when northern Western Australia was opened up by adventurous and ambitious cattlemen in the 1870s and ‘80s, they found a vast land of great contrasts. In the annual monsoonal wet there were rivers of huge volume pouring out to sea, and in the dry, rainless winters, the waterholes dried up and the rivers became nothing more than a string of ponds. No river was more emblematic of this disparity than the Ord.
During the ‘big wet’ the Ord poured 2500 gigalitres of water into the sea every single day. That is enough water to keep modern day Perth going for 10 years. In the often-used metric of Sydney Harbours, that is nearly five Sydney Harbour-loads each day.
A serious local drought from 1935–42 and the rise of Japan as a global power during the 1920s and ‘30s forced the Western Australian Government to focus on the region as it was one of the nearest points of the Australian continent to this militaristic and expansionist nation, both as a potential aggressor and, along with its neighbours, as a possible market.
In 1941, an experimental farm was established on the Ord, which demonstrated the region’s capabilities with a wide range of crops growing prolifically under irrigation. While proposals to dam the Ord go as far back as the end of the 19th century, it wasn’t until 1949 that the WA Government submitted the first serious pitch to the Federal Government for the funding of a dam on the Ord to support wide ranging irrigation. This proposal, as well as a later submission in 1956, failed to achieve the necessary support needed, but in 1959 a grant enabled the start of work on a large dam and irrigation project.
The first stage was the construction of the Kununurra Diversion Dam on Bandicoot Bar, a natural barrier that created a large pool of water behind. This dam is a set of 20 radial gates which, in times of flood, can be opened to permit water to flow through to avoid flooding nearby agricultural land on the Ivanhoe Plains. As the river flow declines and the dry season commences, the gates can be closed to prevent loss of water and divert it into a nearby irrigation channel to ensure water supply all year round.
This led to the establishment of the town of Kununurra as a service centre, the building of a number of roads, including the main Darwin to Wyndham road — known as the Victoria Highway — a system of irrigation channels, a building of a pumping station and the clearing and grading of land to ensure its suitability for agricultural purposes. The dam was opened after the 1962–63 flood season was finished.
In 1967, a Commonwealth Grant enabled the construction of the Ord River Dam to establish a major water reservoir, to be called Lake Argyle. This dam, known locally as the top dam, was completed in 1972 and created one of the largest man-made water storage facilities in the world, with a capacity of 5641 gigalitres (11.2 on the Sydney Harbour scale). The dam enabled a more controlled flow of water to Lake Kununurra, behind the Diversion Dam, permitting greater efficiency in controlling water flow to irrigation and the opening of irrigation to the Packsaddle Plain.
In the early 1990s, engineers determined that building a weir across the spillway cut, which had been dug to control the flood overflow run-off from the Ord River Dam, could safely raise the level of Lake Argyle by a further six metres. This almost doubled the capacity of Lake Argyle to 10,763 gigalitres (nearly 21 Sydney Harbours) with a surface area of 741sqkm. This was completed in 1995–96, returning the lake’s status as Australia’s largest reservoir, a title which had been lost to Tasmania’s Gordon Dam.
In 1995–96 a hydro-electric power station was developed at Lake Argyle with private funding. It only produces about one per cent of the capacity of the Snowy Mountains Hydro Electric Scheme and the township of Kununurra and nearby Argyle Diamond Mines remain powered by diesel-fuelled electric systems.
Today, agriculture occupies 11,700 hectares across 80 farms. In its early days the Ord’s agricultural output was centred on cotton, but pests decimated the crop. The focus of production shifted to low value crops, but in the 1980s, newer, higher value hybrid seed crops and other produce were introduced and made a considerable difference to profitability. The world’s largest commercial Indian Sandalwood plantations, for which there is a strong export market, have been established in the area.
Ecologically, the Ord River Scheme appears to have created few major problems. The large body of water in Lake Argyle is causing a rising water table in the surrounding region, which is starting to introduce salinity issues, but solutions are under consideration. There is a possibility that Lake Argyle could attract Asian bird life and insects which would not naturally be present, which could introduce pests and diseases such as avian influenza. There is also a potential for harm to the local prawn fishery due to changes in water outflow patterns.
The Ord River Irrigation Scheme has been a long-term project which has required substantial financial input. To date it is estimated to have cost around $1.45 billion but, so far, the return has only been in the order of 17 cents in the dollar.
The annual agricultural production is estimated to be worth around $46.6 million, much of it from exports to South-East Asia, though some product is shipped into all major markets around Australia.
The Australia Institute recently stated: “Attempts to develop northern Australia by subsidising capital-intensive industries like irrigated agriculture have a long and unimpressive history. An example is the Ord River Scheme which currently supports just 260 jobs despite $2 billion spent and decades of effort.”
Discussions of Chinese investment to provide a boost to the scheme are unlikely to realise any rapid change.
Notwithstanding all of this, there is a continued push to expand agricultural activity around the area with the release of more land for farming and expansion of local facilities at Kununurra and Wyndham. For now the scheme is seen pretty much as a failure, though its long-term potential remains significant enough to be a benefit to the national economy for a long time to come.