Douglas Creek

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Subcatchments

  • Tomahawk Creek
  • Stony Creek

Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment has undergone relatively little change in the last 30 years and is still in relatively good condition. The field survey site shows a poor score, with some regeneration and no weeds, however additional sites would be required to characterise the range of riparian conditions encountered in this catchment.

iTRARC Scores

Catchment Class 1 E
Maximum iTRARC Score 14 (B+)
1970s Score 11 (B)
2004 Score 10 (B)
Reduction in Ecosystem Services Very Minor
Increase in Potential for Erosion Small
Reasons for Change in Score
  • Additional gap in the riparian corridor of the main channel

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Douglas R58.8 (C)2 (B)0 (A)
Average 58.8 (C)

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

Wetlands

Tributaries of this sub-division, such as Michael Creek, begin in rainforest-covered mountains west of Ingham and contain many good condition permanent waterbodies. Though these have not been studied, they are considered to be in relatively good condition. Douglas Creek itself and its lower tributaries are largely dry sandy, ephemeral creeks, some with significant bank erosion. Their condition is considered to be typical of the upper Burdekin grazing rangelands.

Reference: Assessing the condition of Wetlands in the Burdekin catchment

For more information see Douglas Creek wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Broken River subcatchment are summarized as follows:

  • Sub-catchment modelled area:1,227 sq. km.
  • Source contributions: Hillslope = 68%; Gully = 16%; Streambank = 16%
  • Area of subcatchment with <50% ground cover: 112 sq. km or 9% of subcatchment
  • Hillslope sediment supply: 381 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 69 kt/yr
  • Total suspended sediment supply (flow weighted; normalized to area): 560 kg/ha/yr
  • Total suspended sediment end-of-subcatchment (flow weighted) yield: 66 kt/yr
  • Event Mean Concentration (EMC - flow weighted): 399 mg/L
  • Mean Annual Flow: 165,886 ML

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

Hillslope erosion is identified as the major source of sediment and particulate nutrients that influence water quality in the Douglas Creek sub-catchment (68%). Despite the fact that only 9% of the hillslope area has less than 50% ground cover, the steeper slopes are likely to cause substantial run-off from the top of the sub-catchment. Gully and streambank erosion also contribute to sediment supply, but to a lesser degree, and are predicted to provide sediment in equal proportions (16% each of total sediment load). Loss of sediment (and particulate nutrients) from all sources (supply) is at moderate level (560 kg/ha/yr). The event mean concentration of sediments is predicted to be moderate to low when compared to the other sub-catchments of the greater Burdekin. This may be influenced by the above average rainfall received in the upper parts of this sub-catchment.

Water Quality Monitoring

Event water quality monitoring has not been conducted in the Douglas Creek catchment.

Relevant information of Water Quality Monitoring:

Environmental Uses and Values

Aquatic Ecosystems

The aquatic ecosystem values of several areas in the Douglas Creek subcatchment, corresponding to the rainforest-covered upper part of the subcatchment, have been identified as having High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. They include: (i) steep sections of the western slopes of the Seaview Ranges within the Einasleigh Bioregion; (ii) sections of the Mount Fox State Forest and a small isolated part of the Girrigun National Park that was formerly known as the Mount Fox National Park; and (iii) the upper reaches of Michael Creek, which take in the Liefway Nature Refuge. The aquatic ecosystem values of other parts of the Douglas Creek subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing.

Stock Watering

Water supply for production of healthy livestock.

Cultural and Spiritual

Custodial use of water by Nywaigi traditional owners.

References:

Landuse

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

  • Grazing: 95.6%
  • Conservation & minimal use: 3.25%
  • Production forestry: 1%
  • Mining: Limited mining water use activity use identified.
  • Urban & semi urban: Limited urban & semi urban water activity use identified.
  • Water: Limited water activity use identified.

Grazing Land

Douglas Creek is a relatively small sub-catchment where land use is dominated by grazing on natural 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 Douglas Creek sub-catchment is proportioned as follows:

  • A Condition: 17%
  • B Condition: 58%
  • C Condition: 25%
  • D Condition: 0%

Data from the Douglas Creek sub-catchment is based on 12 observations.

On the basis of the rapid assessment, the Douglas Creek sub-catchment is estimated to have the largest proportion of land in fair (B) condition (58%), followed by poor (C) condition (25%) and good (A) condition land (17%). Data not available for (D) condition land.

Ground Cover

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

  • ( BC) Bare Cover: 0%
  • ( LC) Low Cover: 6%
  • ( MC) Moderate Cover: 43%
  • ( HC) High Cover: 51%
  • (VHC) Very High Cover: 0%

Data from the Douglas Creek sub-catchment are based on 63 observations.

On the basis of the rapid assessment (2004-2007), the Douglas Creek sub-catchment is estimated to have the highest proportion of land within the high (HC) ground cover category (51%), followed by moderate (MC) cover (43%) and low (LC) cover (6%) categories.

Resource Condition Summary

Douglas Creek is a relatively small subcatchment where land use is dominated by grazing on native pastures. Approximately 3% of the land area is set aside for conservation and minimal use, while there are many abandoned and operational mines throughout the subcatchment. The condition of riparian habitat in this subcatchment has undergone relatively little change over the last 30 years and remains in fair (B) condition. Douglas Creek and many of its tributaries, such as Michael Creek, begin in rainforest-covered mountains west of Ingham and contain many permanent waterbodies which are thought to be in good condition, though they have not been well studied. The lower reaches and tributaries of Douglas Creek are largely dry, sandy ephemeral creeks.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality in the Douglas Creek subcatchment. Gully and stream bank erosion are also predicted to contribute substantially to the total sediment load. The rate of soil erosion is predicted to be moderate and close to both the basin and BWQIP region averages, while the total soil loss to waterways from the subcatchment is comparatively low due to its small area. Douglas Creek is reported to have some areas with significant streambank erosion. Grazing land condition is assessed as having a high proportion of land in fair (B) condition, while substantial areas of poor (C) and good (A) condition land is also apparent. This is also reflected in the ground cover assessment (2004-07). Analysis of ground cover from satellite imagery (reference) identifies an area of vulnerable 'D' condition land in the middle of the subcatchment, while the mean ground cover over the entire subcatchment fluctuated relatively little between 1999 and 2006 (between 97% and 85%).

Water quality in the Douglas Creek subcatchment is predicted by models to have moderately elevated sediment concentrations and loads during wet season event flows. There are no water quality monitoring data, however, with which to compare the modelled concentrations and loads.

Draft Environmental Values

Several areas in the Douglas Creek subcatchment, corresponding to the rainforest-covered upper part of the subcatchment, have been identified as having High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. They include: (i) steep sections of the western slopes of the Seaview Ranges within the Einasleigh Bioregion; (ii) sections of the Mount Fox State Forest and a small isolated part of the Girrigun National Park that was formerly known as the Mount Fox National Park; and (iii) the upper reaches of Michael Creek, which take in the Liefway Nature Refuge. The aquatic ecosystem values of other parts of the Douglas Creek subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing. Little is known about the human use Environmental Values of Douglas Creek subcatchment, which are thought to be limited to use for stock watering, and the cultural and spiritual values of the Nywaigi traditional owners.

Maps

Photos

More photos of Douglas Creek (Kangaroo Hills Station)

References

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

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