Tributary of the Torrens River, 3 km north from Mount Pleasant
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 dominated by introduced grasses
- Some areas of bank erosion evident
About the location
Tributary of the Torrens River is a small stream in the Southern Mount Lofty Ranges that rises about 4 km NNE from Mount Pleasant and flows into the Torrens River just upstream from Mount Pleasant. The monitoring site was located off the Mount Pleasant-Keynton Road, about 3 km north from Mount Pleasant. The major land uses in the 471 hectare catchment are stock grazing, irrigated vines and recreation, with smaller areas of remnant native vegetation, forestry and rural residential living.
The creek was given a Poor rating because the site sampled showed evidence of major changes in ecosystem structure, and moderate changes to the way the ecosystem functions. There was considerable evidence of human disturbance including a degraded riparian zone and the large extent of vegetation clearance that has occurred in the local catchment.
The sediments were dominated by detritus, clay and sand, with some silt also present in places. A small amount of bank erosion extended over about 10% of the site in spring, presumably caused by flood damage during recent winter flows.
About 10% of the channel was covered by several types of emergent plants (Isolepis, Juncus, Rumex and Typha). The narrow riparian zone consisted of a few scattered gum trees and paperbarks over introduced grasses (mostly Phalaris) and weeds. The surrounding vegetation was largely cleared cattle grazing land with a few isolated gum trees remaining in the local landscape. A golf course was also situated near the site sampled.
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.|
|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.|
|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.