Warragamba dam – Australia
Warragamba Dam is Sydney's largest drinking water catchment. It is 9,050 square kilometres. Supplies water to more than 3.7 million people in Sydney and in the lower Blue Mountains. When the dam is full it holds 2.6 million megalitres of water. More than 80% of Sydney's water comes from Warragamba Dam. The water comes from the COxs and Wollondilly rivers which flow into Warragamba Dam, which is one of the worlds largest water supplies. WaterNSW manages the dams untreated water supply, WaterNSW supplies high quality raw water that is then treated to Australian drinking water guidelines.
The 1998 Sydney water crisis involved the suspected contamination by the microscopic pathogens cryptosporidium and giardia of the water supply system of Greater Metropolitan Sydney, between July and September 1998. – management they had to boil water during this period to rid of pathogens. - Now they do a lot of water quality tests frequently so that the water is always safe and clean for drinking in Sydney
When drought has affected the dam as in March 1983 the lake reached a low of 45.4%. As the New South Wales State Government tried to reduce this risks of drought they implemented water restrictions such as fines.
Some facts: The dam is made out of concrete and took 12 years to build, it holds about 4 times more water than Sydney harbor and accounts for 8-% of Sydney’s water supply. After heavy rain and the lake begins to get full, water is released down the spillway which was completed in 2002 for protection from an extreme flood.