and a series of National Works were sanctioned to consolidate the system. Thus all of the principal features of an extensive irrigation system were in place by the beginning of the 20th century, but the level of the Murray at the mouth of Gunbower Creek was still only sufficient to feed the system by gravity at times of high water.
The Torrumbarry Weir was only constructed when successful negotiations between the State governments of Victoria, New South Wales and South Australia resulted in the 1915 formal River Murray Agreement. This proposed the construction of storage reservoirs in the river's headwaters as well as a series of locks and weirs in South Australia and along the Victoria NSW border. Construction on the Torrumbarry Weir and Lock was started in 1919 and completed in 1924. The removable weir raised the water level enough to provide constant gravitational flow to the system and render the various downstream pump installations redundant.
The original Torrumbarry Weir is no longer in use. In 1992 leaks were noticed coming from the concrete apron of the weir, and after a thorough engineering investigation it was decided to replace it. Work began in June 1994 on a new $36 million construction, and this was operational by August 1996. The old lock was retained and the steam winch and racks of trestles were preserved on the original island created in the bend of the Murray.
The original weir comprised a concrete-reinforced rubble wall incorporating 14 removable steel trestles which were equipped with drop bars and ran on railway lines so they could be winched out of the river in flood times or for maintenance. The wall remains, and the old trestles, steam boiler and winch-house are visible on the original island created in the bend of the Murray. To west of the original weir is a lock chamber which was designed to enable river traffic to bypass the weir.
A modern concrete weir equipped with large electrically-operated radial gates was constructed in 1996. This required the realignment of the river.
The irrigation system to which the old weir gave effect in 1924 comprises a series of natural watercourses and water bodies connected by artificial channels and infrastructure. This forms a cohesive network along which water from the River Murray can be supplied for irrigation within the Torrumbarry Irrigation Area.
A large interpretive centre has been built on the west bank, close to the western end of the new weir. A section of one trestle is on display in that centre.
This site is on the River Murray, about 9km east of Gunbower and lies amidst the traditional lands of the Wamba Wamba, Barapa Barapa and Wadi Wadi Peoples.
How is it significant?
The Torrumbarry Weir Complex is of historical and scientific significance to the State of Victoria. It satisfies the following criterion for inclusion in the Victorian Heritage Register:
Criterion A Importance to the course, or pattern, of Victoria's cultural history
Criterion D Importance in demonstrating the principal characteristics of a class of cultural places and objects
Criterion F Importance in demonstrating a high degree of creative or technical achievement at a particular period.
The Torrumbarry Weir Complex is historically significant because it gave full effect to half a century of irrigation projects, which together as the 'Torrumbarry Irrigation System', helped to establish the Goulburn Murray Irrigation District as 'Victoria's food bowl'. The opening of Torrumbarry Weir established a gravitation system which signalled the end for the costly pumping stations nearby, as water no longer had to be lifted into the irrigation system. The additional and more reliable irrigation water supply afforded by this gravity-fed system was vital to the region's history of land improvement and economic growth through agriculture, and the system played a pivotal role in the success of resettlement and closer settlement programs in the area, particularly in its early years with Soldier Settlement schemes. The Torrumbarry Weir was only constructed following successful negotiations between the State governments of Victoria, New South Wales and South Australia which resulted in the 1915 formal River Murray Agreement. [Criterion A]
The Torrumbarry Weir Complex is the only combined weir and lock system located entirely in Victoria. It was the second major structure to be constructed to enable regulation of the Murray River, and the first on the river to be constructed with the principal purpose of improving irrigation. It was also the first structure constructed on the Victoria-New South Wales section of the Murray, and, together with the Mildura Weir of similar design, it is the only Australian designed weir and lock on the Murray. The wider Torrumbarry Irrigation System, which was given full effect through construction of the Torrumbarry Weir, is an essentially intact and rare example of an irrigation system comprising a combination of natural and man-made elements and is the major component in the Kerang-Cohuna irrigation system, one of the largest irrigation systems in Victoria. [Criterion D]
The Torrumbarry Weir Complex is scientifically significant because its design demonstrates a new and innovative solution to irrigation requirements on the Murray. It was innovative as a dam which could be entirely removed from the water during high-water to allow dead trees from the Barmah/Millewa Forest to pass down stream, which was a creative response to the peculiar characteristics of this river system. While it had some operational shortcomings, the weir has largely been effective in delivering water to those dependent on it. [Criterion F]
The Torrumbarry Weir Complex is also significant for the following reasons, but not at the State level:
The site has close links the engineer J.S. Dethridge, Commissioner of the Victorian State Rivers and Water Supply Commission who was a major contributor to the original design and implementation of the system for controlling the waters of the Murray. He provided the original design for Torrumbarry Weir and is also famous for designing the Mildura Lock and Weir, the only other lock and weir of similar design. He also designed the Dethridge meter, a volumetric water meter previously widely used across Australia for the measurement of irrigation water.
The Torrumbarry Lock has supported the role of the Murray in providing transportation to inland Victoria and New South Wales. It has important associations with the historic Port of Echuca, allowing boats access to the Echuca slip for restoration, and for private and commercial tourism operations.