This service provides Australian surface hydrology, including natural and man-made features such as water courses (including directional flow paths), lakes, dams and other water bodies. The information was derived from the Surface Hydrology database, with a nominal scale of 1:250,000. The National Basins and Catchments are a national topographic representation of drainage areas across the landscape. Each basin is made up of a number of catchments depending on the features of the landscape. This service shows the relationship between catchments and basins. The service contains layer scale dependencies.

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No abstract available

This report presents the results of a study by Geoscience Australia of Stokes Inlet and Wellstead Estuary, located in southwestern Western Australia, based on data collected during surveys in March 2006 and May 2007. It includes the present day rates of organic matter breakdown in the sediments of these estuaries, sediment and porewater properties, sedimentation rates, and an account of the historical environmental changes to these estuaries based on the sediment record. In the report you will find: 1. Purpose and background 2. Environmental Setting 3. Methods 4. Benthic Chambers 5. Sediment Cores and Grabs 6. Results and Discussions 7. Environmental conditions during the survey 8. Present-day nutrient dynamics in Stokes Inlet 9. Palaeoenvironmental reconstruction 10. Key conclusions

This project was conducted by Geoscience Australia in collaboration with the Water Science Branch of the Department of Water, Western Australia, to acquire baseline information supporting the condition assessment for Hardy Inlet. The project contributes to the Estuarine Resource Condition Indicators project funded by the Strategic Reserve of the National Action Plan for Salinity and Water Quality / National Heritage Trust and forms part of the Resource Condition Monitoring endorsed under the State (Western Australia) Natural Resource Management framework. Two surveys were undertaken in Hardy Inlet in September 2007 and April 2008 with the aim to develop an understanding of the historical environmental changes and current nutrient and sediment conditions for the purpose of developing sediment indicators to characterise estuary condition.

In early autumn 2006 (14th March to 4th April), Geoscience Australia conducted a field survey to investigate the major processes controlling water quality in Wellstead Estuary, Gordon Inlet and Beaufort Inlet. This project aimed to address critical knowledge gaps in understanding the impact of sediment-water interactions on water quality in each estuary, in particular, to identify the major controls on nutrient abundance and availability. The impacts of sediment-water interactions on overall water quality took into account: 1. shallowness of the estuaries and long water residence time; 2. productivity of microbenthic algae; and 3. the type of aquatic plant growth. Recommendations for the future management of these estuaries included: 1. Reducing nitrogen loads from the catchments of Wellstead Estuary and Gordon Inlet, and reducing the phosphorus loads from the catchment of Beaufort inlet; 2. Monitoring the abundance of macroalgae in Wellstead Estuary, the abundance of macrophytes in Gordon Inlet and the water column Chl-a concentrations in Beaufort Inlet.

In April 2005, Geoscience Australia (GA) conducted a field survey of the waterbodies of the Torbay catchment drainage system. The Torbay Catchment Group and the Western Australian Department of Environment commissioned this study in order to address critical knowledge gaps in their understanding of the major components of the nutrient budget. In particular, the role of benthic nutrient fluxes, their magnitude, and total benthic nutrient supply to the water column for phytoplankton growth. The waterbodies studied were Torbay inlet, Lake Powell, Marbellup Brook and Lake Manarup. The key findings of this study were: 1. the sediments are a major source of nutrients to the water column of all waterbodies; and 2. denitrification, nitrogen fixation and benthic photosynthesis are critical processes influencing overall water quality.

Geoscience Australia has conducted four surveys in the Swan River Estuary to investigate benthic nutrient fluxes and their impact on water quality. Surveys were undertaken in March 2000, March 2001, September 2001 and October 2006, and both the upper and lower sections of the estuary were sampled. This report details the findings of the most recent benthic nutrient survey (October 2006) and compares benthic fluxes at selected sites during all four surveys. During the October 2006 survey, very high nutrient fluxes were recorded in the upper estuary muddy sites. Combined with very low denitrification efficiencies, large sediment nutrient pool sizes and hypoxic bottom waters, these muds are a significant source of bioavailable nutrients to the water column. Between 2000 and 2006 there has been a significant increase in the amount of organic matter decomposition and nutrient release from the muddy sediments in the upper estuary. A similar pattern is observed in the central basin, however, the change is not as severe. The shallow sandy margins of the lower estuary are sites of photosynthetic production, however, these differ between benthic and pelagic production depending on the light attenuation. When light is available at the sediment surface benthic production is evident, when light penetration is insufficient to reach the sediment surface pelagic production is more evident.

Boring by the Alice Springs Works Department and by Webb Bros. of Mt. Riddock Station showed that subterranean water supplies in the schists and gneisses in this area are usually small in quantity and that the water is brackish. The best chances of obtaining water for the mining fields seems to lie in sinking relatively shallow wells on the creeks and depressions running northward from the Harts Range. These depressions are believed to contain from 30 to 60 ft. of alluvium. Eight possible sites for wells were selected, two being within the foothills of the main range and six at a distance of 1.5 to 2 miles from the foothills of the range. Six of these sites are now being tested by a light hand-boring plant. This plant is expected to penetrate the alluvium quickly and wells will be sunk where favourable results are obtained. The sites selected are within easy reach of the following mines: Jenkins' Mine, The Spotted Tiger Mine, B. Rech's (Rex?) Mine, Hit and Miss Mine, Central Mine and Eldorado Mine.

On May 3rd, and again on June 1st, the author visited the Cotter dam to investigate a reported loss of water from the fault on the northern side of the wall. This report gives an account of these visits, together with the author's observations and conclusions in relation to the reported water loss.