Water in Lake Argyle

by Hugh Milne
(Ingle Farm SA )

I have read in the past that the amount of water that flows over the top of Lake Argyle when full is referred to as SIDHARBS per day. This is the volume of water in Sydney Harbour. If this is true, how many per day and how many weeks or months does this go on for?

Response to: Water in Lake Argyle

That's the first time I hear that. People love comparing Lake Argyle to Sydney Harbour, but I haven't seen the overflow described like that. SIDHARBS per day, I like it!

As for your question how many per day and for how long... The flow out of the Lake is not controlled when it overflows, and it overflowss for most of the year. You can't control how much water enters Lake Argyle so you can't control how much flows out.

It depends how much it has rained, and as I explain on the pages about the climate and weather, that varies wildly. If you get a cyclone come through and dump a lot of water i the catchment area, then the overflow turns into a raging torrent and the water level can be many metres above it.

We usually describe the spillway by saying how many metres above the overflow the water is, not by the volume.

Imagine the size of the lake and then imagine it five to ten metres above the overflow. That gives you an idea of the force behind that water...

It can be so violent that many kilometers downstream they have to close Lake Kununurra to boats in the area where Spillway Creek (the overflow) enters Lake Kununurra because it becomes too dangerous.

In such a season Spillway Creek can keep flowing until late in the dry season. Other seasons there may be very little rain in the Lake Argyle catchment area. Then what's happening at the overflow would be nothing to write home about.

Photo by Phillie Casablanca

Lake Argyle