Where is Sydney's main water catchment area?

Sydney is the largest city in
Australia, with over 4.6 million people and covering over 12,000
square kilometers. Because Sydney is settled in a Coastal Basin, it
must get the majority of its fresh water from rivers and lakes inland. Any area where
the landscape collects water without human intervention is called a
Catchment; the Sydney Catchment Authority is
the agency tasked with protecting, managing, and operating the various catchment areas
around the city.

The SCA is a New South
Wales government agency, and it operates the largest fresh water catchments.
In managing the natural landscape, the SCA has built several dams which allow the
natural water flow to collect into man-made lakes, thus ensuring a greater natural
supply of water in times of need.

Collecting water from
five rivers into a natural ravine, the Warragamba Dam creates
Lake Burragorang in Australia, with about 9,051square kilometers of
water storage. From the SCA website:

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Lake Burragorang is the largest urban water
supply in Australia, containing four times the volume of water of Sydney Harbour. It
provides about 80 per cent of the water supply for nearly four million people in the
Sydney region.

As well as
supplying fresh water to three filtration plants, the Warragamba Dam contains a
50 megawatt hydroelectric power station, which operates only when
the lake is at a high level.

Properly maintaining catchment
areas is of vital importance to the well-being of Australian citizens. Without a
reliable and healthy source of fresh water, living conditions would be worse and
agriculture would suffer. As of 2006, Australia used 493 litres of water per
person per day, the second highest water usage in the world. Fresh water is a
vital resource and the SCA is dedicated to keeping Sydney's Water Catchment areas
intact, productive, and secure.