Monday, 11 July 2011

Kununurra - Lake Argyle

This morning we went on a terrific trip on Lake Argyle, the enormous storage facility for the Ord River Scheme. The drive out there, about an hour from Kununurra, is beautiful, and certainly gives you yet another perspective on the area. As you wind through the hills there is nothing to see then out of nowhere the water appears. It looks like you have come to the sea, but it is fresh water.

Our time started with a half hour video on the construction of the dam wall, and associated works which occurred over the dry seasons of 1969 – 1971. The work was completed on time and on budget for just $22m. The one thing that really stands out is the standards of the day, men working in the open with no shirts, no air conditioned cabs on plant, and cigarettes everywhere. So much so that when they ‘fired up’ the largest single non-nuclear blast in Australia they simply lit the end of the fuse with one of the bloke’s cigarettes. Fancy smoking on a site where they were developing a blast for weeks with hundreds of holes filled with explosive.

The dam itself is over 300m high, and wider than that at the base, with all materials coming from the immediate area, a core of clay, a barrier of sand and stone, and many thousands of tonnes of rock both upstream and downstream. The design capacity is equivalent to 21 Sydney Harbours, but at present it is way over full, and is the equivalent of about 42 Sydney Harbours, measuring about 55 km north to south, and up to 40 km east to west. Hard to get your head around really!

At last year’s audit over 35,000 fresh water crocodiles were formally estimated as the population, and there is a heap of other wildlife including short eared rock wallabies, whistling kites, black neck storks, spiders and snakes amongst many others. Some of the larger islands still have wild cattle on them, despite many rescue operations both when the lake was initially filled, and after subsequent dry seasons. Conservationist Harry Butler came to prominence after he set up a program to rescue wild animals from drowning etc when the lake was filling. It was known as the Noah’s Ark Program, and he continues to be recognised for his contribution through the naming of a cove and waterfall after him. However dingoes and feral cats on the islands have recently disappeared after suffering from high speed lead poisoning.

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