Limited riparian zone dominated by exotic plants and weeds.
Area map
About the location
Congeratinga Creek is a small network of streams which rises in the Second Valley Forest on Fleurieu Peninsula. It flows through land used mainly for pine plantations (46%) and grazing livestock (37%), into the Wirrina Reservoir. The site selected for monitoring was located off Main South Road, just over one kilometre northeast of Second Valley.
The creek was given a Fair rating at this site because the ecosystem showed evidence of moderate changes to animal and plant life, and some changes to the way the ecosystem functions. Flow patterns and the riparian zone had been seriously affected by human activity, with evidence of erosion and moderately high nutrient levels likely to occur during the wetter seasons.
Findings
The narrow channel was dry at the time of inspection in spring 2008. Cobbles, pebbles and boulders covered the creek bed, as well as large amounts of leaf litter from overhanging River Red Gums. Most rocks in the channel were blackened underneath, indicating the sediments were anaerobic when wet. Occasional floods had eroded large sections of the creek.
Patches of Stiff Flat Sedge (Cyperus vaginatus) were the only aquatic plants found at the site. A narrow, five-metre band of River Red Gums formed the riparian zone. Exotic fruit trees, woody weeds and introduced herbs and grasses such as wild rose, blackberries, fennel, phalaris and kikuyu dominated the understorey. Cereal cropping occurred in the surrounding area.
Special environmental features
None identified.
Pressures and management responses
Pressures
Management responses
Livestock have direct access at the site and upstream, causing sediment erosion and adding excessive nutrients (which leads to habitat disturbance, algal growth and aquatic weeds).
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 site and upstream, providing minimal buffer protection from catchment landuses (reducing habitat quality).
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.
Large decrease in natural water flows (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 and prepared in conjunction with the Adelaide and Mt Lofty Ranges NRM Board.
Observed Condition
Expected Condition
