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9.4 Caring for the country: 5. Maintaining water flow
| Syllabus reference (October 2002 version) | ||
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5. Maintenance of environmental flows and natural processes in water |
Students learn to: | Students: |
Extract from Earth and Environmental Science Stage 6 Syllabus (Amended October 2002). © Board of Studies, NSW.
[Edit: 22 Jun 06]
Prior learning: Preliminary module 8.4 (subsections 2 & 4)
Background: The NSW and Victorian governments have introduced legislation to return some of the flow of the Snowy River that had previously been diverted to the Murray River for irrigation.
The Macquarie Marshes are a really important wetland for a variety of organisms, including birds, fish and aquatic invertebrates. They have been drying up recently due to the drought and extraction of water by irrigators.
present information as a flow chart to summarise the steps in forms of sewage treatment
- Use the library to access books and CD-ROMs to gather
information about sewage. Also try the Internet. On the Sydney
Water's Earth and Environmental Science site
, there is information about
how to plan and carry out an excursion to a sewage treatment plant. - If you can visit a sewage treatment plant in your local area, this will give you a much better understanding of how the material is treated and you could then construct your own flow diagram.
- You could use butcher’s paper or a computer print out with large print to present your flow chart. Make sure it includes all the steps of sewage treatment from when sewage reaches the treatment plant to when treated water is returned to the environment. Show the products of each step in the process. Identify what happens to the wastes.
assess management strategies and technologies used to assist in the maintenance of natural processes in surface water by:
- licensing irrigation/bore water users
- treating stormwater
- providing environmental flows from dams
Licencing irrigation/bore water users
Licences regulate the amount of water available to users and means that the amount of water available to use as irrigation water can be monitored and controlled. More water must be available to flow past the properties than is used, as environmental flows are essential for the health of the river. This is currently the practice in NSW and with some of the Artesian Bore users. A licence to irrigate allows a specific amount of water to be used each year. A problem in this system can occur in very wet seasons when a full allocation is used even though it is not required by some farmers.
Treating Stormwater
This technology can prevent stormwater pollutants, including high nutrient loads, rubbish, organic pollutants and chemical pollutants, such as oil from vehicles, bitumen from roads and silt, from entering the riverine ecosystems. Much stormwater directly enters the ocean through ocean outfalls, leading to rubbish, such as plastic and animal droppings, being carried out to sea. This is harmful to marine animals.
One stormwater technology that is being used by many council’s is the installation of gross pollutant traps.
How
Sydney Water treats its stormwater
Sydney Water
Providing environmental flows from dams
Some rivers have either totally or partially ceased flowing due to the water being tied up in water storage or diverted into irrigation schemes. The Murray–Darling Basin Commission has allocated a certain amount of water to flow from dams to mimic flood conditions in the Barmah–Millewa Redgum Forests, allowing plants, birds, native fish, reptiles and frogs the opportunity to breed. Schemes such as these should be expanded and researched to allow scientists to identify if broader and longer term benefits to society and the environment can be achieved.
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