The Lachlan River is considered to be the fourth longest river in Australia. Its source is on the Breadalbane Plain near Goulburn, on the Great Dividing Range. From here it flows westwards out onto the fertile plains of the Riverina and onto the semi-arid woodlands. The river ends at the Great Cumbung Swamp. Water will only reach the Murrumbidgee River during large floods.
I used the phrase "considered to be the fourth longest river" based on the approximations provided by GeoAustralia, but from my own analysis it closely ties with the third placed Darling River. Tracing satellite images in QGIS, I calculated that the Lachlan River at 1,547 km if it flows all the way to the Murrumbidgee River, and equals the length calculated for the Darling River. The main discrepancy between the measurements is that the Lachlan River snakes it way down at a much finer level than the Darling River, adding 15% to the estimated length.
|Murray River||NSW, VIC, SA||2,508 km|
|Murrumbidgee River||ACT, NSW||1,616 km||1,485 km|
|Darling River||NSW||1,547 km||1,545 km|
|Lachlan River||NSW||1,547 km||1,339 km|
|Cooper Creek||QLD, SA||1,113 km|
|Flinders River||QLD||1,013 km|
|Diamantina River||QLD, SA||941 km|
The main section of the river is below Cowra. This starts off in the lower inland slopes of the Great Dividing Range but is mostly on the flat expansive alluvial plains of the South West Slopes and Riverina regions that provide fertile agricultural land for many farms.
0 km(-253 km)
253 km(0 km)
313 km(60 km)
416 km(162 km)
631 km(378 km)
763 km(509 km)
1,038 km(785 km)
1,240 km(987 km)
Hotel and maybe a general store.
1,494 km(1,241 km)
This marks the end of flow under dry conditions. Good flows will make it into the Great Cumbung Swamp, but only large floods make it to the Murrumbidgee River.
Appears to be no stores here. The 4 Mile gauge is about 15 km upstream.
1,547 km(1,294 km)
As noted, this only flows during larger flood conditions. It is 131 km from Balranald, 235 km from the Murray.
Key towns along the river are shown below.
- Murrumbidgee River
Refer to the planning page for a complete distance table including most weirs and important rivers.