water supply and sanitation in australia water supply and sanitation in australia as australia's supply of freshwater is increasingly vulnerable to droughts, possibly as a result of climate change, there is an emphasis on water conservation and various regions have imposed restrictions on the use of water. australia: water and sanitationdatawater coverage (broad definition)100%sanitation coverage (broad definition)90%continuity of supply (%)mostly continuousaverage residential water use (l/p/d)191 liter/person/day (2007)average domestic water and sewer billa$350/month or us$270/monthshare of household meteringn/aannual investment in wssa$2 bn/us$1.74 bn (2007–08) or us$81/capitashare of self-financing by utilitieshighshare of tax-financinglowshare of external financingnoneinstitutionsdecentralisation to municipalitiesin some states (primarily in queensland and tasmania)national water and sanitation companystate water and sanitation companieswater and sanitation regulatornoresponsibility for policy settingshare between states/territories and the commonwealth (national government)sector lawnonumber of urban service providers> 33number of rural service providersn/a in 2006, perth became the first australian city to operate a seawater desalination plant, the kwinana desalination plant, to reduce the city's vulnerability to droughts. a plant at kurnell has also been built and supplies sydney metropolitan area with water during droughts and low dam levels. more plants are planned or are under construction in gold coast, melbourne, and adelaide. the use of reclaimed water is also increasingly common. however, some desalination plants were put in stand-by modes in 2010 following above average rainfall levels and floods in 2010. governments of australian states and territories, through state-owned companies, are in charge of service provision in western australia, south australia and the northern territory, while utilities owned by local governments provide services in parts of queensland and tasmania. in victoria, new south wales and southeast queensland, state-owned utilities provide bulk water which is then distributed by utilities owned by either local or state governments. the minister for water is responsible for water policies at the federal level. water resources and water use australia is the driest inhabited continent on earth, and among the world's highest consumers of water. amongst oecd nations australia is ranked fourth-highest in water use per capita. total water runoff in 2004–05 was estimated at 243 billion cubic meters (bcm) and total groundwater recharge was estimated at 49 bcm, giving a total inflow to australia's water resources of 292 bcm. over 50 per cent of runoff occurred in northern australia. only 6 per cent of australia's runoff was in the murray-darling basin, where 50 per cent of australia's water use occurs. australia's total large dam storage capacity was 84 bcm. while surface water is well known, groundwater resources are not well known. in 2004–05 the national water commission undertook water balance assessments for 55 priority geographic areas across australia. of these water management areas six were overused (consumptive use was greater than sustainable yield) and seventeen had a high level of consumptive use as a proportion of inflows (consumptive use greater than 30 per cent of inflows). two water management areas (great artesian basin and mereenie sandstone – alice springs) had consumptive use greater than total annual inflow. total water use in australia in 2004–05 was nearly 80 bcm, with about 75 per cent of this water returned to the environment following in-stream uses such as hydroelectric power generation. consumptive use of water in the australian economy in 2004–05 was 18.8 bcm (6.4 per cent of resources), with the agriculture sector the largest user (65 per cent), followed by household use (11 per cent). residential water use declined from 243 liter/person/day in 2003 to 191 in 2007. according to the prime minister's office, as the impact of climate change intensifies, australia faces increasingly acute long-term water shortages with lower rainfall, rivers drying up and dam water levels falling. in most parts of australia, surface water stored in reservoirs is the main source for municipal water supply, making water supply vulnerable to droughts; only a much smaller share comes from groundwater. non-conventional water sources, such as seawater desalination, play an increasing role in australia's water supply, with one desalination plant commissioned to supply perth and others being built in sydney, the gold coast, melbourne, adelaide, and another is planned to be built at port augusta. the use of reclaimed water – the non-potable reuse of treated wastewater for irrigation of green spaces, golf courses, agricultural crops or industrial uses – is common and increasing in australia. among the 20 largest water utilities in australia, the largest volume of recycled water supplied was by sa water in adelaide (25,047 ml or 29.6% of sewage collected), while the lowest volume of recycled water was by actew in canberra (2,104 ml or 7.4% of sewage collected). adelaide the happy valley reservoir stores water for supply to adelaide. adelaide receives its drinking water from six sources: the river torrens, flowing from the adelaide hills through the city into the sea, with storage provided in the millbrook reservoir, kangaroo creek reservoir and hope valley reservoir; the onkaparinga river south of adelaide with storage in the mount bold reservoir, downstream of which water is diverted by the clarendon weir via a tunnel to the happy valley reservoir on the field river; the barossa reservoir, the warren reservoir, south para reservoir and the little para reservoir north-east of adelaide; most years the flow to these reservoirs is supplemented by water pumped from the river murray through two pipelines, the mannum–adelaide pipeline to the reservoirs on the river torrens, the south para reservoir and warren reservoir, and the other from murray bridge to the reservoirs on the onkaparinga river; the myponga reservoir on the myponga river about 60 km south of adelaide, supplying about 5% of the city's water supply. the adelaide desalination plant with the capacity to supply up to 50% of adelaide's water needs, but currently only supplying approximately 4%. the amount of water required from the river murray varies from about 40 per cent of adelaide's water needs in a normal rainfall year to as much as 90 per cent in a dry year. at full capacity the above-mentioned reservoirs hold about 200 million cubic meters of water, or a little less than 1 year's supply for metropolitan adelaide. a desalination plant near port augusta has been proposed which will supply almost all the residential water needs of towns on the spencer gulf. brisbane and gold coast water storage, treatment and bulk supply for brisbane is handled by seq water, which sells on to brisbane water for distribution to the greater brisbane area. water for the area is stored in three major dams; wivenhoe dam on the brisbane river, somerset on the stanley river and north pine on the north pine river. water is also provided by a number of smaller dams that are connected via the seq water grid. the wivenhoe dam is shared with the gold coast, which has two more water sources, the hinze dam and the smaller little nerang dam, both on the nerang river. groundwater from north stradbroke island is also transferred to the mainland to supplement the area's water supply. gold coast water has constructed a desalination plant at tugun, commissioned in 2009. a southern regional pipeline is also under construction that will share gold coast water with the rest of south east queensland. the a$2.5 billion western corridor recycled water project whose construction began in 2006 includes the construction of three new wastewater treatment plants, 200 km of pipelines and 12 pumping stations. it will provide reclaimed water to industrial users, agricultural users and to supplement drinking water supplies in wivenhoe dam. a severe drought in 2005-2007 triggered major investments, including the tugun desalination plant and the western corridor recycled water project. when rainfall became abundant in 2008-2010 and reservoirs were full, the state government decided in 2010 to put the tugun plant in stand-by mode, operating at less than 10% of capacity, and to close down a new advanced wastewater treatment plant on gibson island in order to save power and chemicals. canberra canberra draws its water supply from three separate catchment systems: the cotter river catchment, within the act; the googong system on the queanbeyan river in new south wales; and the murrumbidgee river, at the cotter pump station. all these rivers drain into the murray river which is ultimately part of the murray-darling basin. melbourne the silvan reservoir supplies water to melbourne. an adequate supply of fresh drinking water and the proper disposal of sewage was an early priority in melbourne. in 1853, a commission of sewers and water supply was established to improve the provision of each. the yarra river above the falls was the main source of drinking water till the completion of the yan yean reservoir. construction began in december 1853 and was completed on the last day of 1857. the commission was unable to find the money to create a sewer system for melbourne. as a result, the yarra below the falls continued for years as a dumping ground for sewerage, offal and other noxious waste. some 90% of melbourne's drinking water comes from uninhabited mountain ash forests high up in the yarra ranges east of melbourne. more than 157,000 hectares has been reserved for the primary purpose of harvesting water. these water supply catchments have been closed to the public for more than 100 years. melbourne's water supply system is based on the principle that it is better to start with the highest quality source water than having to treat it to reach required standards. according to melbourne water, melbourne is one of only about five cities in the world that has such protected catchments. water from the forests flows through streams in reservoirs, which provide security of supply for times of drought. one of these reservoirs is formed by the thomson dam on the thomson river located about 130 km east of melbourne in gippsland, from where water flows through a 19 km long tunnel through the great dividing range into the upper yarra reservoir and then onto silvan reservoir for distribution as drinking water in melbourne. the millenium drought resulted in depletion of much of the water in the reservoir of the thomson dam but as of 2022 it is approaching full capacity. in june 2007, the victorian state government announced a new plan to provide water security for victoria's growing population and economy by diversifying and boosting water supplies, networking the state's water resources in a victorian water grid and enabling a rapid and flexible response to changing future water needs. the plan includes a$4.9 billion of projects to secure melbourne and victoria's water supplies for the long term, including: the 150 billion litre per year, a$2.2 billion melbourne desalination plant in wonthaggi which would be the largest desalination plant in australia, supplying 30% of melbourne's water needs, for which a build–operate–transfer (bot) contract was awarded in mid-2009 to a consortium led by the french multinational suez; a major irrigation upgrade in the food bowl in northern victoria to deliver water savings to be shared equally between irrigators, the environment, and melbourne; and a major expansion of the victorian water grid with pipelines to connect melbourne's water system with the desalination plant and northern irrigation upgrades. these projects are expected to deliver a 50 per cent boost to melbourne's water supply within five years and allow water to be moved where it is needed most. perth the new victoria dam, shown here at 30.6% of capacity, supplies water to perth. perth receives approximately 10% to 20% of its water from a series of reservoirs, 40% from groundwater sources (mostly from the gnangara groundwater system north of perth), and 40% from two seawater desalination plants. perth's climate has dried considerably since the 1970s and average inflows to perth's metropolitan dams have dropped to around 60 gigalitres a year on average compared with 340 gigalitres in 1975. in 2006, perth became the first australian city to operate a reverse osmosis seawater desalination plant, the kwinana desalination plant, and a second seawater desalination plant began operation in 2013 in binningup near bunbury. together these two plants can deliver 145 gigalitres of water each year. stage 1 of a groundwater replenishment scheme has commenced, and when fully operational in 2019 it will have the capacity to recharge 28 gigalitres of highly treated wastewater to the groundwater supplies. sydney warragamba dam is the main source of water supply for sydney. more than four million people