Suspended sediment in the water column can block light, making water appear darker and murkier. All water bodies naturally have some level of suspended sediments, though waterways fed by rapidly eroding catchments and collapsing banks tend to have more. Therefore, activities that result in erosion not only impact on the fertility and structure of the land but also the turbidity and quality of nearby water. Suspended sediment can also result from the resuspension of bottom particles through activities like dredging, mining, trawling and boat wash. Tides can also resuspend sediment, and cause naturally high turbidity levels in tide-dominated waterways.
View a conceptual model of potential causes of a change to aquatic sediments and the condition responses observed as a result of this change.
There are a number of causes and symptoms related to this stressor. The following indicators are recommended for the stressor ‘Aquatic sediments’:
Indicators of suspended sediment sources:
- Catchment land-use
- Percentage of catchment cleared
- Percentage length of river system with no riparian vegetation
- Number of point sources per km estuary
- Boating activity within the estuary
- Unsealed road density
- Percentage of catchment with intensive agriculture on steep slopesIntensive agriculture on steep slopes
- Percentage of catchment with less than 70% ground cover
- Dredging activity in river system
Indicators of direct pressure:
- Percentage difference between pre-European sediment load and current load
- Natural water clarity
Physical-chemical condition indicators:
Biological condition indicators:
- Change in seagrass extent
- Percentage cover of seagrass
|Possible causes||Possible symptoms|
|The actions/events/situations that might arise induce this stress:
||The actions/events/situations that might arise from a change to the stressor:
Other information on suspended sediments
Global Environment Monitoring System (GEMStat) is designed to share surface and ground water quality data sets collected from the GEMS/Water Global Network, including over 1,400 stations, two million records, and over 100 parameters (including suspended solids).
Australian Natural Resources Atlas. One of the key information delivery mechanisms for the National Land and Water Resources Audit. Search the Australian Natural Resource Atlas for information about surface water quality monitoring programs (including turbidity measurements) in Australia
Australian Natural Resources Data Library. You can search for metadata (data about data) here.
Digital atlas of Australian soils is a digital version of the set of ten maps known as the ‘Atlas of Australian Soils, Sheets 1 to 10, with explanatory data’.
Interactive maps. These online interactive maps on the webpage allow you to view maps of suspended solids from coastal areas around Australia, using the MODIS Satellite Oceanic Classes (Level 3) data.
The Simple Estuarine Response Model II (SERM) website contains summary statistics of coupled biological – physical estuarine models as applied to over 700 Australian estuaries. The results of these simulations, along with the original ‘generic’ SERM simulations, can be accessed interactively using the SERM II interface.
ACT Waterwatch.The Waterwatch database program allows you to enter your Waterwatch data and store it as a record or file; develop graphs and produce short reports about your data; and perform simple analyses on the Waterwatch data you have collected from your catchment. It can be downloaded from this site.
Australian Capital Territory
Australian Natural Resources Atlas. Australian Capital Territory Department of Urban Services was involved with water quality monitoring. A water quality report is available for the Murrumbidgee River only, containing turbidity information.
New South Wales
Australian Natural Resources Atlas. Data were primarily provided by the Department of Land and Water Conservation’s Key Sites Surface Water Quality Program. Click on the basin name in the table to view a water quality report for that basin.
Murray Darling Basin Soil Information. This site has been created to promote awareness and access to key soil information for the Murray-Darling Basin. Industry, land managers, regional planners, scientists and educators are some of the groups to whom the data is likely to be of significant use.
NSW State of the Environment Reports.
Streamwatch – Australian Museum. This site has water quality data available from different regions throughout New South Wales (including suspended solids) are available for most streamwatch sites.
Waterwatch NSW. Choose a Waterwatch site from an interactive map of New South Wales. Water quality data (including suspended solids) are available for most Waterwatch sites.
Waterinfo. The NSW Department of Infrastructure, Planning and Natural Resources has over 200 datasets of water quality results from discrete samples. This page provides a list of stations with links to discrete water quality data available for each station. Data is updated weekdays overnight.
Australian Agriculture and Natural Resources Online (AANRO). An integrated knowledge discovery tool for agriculture and natural resources. Search AANRO for agriculture and natural resources information
Australian Coastal Atlas. The QEPA’s water quality data is now available on the internet via the Australian Coastal Atlas (ACA). The ACA allows maps to be produced from a number of available data layers. Water quality monitoring sites can be presented on a map and viewed at a number of different scales alongside other datasets
Australian Natural Resources Atlas. 262 sites, (163 DNR & 99 EPA) were reported covering 34 basins. Click on the basin name in the table to view a water quality report for that basin. Data includes turbidity
Coastal Habitat Resources Information System (CHRIS). Interactive maps showing coastal habitats, with options for showing water quality monitoring data, including turbidity and suspended sediments
Department of Natural Resources and Mines. Data on the ambient quantity and quality of the State’s freshwater resources in streams and aquifers is available to the public in digital format under a range of fee and access arrangements.
The Ecosystem Health Monitoring Program (EHMP) have water quality maps of Moreton Bay and its river estuaries. Among the water quality indicators are turbidity and Secchi depth. Choose to view monthly water quality maps, seasonal medians or animations for each month.
Watershed. This web site provides access to gauging station information, streamflow data summaries and chemical analyses of water samples from the surface water data archive
Waterwatch Gold Coast. This site provides some water quality data from the Waterwatch program, including suspended solids and turbidity, from a number of creeks in the Gold Coast Region
Australian Natural Resources Atlas. The Department of Environment, Heritage and Aboriginal Affairs (DEHAA) and the South Australian Environment Protection Authority (EPA) are involved with this monitoring program. Click on the basin name in the table to view a water quality report for that basin. Data includes turbidity.
State of the Environment Report – Area Affected By Water Erosion. This page is from the state of the Environment Report for Tasmania and has maps of the extent and severity of gully, tunnel, and sheet and rill erosion on private land in Tasmania for 1992.
State of the Environment Report Turbidity in Tasmanian estuaries 19992000. Data from the State of the Environment Report, which shows average (each sampling event) and yearly median values for turbidity, from surface waters, for each estuary, for the dates JulyAugust 1999 to MayJune 2000.
Water Information Resources & Electronic Data (WIRED) is a joint State and Federally funded system providing on-line access to a range of water information products including water management policies, current river levels and flows, catchment reports, and data summaries for individual sampling/flow sites.
Australian Natural Resources Atlas. Victorian Department of Natural Resources and Environment (DNRE), Environment Protection Agency (EPA) and Melbourne Water are involved with this water quality monitoring program. Click on the basin name in the table to view a water quality report for that basin. Data includes turbidity
Murray-Darling Basin Commission’s Water Quality Monitoring Program. Information about this program can be found on this site. It has water quality data from the Murray Darling Basin for the years 1994-1995
Water Measurement Information System This site combines data from a number of community and scientific based monitoring programs into one easily accessible resource. Data includes suspended solids and turbidity
Waterwatch – Turbidity information maps This web site is designed to allow Waterwatchers to enter and upload their turbidity information and generate regional turbidity maps. Maps are available for the years 20002005.
Australian Natural Resources Atlas. The Western Australia Water and Rivers Commission (WRC) was involved with the water quality monitoring program. Turbidity data from only four basins were available for analysis.
Statewide assessment of river water quality Click on a drainage basin to access water quality data. Data is presented on maps, and includes turbidity and suspended solids when available.
Computational Aquatic Ecosystem Dynamics Model (CAEDYM) consists of a series of mathematical equations representing the major biogeochemical processes influencing water quality, including primary production, secondary production, nutrient and metal cycling, and oxygen dynamics and the movement of sediment.
The Catchment Modelling Toolkit is a repository of software and supporting documentation intended to improve the efficiency and standard of catchment modelling. Information about the models and how to access them can be obtained from this site. This site also provides information on how to choose an appropriate model.
SEDBASIN program analyses sedimentation of suspended sediment in a sedimentation basin. It also calculates design storm runoff from urban catchments.
Community model for coastal sediment transport. The U.S. Geological Survey and others are promoting the development of an open-source numerical model for sediment-transport in coastal regions. This page provides contact details for more information.
Existing models. This page links to a PDF file which summarizes some of the characteristics of existing hydrodynamic or coupled hydrodynamic / sediment-transport models that might be suitable starting points for a community model effort, some of which are available to download.
MODEIN computes total sediment discharge at a cross section of an alluvial stream having primarily a sand bed from measured hydraulic variables, the concentration and particle-size distribution of the measured suspended sediment, and the particle-size distribution of the bed material.
AQUASEA is a model to solve tidal flow problems in estuaries and coastal areas, lake circulation, and problems involving transport of mass, heat and suspended solids models and modelling software. Information about this product can be found on this site.
SSFATE is an integrated system combining a Geographic Information System (GIS) with a computational model that predicts the transport, dispersion, and settling of suspended sediments released to the water column as a result of dredging operations. Information about this product can be found on this site.
Soil and Water Assessment Tool (SWAT) is a river basin scale model developed to quantify the impact of land management practices in large, complex watersheds.
US EPA Water Quality Models. The U.S. Environmental Protection Agency provides links to a number of water quality models for simulating the movement of precipitation and pollutants from the ground surface through pipe and channel networks, storage treatment units and finally to receiving waters.
USGS Hydrologic and Geochemical Models are widely used to predict responses of hydrologic systems to changing stresses, such as increases in precipitation or ground-water pumping rates, as well as to predict the fate and movement of solutes and contaminants in water. Today, USGS models are available for free on the internet.