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foreword this is the second annual water operations report prepared by snowy hydro this report has been written and widely distributed for the benefit of all of the company s stakeholders and the people of the local communities associated with the snowy scheme this report describes in high level summary form how the snowy scheme operates the water operations during the 2008-09 water year and how snowy hydro met its obligations under the snowy water licence snowy hydro makes available to the public a large amount of information with respect to the water operations of the snowy scheme principally through our company s website www.snowyhydro.com.au this water operations report is an important element of that package of publicly available information snowy hydro is committed to improving public understanding and appreciation of the many responsibilities and obligations that the company has with regard to the water resources of the snowy scheme it is therefore our hope that all of the company s stakeholders and the people of the local community read this report opposite you will find an independent report that gives assurance of the accuracy of the data contained within this report further information including terminology calculation of data and snowy water licence obligations can be found by visiting www.snowyhydro.com.au or www.dwe.nsw.gov.au david harris executive officer water snowy hydro limited 2 2 89[close]
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khancoban pondage contents key highlights in this water operations report purpose of this report overview of snowy hydro the snowy water licence and our business downstream from the snowy scheme drought and water releases how the snowy scheme works the snowy-tumut development the snowy-murray development inflows snowy scheme inflows snowy scheme inflows for 2008-09 13 14 4 5 6 7 8 9 10 11 12 western river releases river murray catchment murrumbidgee river catchment environmental releases snowy river environmental flows snowy river increased flows guthega dam 15 16 17 18 19 snowy montane rivers increased flows storages snowy scheme storage for 2008-09 lake levels 20 21 3[close]
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key highlights snowy hydro complied with the snowy water licence requirement to target the required annual release to the river murray catchment in the 2008-09 water year snowy hydro complied with the snowy water licence requirement to target the required annual release to the murrumbidgee river catchment in the 2008-09 water year snowy hydro complied with the snowy water licence requirement to target environmental releases into the snowy river from jindabyne dam in the 2008-09 water year snowy hydro complied with the snowy water licence requirement to target environmental releases from tantangara dam in the 2008-09 water year the current drought sequence of 12 years is worse than what the snowy scheme was intended to cope with and includes the lowest inflow year on record during 2006-07 a number of consecutive years of above average inflows are now required to see snowy scheme storage levels increase to long term average levels snowy hydro is meeting both electricity and water obligations even through a drought sequence worse than what the snowy scheme was intended to cope with snow on the range tumut pond dam 4 4[close]
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purpose of this report the main purpose of this water operations report is to provide the company s stakeholders and the people of the local communities associated with the snowy scheme with information on how snowy hydro performed in the 2008-09 water year in meeting the obligations imposed on it by the snowy water licence those obligations essentially relate to 1 targeting water releases to the river murray and murrumbidgee river catchments the annual volumes of which are determined according to formulae set out in the snowy water licence targeting water releases from jindabyne dam into the snowy river for environmental purposes snowy river increased flows and facilitating potential additional natural flows over nominated snowy scheme aqueducts and targeting releases from tantangara dam both for environmental purposes snowy montane rivers increased flows 2 3 lake jindabyne the snowy water year commences on 1 may and concludes on 30 april each calendar year volumes in this report are quoted in gigalitres gl 1 gigalitre is equal to 1,000 megalitres ml 1 megalitre is equal to 1 million litres since the commencement of the operation of the snowy scheme water release volumes have been set as targets and any minor differences between the target and actual release volumes excess or shortfall are carried over to the next water year this is done in the form of overs and unders and is expressly permitted in the snowy water licence in recognition of the difficulties inherent in achieving precise release volumes using infrastructure on the large scale of that comprising the snowy scheme 5 for additional detail on the background and methods for the derivation of figures in this report further information is available on our website at www.snowyhydro.com.au 5[close]
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overview of snowy hydro although the snowy scheme was designed to produce electricity one of the key objectives of the three governments was to mitigate the effects of drought on irrigated agriculture in nsw and victoria in essence they wanted to improve the security of water supply to farmers along the river murray and murrumbidgee river the snowy scheme only became a reality when the governments worked out a way to pay for the construction and maintenance of the snowy scheme which was from the sale of the snowy scheme s electricity output the snowy scheme was built over a 25 year period from 1949 to 1974 it includes sixteen major dams seven power stations 145km of interconnected tunnels and 80km of aqueducts the snowy mountains hydro-electric authority was responsible for the construction and maintenance of the snowy scheme under the direction of the snowy mountains council from 1998 when the national electricity market nem was formed the electricity output from the snowy scheme had to be bid into the market with all other energy companies in an open competitive marketplace snowy hydro trading pty ltd was formed to trade the electricity output of the snowy scheme in the nem in 2002 the snowy mountains council and the snowy mountains hydro-electric authority were abolished and the snowy scheme was corporatised to create snowy hydro limited laverton north gas fired power station tumut 3 power station also snowy hydro trading became a non-operating subsidiary of snowy hydro snowy hydro today is a growing business providing a range of financial hedge and renewable energy products to participants in the competitive nem snowy hydro operates the 3800 megawatt mw snowy scheme snowy hydro also owns and operates the 300mw valley power gas-fired power station and the 320mw laverton north gas-fired power station both located in victoria red energy an electricity and gas retailer operating in three states with over 200,000 customers is a subsidiary of snowy hydro limited snowy hydro operates under an independent board and the company s shares are owned by the nsw government 58 vic government 29 and the commonwealth government 13 murray 1 power station 6 6[close]
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the snowy water licence and our business to ensure that the benefits of the snowy scheme could be maximised for both water security and electricity generation a set of operating principles and water accounting rules was developed under the 1957 snowy agreement on corporatisation in 2002 the key elements of those operating principles and water accounting rules were codified and carried forward in the snowy water licence issued by the nsw government the snowy water licence is not a freedom to act as is the case with most licence arrangements rather it is a bundle of a few rights and numerous legally binding and enforceable obligations the many legally binding obligations imposed on snowy hydro under the snowy water licence include obligations with regard to targeting water releases from the snowy scheme the calculation of the volume of water to be released from the snowy scheme each year to each of the river murray and murrumbidgee river catchments the required annual releases is prescribed by the snowy water licence it is not determined by snowy hydro snowy hydro s rights to collect divert store and release water under the snowy water licence in no way represent any form of ownership of the water all of the water in the snowy scheme is owned by the interests who have an entitlement to releases from the snowy scheme this includes the states of new south wales and victoria irrigators from those states and of course the environment 7 7 water releases from lake jindabyne into snowy river jounama release gates in practical terms to generate electricity snowy hydro must release water from the snowy scheme and to release water from the snowy scheme snowy hydro must generate electricity in this way water releases electricity generation and their associated market impacts are inseparably linked the mandatory nature of the obligations imposed on snowy hydro by the snowy water licence means that as a practical matter snowy hydro operates the snowy scheme to first meet its water release obligations and then to maximise electricity market opportunities within the constraints imposed by the snowy water licence downstream water users have never been charged for the water regulation services provided to them each year by the snowy scheme snowy hydro has to fund both the debt and operating costs of the snowy scheme through its participation in the highly competitive nem those electricity revenues pay for the increasing costs of maintaining and operating the snowy scheme including the costs associated with making environmental flows the calculation of the volume of water to be released from the snowy scheme each year to each of the river murray and murrumbidgee river catchments the required annual release is prescribed by the snowy water licence it is not determined by snowy hydro.[close]
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downstream from the snowy scheme snowy scheme releases and the other river murray and murrumbidgee river catchment inflows are re-regulated by the hume dam on the river murray and blowering dam on the tumut river neither of which are controlled by snowy hydro snowy hydro has no influence or involvement in the allocation or delivery of water to downstream water users for example to irrigators water releases for irrigation and environmental uses along the upper river murray are managed by the murraydarling basin authority principally through releases from dartmouth and hume dams the snowy scheme does not make releases into dartmouth dam water releases for irrigation and environmental uses along the murrumbidgee river are managed by nsw state water principally through releases from blowering and burrinjuck dams again the snowy scheme does not make releases into burrinjuck dam snowy scheme govt owned and operated murrumbidgee irrigation ltd burrinjuck dam nsw state water murrumbidgee river snowy tumut development blowering dam nsw state water coleambally irrigation ltd snowy murray development murray irrigation limited nsw hume dam river murray water nsw river murray vic goulburn murray water vic dartmouth dam river murray water 8 8[close]
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lake eucumbene drought and water releases snowy hydro s primary obligation under the snowy water licence is to release a calculated volume of water annually to each of the river murray and murrumbidgee river catchments each of these volumes is calculated principally by reference to inflows in drought years like we are experiencing at the moment the volume of water to be released from the snowy scheme is reduced under the formulae set out in the snowy water licence this is known as the dry inflow sequence volume disv reduction this reduction to the volume of water despite the challenges in recent years of critically low inflows snowy hydro is meeting both electricity and water obligations even through a drought sequence worse than what the snowy scheme was designed to cope with to be released from the snowy scheme has been applied since the 2006-07 water year which was the lowest year on record for inflows into the snowy scheme in 2006/07 only 683 gigalitres flowed into the snowy scheme storages compared to long term average annual inflows of around 2,800gl in the absence of a number of consecutive years of above average inflows the storages in the snowy scheme will not recover for some years underscoring the importance of snowy hydro s investment into gas fired electricity generation without this foresight and investment the financial implications on the business would have been severe ongoing inflows have resulted in low storages which will affect snowy hydro s ability to make long term average releases in 2009-10 and beyond 9 9[close]
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tumut canberra blowering power station how the snowy scheme works recognised as one of the greatest civil engineering wonders of the modern world the snowy scheme has the added distinction of being one of the most complex multipurpose mutli-reservoir hydro schemes ever built the snowy scheme s features include seven major power stations murray 1 murray 2 blowering guthega tumut 1 located 366m below ground level tumut 2 located 244m below ground level and tumut 3 one pumping station at jindabyne and a pump storage facility at tumut 3 16 major dams and a total storage capacity of 7000 gigalitres or almost 12 times the volume of sydney harbour 145km of inter-connected tunnels and pipelines and 80km of aqueducts 31 turbines with a generating capacity of 3800mw the snowy scheme was designed to collect and store water including water that would naturally flow east of the snowy mountains to the coast diverting it through trans-mountain tunnels and power stations and then releasing it west of the snowy mountains into the catchments of the river murray and the murrumbidgee river where it can be used for town water supply irrigation and environmental uses the snowy scheme comprises two major developments the northern snowy-tumut development and the southern snowy-murray development khancoban pondage blowering reservoir jounama pondage tumut 3 power station talbingo talbingo reservoir tantangara reservoir tumbarumba tumut 2 ug power station tumut 1 ug power station kiandra cabramurra adaminaby lake eucumbene khancoban murray 1 power station murray 2 power station cooma guthega power station jindabyne lake station pumpingjindabyne lake jindabyne berridale mt kosciuszko thredbo jindabyne power or pumping station dalgety underground power station tunnel snowy hydro limited water catchment boundary kosciuszko national park river water storage 10 10[close]
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the snowy-tumut development the snowy-tumut development consists of four power stations and 15 generating units the snowy-tumut development collects the headwaters of the upper murrumbidgee tooma and eucumbene rivers those waters are diverted through trans-mountain tunnels to tumut pond dam there they join the waters of the tumut river and flow through tumut 1 and tumut 2 underground power stations discharging into talbingo reservoir water stored in talbingo reservoir then passes through the tumut 3 power station and into jounama pondage blowering power station is located on blowering dam and is leased from state water water releases from blowering dam are controlled by state water a nsw state owned corporation to provide for town water supply irrigation and three of the six generators at tumut 3 power station have pumps that can be used to pump water from jounama pondage back up into talbingo reservoir thereby recycling water water is released from jounama dam into blowering reservoir a small hydro power station is currently under construction at jounama dam on the murrumbidgee river as at gundagai the snowy scheme contributes inflows of around 25 during average inflow years but 60 during drought years environmental use requirements blowering power station is therefore a run of river plant that operates as state water releases water from blowering dam into the tumut river which joins the murrumbidgee river near gundagai blowering reservoir 1500 metres tooma reservoir olgilvies intake deep creek intake jounama pondage blowering power station talbingo reservoir outstation intake burns creek intake 1200 tumut 3 power station tumut river tumut 2 pondage tumut pond reservoir tumut 2 power station tumut 1 power station happy jacks pondage murrumbidgee river 900 600 tumut river 300 0 to murrumbidgee irrigation area lake eucumbene tantangara reservoir power or pumping station underground power station tunnels and shafts tumut river 11 11[close]
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2100 metres khancoban pondage murray 1 power station geehi reservoir guthega pondage island bend pondage jindabyne pumping station lake jindabyne lake eucumbene 1800 murray 2 power station bourkes gorge intake burrungubugge intake 1500 snowy river geehi river 900 snowy river 1200 eucumbene river 600 geehi river swampy plains river 0 to murray irrigation area murray 2 pondage guthega power station power or pumping station tunnels and shafts 300 the snowy-murray development the snowy-murray development consists of three power stations and 16 generating units water in the upper snowy river is diverted at guthega dam through guthega power station inflows into the relatively small guthega pondage are seasonal during times of high inflows water flowing into island bend pondage is directed to lake eucumbene for storage and subsequently transferred to the river murray catchment pumps lift water from lake jindabyne normally using off-peak power to discharge into geehi reservoir on the western side of the great dividing range water from lake jindabyne cannot be pumped back to lake eucumbene on the river murray as at the hume dam the snowy scheme contributes inflows of around 8 during average inflow years but 33 during drought years at times of low inflows water from island bend pondage is diverted directly to geehi reservoir through a transmountain tunnel together with water which flows back from lake eucumbene from geehi reservoir with additional water from the geehi river the water passes through murray 1 and murray 2 power stations khancoban dam regulates water released from murray 2 power station down the swampy plain river which is a tributary of the upper river murray 12 12[close]
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inflows snowy scheme inflows the historical record of annual inflows into the snowy scheme is characterised by high variability with annual inflows ranging from less than 700gl to well over 5,500gl of particular note is the now unprecedented dry inflow sequence that started in 1996-97 and which includes the lowest inflow year on record during 2006-07 there has only been one year in the last 12 years that has seen slightly above average inflows this is the primary reason why lake levels have dropped over the past decade and remain at low to very low levels inflows from snowmelt snowy scheme inflows from may 1905 to april 2009 7000 island bend dam 6000 snowy scheme inflows gl pa 5000 4000 3000 average inflow 2000 1000 0 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 water year 13 13[close]
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snowy scheme inflows for 2008-09 drought conditions continued during the 2008-09 water year this negatively impacted on the snowy scheme with only 1,821gl of inflows this is about 65 of the long term average annual inflow of 2,800gl lake eucumbenee snowy scheme inflows for may 08 apr 09 6000 c ritical inflow m onths wettest on record 5500 5000 4500 cumulative inflows gl 4000 3500 3000 2500 2000 1500 1000 500 0 m ay jun jul a ug s ep o ct n ov month d ec jan f eb m ar a pr average actual 2008/09 driest on record 14 14[close]
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