Fanning River

From Dry Tropics Wiki
Jump to: navigation, search


Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment has undergone little change since the 1970s and remains in relatively good condition. The field surveys tell a slightly different story with all sites listed as poor or very poor. The combination of good regeneration and poor weediness may indicate low grazing pressure, in which case it may be the weediness that is leading to the low TRARC scores.

iTRARC Scores

Catchment Class 1 E
Maximum iTRARC Score 14 (B+)
1970s Score 11 (B)
2004 Score 10 (B)
Reduction in Ecosystem Services No Change
Increase in Potential for Erosion Small
Reasons for Change in Score
  • Increase in the number of low cover hill slopes adjacent to the stream network

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Gorge Waterhole48.3 (D)2 (B)2 spp: 10% cover (C)
Sandalwood Waterhole55 (C)3 (A)2 spp: 20% cover (C)
Poison Waterhole57.1 (C)2 (B)2 spp: 30% cover (C)
Stake Ck Waterpoint61.2 (C)2 (B)2 spp: 52% cover (D)
Average 55.4 (C)

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

Wetlands

This river has two main arms (east and west branch) arising within the Herveys Range, west of Townsville, then falling through a steep gorge country before flattening out in savanna rangelands. Many waterholes are present in the gorge country but due to inaccessibility (no vehicles and being part of a live-firing and bombing range), nothing is known about those reaches. The headwaters have higher rainfall than many other rivers, though not as much as the rivers to the north (eg, Keelbottom, Star). The west arm within and above the gorge contains a number of permanent waterholes, though the presence of water in the lower half of the river is limited. The east arm does not have any large permanent waterholes (except maybe in the gorge section), though smaller ones are present. The upper portions of the river (including both the east and west arms) are within the Townsville Field Training Area, a military training area since 1977. Thus the land use is different to other parts of the upper Burdekin and despite many years of military use, it is considered to be in very good condition (Ash et al. 2000). The Department of Defence has commissioned monitoring of the waterholes of the training area since 1994, mostly for water quality, sediment quality, macroinvertebrates (summarized in Burrows and Butler 2000 and Loong et al. 2006), riparian vegetation (Dowe 2006) and catchment run-off (CSIRO 2006) but also on two occasions for fish (Burrows and Tait 1999, Loong et al. 2006). The limnology of Poison Waterhole, on the upper Fanning River (west branch) was assessed by Loong et al. (2005). The lower Fanning River and its tributaries flow through grazing lands and are largely dry creeks with few permanent waterholes. Their condition is considered to be typical of upper Burdekin grazing rangelands.

Reference: Assessing the condition of Wetlands in the Burdekin catchment

For more information see Fanning River wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Fanning River sub-catchment are summarized as follows:

  • Subcatchment modelled area: 1,099 sq. km.
  • Source contributions: Hillslope = 88%; Gully = 9%; Streambank = 4%
  • Area of subcatchment with <50% ground cover: 453 sq. km or 41% of subcatchment
  • Hillslope sediment supply: 674 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 85 kt/yr
  • Total suspended sediment supply (flow weighted; normalized to area): 770 kg/ha/yr
  • Total suspended sediment end-of-subcatchment (flow weighted) yield: 79 kt/yr
  • Event Mean Concentration (EMC - flow weighted): 729 mg/L
  • Mean Annual Flow: 108,507 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 affecting water quality within the Fanning River subcatchment (88%), and is predicted to contribute 487 kg/ha/yr. It is estimated that approximately 41% of the sub-catchment has poor ground cover (<50%). Total sediment losses from all sources is predicted to be high (770 kg/ha/yr). Similarly, the event mean concentration of suspended sediment is predicted to be quite high (729 mg/L).

Water Quality Monitoring

The monitoring site in the Fanning River catchment is located next to the Flinders Highway and has been sampled by the ACTFR for 2 years (2004/05 and 2005/06). The catchment area for this monitoring site is 1,095 sq km, of which 96.6% is used for grazing. Suspended sediment concentrations (and associated particulate nitrogen and phosphorus) over the monitored period have been relatively low (318 mg/L) compared to other catchments in the Burdekin rangelands as well as to the modelled estimates of sediment export, although this comparison is based on a limited pool of monitoring data.

Relevant information of Water Quality Monitoring in the Upper Burdekin River Basin:

Environmental Values

Aquatic Ecosystems

The upper portion of the Fanning River subcatchment, corresponding to the largely forested headwaters contained within the Townsville Field Training Area, has been identified as containing High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. This area is contiguous with HEV areas in neighbouring subcatchments. The aquatic ecosystem values of the lower and middle reaches of the Fanning River subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing. Nevertheless, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained.

The aquatic ecosystem values of Fanning River

Stock Watering

Water supply for production of healthy livestock.

Cultural and Spiritual

Custodial use of water by Juru traditional owners.

References:

Landuse

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

  • Grazing: 96.6%
  • Conservation & minimal use: 2.5%
  • Urban & semi urban: Limited urban & semi urban water activity use identified.
  • Water: Limited water activity use identified.

There are many old and current mine sites present in this subcatchment, while only very limited urban & semi urban land use is identified.

Grazing Land

Fanning River is a relatively small subcatchment where land use is predominantly 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 Fanning River sub-catchment is proportioned as follows:

  • A Condition: 40%
  • B Condition: 35%
  • C Condition: 17%
  • D Condition: 8%

Data from the Fanning River sub-catchment is based on 65 observations.

On the basis of the rapid assessment, the Fanning River sub-catchment is estimated to have the largest proportion of land in good (A) condition (40%), followed by fair (B) condition (35%) and poor (C) condition land (17%). 8% of observed land was in very poor (D) condition.

Ground Cover

Ground Cover in the Fanning River sub-catchment is proportioned as follows:

  • ( BC) Bare Cover: 0%
  • ( LC) Low Cover: 12%
  • ( MC) Moderate Cover: 25%
  • ( HC) High Cover: 58%
  • (VHC) Very High Cover: 5%

Data from the Fanning River sub-catchment are based on 65 observations.

On the basis of the rapid assessment (2004-2007), the Fanning River sub-catchment is estimated to have the highest proportion of land within the high (HC) ground cover category (58%), followed by moderate (MC) cover (25%) and low (LC) cover (12%) categories. 5% of land was estimated to fall into the very high cover (VHC) category.

Resource Condition Summary

Fanning River is a relatively small subcatchment where land use is predominantly grazing on native pastures. Conservation and minimal use comprises less than 3% of the subcatchment. Many abandoned and active mines are scattered throughout the central and lower parts of the subcatchment. Riparian areas in the subcatchment have undergone little change in the last 30 years and remain fair (B) condition. This river has two main arms arising within the Hervey Range, west of Townsville, then falling through a gorge before flattening out in savannah rangelands. The west arm within and above the gorge contains a number of permanent waterholes, though the presence of water in the lower half of the river is limited. The aquatic ecology and characteristics of this river have been reasonably well studied and the upper portions are generally considered to be in good condition. The lower Fanning River and its tributaries flow through grazing lands and are largely dry, sandy creeks with few permanent waterholes.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality within the Fanning River subcatchment. The rate of soil erosion is predicted to be moderate and above the basin average, while the total soil loss to waterways from the subcatchment is comparatively low due to its small area. Grazing land condition is assessed as having relatively high proportions in good (A) and fair (B) condition. However, a substantial proportion of observed land was also in poor (C) and very poor (D) condition. This is also reflected in the ground cover assessment (2004-07). Analysis of satellite imagery (reference) identifies areas in the middle and lower reaches of Fanning River and its tributaries that are marginal and high vulnerability and 'D' condition. The mean ground cover across the entire subcatchment declined from 92% in 1999 to 65% in 2004, and had recovered to 90% in 2006.

Water quality in the Fanning River subcatchment is predicted by models to have moderately elevated sediment concentrations during wet season event flows. However, water quality monitoring data from the subcatchment have recorded much lower suspended sediment (and associated particulate nutrient) concentrations than predicted by models. It appears likely, therefore, that the SedNet model is overestimating erosion from this subcatchment, possibly due to its steep topography and inter-annual variability in ground cover.

Draft Environmental Values

The upper portion of the Fanning River subcatchment, corresponding to the largely forested headwaters contained within the Townsville Field Training Area, has been identified as containing High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. This area is contiguous with HEV areas in neighbouring subcatchments. The aquatic ecosystem values of the lower and middle reaches of the Fanning River subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing. Nevertheless, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained. The human use Environmental Values of the Fanning River subcatchment are understood to be limited to stock watering and the cultural and spiritual values of the Juru traditional owners.

Maps

References

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

This is a legacy website. Content is not being updated but is kept as an archive.
Updated NRM information is now held in the NQ Dry Tropics NRM Information Portal at http://nrm.nqdrytropics.com.au/.
while corporate information about NQ Dry Tropics is held on our main website at http://www.nqdrytropics.com.au
NQ Dry Tropics Website