| Avoca | |
| Name Native: | [1] |
| Map: | Map_of_Avoca_River.svg |
| Map Size: | 300 |
| Pushpin Map Size: | 300 |
| Subdivision Type1: | Country |
| Subdivision Name1: | Australia |
| Subdivision Type2: | State |
| Subdivision Name2: | Victoria |
| Subdivision Type3: | Region |
| Subdivision Name3: | Riverina bioregion (IBRA), Central Highlands, Wimmera |
| Subdivision Type4: | Local government areas |
| Subdivision Name4: | Buloke, Gannawarra |
| Subdivision Type5: | Towns |
| Subdivision Name5: | ,,, |
| Length: | 270km (170miles) |
| Discharge1 Avg: | 5m3/s |
| Source1: | Pyrenees Ranges, Great Dividing Range |
| Source1 Location: | below Mount Lonarch |
| Source1 Coordinates: | -37.2342°N 143.4058°W |
| Source1 Elevation: | 307m (1,007feet) |
| Mouth: | Lake Bael Bael, Kerang Lakes |
| Mouth Coordinates: | -35.6992°N 143.7422°W |
| Mouth Elevation: | 74m (243feet) |
| River System: | Northcentral catchment, Murray-Darling basin |
| Basin Size: | 12352km2 |
| Tributaries Left: | Glenlogie Creek, Number Two Creek, Mountain Creek (Victoria), Cherry Tree Creek, Smoky Creek, Tarpaulin Creek, Campbell Creek (Victoria) |
| Tributaries Right: | Sandy Creek (Victoria), Brown Hill Creek (Victoria), Fentons Creek (Victoria), Sandy Creek (Victoria), Yeungroon Creek, Mosquito Creek (Victoria) |
| Custom Label: | Nature reserve |
| Extra: | [2] [3] |
The Avoca River, an inland intermittent river of the northcentral catchment, part of the Murray-Darling basin, is located in the lower Riverina bioregion and Central Highlands and Wimmera regions of the Australian state of Victoria. The headwaters of the Avoca River rise on the northern slopes of the Pyrenees Range and descend to flow into the ephemeral Kerang Lakes.
The Avoca River drains a substantial part of central Victoria. It rises at the foot of Mount Lonarch, near the small town of Amphitheatre, and flows north for [4] joined by thirteen minor tributaries, and through the towns of, and . 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,[5] 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,[5] a network of ephemeral swamps west of Kerang and about south of the Murray River.[2]
Although the Avoca River has a substantial 12000km2 catchment area,[4] the fifth-largest in Victoria, most of that area is on the northern plains where rainfall averages only about per year,[4] and where there is little runoff because the terrain is very flat. The mean annual runoff of 137GL per annum accounts for only 0.67% of Victoria's runoff.[6] Most of the water flowing in the Avoca River originates in the small upper portion of the catchment area, where rainfall averages about per year,[4] most of it falling in the winter and spring.[7]
Of all the Victorian rivers in the Murray-Darling basin, the Avoca River is the most variable.[4] The average annual flow is 85GL, but recorded actual flows have varied from almost five times the average figure in very wet years, when the river can flood, to 0.5% of the average in drought years, when the flow is less than 50ML per day. In dry years, the flow can stop for many months.[3]
Although it is the only river of significance in the area, no major water storages have been constructed on it, but there are 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, it is often not flowing. During low-flow periods, the water is usually too saline to use on crops, but can still provide drinking water for sheep and cattle.[3]
The river is crossed by the Pyrenees Highway at Avoca, and the Borung Highway and the Calder Highway at Charlton.[2]
As the river is relatively long, Aboriginal peoples from various cultural groups lived near the river course. In the 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] [8]