Lake Boonderoo, 16 kilometres south of the Trans Railway Access Track, is fed by Ponton Creek, a 380 kilometre long watercourse that results from the overflow of Lake Raeside.

Since records have been kept the lake has flooded only twice – 1975 and 1995. This timeframe was confirmed by examination of the growth rings in trees killed by submersion after the first flooding.

1975

Cyclone Trixie crossed the Western Australia coast at Exmouth in February 1975 and dissipated as a cyclone around Meekatharra. The remaining rain-bearing depression brought heavy falls to the Murchison, Goldfields, a corner of the Arid Interior, and the Nullarbor.

Floodwaters from Ponton Creek cut the Trans Australia Railway and flooded what was then known as Yandallah Claypan to a depth of 15-20 metres. The lake extended to an area of approximately 26 km². The water remained till about 1977. Prior to this flooding the small, grassed claypan was used by the station as a small airstrip.

The flow of Ponton Creek where it crosses the Trans Australia Railway and Access Track was reported to have maintained a rate of 6 cubic metres per second (cumecs) (6000 litres/s) for nearly three weeks.

1995

In 1977 the claypan was renamed Lake Boonderoo  – recognition that, after the 1975 flood event, it was more than a dry claypan.

Cyclone Bobby crossed the Western Australian coast near Onslow on 25 February 1995. The weakening cyclone maintained a southward overland track for another 24 hours then turned south-eastwards and finally weakened into a rain bearing depression over southern parts of Western Australia early on 27 February.

Heavy, persistent rain cut the Eyre Highway for several days and a section of the Trans Australia Railway was washed away by the Ponton Creek floodwaters. The massive amount of water entering Lake Boonderoo filled it in little more than a day. The lake was more than 20 metres deep and covered an area of approximately 75 km². With a number of subsequent non-flooding rain events the water in the lake persisted for about 12 years. It was totally gone by 2008.

Extent of Lake Boonderoo 1995-2008

References

Tropical Cyclone Trixie
https://www.bom.gov.au/cyclone/history/pdf/trixie.pdf.

Geonoma, Landgate.

Russell Swann (with excerpts from Eric Swann), Pastoral Lease History, Kanandah, Boonderoo and Koonjarra leases, An inventory and condition survey of the Western Australian part of the Nullarbor region, Technical Bulletin No 97, Department of Agriculture and Food, South Perth, Western Australia, 2010.

Boating on the Nullarbor
https://www.adventures.net.au/boat/boating-on-the-nullarbor-1995.

Tropical Cyclone Bobby
https://www.bom.gov.au/cyclone/history/bobby.shtml.