Warragamba Dam Booklet
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WARRAGAMBA SYSTEM WARRAGAMBA DAMS OF GREATER SYDNEY AND SURROUNDS Warragamba 1 Sydney’s drinking water is collected from five catchment areas, occupying 16,000 square kilometres. Water is stored in 21 dams, holding over 2.5 million megalitres of water. The Warragamba Catchment supplies Warragamba Dam, Sydney’s most important source of water. Completed in 1960, Warragamba Dam holds about four times more water than Sydney Harbour and currently accounts for about 80 per cent of the region’s available water supply. < WARRAGAMBA DAM 2 Introducing WaterNSW WaterNSW is Australia’s largest water supplier. We provide two-thirds of the water used in NSW and develop infrastructure solutions for water supply security and reliability. We operate and maintain 42 large dams and we deliver water for agriculture and drinking water supply customers. WaterNSW also protects the health of Sydney’s drinking water catchment to ensure highest quality drinking water is consistently available. 1 Blue Mountains Catchments Greaves Creek Dam Woodford Sydney’s Medlow Dam Dam Cascade Dams drinking water Lithgow C o er x iv s R R y i r v u e b r s e k w a H Katoomba Prospect catchments Reservoir Warragamba Dam Pipelines Prospect Water Filtration Plant Sydney er iv anal Nepean R Lake ver wmung R Ri Burragorang Upper C a Ko or n o iv r er o W Woronora Dam Broughtons Pass Weir Pheasants Nest Weir Na ttai R Nepean Dam Cataract Wing iv e er Dam c a r r Avon Wollongong ib e Cordeaux e R Dam Crookwell iver Bowral Dam Wingecarribee Reservoir er Riv Fitzroy Falls illy nd lo Reservoir ol Bendeela Pondage Goulburn W Lake Yarrunga Tallowa Nowra Dam er iv R Canberra n e v a lh a o h S Braidwood Sydney’s drinking water catchments Pumping station Canals and pipelines Dam Cooma 2 The catchments A catchment is an area where water is WaterNSW helps protect five catchment areas, collected by the natural landscape. In which provide water to greater Sydney and a catchment, all rain and run–off water local communities. eventually flows to a creek, river, lake or ocean, They are: or into the groundwater system. • Warragamba Catchment Natural and human systems, such as rivers, • Upper Nepean Catchment bushland, farms, industry, homes, plants, • Woronora Catchment animals and people can exist alongside one • Shoalhaven Catchment another in a catchment. • Blue Mountains Catchment The catchments occupy about 16,000 square kilometres in total. They extend from north of Lithgow and Blackheath in the upper Blue Mountains, south to the source of the Shoalhaven River near Cooma, and from < WARRAGAMBA CATCHMENT Woronora in the east to the source of the Wollondilly River near Crookwell. 3 Warragamba Catchment Located about 65 kilometres west of Sydney in a narrow gorge on the Warragamba River, Warragamba Dam is one of the largest domestic water supply dams in the world. Water is collected from the catchments of the Wollondilly and Coxs River systems, covering an area of 9,050 square kilometres, to form Lake Burragorang behind Warragamba Dam. Lake Burragorang is the largest urban water supply in Australia, containing about four times the volume of Sydney Harbour. It is the main water supply for more than four million people in the greater Sydney region. 4 Sydney’s evolving water supply system Australia is one of the driest inhabited Convict labour then developed Busby’s Bore, a continents on earth. Water has been vital to four kilometre tunnel leading from the Lachlan the survival and prosperity of Sydney since Swamps, (now Centennial Park) and ending in the first days of the new colony. The need to the south–east corner of Hyde Park. ensure a reliable water supply through times By 1852, drought and increasing population of drought and variable seasonal rainfall has led to the call for a more permanent water driven the development of several complex supply for Sydney. A third water source, the and innovative water supply schemes. < TUNNEL INTERIOR Botany Swamps Scheme, began operations in Sydney’s first water supply came from the Tank UNDER OXFORD STREET late 1859 but within 20 years this once copious Stream, named for the ‘tanks’ or reservoirs cut < VICTORIA BARRACKS: supply of fresh water was depleted. into its sides to hold water. The stream, which SHAFT DOWN TO The Upper Nepean Scheme was Sydney’s wound its way through the colony before BUSBY’S BORE fourth source of water supply. Completed in emptying into Sydney Harbour at Circular 1888, the Scheme diverted water from a series Quay, degenerated into an open sewer and of weirs on the Cataract, Cordeaux, Avon and was abandoned in 1826. Nepean rivers to Prospect Reservoir via 64 kilometres of tunnels, canals and aqueducts, known collectively as the Upper Canal. The building of Cataract, Cordeaux, Avon and Nepean dams between 1907 and 1935 greatly increased the Scheme’s capacity. < BUSBY’S BORE OUTLET, HYDE PARK. PAINTING BY J.SKINNER 5 Why Warragamba Dam was built Warragamba River was a short stretch of water, only about 23 kilometres long, that ran from the junction of the Coxs and Wollondilly rivers to its junction with the Nepean River. The Warragamba River offered two important advantages as a site for a major dam. Firstly it had a large catchment area, and secondly the river flowed through a long narrow gorge. A comparatively tall and narrow dam capable of impounding a vast amount of water could be built. Its potential was identified as early as 1845. The first sketch plans were drawn up in 1867, but plans were deferred during the < WOLLONDILLY RIVER IN BURRAGORANG VALLEY In the interim, the Warragamba Emergency construction of the Upper Nepean dams BEFORE FLOODING Scheme was built to urgently address Sydney’s between 1907 and 1935. An increasing demand critical water shortage. This scheme consisted of for water from an expanding population, and a weir and pumping station on the Warragamba a record drought from 1934 to 1942, forced the River and a pipeline to Prospect Reservoir. It development of Warragamba Dam to ensure began operating in 1940 and was in use for a reliable water supply. almost 19 years until the dam was completed. 6 How Warragamba Dam was built Warragamba Dam was a major engineering > LEFT TO RIGHT feat of the mid 20th Century. CELEBRATING THE TWO MILLIONTH TON OF Following extensive geological examination, two CONCRETE POURED temporary dams and a tunnel to divert the river WARRAGAMBA WALL were built first. More than 2,300,000 tonnes of UNDER CONSTRUCTION sandstone were removed from the site. INTERLOCKING Concrete was mixed on site using 305,000 CONCRETE BLOCKS tonnes of cement and 2,500,000 tonnes of sand and gravel. The sand and gravel were transported from McCann’s Island in the Ice was mixed with the concrete to control Pedestrian access between the Warragamba Nepean River via a unique aerial ropeway. heat generation and to prevent cracks from township and the work area was provided by forming. One of the first pre–stressed concrete two suspension bridges, one across Folly Creek The dam was built in a series of large towers in Australia was built to house the ice– and the other across the Warragamba Gorge interlocking concrete blocks. A system of making plant. just downstream of the dam. overhead cableways lifting 18 tonne buckets was used to place the concrete. Residents living in the Burragorang Valley, When the then Premier of NSW, the Hon. which was to be covered by rising waters, were Robert J. Heffron MP, officially opened relocated. More than 64 square kilometres of Warragamba Dam on 14 October 1960, trees were cleared so they would not rot and thousands of guests, workers and their families float downstream, to block the dam’s outlets gathered for a day of celebration. and crest gates. 7 Life in the Warragamba township Construction History Warragamba was established specifically as a Geological investigations 1942 construction town. At its peak the town housed about River diversion works 1946 3,500 people, in mostly prefabricated cottages, as well as barracks for single men and women. Some 1800 men Site works 1948 from at least 25 nationalities, many of whom were post WWII immigrants, worked alongside each other with Excavation 1950 little friction. Concrete pour 1953 Work, family and social activities all centered around Completed and opened 1960 building the dam. The Water Board provided roads, utilities and other services but many of the town amenities Wall raised five metres 1989 could not have existed without the voluntary labour and Auxiliary spillway completed 2002 fundraising activities of the residents. Deep water pumping station refurbished 2006 Unlike other communities that disappeared almost overnight once dam construction ended, Warragamba < TOP TO BOTTOM Electrical upgrade completed 2009 has remained a close–knit township which even WARRAGAMBA Crest gate upgrade completed 2012 today proudly highlights its relationship with its PRESCHOOL, 1955 awe–inspiring neighbour. FESTIVAL OF CAROLS, 1964 8 How the dam works Warragamba Dam supplies bulk water to three How the dam is monitored water filtration plants where it is filtered and distributed to people living in Sydney and the WaterNSW officers inspect and monitor lower Blue Mountains. Warragamba Dam through a network of more than five kilometres of galleries. They The best quality water is selected and drawn monitor water pressure, seepage, and any through screens at three outlets in the physical changes in the dam structure and upstream face of the dam. After flowing by its foundations to ensure these are within gravity to the valve house, two pipelines feed acceptable limits. the raw water to Prospect water filtration plant and via off–takes to smaller filtration Warragamba Dam was designed to deflect plants at Warragamba and Orchard Hills.