Diamantina River rises in Kirbys Nob, east of Selwyn in Queensland. Through the majority of the 720 km distance to Birdsville it runs as a braided channel with a mean slope of 2.7 x 10-4.
At Birdsville, where the catchment area is 115 000 km2, there is only one site along the central reach where the Diamantina is sufficiently confined for accurate measurement.
The Water Resources Commission of Queensland has kept records of water levels at this point or nearby since 1948. Extensive flood gaugings to determine stage/discharge relationship have been undertaken by the
South Australia n Engineering and Water Supply Department in 1977 and 1981 (Aeuckens, 1980; Marks, 1981). The mean annual flow for the period 1950-83 was 1.42 km3/year with a
standard deviation of 2.29 km3. The highest annual flow was 10.6 km3 in 1974 and the highest monthly flow 6.84 km3 in February of that year with the highest instantaneous flow of 4680 m3/s.
Diamantina floods reach Birdsville relatively frequently, and having done so, most likely flow to Lake Eyre. Bonython (1963) and Graetz (1980) give an estimate of past
floods and comparisons on progress of floods in Cooper Creek and the Diamantina River.
Leaving Birdsville, the Diamantina River runs 80 km south to Goyder Lagoon, a 1300 km2 swamp
on the junction with Eyre Creek. Twidale (1972) classes the so-called 'lagoons' in the channel country of south-west Queensland and in the lower reaches of Eyre Creek and the Diamantina River in South
Australia as another type of playa. They are receptacles for overflow waters from major rivers and develop in major distributary areas. They receive sediment from the catchment, mostly fine silt and sand, and are
gradually being filled. Their surfaces are black or grey due to their cover of desiccated organic slime, and are interrupted by innumerable channels, most of which are sinuous and clearly of riverine origin.
The Georgina River system covers an area of 205 000 km2. In the upper reaches the Georgina River is joined by the Sandover River, then by the Burke and the Hamilton rivers, becoming
known in its lower reaches as Eyre Creek.
The length of the main channel is 1130 km with a mean slope of 1.9 x 10-4. A good indication of flows is available at GS 001203
Roxborough Downs. The annual flow in 1974 was 5.71 km3 with a highest discharge of 3 530 m3/s. Higher flows have been recorded in 1977 with values
of 6.27 km3 and 3 830 m3/s respectively. Mean flow for 1967-83 was 1.23 km3 with a standard deviation of 1.96 km3. David Brooks of Birdsville states that major floodings of Eyre Creek occurred in 1933, 1944, 1950, 1953, 1971-74 and 1976-77 (personal communication, 1985). The major part
of runoff probably originates from northeastern tributaries of the Georgina River. Here, at GS 001202 - Burke River at Boil, 2.60 km3 has been recorded in 1974 from a catchment of only 15 540 km2, giving a peak discharge of 2890 m3/s. Consistently high annual flows at this location give a mean annual flow of 0.58 km3 with a standard deviation of 0.65 km3.
The combined waters of the Diamantina and the Georgina rivers fill Goyder Lagoon which drains to Lake Eyre by the Warburton. During floods, the area to the north of the Lake is a maze of channels and
lakes, but the main flow paths are discernible along the Warburton and the Kallakoopah, which branch and then rejoin near the Lake. Another branch, the Kalaweerina, enters the Lake independently.
total catchment area of the Diamantina system entering the Lake via the Warburton and its branches is 365 000 km2.