Levi Creek, near Frankton
2010 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2010.
- Likely to be nutrient enriched when wet due to the surrounding land uses.
- Riparian vegetation consisted of native species and a weedy rush.
- Fine silt deposits in the creek and areas of minor bank erosion.
About the location
Levi Creek is a small stream in the northern Mount Lofty Ranges. It rises near Mount Rufus and flows in an easterly direction where it eventually disappears underground in the Craigie Plains, about 20 kilometres west of Blanchetown. The major land uses are sheep grazing and areas of native vegetation.
The monitoring site was located off North Hills Road, over two kilometres south-east of Frankton.
The creek was given a Fair rating because the site sampled showed moderate changes in ecosystem structure and some changes to the way the ecosystem functions. There was evidence of human disturbance, including fine sediment deposition and a degraded riparian zone.
The 15–20 metre wide creek was dry in autumn and spring 2010. The site inspected showed no evidence of being wet in recent times and it is likely that the creek only holds water for up to several weeks of the year after heavy rains.
Macroinvertebrate and water quality data were consequently not available for this site.
The sediments were dominated by detritus, clay, gravel, pebbles, cobbles, silt and boulders. The sediments appeared to be well aerated and showed no evidence that they were occasionally lacking in oxygen. A deposit of 1–5 centimetres of silt covered the creekbed and about 10 metres of the bank showed signs of erosion due to past flood damage.
No signs of any dried filamentous algal growths were recorded in the channel. The only aquatic plant recorded in the creek was a pest plant called Sharp Rush (Juncus acutus) that covered more than 10% of the site.
The narrow riparian zone consisted of native plants such as wattles and saltbush, and Sharp Rush. The surrounding vegetation included grazing land and patches of eucalypt woodland (gum trees, acacias, melaleucas and various native shrubs).
Special environmental features
Pressures and 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 SA Murray–Darling Basin NRM Board acknowledges the significant impacts that livestock have on aquatic environments and seeks to provide free technical advice and incentives to land managers for fencing and other works as funding permits. Funding incentives are limited in value and extent and require land managers to volunteer to be involved.|
|Limited riparian vegetation at the site and upstream, providing minimal buffer protection from catchment landuses (reducing habitat quality).||The SA Murray–Darling Basin NRM Board recognises that the management of riparian vegetation requires a long-term, integrated approach to achieve ecosystem benefits. The board therefore provides free technical advice on a range of topics for land managers and various incentives for works as funding permits.|
|Widespread introduced trees and weeds in the riparian zone at the site and upstream in the catchment (reducing habitat quality).||The SA Murray–Darling Basin NRM Board recognises the limitations of available funds relative to the scale of the degradation caused by introduced trees and weeds. The NRM Board provides free technical advice and community education to assist land managers in dealing with the integrated management of aquatic weeds. The NRM Board also has a targeted process, as directed by State Government, to strictly prioritise its investment in weed control activities as funds are limited. The NRM Board actively seeks funding opportunities for weed control; most opportunities are for locations where biodiversity outcomes can be achieved.|