Due to Australia’s unstable water supply and rainfall, dams are incredibly important in water security, one in particular supplies the majority of Sydney’s water – Warragamba Dam. Although dams have the capacity to be incredibly harmful to the environment, strategic management at Warragamba dam limits such impacts. The Sydney Catchment Authority, a NSW Government agency created under the Sydney Water Catchment Management Act 1998, has acknowledged that Warragamba Dam can affect the natural flow of water downstream. Providing water to the river through environmental flows is one way the SCA helps to restore ecological processes and biodiversity of water-dependent ecosystems. Currently, the SCA releases 43.3 million litre of water per day from Warragamba Dam into the Nepean River for environmental and riparian purposes. These environmental flows have many purposes, protecting aquatic ecosystems, reducing aquatic weeds and frequency of algal blooms, improving river health, improving conditions for native fish, such as eels, carp, trout, macquarie perch, catfish, and goldfish frogs, water birds and river-dependent plants and animals that rely on different flows to trigger migration and breeding as well as protecting river condition for recreation such as boating and swimming. Warragamba Dam, having experienced issues such as a toxic algal bloom in 2007, has implemented rigid rules and management in order to preserve the health of surrounding ecosystems as well as water quality. Other management strategies include:
- Educating farmers on the importance of erosion control to prevent contamination from faecal matter, to stop algal blooms.
- Providing grants to help build fences to prevent contamination from erosion and sediment which can lead to algae blooms and negatively impact ecosystem.
- Frequent testing of the water to ensure highest quality and to monitor the health of organisms and ecosystem