Unnamed creek, west from Myponga Beach
2011 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2011
- Likely to be enriched with nutrients when wet due to the surrounding land uses
- Riparian vegetation limited to introduced grasses and weeds
- Ephemeral creek only likely to hold water for brief periods following heavy rainfall events
About the location
This is a small, first-order tributary in the Southern Mount Lofty Ranges that flows into a more extensive unnamed creek that turns north-west and ultimately discharges into Aldinga Bay, about 3 km west from Myponga Beach. The monitoring site was located on a track off Reservoir Road, about 1.5 kilometres north from Mount Jeffcoat on the Fleurieu Peninsula. The entire catchment area of 9 hectares is used for stock grazing; no areas of remnant native vegetation remain.
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 the highly disturbed riparian habitat and lack of native plants in a generally cleared catchment.
The sediments were dominated by bedrock and sand, with gravel, detritus, boulder and cobble also present. Samples taken from below the surface were grey in colour and showed no evidence that the sediments were anaerobic or lacked oxygen. At least 10 m of bank showed signs of erosion due to sheep accessing the channel and the effects from recent flooding along the creekline.
No aquatic plants were recorded at the site and the very narrow riparian zone comprised introduced grasses and weeds. The surrounding landscape consisted of steep-sided hills covered by introduced grasses.
Special environmental features
Pressures and 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.