Adams Creek, Elizabeth Park
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 trees, grasses and weeds
- Minor areas of bank erosion.
About the location
Adams Creek is a small stream in the Southern Mount Lofty Ranges that rises north from the Little Para Reservoir and flows in a westerly direction through Elizabeth, where it has been diverted underground and ultimately drains into the Helps Road Drainage system. The monitoring site was located opposite Toolunga Court in Elizabeth Park, towards the downstream extent of the creek before it becomes channelised. The major land uses in the 1,093 hectare catchment are stock grazing, irrigated vines, remnant native vegetation and residential living, with smaller areas used for cereal cropping, forestry, and other agricultural activities.
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 degraded riparian habitats, bank erosion and silt deposition in this urban stream.
The sediments were dominated by detritus, cobble and pebble, with some gravel, sand, silt and clay also present. Samples taken from below the surface were grey in colour and showed no evidence that the sediments were anaerobic or lacked oxygen. A small amount of silt, about 1 cm deep, covered parts of the channel and about 10 m of bank showed signs of erosion in spring due to recent flood damage.
A few pennyworts (Hydrocotyle) were the only aquatic plants seen in this creek in autumn. The very narrow riparian zone consisted of introduced trees such as poplars and olives over grasses and weeds. The surrounding vegetation was urban gardens and a recreation park, with associated planted trees and grasses.
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.|
|Stormwater runoff containing high nutrient and sediment loads discharging to the creek (causing habitat disturbance, algal growth and aquatic weeds).||The Adelaide and Mount Lofty Ranges NRM Board has a well developed stormwater quality improvement, harvesting and reuse program which has installed (and maintains) gross pollutant (and silt) traps in several watercourses across the region to catch litter, debris and silt in order to minimise impacts and damage to seagrass in the receiving marine environment. Stormwater captured is also treated through artificial wetlands across the region which act as suspended solid and nutrient filters; these wetlands also provide important habitat for many native species.|
|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.