How to use this survey
Inventory and condition surveys can assist people in the pastoral industry to plan for the sustainable use of natural resources and the protection of those areas suffering from degradation or at risk of degradation.
The Ashburton River Catchment survey was undertaken between 1976 and 1978 by A Payne, A Mitchell and W Homan. This survey was published in 1988 as Technical bulletin 62 An inventory and condition survey of rangelands in the Ashburton River catchment, Western Australia.
The survey report identifies and describes the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assesses the impact of pastoralism and makes land management recommendations, including recommended carrying capacities for each pastoral lease.
The department has surveyed and reported on 14 rangeland areas since 1972. Most of Western Australia’s rangeland pastoral leases have been surveyed, except for pastoral leases in the Southern Goldfields region and to the north-east of Wiluna-Meekatharra. The 15th rangeland survey — in the Southern Goldfields region, covering the area known as the Great Western Woodlands — is in progress and will be published in 2018.
Survey area and inventory summary
The area surveyed covers about 93 600 square kilometres and includes the catchment of the Ashburton River and part of the catchment of the Yannarie River.
About 61 130 square kilometres (65%) of the area is occupied by 30 pastoral leases grazing sheep and/or cattle. The remainder consists of reserves of various kinds and unallocated Crown land which is unsuitable for pastoral purposes.
The survey report provides condition statements for the whole survey area and for each land system. Pasture and soil condition was assessed at a number of points throughout the survey area. Findings include:
- 64% of points were in good or very good rangeland condition
- 27% were in fair rangeland condition
- 9% were in poor or very poor rangeland condition.
The worst areas of degradation and erosion are on the most valuable pastoral lands. These areas are readily accessible, close to permanent water supplies and support palatable pastures. Therefore, they received preferential overuse in the early days of settlement and sensitive parts are now seriously degraded.