State of the Environment

2006

Indicator: IW-18 Exceedance of suspended solids water quality triggers

Data

Nutrient and suspended sediment load subindex for each State and the Australian Capital Territory
Total length of reach (km) in each category and percentage of total in parentheses Percentage of total length with data
Largely unmodified Moderately modified Substantially modified Extensively modified
Queensland 2 809 (4) 12 660 (20) 40 347 (64) 7 573 (12) 88
New South Wales 1 692 (3) 23 784 (41) 27 630 (48) 4 678 (8) 97
Australian Capital Territory 9 (3) 89 (33) 172 (64) 0 (0) 100
Victoria 4 419 (29) 5 067 (33) 5 287 (35) 410 (3) 96
Tasmania 3 233 (59) 1 811 (33) 429 (8) 0 (0) 98
South Australia 210 (3) 2 860 (39) 4 112 (55) 203 (3) 76
Western Australia 870 (4) 2 988 (15) 15 759 (78) 461 (2) 98
Total 13 242 (8) 49 258 (29) 93 736 (55) 13 324 (8) 81

Source: National Land and Water Resources Audit 2002, Australian Catchment, River and Estuary Assessment 2002, volumes 1 and 2, Land and Water Australia, Canberra, viewed 13 Dec 2005, http://audit.ea.gov.au/anra//coasts/docs/estuary_assessment/River_Findings.cfm, Table 16

What the data mean

Nutrient and suspended sediment loads are greater than natural levels for over 90% of the river length and are extensively modified in almost 10% the total river length. Increases in total phosphorus and suspended sediment loads are strongly linked to degradation of water quality.

Data Limitations

Data has not been update since 2002.

Issues for which this is an indicator and why

Inland Waters - Habitat scale influences - Water Quality (for surface and groundwater) - Sediment and turbidity 

Number of exceedences of water quality triggers for suspended solids is a direct measure of this pressure.

Other indicators for this issue:

Inland Waters - Catchment scale influences - Land and vegetation condition - Erosion 

Suspended solids is in part a measure of instream sedimentation. Number of exceedences of water quality triggers for suspended solids is a measure of this pressure.

Other indicators for this issue:

Inland Waters - Catchment scale influences - Land and vegetation condition - Nutrients and sediments - sources and loads 

Number of exceedences of water quality triggers for suspended solids is one measure of the likelihood that excess nutrients are being transported.

Other indicators for this issue:

Inland Waters - Habitat scale influences - In-stream habitat - woody debris and sand slugs 

Where the supply of sediment from upstream exceed a river's flushing capacity, this material will accumulate and smother stream bed habitats and fill deep pools. Sand and gravel are too unstable for growth of benthic organisms and loss of deep pools also means a loss of refugia and breeding grounds. Sediments also supply nutrients and change the food web structure of an ecosystem.

Number of exceedences of water quality triggers for suspended solids is an indirect measure of this pressure.

Other indicators for this issue:

Inland Waters - Response of biota - Bacteria and algae 

Suspended solids are a source of nutrients, which, when added to aquatic environments can lead to algal blooms under the right conditions. Number of exceedences of water quality triggers for suspended solids is one measure of the likelihood that excess nutrients are being transported.

Other indicators for this issue:

Human Settlements - Liveability of human settlements - Water quality 

Water quality can be diminished through increased suspended solids. Number of exceedences of water quality triggers for suspended solids is a direct measure of this pressure on both human and environmental water supply.

Other indicators for this issue:

Key

   Links to another web site
   Links to data in the DRS
   Opens a pop-up window

PDF files

Adobe Acrobat Reader  is required to view PDF files.

If you are unable to access a PDF file, please contact us to organise a suitable alternative format.