Unnamed Creek, Mount Bold Reservoir, Mt Bold Reserve
2013 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2013
- Likely to be generally low in nutrients when wet due to the extent of dense vegetation in the upstream catchment
- Riparian vegetation mostly comprised River Red Gums over weeds and grasses
- No sign of any bank erosion or deposit of fine sediment in the channel
About the location
The Unnamed Creek is a very small first order stream that rises at an elevation of 360 m and flows north for about 750 m, before discharging into the southern part of Mount Bold Reservoir. The only land uses in the 76 hectare catchment were plantation forestry (54%) and managed resource protection (46%). The site was located via a track off Razor Back Road, about 200 m south from Mount Bold Reservoir.
The creek was given a Good rating because the site sampled showed evidence of relatively minor changes in ecosystem structure and function. There was only a small amount of evidence that human disturbance had degraded the creek due to the extent of woody weeds growing in the understorey of the riparian zone.
The 1 m wide channel was dry in both autumn and spring 2013. No macroinvertebrate or water quality data was consequently available for this site.
The sediments were dominated by detritus, with smaller amounts of sand and clay also present; samples taken from below the surface were grey and black silts, sands and clays, which indicate that the sediments may have been anaerobic or lacking in oxygen when the creek dried recently. There was no evidence of any bank erosion or animal droppings seen in the vicinity of the site inspected during 2013.
Over 10% of the channel was covered by aquatic plants, including rushes (Juncus), sedges (Carex) and pennyworts (Hydrocotyle).There was no evidence of any dried filamentous algal mats on the dry sediments of the creek to indicate that it was enriched with nutrients when it last held water. The riparian zone extended over 5m wide on each bank and was dominated by River Red Gums and acacias over dense growths of weedy blackberries and broom, native shrubs (Goodenia ovata), rushes and introduced grasses. The surrounding vegetation near the creek comprised native forest on one bank and pines mixed with native vegetation on the other bank.
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.|
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.