Constructed between 1887 and 1891, the Goulburn Weir is located on the Goulburn River, approximately 8 km north of Nagambie in Central Victoria, and was the first major diversion structure built for irrigation in Australia. Considered very advanced, it appeared on the Australian half sovereign and ten shilling banknotes from 1913 until 1933.

Completed in 1891, Goulburn Weir was the first major diversion structure built for irrigation development in Australia. It enabled gravity diversion into Waranga Swamp via what was then the National Channel (now Stuart Murray Canal). In 1905, the swamp was dammed to form Waranga Basin, the first major storage built in the Goulburn system. The East Goulburn Main (EGM) Channel was constructed to supply the Shepparton District in 1910. Construction of the Waranga Western Main (WWM) Channel from Waranga Basin to the Serpentine Creek in 1912 provided the platform for a major extension of irrigated agriculture in the Tragowel Plains District. Following the Eildon Reservoir expansion, the Stuart Murray Canal was duplicated from Goulburn Weir to Waranga Basin by the Cattanach Canal and the EGM Channel was enlarged. These works enabled the diversion of approximately 10,000 ML/day from Goulburn Weir for irrigation.

The Goulburn Weir was considered a project of national significance when completed in 1891. In 1893, the Victorian Government funded the book “Goulburn Weir and its dependant systems of works”, by Stuart Murray, lead engineer of the weir’s construction. The book is still listed in some university library catalogues. Engineering students attend field trips to the weir to observe a gravity dam in operation and to examine and discuss changes made to the weir to extend its operational life.

Description

Goulburn weir is a concrete structure, 212 m long and 15 m high, founded on bedrock, its downstream face stepped with granite blocks quarried from nearby Mount Black. The original superstructure included 21 cast and wrought iron gates mounted between cast iron piers. Powered by water driven turbines, the gates lowered into recesses in the weir crest to pass river and flood flows. The weir is currently a fully operating water supply asset, diverting water down four major carriers (Stuart Murray Canal, Cattanach Canal, East Goulburn Main Channel and the Goulburn River) to supply irrigation, urban and environmental water across Northern Victoria and mitigate flood events on the Goulburn River.

The weir was illuminated with electricity from one of the first hydro-electric turbines in the southern hemisphere. The electricity powered five arc-lamps, each capable of outputting 2,000 candles of light to illuminate the weir at night for flood operations, to assist in weir gate operations and to detect floating debris so that it was safely guided over the weir. Works to stabilise the deteriorating weir structure were completed in 1983, with major refurbishment in 1987, aided by advice on architectural and heritage matters from expert consultants, and the engagement of specialist contractors.

Nine steel radial gates mounted between concrete piers replaced the main weir superstructure. Two original gates and their lifting gear were retained to preserve part of this unique piece of engineering history. The weir raises the level of the Goulburn River so water can be diverted by gravity along channels to supply irrigation water. The weir’s gates can release up to 96,000 ML daily. Water travels via the Stuart Murray Canal, Cattanach Canal and the East Goulburn Main Channel to supply the Central Goulburn and Shepparton Irrigation Areas, and the Rochester and Pyramid Hill Irrigation Areas via Waranga Basin.

The weir also forms Lake Nagambie around which recreation, farming and housing developments have grown. Lake Nagambie covers 1,130 ha and when full holds 25,500 ML of water. Lake Nagambie is a very popular destination for visitors from around the country and is home to Victoria’s premier Regatta Centre. The constant water level provided by the weir means locals and visitors can enjoy rowing, fishing, boating, water skiing, wakeboarding and canoeing all year round.

The Goulburn Irrigation System supports some of Victoria’s best irrigated agriculture, including horticulture and dairy. Typically, 91 % of water released from Lake Eildon is diverted for irrigation purposes at Goulburn Weir, averaging 846,000 ML annually. The Goulburn Weir Complex is recognised by the National Trust of Australia (Victoria) as a place of state significance and as a place of high significance by Heritage Victoria.

Maintenance and upgrade works are consistently required to maintain the weir’s functionality. In the past, GMW has implemented works to minimise the impact on the structure of flood events and earthquakes, including the installation of ground anchors between 1980-1987, etc.