Yelloch Creek, south of Hynam
2009 Aquatic Ecosystem Condition Report
- Dry in autumn and spring 2009.
- Likely to be enriched with nutrients when wet due to the surrounding land uses.
- Riparian vegetation consists of gum trees over introduced grasses.
- Silt deposits in the channel.
About the location
Yelloch Creek is a moderately sized stream in the lower South East with a catchment area over 300 km2. It rises between Apsley and Edenhope in western Victoria and flows in a westerly direction where it eventually joins Mosquito Creek. The major land uses are grazing and cropping.
The monitoring site was located just inside the South Australian border on Laurie Park Road, about 18 kilometres east–south–east of Naracoorte.
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 poor riparian habitat and fine sediment deposition.
The creek was dry in autumn and spring 2009, so macroinvertebrate and water quality data were not available for the site inspected.
The sediments were dominated by detritus, clay, silt and sand; samples taken from below the surface were aerated but would be expected to become blackened and anaerobic when wet due to the large amount of organic matter present in the sediment. A moderate amount of fine silt, 1–5 centimetres thick, was deposited in the deeper parts of the creekbed.
A large growth of spikerush (Eleocharis) covered more than 35% of the creek. There was also a detectable amount of dried filamentous algae recorded within the channel. This shows that the creek supported at least two plant indicators that commonly thrive in nutrient enriched streams and drains.
The narrow riparian zone consisted of River Red Gums over introduced grasses. The surrounding vegetation at the site was cropping land and pasture.
Special environmental features
Pressures and management responses
|Drought||Through ground and surface water allocation planning and the South East Regional NRM Plan water affecting activity permit process the NRM Board seeks to manage water for environmental, social and economic purposes in a range of climatic scenarios.|
|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 South East NRM Board supports targeted projects that provide opportunities for landholders to access grants for fencing for stock exclusion from time to time for priority catchments.|
|Limited riparian zone vegetation at the site and upstream, providing minimal buffer protection from catchment landuses (reducing habitat quality).||The South East NRM Board assists landholders to access targeted grant opportunities for revegetation and ecosystem protection when funding is available. The Board also works closely with landholders consistent with the Board’s Regional Pest Management Plan to control weeds on their property and to assist in halting their spread to other properties.|