Avoca River

The Avoca River drains a substantial part of central Victoria. The river rises at the foot of Mount Lonarch near the small town of Amphitheatre, and flows north for 270 kilometres (170 mi)[5] joined by thirteen minor tributaries and through the towns of Avoca, Charlton and Quambatook. Two major distributaries leave the Avoca River between Charlton and Quambatook, Tyrrell Creek, flowing to Lake Tyrrell and Lalbert Creek flowing to Lake Lalbert. Although the Avoca River basin is part of the Murray-Darling basin,[6] the Avoca River does not empty into the Murray. Nowhere a large stream, it dwindles as it flows north, eventually terminating in the Kerang Lakes,[6] a network of ephemeral swamps west of Kerang and about 20 kilometres (12 mi) south of the Murray River.[3]

Although the Avoca River has a substantial 12,000-square-kilometre (4,600 sq mi) catchment area,[5] the fifth-largest in Victoria, most of that area is on the northern plains where rainfall averages only about 350 millimetres (14 in) per year,[5] and where there is little runoff because the terrain is very flat. The mean annual runoff of 137 gigalitres (30×10^⁹ imp gal; 36×10^⁹ US gal) per annum accounts for only 0.67% of Victoria's runoff.[7] Most of the water flowing in the Avoca River originates in the narrow upper portion of the catchment area, where rainfall averages about 600 millimetres (24 in) per year,[5] most of it falling in the winter and spring.[8]

Of all the Victorian rivers in the Murray-Darling basin, the Avoca River is the most variable.[5] The average annual flow is 85 gigalitres (19×10^⁹ imp gal; 22×10^⁹ US gal), but recorded actual flows have varied from almost five times the average figure in very wet years to 0.5% of the average in drought years. It has an extremely variable flow, ranging from floods to long periods of low flow, being less than 50 megalitres (11×10^⁶ imp gal; 13×10^⁶ US gal) per day. In dry years, flow stops for many months.[4]

Although it is the only river of significance in the area, the Avoca River has had no major water storages constructed on it, merely six weirs of only local significance. Little use of the river is made for irrigation, because during the peak demand periods of summer and autumn, the river is often not flowing. During low-flow periods, the Avoca River water is usually too saline to water crops with, but can still provide drinking water for sheep and cattle.[4]

The river is crossed by the Pyrenees Highway at Avoca; and the Borung Highway and the Calder Highway at Charlton.[3]

As the river is relatively long, indigenous peoples from various cultural groups lived near the river course. In the indigenous Djadjawurrung, Wathawurrung, Wergaia, and Wembawemba languages, the river has several names including Natte yaluk and Boca both with no clearly defined meaning; Bangyeno Banip meaning bunyip waterholes; Djub-djub-galg meaning a place where melaleuca was abundant; Witchelliba with witji meaning basket grass and bar meaning river; and Yangeba with no clearly defined meaning.[1][2]

• List of rivers of Victoria

Wikimedia Commons has media related to Avoca River.

• "Wimmera-Avoca". Murray-Darling Basin Authority. Australian Government. 2014. Archived from the original on 23 October 2014. Retrieved 18 October 2014.
• "Avoca River longitudinal profile" (PDF). Murray-Darling Basin Authority (PDF). Australian Government. Archived from the original (PDF) on 15 February 2014.
• "Avoca". Our rivers. Environment Victoria.