Background

Most stormwater run-off after heavy rainfall flows down drains into creeks and rivers, eventually flowing out to sea. The run-off carries with it sediment, organic matter, and pollutants such as litter and nutrients which result from human activity. These reduce water quality and can lead to problems such as algal blooms, poisoning of organisms and entanglement of aquatic species in litter.

Wetlands are among the most productive and diverse ecological systems on earth. They support an enormous variety of plants and animals, such as water birds, insects, crustaceans and invertebrates. Many vulnerable species such as the Growling Grass Frog are found only in wetlands. An important function of wetlands is their ability to remove nutrients from stormwater runoff to improve water quality. Fine particles attach to plant stems while large particles sink to the bottom.

Ecolinc has a stormwater wetland, which is fed by run-off directed from the surrounding area. The still water allows for sediment and other pollutants to settle to the bottom, where they are consolidated by the root systems of aquatic plants. These plants also trap and filter litter and leaf material, and absorb and utilise the nutrient content to grow. After the water has travelled through the wetland, the cleaner overflow is released back into the nearby Werribee River.

Prior Knowledge

No prior knowledge required.

Learning Intentions

In this activity students will:

• Understand the impact of stormwater pollution in waterways.
• Appreciate how constructed wetlands can be used to reduce stormwater pollution.
• Become familiar with a number of chemical and biological tests that can be used to determine water quality.

Activities

The students will:

• Examine the Ecolinc stormwater wetland and Werribee River noting human impact
• Conduct a range of chemical tests on water samples
• Use macroinvertebrates to biologically determine the water quality of the selected sample.

Victorian Curriculum

• Water is an important resource that cycles through the environment (VCSSU101) [1]
• Classification of environmental resources and the forms that water takes as a resource (VCGGK105) [2]
• Ways that flows of water connect places as they move through the environment and the ways this affects places (VCGGK106) [3]
• Causes of an atmospheric or hydrological hazard and its impacts on places, and human responses to it to minimise harmful effects on places in the future (VCGGK110) [4]