Water Journal : Water Journal November 2015
WATER NOVEMBER 2015 10 Postcard POSTCARD FROM THE ORD -- FROM CHRIS DAVIS, TECHNICAL EDITOR, WATER JOURNAL The Ord River Irrigation Area, in the far north-east of Western Australia, is one of Australia's most well-known water projects. Apart from its engineering and agrarian attributes, the Ord is renowned for its magical scenery, typical of the Kimberley. The vibrant red rocks, blue skies and brilliant green vegetation, offset by ashes of stark white tree trunks and bleached rock, all combine to create a landscape that is barely believable. Construction of the Ord River Diversion Dam started in late 1960 and it was of cially opened in July 1963 by then Prime Minister, Robert Menzies. The dam holds back Lake Kununurra, which feeds the Ord River Irrigation Area by gravity via the Main Channel. The town of Kununurra was established on the shores of the lake and is the hub of local activity. The main Ord River Dam holds back the waters of the Ord River in Lake Argyle, which is Australia's largest reservoir, covering an area of 741km². Work on the dam began in 1969 and it was completed in 1972. The dam is a rock wall construction with a clay core and the wall is 98.5m above the river bed. A feature of the construction was that all the material used in the wall came from within 500m of the site. A more recent addition is the hydropower station, a 3.6MW unit completed in the mid- 1990s. It supplies electricity to Kununurra and the nearby Argyle diamond mine, but only meets about 10 per cent of the mine's total demand. Construction of the two dams changed the ecosystem, which now suits freshwater crocodiles very well but is inhospitable for their predators. As a result, there are now an estimated 35,000 crocodiles living in the Ord and the Lake above the Diversion Dam. Females lay their eggs in the sand banks near the water's edge and have nothing to do with them after that. When the eggs hatch, the juveniles head for the nearest reed beds and pandanus palms, where they can hide from predators. They live mainly on insects and, surprisingly, even an adult's diet is made up of 70 per cent insects. Of course, the Ord River Irrigation area was motivated by irrigation, but various challenges have prevented realisation of the goal. Not least of these is the intensity of the short wet season, making movement and working in the elds very dif cult. Initial plans for cotton, rice and sugarcane were never consummated. Recently, sandalwood plantations (covering a third of the irrigated land and initially encouraged by the now notorious managed investment scheme deals) have reached maturity, after 14 years. Market leader, TFS Corporation, is bullish about the future of the ckle and exotic crop and has posted improved results for 2015. The Ord River Irrigation Area is a proving ground for the notion of Australia's North becoming an agricultural food bowl. National ambitions for the North need to be tempered by the lessons of the Ord. What is certain, though, is that the Kimberley, of which the Ord is just a part, is one of the world's tourist gems -- preserving it will guarantee a sustainable industry. Go see.
Water Journal September 2015
Current Feb 2016