Wetlands: Natural and Constructed
Wetlands were long regarded as wastelands but are now recognised as important features in the landscape that provide benefits for people and other animals. Wetlands are home to an abundant variety of plants, water bugs, reptiles, birds, fish, frogs and mammals - they are considered to be 'biological supermarkets'. They are among the most productive environments in the world and form a link between our land and water resources.
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A Natural Wetlands |
A Constructed Wetland |
Constructed wetlands (made by humans) are built to act like natural wetlands. They are used to help treat stormwater and catch floodwaters. Constructed wetlands include dams, lakes and ponds.
Stormwater comes from urban areas after rain. As water flows across roads and other hard surfaces it can pick up pollution such as rubbish, chemicals and sediment. This polluted stormwater can be caught and filtered by constructed wetlands before it enters a waterway.
In urban areas, there are usually large sections of paved surfaces where the water cannot soak in, as it would with natural soil cover. More water therefore runs off these surfaces adding to flood levels in waterways. Constructed wetlands can accommodate and slow down some of this floodwater before it reaches the waterways.
Rock riffles are a feature of constructed wetlands and help to slow down the water speed to reduce the impact of flooding.
Rock Riffles at William Lawson Wetlands