Burdekin River (Above Dam)

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Subcatchments

Smaller Catchments within the Burdekin River (dam) Catchment include:

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 gone from relatively poor (C+) to very poor (D) condition in the last 30 years. This change has been the result of clearing along headwater streams, floodplain clearing and an increased amount of gullying/scalding. The field based surveys also indicate that this subcatchment is in poor condition, the presence of regeneration at all sites provides hope for the future, however the presence of weeds at all sites is problematic.

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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.

Much of this sub-division is inundated by Charters Towers Weir and Lake Dalrymple, formed by construction of the Burdekin Falls Dam. Lake Dalrymple is persistently turbid (Griffiths and Faithful 1996, Burrows and Faithful 2003, Butler 2006, Burrows and Butler 2007) and the water quality and aquatic habitat are thus highly modified from the natural condition of this river reach, although it is still considered to be relatively functional (Butler 2006) and is listed in the Directory of Important Wetlands in Australia. The deep still water pool formed by the Charters Towers weir is also a significant departure from natural, though not as much as for the Burdekin Falls Dam. The Charters Towers Weir does not affect the river below it, which has almost perennial clear water flow and its condition is typical for the Upper Burdekin River. The tributaries of this sub-division are ephemeral creeks without permanent waterholes, providing limited aquatic habitat value. The limnology of two site along the Burdekin River (one at Big Bend and one at the Sellheim DNRW gauging station) were assessed by Loong et al. (2005).

Burdekin River Dam wetland condition summary...

Water

Both hillslope and streambank erosion are identified as the major sources of sediment and particulate nutrients affecting water quality within the Burdekin River (above dam) subcatchment. This subcatchment is essentially a flood plain with little relief but with a significant area with poor ground cover (42%). Hillslope erosion is, consequently, predicted to be moderate (505 kg/ha/yr). Loss of sediment and particulate nutrients from all sources is predicted to be very high (1,082 kg/ha/yr) because of the large contributions from both hillslope and streambank erosion.

For more information see the Water Quality Information Page

Landuse

Principle land uses within the Burdekin River (above dam) subcatchment as a proportion of total area:

Grazing: 93%

Conservation & minimal use: 3.4%

Water: 3.1%

Mining: Limited mining activity use identified.

Irrigated horticulture & cropping: Limited irrigated horticulture and cropping use identified.

Urban & semi urban: Limited urban & semi urban acitivity use identified.

Grazing Land

Burdekin River (above Dam) is a medium sized sub-catchment where the land use is dominated by grazing on natural pastures. Only approximately 3% of the land area 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 4,666 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 Burdekin River Dam sub-catchment is proportioned as follows:

A Condition: 7%
B Condition: 22%
C Condition: 55%
D Condition: 16%

Data from the Burdekin River Dam sub-catchment is based on 228 observations.

On the basis of the rapid assessment, the Burdekin River Dam sub-catchment is estimated to have the largest proportion of land in poor (C) condition (55%), followed by fair (B) condition (22%) and very poor (D) condition land (16%). Only 7% of observed land was in good (A) condition.

Ground Cover

Ground Cover in the Burdekin River (above dam) sub-catchment is proportioned as follows:

( BC) Bare Cover: 2%
( LC) Low Cover: 51%
( MC) Moderate Cover: 33%
( HC) High Cover: 13%
(VHC) Very High Cover: 1%

Data from the Burdekin River (above dam) sub-catchment are based on 234 observations.

On the basis of the rapid assessment (2004-2007), the Burdekin River (above dam) sub-catchment is estimated to have the highest proportion of land within the low (LC) ground cover category (51%), followed by moderate (MC) cover (33%) and high (HC) cover (13%) categories. 2% of land was estimated to fall into the bare cover (BC) category.

Resource Condition Summary

Burdekin River (above dam) 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 conservation and minimal use, while there are a very large number of abandoned and operational mines throughout the subcatchment. The condition of riparian habitat in the subcatchment has declined over the last 30 years as a result of clearing along headwater streams, floodplains and an increased amount of gullying, and is currently assessed to be in very poor (D) condition. Field surveys support this assessment. This section of the Burdekin River has perennial and clear flow over a sandy bottom. The Burdekin River is inundated at two sites by Charters Towers Weir and Lake Dalrymple, formed by construction of the Burdekin Falls Dam. The water quality and aquatic habitat of these impoundments are thus highly modified from the natural condition, although the Burdekin Falls Dam is still considered to be relatively functional and is listed in the Directory of Important Wetlands in Australia. The Charters Towers Weir does not affect the river below it, which has almost perennially clear water and its condition is typical for the upper Burdekin River. The tributaries of this subcatchment are ephemeral creeks without permanent waterholes, thus providing limited aquatic habitat.

Both hillslope and streambank erosion are identified as the major sources of sediment and particulate nutrients affecting water quality within the Burdekin River (above dam) subcatchment. The rate of soil erosion is predicted to be high and well above the basin and BWQIP region averages, while the total soil loss to waterways from the subcatchment is also comparatively very high. Grazing land is assessed to be predominantly in poor (C) condition, with a substantial area in very poor (D) condition. This is also reflected in the rapid ground cover field assessment (2004-07). Analysis of ground cover from satellite imagery (reference) identifies a large area of marginal 'D' condition land towards the top of the subcatchment, while the mean ground cover across the entire subcatchment declined from 93% in 1999 to 63% in 2004, and had only recovered to 79% in 2006. Significant streambank erosion and gullying along the Burdekin River in this subcatchment has been reported.

Water quality in the Burdekin River is predicted by models to have moderately elevated sediment concentrations during wet season event flows. However, water quality monitoring data from the Burdekin River at Selheim is not useful to specifically characterise water quality for the Burdekin River (above dam) subcatchment area because it drains almost the entire Upper Burdekin Basin.

Burdekin River (above dam) is identified as a priority subcatchment for rehabilitation on the basis of its very high contribution to the total sediment load within the basin, the large area of marginal 'D' condition land, and reported streambank erosion and gullying.

Draft Environmental Values

Two areas within the Burdekin River (above dam) subcatchment, both in the upper part of the subcatchment, have been identified as containing High Ecological Value (HEV) waters by the BWQIP ecological values technical panel. These correspond to: (i) part of Dalrymple National Park, including Iron Pot Springs; and (ii) a section of the Townsville Field Training Area. The aquatic ecosystem values of other parts of the Burdekin River (above dam) subcatchment, including the Burdekin River itself, 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 subcatchment include recreation and tourism (swimming, boating and visual appreciation), stock watering, industrial use, drinking water, human consumption, and the cultural and spiritual values of the Kudjala and Birri traditional owners.