Murrumbidgee River - Flow

Flow

The reaches of the Murrumbidgee in the Australian Capital Territory (ACT) are now affected by the complete elimination of large spring snow melt flows and a reduction of average annual flows of almost 50%, due to Tantangara Dam. Tantangara Dam was completed in 1960 on the headwaters of Murrumbidgee River and diverts approximately 99% of the river's flow at that point into Lake Eucumbene. This had extremely serious effects on native fish populations and other native aquatic life and has led to serious habitat loss. It is said that the Murrumbidgee River through the ACT is only half the river it used to be.

The mainstream of the river system flows for 900 km (559 mi). The river's headwaters arise from the wet heath and bog at the foot of Peppercorn Hill situated along Long Plain which is within the Fiery Range of the Snowy Mountains; and about 50 kilometres north of Kiandra. From its headwaters it flows to its confluence with the Murray River. The river flows for 66 km (41 mi) through the Australian Capital Territory near Canberra, picking up the important tributaries of the Gudgenby, Molonglo and Cotter Rivers. The Murrumbidgee drains much of southern New South Wales and all of the Australian Capital Territory, and is an important source of irrigation water for the Riverina farming area.

The river system's current channels are relatively new with the Upper Murrumbidgee being an anabranch of the Tumut River (that once continued north along Mutta Mutta Creek) when geological uplift near Adaminaby diverted its flow. The contemporary Murrumbidgee starts at Gundagai but generally the stream that now includes the Upper Murrumbidgee is described as being part of the full river.

In June 2008 the Murray-Darling Basin Commission released a report on the condition of the Murray-Darling basin, with the Goulburn and Murrumbidgee Rivers rated in a very poor condition in the Murray-Darling basin with fish stocks in both rivers were also rated as extremely poor, with 13 of the 22 native fish species found in the Murrumbidgee River.