Riparian vegetation consisting of introduced grasses and weeds
Areas with minor bank erosion.
Area map
About the location
Pine Creek is a small stream in the Northern Mount Lofty Ranges that rises near Bethel in the Light Ranges and flows in a south-westerly direction before discharging into the Light River at Linwood. The monitoring site was located on a track off Church Road, 6.5 km south-east from Tarlee. The major land uses in the 240 hectare catchment are cereal cropping and stock grazing, with smaller areas used for irrigated vines, growing legumes and remnant native vegetation.
The creek was given a Very Poor rating because the site sampled showed evidence of major changes to both the animal and plant life inhabiting the stream, and a significant breakdown in the way the ecosystem functions. There was considerable evidence of human disturbance including severely degraded riparian habitats, general lack of native vegetation in the wider catchment and some minor areas of bank erosion.
Findings
The 15 m wide channel was dry in both autumn and spring 2011. No macroinvertebrate or water quality data was consequently available for this site.
The sediments were dominated by detritus and clay, with silt and sand also present. Samples taken from below the surface were sandy grey loams and showed no evidence that the sediments were anaerobic or lacked oxygen. A small amount of bank erosion was noted in spring when about 10 m of the side of the creek showed signs of slumping, presumably caused by recent flood damage in winter.
No aquatic plants were recorded growing in the creek. The riparian vegetation lacked any trees or shrubs and only consisted of wheat, other introduced grasses and weeds. The surrounding vegetation was cereal cropping and sheep grazing land with little to no native vegetation remaining in the local catchment.
Special environmental features
None detected.
Pressures and management responses
Pressures
Management responses
Livestock having direct access at the site and upstream (causing sediment erosion and adding excessive nutrients).
The Adelaide and Mount Lofty Ranges NRM Board’s land management program encourages and promotes managing land to improve water quality. This includes incentives for waterway and wetland fencing to exclude or limit stock from entering riparian zones.
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.
Limited riparian zone vegetation at the creek and upstream (reducing habitat quality, increasing sediment erosion).
The Adelaide and Mount Lofty Ranges NRM Board’s land management program encourages and promotes managing land to improve water quality. This includes incentives for revegetation programs around waterways and wetlands and stock exclusion as well as educating landholders about the importance of riparian vegetation in managing soil erosion.
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.