Basalt River

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Topography

Vegetation

Riparian Habitat

The following information is summarized from the ACTFR report: Assessing the condition of riparian vegetation in the Burdekin catchment using satellitte imagery and field surveys by Leo Lymburner and John Dowe. 2006. This report can be accessed from the report section below.

iTRARC analysis of Riparian Habitat indicates that this subcatchment has a limited range of riparian habitats and has experienced a slight decrease in condition since the 1970s. The absence of forest and closed forest from riparian zones in this catchment contribute to its low 1970s and 2004 scores. The naturally low canopy cover within this catchment may contribute to the low field survey scores. Regeneration is present and weeds appear relatively limited, indicating moderate riparian condition in the future.

Basalt River riparian habitat condition summary ...

Wetlands

The following information is summarized from the ACTFR report: Assessing the condition of Wetlands in the Burdekin catchment using existing GIS and field knowledge for CCI by Mirjam Maughan, Damien Burrows, Barry Butler, Leo Lymburner and George Lukacs. 2006. This report can be accessed from the report section below.

Stockyard Creek is a largely dry sandy creek but the Basalt River contains numerous large permanent waterholes, maintained by discharge from the basalt aquifers of the area. These waterholes are deep and clear, with relatively high conductivity. They are generally in good condition and have the advantage of large water volumes (dilution) to make them more resistant to disturbance.

These wetlands have not been well studied, but due to relatively low intensity of land use (rangeland cattle grazing), it is considered that changes to water quality and aquatic habitat are typical for this type of land use. Some preliminary water quality and aquatic invertebrate data for this area is available from Burrows and Butler (2003) and several waterholes on the lower Basalt River were part of an aquatic invertebrate study by Betts (2003). The limnology of the Basalt River at Bluff Downs homestead (also a DNRW gauging station) was assessed by Loong et al. (2005). The exotic African fish tilapia have recently invaded the Basalt River (Veitch et al. 2006).

Basalt River wetland condition summary ...

Water

Hillslope erosion is identified as the major source of sediment and particuate nutrients affecting water quality within the Basalt River subcatchment. This is thought to be associated with the relatively large proportion of hillslope with low ground cover (25%). Loss of sediment and associated particulate nutrients from all sources (supply) is considered to be relatively low (313 kg/ha/yr). The moderate concentrations of sediments (predicted) are a consequence of the relatively lower rainfall and mean annual flow.

For more information see the Water Quality Information Page

Landuse

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

Grazing: 96.3%

Conservation & minimal use: 3.3%

Water: .06%

Urban & semi urban: Limited urban & semi urban water activity use identified.

Grazing Land

Basalt River is a medium sized sub-catchment where the land use is dominated by grazing on natural pastures. Only approximately 3% is set aside for minimal use in the headwaters of Stockyard Creek.

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 Basalt River sub-catchment is proportioned as follows:

A Condition: 34%
B Condition: 41%
C Condition: 21%
D Condition: 4%

Data from the Basalt River sub-catchment is based on 180 observations.

On the basis of the rapid assessment, the Basalt River sub-catchment is estimated to have the largest proportion of land in fair (B) condition (41%), followed by good (A) condition (34%) and poor (C) condition land (21%). 4% of observed land was in very poor (D) condition.

Ground Cover

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

( BC) Bare Cover: 2%
( LC) Low Cover: 3%
( MC) Moderate Cover: 34%
( HC) High Cover: 36%
(VHC) Very High Cover: 24%

Data from the Basalt River sub-catchment are based on 178 observations.

On the basis of the rapid assessment (2004-2007), the Basalt River sub-catchment is estimated to have the highest proportion of land within the high (HC) ground cover category (36%), followed by moderate (MC) cover (34%) and very high (VHC) cover (24%) categories. 2% of land was estimated to fall into the bare cover (BC) category.

Resource Condition Summary

Basalt River is a medium sized subcatchment where the land use is dominated by grazing on native pastures. Approximately 3% of the land area is set aside for minimal use in the headwaters of Stockyard Creek, while there are many abandoned and operational mines within the eastern part of the subcatchment. Riparian habitat in this subcatchment has undergone limited change over the last 30 years, with a very small increase in the number of gaps in headwater streams, and is currently assessed to be in poor (C) condition. Field surveys show that regeneration is present and weeds appear relatively limited, indicating moderate riparian condition in the future. The Basalt River contains numerous large permanent waterholes that are maintained by discharge from the basalt aquifers of the area. These waterholes are deep and clear, and have the advantage of large water volumes (dilution) to make them more resistant to disturbance. Stockyard Creek, in contrast, is a largely dry sandy creek. Water bodies of the Basalt River subcatchment have not been well studied, but due to the relatively low intensity of land use their condition it is considered to be generally good.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality within the Basalt River subcatchment. The rate of soil erosion is predicted to be low and well below the basin and BWQIP region averages, while the total soil loss to waterways from this subcatchment is also quite low. Grazing land condition is assessed as having the highest proportions in good (A) and fair (B) condition, while poor (C) condition land is evident. This is also reflected in the rapid ground cover field assessment (2004-07). Analysis of ground cover from satellite imagery (reference) identifies areas of low cover, and highly vulnerable and marginal 'D' condition land in the east of the subcatchment.

Water quality in the Basalt River subcatchment is predicted by models to have only slightly elevated sediment concentrations and loads during wet season event flows. Comparisons are difficult to draw between the monitoring and modeling datasets due to the small sample size collected over only two wet seasons but, while generally consistent, the monitoring data recorded higher concentrations of sediment than predicted by the models.

Draft Environmental Values

The aquatic ecosystem values of the Basalt 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 are identified in the subcatchment. Little is known about the human use Environmental Values of the Basalt River subcatchment, which are thought to be limited to use for stock watering, and the cultural and spiritual values of the Kudjala traditional owners.