Rosetta Creek

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Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment was in good condition in the 1970s but decreased to poor condition in 2004. This was primarily due to riparian clearing, an increase in number of low cover hill slopes adjacent to the stream network, and an increase in the amount of gullying/scalding. The field based TRARC data supports this assessment of the catchment being in poor condition. It is interesting to note the first four D condition TRARC sites all have no regeneration and no weeds, a pattern which is consistent with over-grazing, which in turn is consistent with an increase in the number of low cover hillslopes over the last 30 years.

iTRARC Scores

Catchment Class 2 A
Maximum iTRARC Score 24 (A+)
1970s Score 14 (B+)
2004 Score 3 (C)
Reduction in Ecosystem Services Large
Increase in Potential for Erosion Large
Reasons for Change in Score
  • Clearing of forest along headwater streams
  • Increase in the number and % of gaps in the riparian corridor of the main channel and anabranches
  • Increase in floodplain bare soil
  • Increase in the number of low cover hillslopes
  • Increase in gullying/scalding

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Four Mile Waterhole33.4 (D)0 (D)0 (A)
Relner Waterhole47.4 (D)0 (D)0 (A)
Bundoba Waterhole48.2 (D)0 (D)0 (A)
Police Ck [#1]48.7 (D)0 (D)0 (A)
Police Ck [#2]55.1 (C)1 (C)1 sp: 10% cover (B)
Police Ck [#3]71.4 (B)2 (B)0 (A)
Police Ck, Murray Waterhole57.2 (C)2 (B)1 sp: 5% cover (B)
Blacks Ck59.4 (C)2 (B)0 (A)
Homestead Waterhole66.7 (B)2 (B)1 sp: 15% cover (B)
Blacks Ck67.7 (B)2 (B)1 sp: 15% cover (B)
Average 55.5 (C)

Reference:Assessing the condition of Riparian Vegetation in the Burdekin catchment

Wetlands

This sub-divisions includes numerous channels and off-channel waterbodies as well as a weir pool at Mt. Coolon, and waterholes present are likely to be highly and persistently turbid. This sub-division is poorly known ecologically and condition is not well known, but not likely to be substantially different from that of other adjoining sub-divisions.

Reference: Assessing the condition of Wetlands in the Burdekin catchment

For more information see Rosetta Creek wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Rosetta Creek subcatchment are summarized as follows:

  • Subcatchment modelled area 2,520 sq. km.
  • Source contributions: Hillslope = 65%; Gully = 31%; Streambank = 5%
  • Area of subcatchment with <50% ground cover: sq. km or 25% of subcatchment
  • Hillslope sediment supply: 249 kg/ha/yr
  • Gully sediment supply: 117 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 97 kt/yr
  • Total suspended sediment end-of-subcatchment (flow weighted) yield: 80 kt/yr
  • Event Mean Concentration (EMC - flow weighted): 553 mg/L
  • Mean Annual Flow: 144,232 ML

Reference: Improved SedNet Modelling of Grazing Land in the Burdekin Catchment

Rosetta Creek produces a moderate mean annual flow of 144,232 ML and moderate total suspended sediment supply. Subsequently the event mean concentration is moderate at 533mg/L. Approximately two thirds (65%) of the total sediments and associated nutrients derive from hillslope erosion (249 kg/ha/yr) and one third (31%) from gully erosion (117 kg/ha/yr. This is probably the result of the Rosetta Creek subcatchment having one quarter of it's area exposed to less than 50% ground cover.

Water Quality Monitoring

There are no water quality data available for this catchment.

Relevant information of Water Quality Monitoring in the Suttor River Basin:

Environmental Uses and Values

Aquatic Ecosystems

The aquatic ecosystem values of the Rosetta Creek subcatchment are poorly known and, while considered to be Slightly to Moderately Disturbed SMD) condition as a consequence of the surrounding land use for cattle grazing, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained. No High Ecological Value (HEV) waters have been identified in the subcatchment.

The Rosetta Creek subcatchment contains the Why Not Aggregation, listed on the Directory of Important Wetlands. This wetland is a stock-water dam, formed by damming a drainage depression. It was listed because it provides an environment for aquatic plants that support birdlife. However, it is a modified water body and therefore, not considered as a containing HEV waters.

Stock Watering

Water supply for production of healthy livestock.

Drinking Water

Drinking water is reported to be used from the Rosetta Creek using a water spear.

Cultural and Spiritual

Custodial use of water resources by Jangga and Birri traditional owners.

References:

Landuse

Principle land uses within the Rosetta Creek subcatchment as a proportion of total area:

  • Grazing: 99.8%
  • Water: Limited water activity use identified.
  • Urban & semi urban: Limited urban & semi urban water activity use identified.
  • Mining: Limited mining water activity use identified.

Grazing Land

Rosetta Creek is a relatively small subcatchment where land use is exclusively grazing on natural and modified pastures.

Land Condition

Definition of ABCD land condition framework

Results of a Rapid Land Condition Assessment (adopted from Hassett et al. 2000) are presented below. The assessment has been devised to subjectively characterise condition while traversing the BDT region by vehicle. The data are based on a total of 4666 observations across the Burdekin region between 2004 and 2007.

The data were collected to provide independent information on land condition and provide a regional perspective. Resource assessment data are most useful when interpreted with other sources of data e.g. time-series remote sensing, modelling and water quality monitoring.

The estimated condition of the Rosetta Creek sub-catchment is proportioned as follows:

  • A Condition: 8%
  • B Condition: 47%
  • C Condition: 36%
  • D Condition: 9%

Data from the Rosetta Creek sub-catchment is based on 66 observations.

On the basis of the rapid assessment, the Rosetta Creek sub-catchment is estimated to have the largest proportion of land in fair (B) condition (47%), followed by poor (C) condition (36%) and very poor (D) condition land (9%). 8% of observed land was in good (A) condition.

Ground Cover

Ground Cover in the Rosetta Creek sub-catchment is proportioned as follows:

  • ( BC) Bare Cover: 0%
  • ( LC) Low Cover: 13%
  • ( MC) Moderate Cover: 29%
  • ( HC) High Cover: 48%
  • (VHC) Very High Cover: 10%

Data from the Rosetta Creek sub-catchment are based on 62 observations.

On the basis of the rapid assessment (2004-2007), the Rosetta Creek sub-catchment is estimated to have the highest proportion of land within the high (HC) ground cover category (48%), followed by moderate (MC) cover (29%) and low (LC) cover (13%) categories. 10% of land was estimated to fall into the very high cover (VHC) category.

Resource Condition Summary

Rosetta Creek is a relatively small subcatchment where land use is exclusively grazing on natural and modified pastures. The riparian habitat of the subcatchment has deteriorated over the last 30 years, principally due to clearing along headwater streams and on the floodplains, and is currently assessed to be in poor (C) condition. The subcatchment waterways are poorly known ecologically, with even basic knowledge on the number and location of permanent or significant water bodies not recorded. The waterways are understood to include numerous channel and off-channel water bodies that are likely to be highly and persistently turbid.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality within the Rosetta Creek subcatchment, while gully erosion is also identified as a significant contributor to the total sediment load. The rate of soil erosion is predicted to be quite low and similar to the Basin average, while the total soil loss from the subcatchment to waterways is also comparatively low. Land condition is assessed as having the highest proportions in fair (B) and poor (C)condition, while some very poor (D) and good (A) condition grazing land is also apparent. This is also reflected in the rapid ground cover assessment (2004-07) and analyses of ground cover from satellite imagery (reference), which also identify areas of highly vulnerable and marginal 'D' condition land within the subcatchment. The mean ground cover declined substantially from 90% in 1999 to 63% in 2004, and had recovered to 78% in 2006.

Water quality in the Rosetta Creek subcatchment is predicted by models to be moderately impacted by suspended sediment during wet season event flows, with elevated concentrations at the end-of-subcatchment. There are no water quality monitoring data with which to compare the modelled loads and concentrations.

Draft Environmental Values

The aquatic ecosystem values of the Rosetta Creek subcatchment are poorly known and, while considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained. No High Ecological Value (HEV) waters have been identified in the subcatchment. Little is known about the human use Environmental Values of the subcatchment, which are thought to be limited to stock watering, drinking water, and the cultural and spiritual values of the Jangga and Birri traditional owners.

Maps

References

RosettaCreek.jpg
Download Catchment Layer as *.kml (requires Google Earth)

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