Riparian vegetation consists of gums with a weedy understory and grazing land beyond
Area map
About the location
Gould Creek rises near Samson Flat and flows in a westerly direction before entering the Little Para reservoir. The major land uses in the 1639 hectare catchment are residual native cover (46%) and grazing pasture (45%). The monitoring site was located downstream of Gould Creek Road.
The river was given a Poor rating because the site sampled showed evidence of major changes in ecosystem structure and function. There was evidence of human disturbance due to nutrient enrichment of the stream, and riparian understory vegetation was dominated by weedy species. Only a limited number of tolerant macroinvertebrates were present in 2015.
Findings
A sparse diverse community of at least 13 species of macroinvertebrates was collected from connected slow-flowing pools in this creek, approximately 1.5 m wide and 13 cm deep in autumn 2015 but was dry in spring. The site was dominated by mosquito larvae. Other species collected in smaller numbers included a range of generalist and pollution tolerant species, predacious diving beetles and water scavenger beetles, non-biting midges and other fly larvae (Stratiomyidae and Ceratopogonidae), a common species of mayfly (Tasmanocoenis) and backswimmers. No sensitive, rare species, or flow-dependent species were collected. The introduced snail Physiella, water skinks and ducks were also seen in the creek.
The water was brackish (salinity 1,622 mg/L), moderately well oxygenated (57% saturation) and clear, with moderate to high concentrations of nutrients such as nitrogen (0.689 mg/L) and phosphorus (0.029 mg/L).
The sediments were dominated by boulders, cobbles and pebbles with some silt and detritus also present. Samples taken from below the surface were sandy grey and showed no evidence of being anaerobic, or lacking oxygen. Small deposits of silt covered the streambed to a depth of between 1 and 5 cm in places and no significant areas of bank erosion were seen. Sheep droppings were noticed on the banks of the creek suggesting stock have access to the site and may be trampling the banks to access the water.
A small amount of phytoplankton (chlorophyll a 0.17 µg/L) but no filamentous algae was noticed at the site. More than 10% of site was covered by a range of emergent plants such as Cyperus, Eleocharis, Hydrocotyle and Rumex. The riparian zone consisted of gums and weedy grasses with the surrounding vegetation being pasture grass used for sheep grazing and scattered gums also present.
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.
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.
Observed Condition
Expected Condition
