Water Sustainability

Do our future generation really have sufficient fresh water?

Facts of Sydney and Water

• Sydney’s population has doubled since the 50’s and is still increasing due to

civilisation and policy of centralisation. The population is now 4,284,379.• 151000 litres/person annually OR annual total of 634,742 mega litres; this equals

to 20.128 ton/sec.

• Except for 1998, the last 13 years have seen below average inflows to Warragamba Dam, which supplies 80% of the water supply.

• The population is estimated to reach 5.3 million by 2031 which means water

consumption will increase by at least 20% by then.

• Recycle water only accounts for 4% of Sydney water supply.• Sydney faces the risk of drought and that water crisis is possible in Sydney.

Waste Water and Sewage

http://www.sydneywater.com.au/OurSystemsandOperations/

About Wastewater• Sydney Water collects + treats more than 1,2 billion litres of wastewater each

day. 36 million litres or 3% is recycled daily.• Around 75% of the wastewater is processed at Malabar, North Head and Bondi.

The effect of discharges on water quality and aquatic life is monitored weekly by the Department of Environment and Climate Change to ensure performance standards are met.

• Use of recycled water has increased from 6.2 billion litres a year in 1995 to

approximately 25 billion litres a year. This will grow to 70 billion litres a year by 2015.

• Sydney Water operates 65 Stormwater Quality Improvement Devices (SQIDs), including trash racks, litter booms and sediment traps.

• Trade Waste Policy is in place to control the quantity and quality of trade waste discharged.

• Sydney Water owns 31 sewage treatment plants.http://www.sydneywater.com.au/OurSystemsandOperations/images/WastewaterSystem.jpg; http://www.sydneywater.com.au/OurSystemsandOperations/http://www.sydneywater.com.au/OurSystemsandOperations/WastewaterTreatmentPlants/

Black water vs. Greywater

• Black water contains water from the toilet (or kitchen sink)

• It is treated by chemical or biological agents and disinfected

• It is generally not suitable for reuse

Grey water is contaminated or used water that does not contain sewage e.g. showers, sinks or washing machines.

Grey water is safe to use on gardens if it is either treated or not stored for more than 24 hours.

The amount of Grey water is much more than Black water and is less expensive to be treated

http://www.ecocommunity.com.au/default2.asp?active_page_id=123

Facts and Figures

http://www.cityofsydney.nsw.gov.au/Environment/Water/CurrentStatus/WaterConservation/WaterDemand.asphttp://www.sydneywater.com.au/Publications/Reports/AnnualReport/2007/menu/performance/Goal3.cfmhttp://www.sydneywater.com.au/annualreport/pdf/Annual_Report_Summary_2008_Final.pdf

About 9% of water consumption is used for drinking and personal hygiene. CSIRO projections show that

Sydney’s average annual rainfall

may decrease by 3% by 2030.

In Sydney approx. 70% of piped water waste water which is minimally treated and discharged to the ocean.

Underground SewersFresh water Settlement

Residential and Industrial Pollution

Open Sewers

Sewerage system & development patterns

Increase in population

More water needed

DroughtNew water sourceDams, pumps and pipes

Polluted streams became the first sewerage channels. Later the sewerage network followed the patterns of development.

Henry F.J.J, 1939, The water supply and sewerage of Sydney, Halstead Press, Sydney

What precipitated the development of waste water system?

• Ridding of waste + no backflow• Hygiene and comfort• Minimise spread of disease and pests

Henry F.J.J, 1939, The water supply and sewerage of Sydney, Halstead Press, Sydney

What are the infrastructure that support the waste water system?

• 23,500km of sewer pipes• 663 sewage-pumping stations • 31 sewage treatment plants • $33 million on cleaning,

repairing and relining pipes. (2006-07)

http://www.sydneywater.com.au/Publications/Reports/AnnualReport/2007/menu/performance/Goal3.cfmImage: http://www.digitalapoptosis.com/archives/montreal/Olympic%20Pool.jpg

487 billion litres of treated wastewater (2006-07)

243 500 Olympic pools

What effect has the system had on the city?

+• Improve quality of life – convenience• Control of various pest and diseases• Production of crops (sewerage farms

in the past)• 100% of captured biosolids re-used

(for horticulture and other beneficial purposes)

• Save water• Desalination plant to supply up to 15%

of Sydney’s drinking water by 2009–10• Recycled water to replace 12% of

drinking water supply by 2015 (70 billion litres)

Henry F.J.J, 1939, The Water Supply and Sewerage of Sydney, Halstead Press, Sydneyhttp://www.sydneywater.com.au/Publications/Reports/AnnualReport/2007/menu/performance/Goal3.cfmhttp://www.sydneywater.com.au/annualreport/pdf/Annual_Report_Summary_2008_Final.pdf

-• Backflow of waste from ocean

outfalls• Condensed areas of odour near

treatment plants

Image: http://www.waterforlife.nsw.gov.au/__data/assets/pdf_file/0017/1457/06mwp_chapter_5.pdf

Wollongong - Treatment Plant + recycled water plant.

Limitations of the System

• Expensive to construct/upgrade• Maintenance is difficult (leaking pipes)• Difficult to implement upgrades/dual

systems in existing developments• Loss of resources (water and nutrients)• System bypass due to overflow

http://www.sydneywater.com.au/OurSystemsandOperations/SewageOverflows/

Effects on Nature

Areas that are dammed are flooded

Destruction/modification of natural habitats

Ramifications on biodiversity of area

Concrete channels increase flow velocity

May cause siltation or erosion downstream

Image: http://eduplanner.net/gnu/data/blog/file/kalkin/3544170614_eb43ea15_rhs_warragamba4302C0.jpg

Warragamba Dam

Relationship between Resources

-• Fresh water waste water ocean• Large consumer of energy treatment,

distribution and removal of waste.

+• Recycled water + particles

Irrigation/horticulture (nutrients)/ industrial water supply

http://www.sydneywater.com.au/Publications/Reports/AnnualReport/2007/menu/Performance/Goal4.cfm

The Tank Stream (1788-1826)

Water was a top priority for the first settlement of Australia and Sydney Cove was selected by Governor Phillip due to a rivulet later known as the Tank Stream. (The name came from the three tanks excavated near its channel.)The Tank Stream became the primary water supply of the settlement for almost four decades until it became severely affected by drought and pollution in 1826.Wells and rainfall became the alternatives as a source of water in the following years.In 1850 the swamp areas which fed the Tank Stream were drained to permit further development of the City. Consequently the Tank Stream became little more than an open sewer. By the 1860’s the Tank Stream was covered and converted into part of the city’s main sewer.(The Water Supply and Sewerage of Sydney, F.J.J Henry, 1939)

Busby’s Bore (1830-1858)In 1824 the Governor directed John Busby (a Mineral Surveyor) to search for water. In 1826 Busby reported in favour of drawing a supply from the Lachlan Swamps.Busby’s Bore is a 3.5 km tunnel with an average height of 1.5m and width of 1.2m. It extends from Lachlan Swamps to Hyde Park and has 28 vertical shafts along the way. The project commenced in 1827 and began to supply Sydney with fresh water from seepage springs by 1830 however the project was not complete until 1837.Water became so abundant by 1833 that it became a source of revenue for the government by selling water to merchants at the port.The bore had a capacity of from 1,365,000L to 1,820,000L per day and provided an adequate supply of water to the population of Sydney at the time (20,000).In 1854 a small pumping station plant was constructed along with dams at several locations to increase flow and conserve water. These supplementations allowed Busby’s Bore to remain the sole source of Sydney’s water supply until 1858 when the Botany Swamps Water Supply Scheme commenced.(The Water Supply and Sewerage of Sydney, F.J.J Henry, 1939)

In 1824 the Governor directed John Busby (a Mineral Surveyor) to search for water. In 1826 Busby reported in favour of drawing a supply from the Lachlan Swamps.Busby’s Bore is a 3.5 km tunnel with an average height of 1.5m and width of 1.2m. It extends from Lachlan Swamps to Hyde Park and has 28 vertical shafts along the way. The project commenced in 1827 and began to supply Sydney with fresh water from seepage springs by 1830 however the project was not complete until 1837.Water became so abundant by 1833 that it became a source of revenue for the government by selling water to merchants at the port.The bore had a capacity of from 1,365,000L to 1,820,000L per day and provided an adequate supply of water to the population of Sydney at the time (20,000).In 1854 a small pumping station plant was constructed along with dams at several locations to increase flow and conserve water. These supplementations allowed Busby’s Bore to remain the sole source of Sydney’s water supply until 1858 when the Botany Swamps Water Supply Scheme commenced.(The Water Supply and Sewerage of Sydney, F.J.J Henry, 1939)

The Botany Swamp (1858-1886)

Upper Nepean Scheme (1867-1888)

Explosive population growth and recurring dry seasons result in the need for the fourth source of water supply. The upper Nepean River was chosen for the location of another 4 dam: Cataract Dam, Avon Dam, Cordeaux Dam, Nepean Dam. The scheme diverted water from a series of weirs on the Cataract, Cordeaux, Avon and Nepean rivers to Prospect Reservoir via 64km of tunnels, canals and upper Canals. The prospect reservoir by the time of 1888 has a capacity available for supply of 8,877 million litres of water.

Woronora River Works (1867-1888)

The Upper Nepean Scheme brought only temporary relief to Sydney’s water supply problems. The limit of its practicable capacity and additional sources had to be considered. Then in the early 20th century, recommendations for the construction of Woronora Dam and Warragamba Dam was approved. The construction of Woronora Dam started in 1927 and finished in 1941 at a cost of about $13,000,000. it has the capacity of 71,790 million litres, which is 8 times as big as the prospect reservoir.

Due to rapid development in the Sutherland-Cronulla area, and thereby increased demand for water, new pumping stations were constructed.

Bibliography• http://www.sydneywater.com.au/, viewed 14 January 2009• http://www.ecocommunity.com.au/, viewed 14 January 2009• http://www.cityofsydney.nsw.gov.au/, viewed 14 January 2009• http://farm3.static.flickr.com/, viewed 14 January 2009• Henry, FJJ, 1939, The water supply and sewerage of Sydney, Halstead Press, Sydney• Beasley, M, 1988, The sweat of their brows: 100 years of the sydney Water Board 1888-1988,

The Board, Sydney• Aird, W 1961, The water supply, sewerage and drainage board of Sydney, Metropolitan Water

Sewerage and Drainage Boar, Sydney

• Currently greater Sydney recycles about 25 billion litres of wastewater a year. By 2015, we'll be recycling 70 billion litres of wastewater a year - that's up to 12% of Sydney's water needs.

• HomesOne of Australia's largest residential recycling schemes at Rouse Hill provides recycled water to about 17,500 homes. This will more than double to around 36,000 homes.

• Industry Sydney Water's largest industrial recycling project at Port Kembla provides about 20 million litres of recycled water a day to BlueScope Steel, saving about 17% of the Illawarra's daily water use.

• Environment A new recycled water plant at St Marys will produce up to 18 billion litres a year of highly treated recycled water to help maintain the flow of the Hawkesbury-Nepean River, through the Replacement Flows Project.

http://www.sydneywater.com.au/SavingWater/RecyclingandReuse/

Case Study