Wilpena Creek, Wilpena Pound
2012 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2012
- Likely to be low in nutrient levels when wet because the catchment is in a national park
- Some bank erosion caused by flood damage and both goats and kangaroos regularly access the banks and channel
- Riparian vegetation consisted of native trees and shrubs
About the location
Wilpena Creek is a medium-sized stream that rises in the Wilpena Pound Range in the Flinders Ranges National Park, flows east for over 100 km before eventually discharging into the Siccus River catchment and southern part of Lake Frome; flow only extends into the Siccus River during exceptionally wet years. The dominant land use in the 7,614 hectare catchment, upstream from the site sampled, is national park. The monitoring site was located off a foot-track from Wilpena Road, about 500 m north-west from Wilpena Resort.
The creek was given a Good rating because the site sampled showed evidence of relatively minor changes in ecosystem structure and function. There was evidence of disturbance due to the presence of feral goats accessing the site but the natural vegetation and diversity of sediment types indicates that this ephemeral stream has only been slightly affected by human activities in the catchment.
The sediments were dominated by detritus, with smaller amounts of boulder, cobble, pebble, gravel, sand, silt and clay also present. Samples taken from below the surface were grey sands and showed no signs that the sediments were recently anaerobic, or lacking in oxygen. About 10m of bank showed evidence of erosion caused by past flood damage. Both goat and kangaroo faeces were recorded from the channel and banks during both site inspections and may contribute to localised bank erosion in some years.
No aquatic plants or evidence of any algal remnants was observed at the site. The riparian vegetation was dominated by River Red Gums, native pine and acacias over native shrubs and understorey plants on the moderately well vegetated banks (50-79%% vegetative cover). The surrounding vegetation at the site comprised native woodland dominated by eucalypts, wattles and native pines.
Special environmental features
Wilpena Creek is a largely natural, ephemeral stream in the Flinders Ranges National Park. Few human disturbances are evident due in part to the limited road access, although a feral goat population obviously occurs in the well vegetated catchment. No significant environmental values were recorded from the dry site in 2012. However, when the same site was sampled during a wetter period in 1994-95, a sparse assemblage of aquatic species was recorded and included yabbies and a few flow dependent and/or sensitive species (e.g. blackflies and baetid mayfly Offadens).
Pressures and management responses
|Feral goats are exerting excessive grazing pressure on vegetation, causing erosion and adding excessive nutrients to the watercourse.||The SA Arid Lands Natural Resources Management Board provides technical advice and incentives for the management of introduced weeds and feral pest animals, as funding permits. Pest management efforts are guided by a region-wide strategy, based on risk assessment, to determine priority locations and species. Funding is actively sought from a number of sources to support region-wide integrated management.|