4.3 Summary Descriptions of Each Drainage Division

The Lake Eyre Drainage Division The portion of the arid NT in Lake Eyre Drainage Division is characterised by large rivers that in the past all flowed to Lake Eyre. Currently only the Georgina River in the north-east carries water that regularly reaches Lake Eyre; although, the Sandover River system occasionally connects to the Georgina system via the Sandover floodout. There are several other rivers that run essentially south-south-east from their sources, towards Lake Eyre, but apart from the Finke and the Field rivers, most of these floodout entirely in the NT.

Finke River Basin

The Finke River has the longest path within the NT of any NT River. It is reputed to be the oldest river in the world (Kotwicki 1989), and although this is difficult to substantiate, the upper portion has followed predominantly the same path for millions of years. It extends from the MacDonnell Ranges into South Australia, with two major tributaries also emanating from the ranges: the Palmer and Hugh rivers. Other large tributaries join the Finke, Palmer and Hugh rivers within the greater MacDonnell Ranges area, including Ellery Creek, Petermann Creek, Walker Creek and Areyonga/Illara Creek. Karinga Creek also connects to the Finke River. Similarly, it is probable that Kalamurta Creek connects by surface flow to the Karinga creek, although no connecting channel is mapped on the 1:250k scale topographic maps. Two other significant tributaries, join the Finke in its lower reaches: Goyder Creek and Coglin Creek, both of which rise from hills near the South Australian border, including the Beddome Range. Coglin Creek, also known as Charlotte Waters, joins the Finke at the point that it floods out from its major channel, just north of the South Australian border. The initial floodout of the Finke is a broad forest several kilometres wide. Flowing out from this there are two major channels. One continues south over the border and subsequently floods out again in South Australia, with a minor channel re-crossing into the NT to the east. The other channel, known locally as Snake Creek, heads north-east from Mayfield Swamp on the edge of the initial floodout forest. It is likely that the course of the lower Finke was substantially altered by developing dunes during the last glacial maximum (ice age) about 25,000 - 13,000 years BP (Bowler and Wasson 1983 cited in Patton et al. 1993). Also, various present day distributary channels may have waxed and waned in relative importance in the past 13,000 years. Around the South Australian border, south-east of Kulgera, are some of the upper tributaries of Hamilton Creek which connects to Lake Eyre via the Macumba River.

Connection of Karinga Creek to the Finke River

Karinga Creek is mapped on 1:250,000 topographic maps, however the mapped channels stop about 30km from the Finke River. Wakelin-King's (1989) study of the Karinga Creek salt lakes suggest that they were connected by surface flow from Lake Hopkins in WA through to the Finke River during the period 35,000 to 27,000 years BP. A low calcrete ridge has separated the Karinga Creek catchment from Lake Amadeus to the west, since 27,000 years BP (Wakelin-King 1989). Leo Murphy (pers. comm.), lessee of Idracowra Station, reported substantial water flows from Karinga Creek into the Finke River about five times in the past four decades. Inspection of Landsat 7 ETM+ imagery from 26th May 2000 indicated a linear water-filled depression connecting the mapped Karinga Creek channel to the Finke River, about one month after the heavy rains of late April (Easter weekend) that year.

Wetlands of the Arid NT Volume 1: 39