Cape River

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Topography

The Cape River is classified as ephemeral with few permanent waterholes in its upper section. It has numerous permanent lagoons in the river channels, anabranches and off-river flood paths(see report Greiner and Hall 2006). Below the junction with the Campaspe it is considered to be ephemeral with large waterholes fed from groundwater (Type 3).

Subcatchments

Smaller subcatchments within the Cape River Catchment include:

  • Amelia Creek
  • Cape River
  • Warigal Creek
  • Back Creek
  • Betts Creek
  • Ballabay
  • Black Mountain Creek
  • Cornelia
  • Mount Richardson

Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment has undergone a reduction in condition from excellent (A+) to relatively good (B) in the last 30 years. This reduction is largely due to floodplain clearing and heavy grazing adjacent to the channels. The field based surveys show a wide range of scores from excellent through to poor, with variable levels of regeneration and weediness. The wide range of field survey scores demonstrate the variability that can occur within a subcatchment, in many cases as a response to local management actions.

iTRARC Scores

Catchment Class 2 A
Maximum iTRARC Score 24 (A+)
1970s Score 20 (A+)
2004 Score 11 (B)
Reduction in Ecosystem Services Moderate
Increase in Potential for Erosion Large
Reasons for Change in Score
  • Increased gaps in headwater and anabranching riparian zones
  • Floodplain clearing
  • Increased bare soil on the floodplain
  • Increased scalding/gullying

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Cape R [#1]51.9 (C)2 (B)1 sp:; 15% cover (B)
Cape R [#2]54.4 (C)2 (B)1 sp: 2% cover (B)
Cape R [#3]82.6 (A)2 (B)2 spp: 40% cover (C)
Cape R [#4]91.9 (A)1 (C)0 (A)
Garden Ck43.8 (D)2 (B)0 (A)
Glenhoughton Swamp53.8 (C)0 (D)0 (A)
Teewarrina Waterhole59.7 (C)1 (C)0 (A)
Average 62.6 (C)

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

Wetlands

The main wetlands of the Cape-Campaspe subcatchment are formed by an extensive system of anabranches between these two rivers, and the Campaspe River and Lake Dalrymple. These seasonal wetlands are not listed among the wetlands of National Importance but are likely to be significant to traditional owners and to graziers.

The condition of the Cape River sub-division is fairly typical of upper Burdekin rangelands. Although permanent waterbodies are not common, and the upper catchment has no notable ones, there are a few permanent waterbodies in the lower reaches both within the main channel and in anabranches downstream of Egera. These are in generally good condition. This sub-division has been the subject of significant NHT investment in riparian fencing and management and the water quality has been studied by Burrows (2000, 2001) and the fish by Burrows (2001). Almost nothing is known ecologically of Webb Lake or Lake Moocha, but as ephemeral lakes, they are likely to have some values when water is present.

For more information see Cape River wetland condition summary

Reference: Assessing the condition of Wetlands in the Burdekin catchment

Water

SedNet Modelling of Water Quality

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

  • Subcatchment modelled area: 7,539 sq. km.
  • Source contributions: Hillslope = 64%; Gully = 29%; Streambank = 6%
  • Area of sub-catchment with <50% ground cover: 3,492 sq. km or 46% of subcatchment
  • Hillslope sediment supply: 161 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 189 kt/yr
  • Total suspended sediment supply (flow weighted; normalized to area): 250 kg/ha/yr
  • Total suspended sediment end-of-subcatchment (flow weighted) yield: 94 kt/yr
  • Mean Annual Flow: 853,204 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 Cape River subcatchment (67%) and is predicted to contribute 161 kg/ha/yr. It is estimated that approximately 46% of the subcatchment has poor ground cover (<50%). However, gully erosion is also identified as a significant contributor (29%) to the total sediment load of 189 kt/yr. The rate of soil loss from all sources (supply) is considered quite low (250 kg/ha/yr) when compared to other sub-catchments. The Cape River sub-catchment is the largest of the Burdekin subcatchments, covering 9,136 sq km.

The significant discrepancy between modelled and actual area corresponds to the division between the Cape and Campaspe River sub-catchments that was used in SedNet.

Water Quality Monitoring

The monitoring site in the Cape River catchment is located at the Gregory Developmental Road and has been sampled by the NRW/ ACTFR for 4 years. The catchment area for this monitoring site is 15,861 sq km, of which 77.5% is used for grazing. This site also incorporates the Campaspe River. TSS concentrations at this site were relatively low over the monitoring period (mean concentration of 270 mg/L) compared to other monitored sites within the Burdekin rangelands. A flow-weighted annual suspended sediment load of 247,000 tonnes/year was calculated for the Cape/Campaspe catchment using the monitoring data. This load is lower than that predicted by the SedNet model of 372,000 tonnes/year.

Relevant information of Water Quality Monitoring in the Cape Campaspe River Basin can be found by following these links:

Environmental Values

Aquatic Ecosystems

The aquatic ecosystem values of an area of the Cape River subcatchment, corresponding to the White Mountain National Park and the adjacent area of the White Mountains Resource Reserve, has been identified as containing High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. The area is one of several significant sandstone outcrops occurring along the edges of the Great Artesian Basin in Queensland which provide specialised microhabitats, in particular deep-sheltered gorges and spring-fed aquatic ecosystems. The aquatic ecosystem values of other parts of the Cape River subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing.

High Ecological Value (HEV) - upper reaches of Warrigal and other creeks that lie within National Park;

Change in river condition is minor except for moderate changes in fish population below the junction with the Campaspe River. Eels that used to inhabit the river have disappeared since they have been cut off from the marine environment (where they carry out an integral part of their life-cycle) by the construction of the Burdekin Falls Dam.

Cape River subcatchment draft HEV waters

Irrigation

Less than 60 hectares of cotton and fodder crops are irrigated due to limited water supply.

Stock Watering

Extensive cattle grazing. Cattle watering is carried out mostly through direct access to creeks and rivers.

Drinking Water

Population scattered mainly on pastoral holdings. Total stock and domestic use combined is of 776 ML.

Cultural and Spiritual

The traditional owners are the Kudjala people.

References:

Landuse

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

  • Grazing: 64%
  • Conservation & minimal use: 35%
  • Water: .50%
  • Irrigated horticulture & cropping: Limited irrigated horticulture & cropping activity use identified.
  • Urban & semi urban: Limited urban and semi urban activity use identified.

Grazing Land

Cape River is the largest of the Burdekin subcatchments and covers almost half the Basin. While the main land use is grazing on natural pastures, a very large proportion is set aside for conservation and minimal use.


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 Cape River sub-catchment is proportioned as follows:

  • A Condition: 30%
  • B Condition: 46%
  • C Condition: 21%
  • D Condition: 3%

Data from the Cape River sub-catchment is based on 189 observations.

On the basis of the rapid assessment, the Cape River sub-catchment is estimated to have the largest proportion of land in fair (B) condition (46%), followed by good (A) condition (30%) and poor (C) condition land (21%). 3% of observed land was in very poor (D) condition.

Ground Cover

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

  • ( BC) Bare Cover: 0%
  • ( LC) Low Cover: 14%
  • ( MC) Moderate Cover: 37%
  • ( HC) High Cover: 46%
  • (VHC) Very High Cover:3%

Data from the Cape River sub-catchment are based on 183 observations.

On the basis of the rapid assessment (2004-2007), the Cape River sub-catchment is estimated to have the highest proportion of land within the high (HC) ground cover category (46%), followed by moderate (MC) cover (37%) and low (LC) cover (14%) categories. 3% of land was estimated to fall into the very high cover (VHC) category.

Resource Condition Summary

Cape River is the largest of the Burdekin subcatchments and covers almost half the Basin. While the main land use is grazing on natural pastures, a very large proportion is set aside for conservation and minimal use, while there are also some mining activities at the very top of the subcatchment. Riparian condition in this subcatchment has declined over the last 30 years, largely due to floodplain clearing, and is currently assessed to be in fair (B) condition. This subcatchment consists of ephemeral creeks without major permanent waterbodies, although there are some permanent wetlands in the lower reaches.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality within the Cape River subcatchment, while gully erosion is also identified as a significant contributor. Both the rate of soil loss and total soil loss from the subcatchment are predicted to be comparatively low. Land condition is assessed as having high proportions of fair (B) and good (A) condition land, while a substantial proportion of poor (C) condition land is also apparent. This is also reflected in the rapid ground cover assessment (2004-07). Analysis of ground cover from satellite imagery (reference) identifies areas of vulnerable and marginal 'D' condition land, particularly in the lower reaches of Natal Creek and the upper reaches of Amelia Creek.

Water quality in the Cape River subcatchment is predicted by models to be only slightly impacted by suspended sediment. There are no water quality monitoring data with which to compare the modelled concentrations, while data from further downstream (outside the subcatchment) show lower than predicted sediment loads.

Draft Environmental Values

An area of the Cape River subcatchment, corresponding to the White Mountain National Park and the adjacent area of the White Mountains Resource Reserve, has been identified as containing High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. The area is one of several significant sandstone outcrops occurring along the edges of the Great Artesian Basin in Queensland which provide specialised microhabitats, in particular deep-sheltered gorges and spring-fed aquatic ecosystems. The aquatic ecosystem values of other parts of the Cape River subcatchment are considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing. The human use Environmental Values of the Cape River subcatchment are understood to include stock watering, irrigation, drinking water, and the cultural and spiritual values of the Kudjala traditional owners.

Maps

References

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

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