Lower Suttor River

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Lake Dalrymple straddles the Burdekin River (Dam) subcatchment and the Lower Suttor River subcatchment.

Subcatchments

Smaller subcatchments within the Lower Suttor River Catchment include:

  • Six mile Gully
  • Belyando River
  • Vine Creek
  • Sugarbag Creek
  • Suttor River
  • Boundary Creek
  • Suttor River (Lake Dalrymple)
  • Cape River

Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment has shifted from very good in the 1970s to relatively good in 2004. The changes are due to vegetation clearing and an increase in gullying/scalding. The field surveys show the riparian conditions to be poor at three of the four sites visited. However those sites did show reasonable levels of recruitment and limited weediness.

iTRARC Scores

Catchment Class 2 A
Maximum iTRARC Score 24 (A+)
1970s Score 19 (A)
2004 Score 12 (B+)
Reduction in Ecosystem Services Moderate
Increase in Potential for Erosion Small
Reasons for Change in Score
  • Increased number of gaps on headwater streams
  • Removal of forest from headwater streams and anabranching reaches
  • Minor floodplain clearing
  • Increased bare soil on the floodplain
  • Increased gullying/scalding

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Suttor, Gauging Station46.8 (D)1 (C)0 (A)
Suttor R, Longreed Lagoon56.3 (C)2 (B)1 sp: 1% cover (B)
Suttor R, Belyando Crossing62.6 (C)2 (B)0 (A)
Blackwater Lagoon66.8 (B)2 (B)0 (A)
Average 58.1 (C)

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

Wetlands

This sub-division is better known than most of the Belyando-Suttor system but is still poorly known ecologically compared to the rest of the Burdekin catchment. It contains many large deep, persistently and highly turbid waterholes, including numerous channels and off-channel waterbodies (eg, Longweed Lagoon). Condition is not well known, though some areas suffer the effects of overgrazing. Part of the lower river is inundated by Lake Dalrymple (Burdekin Falls Dam), creating a highly modified habitat.

The limnology of two sites within this sub-division (Longweed Lagoon and the Suttor River at St. Anns) were assessed by Loong et al. (2005). The fish fauna of the Belyando River at Mt. Douglas was assessed in 1976 by Midgley (1977). The fish, water quality and habitat condition of five waterbodies in this area were very briefly assessed by Burrows et al. (1999) as part of an evaluation of Mt. Douglas as a potential dam site. This included finding established populations of yellowbelly, a fish species not native to the Burdekin catchment. Pusey (2006) compared the diets of fish in the lower Suttor River with those of the upper Burdekin River. The riparian vegetation and other environmental issues associated with the potential raising of the Burdekin Falls Dam which, if taken to the full supply level, would flood a significant length of the lower Suttor River (almost to Mt Douglas) were assessed in Burrows (1999).

Reference: Assessing the condition of Wetlands in the Burdekin catchment

For more information see Lower Suttor River wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Lower Suttor River subcatchment are summarized as follows:

  • Subcatchment modelled area: 2,928 sq. km.
  • Source contributions: Hillslope = 54%; Gully = 40%; Streambank = 6%
  • Area of subcatchment with <50% ground cover: 1,255 sq. km or 43% of subcatchment
  • Total suspended sediment (flow weighted) supply: 198 kt/yr
  • Total suspended sediment supply (flow weighted; normalized to area): 675 kg/ha/yr
  • Mean Annual Flow: 2,198,560 ML

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

43% of the Lower Suttor River subcatchment (1,255 sq km) is assessed as having less than 50% ground cover in 2004. The greatest proportion of suspended sediments are provided by hillslope erosion accounting for 61% of the total suspended sediments entering the river (61% corresponds to 366 kg/ha/yr). Gullies, however, also provide large amounts of sediment to this subcatchment, accounting for 40% of total sediment supply, or 189 kg/ha/yr.

Water Quality Monitoring

There are no water quality monitoring 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 Lower Suttor River 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. The human use Environmental Values of the subcatchment are understood to include recreation (secondary & visual appreciation), stock watering, human consumption (fishing), and the cultural and spiritual values of the Jangga traditional owners.

Lower Suttor River subcatchment draft HEV waters

Stock Watering

Water supply for production of healthy livestock.

Secondary Recreation

Sailing and power boating on Lake Dalrymple. Popular for recreational fishing. Recreational fishing for persons aged 18 years and above requires a permit to fish under the Stocked Impoundment Permit (SIP) Scheme.

Visual Recreation

Lake Dalrymple may be considered a tourist attraction. There are no stores, fuel stations or accommodation at the dam, however, there is a camping ground with powered sites and amenities.

Cultural and Spiritual

Custodial use of water resources by Jangga traditional owners.

References:

Landuse

Principle land uses within the Lower Suttor River subcatchment as a proportion of total area:

  • Grazing: 97.6%
  • Water: 1.9%
  • Conservation & minimal use: Limited conservation & minimal water activity use identified.
  • Urban & semi urban: Limited urban & semi urban water activity use identified.
  • Mining: Limited mining water activity use identified.

Grazing Land

Lower Suttor River is a small to medium sized subcatchment where land use is almost exclusively grazing on, predominantly, 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 Lower Suttor River sub-catchment is proportioned as follows:

  • A Condition: 9%
  • B Condition: 28%
  • C Condition: 50%
  • D Condition: 13%

Data from the Lower Suttor River sub-catchment is based on 151 observations.

On the basis of the rapid assessment, the Lower Suttor River sub-catchment is estimated to have the largest proportion of land in poor (C) condition (50%), followed by fair (B) condition (28%) and very poor (D) condition land (13%). 9% of observed land was in good (A) condition.

Ground Cover

Ground Cover in the Lower Suttor River subcatchment is proportioned as follows:

  • ( BC) Bare Cover: 6%
  • ( LC) Low Cover: 37%
  • ( MC) Moderate Cover: 30%
  • ( HC) High Cover: 26%
  • (VHC) Very High Cover: 2%

Data from the Lower Suttor River subcatchment are based on 149 observations.

On the basis of the rapid assessment (2004-2007), the Lower Suttor River subcatchment is estimated to have the highest proportion of land within the low (LC) ground cover category (37%), followed by moderate (MC) cover (30%) and high (HC) cover (26%) categories. 2% of land was estimated to fall into the very high cover (VHC) category.

Resource Condition Summary

Lower Suttor River is a small to medium sized subcatchment where land use is almost exclusively grazing on, predominantly, natural pastures. Riparian habitat in the subcatchment has declined only slightly over the last 30 years, with only minor clearing of riparian vegetation in headwater streams and along floodplains, and is currently assessed to be in fair (B) condition. The subcatchment waterways contain many large deep, in-channel and off-channel water bodies that are persistently and highly turbid. While they are better studied than others in the Suttor Basin, the water bodies remain poorly known ecologically. Part of the lower Suttor river is inundated by Lake Dalrymple (Burdekin Falls Dam), creating a highly modified habitat.

Hillslope and gully erosion are both identified by models as major sources of sediment and particulate nutrients affecting water quality within the Lower Suttor River subcatchment. The rate of soil erosion is predicted to be moderate and considerably higher than the Basin average, while the total soil lost from the subcatchment to waterways is comparatively high due to the size of the subcatchment. Land condition is assessed as having the highest proportion in poor (C) condition, while fair (B), good (A) and very poor (D) condition grazing land is also apparent. This is also reflected in the rapid ground cover assessment (2004-07). Analyses of ground cover from satellite imagery (reference) identify areas of vulnerable and marginal 'D' condition land in the centre and east of the subcatchment.

Water quality in the Lower Suttor River 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. However, the sediment load at end-of-catchment is derived not only from this subcatchment, but also from others entering upstream. 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 Lower Suttor River 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. The human use Environmental Values of the subcatchment are understood to include recreation (secondary & visual appreciation), stock watering, human consumption (fishing), and the cultural and spiritual values of the Jangga traditional owners.

Maps

References

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

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