Resource Condition Summary
The Cape Campaspe Basin is intermediate in size (~ 20,311 sq.
km.) and covers around 15% of the BWQIP region. Common to most of
the BQWIP basins, land use is dominated by grazing on (mostly)
native pastures1. Approximately 18% of the land area is
set aside for conservation and minimal use, mostly as remnant
native vegetation. The condition of riparian habitat is currently
in similar condition throughout the basin and is assessed as fair
(B)2. Cape Campaspe Basin waterways are generally dry
and sandy, with few permanent water bodies3.
Hillslope erosion is identified by models as the major source of
sediment and particulate nutrients affecting water quality within
the Cape Campaspe Basin, while gully erosion is also identified as
a significant contributor4. The rate of soil erosion for
the basin overall is predicted to be comparatively low; well below
the BWQIP region average. There are only relatively small
differences in the rate of soil erosion between subcatchments,
possibly due to a combination of low relief and rainfall. The
Campaspe River subcatchment is predicted to have the highest rate
of soil erosion within the basin and to contribute the most
suspended sediment to the total end-of-basin load, while the Cape
River subcatchment is predicted to have the lowest rate of soil
erosion. Field surveys of grazing land rate nearly half of the land
area to be in poor (C) condition, with another one third of the
basin in fair (B) condition5,6. Analyses of ground cover
from satellite imagery7,8 identify substantial areas of
vulnerable and marginal 'D' condition land, particularly along the
lower reaches of the Campaspe River and Natal Creek.
Water quality in the Cape Campaspe Basin is predicted by models to
have only slightly elevated loads and concentrations of suspended
sediment at the end-of-basin during wet season flow
events4. Modelled and monitored sediment concentrations
are generally consistent; both identify the Campaspe River
subcatchment as the major source of sediments and
nutrients9,10. However, monitoring data indicate that
the models may be overestimating the total suspended sediment load
leaving the Cape Campaspe Basin.
Draft Water Quality Targets
The following water quality Resource Condition Target was
developed based on Best Management Practice Guidelines for Water
Quality Improvement, extensive modelling of a range of management
scenarios, preparation of a discussion paper12 and then, finally, a
series of workshops. These preparatory activities were undertaken
in collaboration with landholders (graziers and cane farmers),
industry representatives, Government, the scientific community and
NQ Dry Tropics staff.
- By 2058, attain a minimum 40% reduction in mean annual sediment
load from the Cape Campaspe Basin (measured at Taemas) from current
(2008) - i.e. a reduction from approximately 325 kt/yr in 2008 to
195 kt/yr by 2058).
Footnotes: see References
