Tributary of Yankalilla River, off Salt Creek Rd, South from Yankalilla
2013 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2013
- Likely to be enriched with nutrients when wet due to the surrounding land uses in the catchment
- Riparian vegetation fenced off from surrounding cropland and dominated by native trees over introduced grasses
- No evidence any bank erosion despite cattle occasionally accessing the creekbed
About the location
This tributary of Bungala River is a small, second order stream in the Southern Mount Lofty Ranges that rises at an elevation of about 160 m, and flows in a north-westerly direction for several kilometres, before discharging into the lower reaches of Bungala River at Normanville. The major land uses in the 37 hectare catchment were cereal cropping and cattle grazing (99%), with the remaining area taken up by farm dams. The site was located off a track from Salt Creek Road, about 3.5 km south from Yankalilla.
The creek was given a Fair rating because the site sampled showed evidence of moderate changes in ecosystem structure and some changes to the way the ecosystem functions. There was evidence of human disturbance due to the extent of damage to the riparian zone in the past, and the lack of remnant native vegetation and large number of in-stream dams in the wider catchment.
The 10m wide channel was dry in both autumn and spring 2013. No macroinvertebrate or water quality data was consequently available for this site.
The sediments were dominated by detritus, with smaller amounts of sand, clay and silt also present; samples taken from below the surface were grey sands and silts, and showed no evidence to indicate that the sediments had been anaerobic or lacking in oxygen when the creek last dried (e.g. sediments not blackened and no anaerobic odour). There was no sign of any significant bank erosion at the site despite cattle accessing and defaecating in the creekbed and on the banks in spring.
There was no evidence of any dried filamentous algal mats or aquatic plants growing in the creek, suggesting that this stream remains dry for most of the year. The riparian zone had been fenced in the past to protect the stream from stock damage and allow the newly revegetated trees to survive. It extended over 5 m wide on each bank and was dominated by native trees such as gums, paperbarks and wattles, over introduced grasses. The surrounding vegetation near the creek comprised cleared cereal cropping land.
Special environmental features
Pressures and management responses
|Widespread introduced weeds in the riparian zone at the site and upstream (reducing habitat quality).||The Adelaide and Mount Lofty Ranges NRM Board has several pest plant (weed) mitigation and control programs. They work closely with landholders to control weeds on their property and to help stop the spread to other properties and waterways.|
|Insufficient natural water flows in the creek resulting from water extraction and climate variability (reducing ecological integrity).||Through water allocation planning the Adelaide and Mount Lofty Ranges NRM Board seeks to manage a sustainable water supply for the region so that there is enough water available for everyone (including the environment) even in drought conditions.|
This aquatic ecosystem condition report is based on monitoring data collected by the EPA. It was prepared with and co-funded by the Adelaide and Mount Lofty Ranges NRM Board.