Winneke and Cardinia Reservoirs in Providing Water for the Society in Melbourne - Case Study Example

Running head: Winneke and Cardinia reservoirs Student’s Name: Instructor’s Name: Course Code: Date of Submission: Table of Contents Table of Contents 2 Introduction 3 Discussion 3 Cardinia Reservoir 3 Winneke treatment plant (Sugarloaf reservoir) 4 Treatment of water process 4 Conclusion 8 References 9 Introduction Water is the basis of life and no society can survive without it. Having importance in everyday life, it is important to keep water clean for consumption in order to prevent diseases that may result from taking contaminated water. It is also important that water be conserved in order to serve the community when the rainfall is inadequate. This paper will discuss two water reservoirs; Winneke and Cardinia and the role they play in providing water for the society in Melbourne. Discussion Cardinia Reservoir Cardinia supplies water to the southern and southern-eastern suburbs together with the Morningston Peninsula. It was completed in 1973 and the area it supplies with water has an average rainfall of 80mm in a month. Cardinia Reservoir has a catchment area of 2800 hectares of offsteam water that is supplied from Silvan. It has a dam which is a rolled earth fill and has a rock embankment. With a maximum height of 85metres from the river to the crest, the dam measures around 1,542 meters in length. Surface area that is occupied by water in the reservoir is approximately 1,295 hectares. Cardinia reservoir has an available total capacity of 286,011 megalitres and usually holds a volume of 215,984 megalitres when it is around 70% full of water (Melbourne water, 2011).Cardinia serves as storage for water that is coming from off stream. It is very helpful in addressing the water shortage problem in Melbourne especially when rainfall is below average as happens in some cases. Winneke treatment plant (Sugarloaf reservoir) Around 20% of Melbourne’s water is treated at Winneke treatment plant which requires full treatment since it is not drawn from a protected catchment area. This plant was commissioned in 1980, and it was the first time that fully treated water was introduced as part of water supply in Melbourne (Melbourne water, 2011). It supplies Yarra valley and City West water customers.Under the occupational health and safety regulations of 2000, Winneke treatment plant is usually classified as a hazard facility. It has a high quantity of chlorine stored within the site which is used for disinfection. Sugarloaf reservoir was built in 1981 and occupies a catchment area of 915hectares which is off stream storage. It has a dam which is rolled rock fillembankment which has an upstream concrete face. The main dam has a maximum height of 89 meters with 1,050 meters of length measuring along the top of the dam. Top water level has a surface area of 440 hectares with the total available capacity being 96,253 megalitres. When full, it has a volume of 95,523 megalitres and the water usually goes into the Northern, Western and Central suburbs (Melbourne water, 2011). Treatment of water process Methods used in treatment of water which has sewage waste in Melbourne are land filtration, grass filtration and lagoons. Land filtration is usually used when there is a high rate of evaporation of the water. Treatment of sewage must be done first before the water can be treated as a final product. It involves removal of biodegradable substances from sewage through absorption of nutrients by the soil. Bays are usually flooded withup to 10 meters deep of sewage which later dries having lost up to 60% of water to evaporation. As plants grow around the sewage cattle and sheep are introduced in the area to graze and during this time organic matter from the sewage forms humus. Pollutants are trapped into the soil and normally digested by bacteria. Sewage filters through the soil as suspended solids remain on it. Grass and roots of plants absorb nitrogen in the nitrification cycle while phosphorous and heavy metals are removed through precipitation and cation exchange through absorption in the soil (Audrey & Richard, 2008). What remains of the water sewage then flows to the treatment plant. Another method used to treat sewage is grass filtration which involves removal of biodegradable material from the sewage through either consumption by bacteria or sedimentation. Bacteria in the grass serve to digest pollutants taking around 4-5 days and then the treated sewage flows into the treatment plant (Audrey & Richard 2008). Lagoon treatment is also another way through which sewage is treated before joining the water treatment plants. It involves passing sewage slowly in a series of ponds that are connected and containing high amount of naturally occurring bacteria. Bacteria convert nutrients which are either inorganic or organic into inorganic products that are easily consumed by algae. Water flows from one pond to the next under gravity. Sludge that contains heavy metals usually settles on the floor of the lagoons. After around 30-90 days of treatment, the water flows into the treatment plant for final processing before it can be released into the consumption system (Audrey & Richards, 2008). Treatment of water at Winneke treatment plant involves coagulation, clarification, filtration, chlorination, and fluoridation. Water which is untreated is usually pumped from the sugarloaf reservoir in the treatment plant whereby lime and aluminum sulphate are added to the water (Melbourne water, 2011). Water is then directed to one of the five sludge blanket clarifiers and it is injected with polyelectrolyte to help in flocculation and sedimentation. After this process, water passes through 14 sand filters before addition of chlorine, fluoride and lime. Treated water then flows to clean water reservoir and later distributed throughout Melbourne. Due to the nature of softness of the Sugarloaf raw water source, pre-lime dosing is done to ensure the ph. of the water meets operational requirements of the treatment plant. After this, alum dosing is done based on quality and quantity of the raw water. Alum helps in the coagulation of clarifiers. Sometimes it is also used to correct the level of alkalinity incase the amount of lime added is incorrect. There are five clarifiers at Winneke one having a circular design (C5) and the other four having a square design (C1-4) (Melbourne water, 2011). Each clarifier is independent of the rest. A difference lies between other reservoirs in Melbourne and Sugarloaf. Most of Melbourne’s water supply system includes reservoirs in protected catchments while Cardinia and sugarloaf reservoirs are off stream and do not collect rain water them. They get their water through pipes and from other reservoirs such as Silvan reservoir (Melbourne water, 2011). Water from these reservoirs is used mainly for domestic purposes having undergone thorough disinfection. Water for agricultural purposes such as irrigating the lawn is only partly purified and fluorinated. In most cases Melbourne water department prohibits use of domestic treated water for irrigating the lawn especially when the rainfall is below expected levels (Melbourne water, 2011). Main issues resulting from the sugarloaf and cardinia projects are stream flow and water quality. There is also a concern for vegetation and wildlife habitat. A water bubbling system is operational at Sugarloaf reservoir to remove manganese and iron compounds hat are stored in the water through oxidation. Water flow into the Yarra River from Sugarloaf reservoir is maintained at a minimum of 245 Ml/day in time of drought to ensure the quality of water is maintained near the original Yarra Brae Dam site (New energy foundation, 2006). Bush fires experienced time and again in catchment areas have a great impact on water supply in Melbourne. In 2009, fires that spread damaged about 30% of Melbourne’s water supply (Melbourne water, 2011). This mostly took place in Maroondah and O’Shannassy catchments. In order to safeguard against the bush fire zone, water was transferred to Cardinia Reservoir. Any future fire outbreaks could lead to devastating effects on catchment areas and threaten Melbourne with water shortage. In case of fire however, quality can be maintained by transferring water from any of the ten storage reservoirs. Long term effects on the other hand are more difficult to deal with as it takes time before vegetation can grow back. There are a number of reasons for the success of the sugarloaf project. One of the reasons for success is the professional staff involved in the work. It was also aided by the government’s commitment to environmental and social equity. To a large extent, sugarloaf is not as productive or economic as the Yarra Brae scheme since the government was willing to adapt a modified form of the same (New energy foundation, 2006).Another reason for success of the project is the fact that engineers were fully involved in the study for solutions of environmental problems that may arise. Involving members of the public in the decision making and keeping them well informed has also been instrumental in the success of the reservoir project. Conclusion In conclusion, Winneke and cardinia have played a major role in ensuring that residents of Melbourne get adequate and quality water for their consumption. Throughout the years, the reservoirs have helped to store water in times when conditions were bad and little rainfall was expected. Being reservoirs that do not directly collect water from rainfall, theyare usually with water throughout the year with a steady water level being maintained. It is important for catchment areas to be protected as a disaster could lead to a shortage of water in Melbourne. Efforts have been made to train specialized team of personnel to act as fire fighters during times when fires are prevalent in the area. This also includes equipping the fire department with adequate equipment to curb fire that may result. Reservoirs in general have aided in ensuring that Melbourne is supplied with quality water throughout the year. Recycling of water has become an adapted method for conservation of the same. In the near future, there is a possibility that recycling will complement rainfall in times of drought. References Audrey, W & Richard, C (2008). Sugarloaf pipeline: Preparing Winneke treatment plant for and increase in capacity. Retrieved 12 August 2011 from http://www.wioa.org.au/conference_papers/08_vic/documents/AudreyWalewijk.pdf Melbourne water. (2011). Water supply and distribution. Retrieved12 August 2011 from http://www.melbournewater.com.au/content/water_storages/water_supply/water_distribut ion/cardinia_reservoir.asp New energy foundation. (2006). IEA Hydropower Implementing agreement Annex VIII- Hydropower Good Practices: Environmental Mitigation measures and benefits case study 06-02: Reservoir Impoundment- Sugarloaf Reservoir, Australia. Retrieved 12 August 2011 from http://www.ieahydro.org/reports/Annex_VIII_CaseStudy0602_Sugarloaf_Australia.pdf Read More