Water Journal November - December 1996

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Volume 23 No 6 November/December 1996 Austra lian Water & Wastewater Association JournalEditorial Board F R Bishop, Chairman B N Anderson, G Cawston, M R C…
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Volume 23 No 6 November/December 1996 Austra lian Water & Wastewater Association JournalEditorial Board F R Bishop, Chairman B N Anderson, G Cawston, M R C hapman P Draayers, W J Dulfer, GA H older M Muntisov, P Nadebaum, J D Parker AJ Pri estley, ] RissmanCONTENTSAdvertising & Administration AWWA Federal Office Editorial: H elen C umming Advertising: Sandra Brennan PO Box 388 Artarmon NSW 2064 Level 2, 44 Hampden Road, Artarmon Tel (02) 94 13 1288 Fax (02) 9413 1047ASSOCIATIONBranch Correspondents ACT - Ian Bergman Tel (06) 248 3133 Fax (06) 248 3806 New South Wales - Mitchell Laginestra Tel (02) 941 2 9974 Fax (02) 9412 9876 Northern Territory - Ken Mcfarlane Tel (089) 24 7363 Fax (089) 24 7161 Queensland - Ted Cusack Tel (07) 3244 9600 Fax (07) 3244 9699 South Australia - Peter Martin Tel (08) 8303 8723 Fax (08) 8303 8750 Tasmania - Dao Norath Tel (03) 62332 596 Fax (03) 623 47 559 Victoria - Mike Muntisov Tel (03) 9600 1100 Fax (03) 9600 1300 Western Australia - Jane Oliver Tel (09) 420 2462 Fax (09) 420 3178Water (ISSN 0310 • 0367) is published six times per year: January, March, May.July, September, November by2 4From the Federal President From the Executive Director MYFeatures Editor EA (Bob) Swinton 4 Pleasant View Cres, Glen Waverly Vic 3150 Tel/Fax (03) 9560 4752NEWSPOINTOFVIEWPost Budget Thoughts on Education and Training for the Water Industry3D avid Waite WATER Drought Management for Victorian Urban Water Supplies8RMoran Some Overseas Impressions3P Mo sse Ozone Technology Seminar Report15WASTEWATER The 'FILTER' Technique for Land Treatment of Sewage Effluent18NS Jayawardane, J Blackwell Water Quality International '96 Chemical and Petrochemical Industry Seminar ReportAustralian Water & Wastewater Inc22 28ENVIRONMENTARBN 054 253 066Federal President Mark PascoeExecutive Director Chris Davis Australian Water & Wastewater Association assumes no responsibility for opinions or statements of facts expressed by contributors or advertisers and editorials do not necessarily represent the official policy of the organisation. Display and classified advertisements are included as an informational service to readers and are reviewed by the Editor before publication to ensure their relevance to the water environment and to the objectives of the Association. All material in Water is copyright and should not be reproduced wholly or in part without the written pennission of the Editor.Subscriptions Water is sent to all AWWA members as one of the privileges of membership. Non-members can obtain Water on subscription at an annual subscription rate of S35 (surface mail).The Pollutec Stormwater Pollution Trap: Fleld Trials29RA Allison, T H F Wong, T A McMahon Port Phllllp Bay Environmental Study34Reviewed by EA (Bob) Swinton BUSINESS Contracting Out: Another Management Fad?39G Hodge Alliance Type Contracts In the Water Industry43S Brown, G Simpson, J Ricketts Quallty Accreditation In the Water Industry47R Cooper DEPARTMENTS International Afflllates National Afflllates From the Bottom of the Well New Products Meetings5 72 17 49WATERDROUGHT MANAGEMENTFOR VICTORIAN URBAN WATER SUPPLIESdevelopments have taken place at a national and state level which have required and/or facilitated a shift from Abstract reactive responses to a pro-active 'risk This paper describes the developmanagement' approach. ment of a drought management plan for The Water Act (1989) Victoria. A the Victori~n water sector by the new Water Act was introduced in Victorian Department of Natural Victoria in 1989 which initiated many Resources & Environment (formerly changes: the Department of Conserva ti on & • local water authorities were granted Natural Resource s). Emphasis is given more autonomy, under general supervito the short term and long term sion by the Minister for Water planning guideline s that h ave been Resources via the annual approval of an developed to assist urban water authorauthority's business plan. They are now ities to formalise their own comprehenexpected to be self-sufficient in sive risk managem en t strategies for planning for and managing their dealing with drought. Such supplies at all times , including strategies involve the integradrought periods. tion of short term 'drought Drought response has been characterised • a framework for formalising response' planning and longer by a crisis management approach water rights in Victoria was term 'strategic' planning for introduce1 which provides the water supply system, with the basis for granting bulk the aim of ensuring that 'accep table' water entitlements (BWEs) These neous demand on drilling resources. quantities of water will be available to Many au thorities required significant BWEs can be traded on a permanent or consumers at all times. Progress to date assistance from government in the form temporary basis . This new system ·will by Victorian water authorities in impleprovide authorities with more flexibilof technical advice and financial subsidies. menting the planning guidelines is Typically, the application of restric- ity 111 manag111g supplies during described. · ti ons on supplies led to calls by the drought. In addition, the existence of public and politicians for the construc- well defined rights to water will Key Words tion of more sto rages by 'the govern- minimise the disputes which inevitably ment' to ensure that sufficient water arise in times of drought. Drought planning, drought manage• only in a severe and widespread ment , security of supply, risk management would be available to satisfy demand during future drought periods. As a drought is the Minister likely to conse quence , many of the State's exercise powers given to him in the Introduction were constructed in ·the years Water Act to declare a water shortage storages The State of Victoria has a long immediately following a drought. and qualify those rights to water. history of drought and has experienced This lack of drought planning and New national drought policy. A four major droughts in the past 30 years the reactive response on the part of National Drought Policy was -in 1967-68, 1972-73, 1976-78 and many water authorities reflects a announced in August 1992, which 1982-83. Despite this history, there has emphasises self-reliance in the planning been a reluctance to accept drought as a perception of drought as an infrequent, abnormal event which temporarily and management of drought response. 'normal' occurrence. As a consequence, No assistance will be available for water disrupts 'n ormal' activities. This drought re~ponse has been characauthorities perception was reinforced by the proviin drought times (except terised by a crisis management of 'disaster' assistance by the State in very 'exceptional' circumsion perhaps approach, resulting in many inefficiencies in response (Keating, 1992; Moran and Federal Governments, which stances). The ethos of self-sufficiency included the reimbursement of expen- formalised in the Victorian Water Act is and Rhodes , 1993). consistent with this new National The major problems in past droughts diture incurred by water authorities on have occurred with non-metropolitan water cartage and emergency ground- Drought Policy. Increasing vulnerablllty to drought. urban supplies. Scattered throughout water bores . There was therefore little for water authorAs noted previously, many of the State's institutional incentive Victoria, there are around 345 towns (with a total population of aro und 1 ities to carry out appropriate planning storages were constructeq in the years to enhance their state of drought immediately following drought periods. million) serviced by local water authorpreparedness. However, this era has come to an end. ities. At the time of the 1982-83 If water supply development were to drought, there were over 300 local Recent Developments continue at the same rate as the current authorities (water trusts and local growth in water consumption (2% per Since th e last major drought 111 councils) with water supply functions. annum), Victoria will have developed Few authorities had contingency plans Vi c.to ria in 1982-83, a number ofR Moran8WATER NOVEMBER/DECEMBER 1996for responding to droughts, other than having restriction policies in place. Re strictions were implemented as the need was recognised (often not early eno ugh) and as the politics of the situation allowed. In many cases, restri ction s alone were not adequate to conserve dwindling supplies and other emergency measures (s uch as the installation of gro undwa ter bores and water cartage), had to be devise d and implemented at short notice. Difficulties were encountered with the timely provision of emergency supplies, e.g. delays of two to three months because of the simulta-WATER all of its available water resources within 35 years (DCE, 1991). It is clear that m ore efficient use n~eds to be made of available resources. Already, financial realities and pressures from the environmental lobby are resulting in the deferral of many construction programs and in supply systems being operated with less available water in drought periods. M any water authoriti es have implem ented demand managem ent succes sful programs , which m eans that their customers are becoming more conservative water users. H owever, as a consequence, in the event of a dro ught, the short- term savings made by introducing restrictions will be smaller than in the past. Improvements In forecasting rainfall deficiencies. Since 1982-83, significantadvances have been made in understanding the El Nino ph eno m enon which is associated with the occurrence of widespread drou ght in eas tern Australia. The Bureau of M eteorology now provides regular forecas ts of seasonal rainfalls (three month s in advance). T his information can provide valuable lead time for auth orities 111 preparing fo r and responding to drought. Increasing sophistication of water resources planning techniques. Therehave also been significan t advan ces in the analytical techniques available fo r water reso urces planning. These techniques, which include simulation modelling of system s using stochastically- generated data, have the potential to provide water managers with a more sophisticated understanding of sys tem performance and security of supply. In turn , this should facilitate more effi cient operation of supply systems, including the development of appropriate operational strategies fo r dro ught periods. H ow ever, local water authoriti es throughout Victoria (p articularly the smaller ones) have been slow to adopt these more sophisticated techniques.effec tive response to drought • long term planning is about managmg the ri sk-within resource constrain ts-by ensuring that water supply system s are designed to provide an appropri ate level of se curity of supply. The distinction is somewhat arbitrary as there are stro ng links between the two co mp onen ts. In dec iding what con stitutes an 'appropriate' level of sec urity of supply, trade- offs will need to be made be twee n the costs of im prove d sys tem sec urity (su ch as additional storage) and the risks of, and cos ts associated with , water shortages of varying severi ty and duration (including the cos ts of providing em erge ncy supplies). A 'drought management plan ' thus needs to integrate planning for short term drough t response and long term strategic planning fo r the supply system , with the aim of ensuring that 'acceptable' quantities of water are available to consumers at all times. T hree majo r produ cts are being deve loped as part of the drought management plan projec t: • S hort T erm Planning G uidelines for Victo ria n Wate r A uthorities • Long T erm Plann ing G uidelines f or Victo rian Water Authorities • A D rouiht R esponse Plan fo r the Victoria n Water Secto r. T he two se ts of planning guidelines, which are designed to help authorities wi th th eir dro ugh t planning, are disc ussed in m ore detail below. With proper planning by authorities, it is expec ted that mos t droughts will be handled at the local/regional level. H owever, in the event of a severe and w idespread dro ught , the droughtShort Term Plannlng Guldellnes The short term planning guidelines (DNREa, in prep) outline a six step framework (summarised in Table 2) that w ater authoritie s n eed to follow in preparing for drought and coping with it when it occurs-i. e. in developing a drought response plan (DRP) . This framework was adapted from approaches to drought planning used in the USA (AmWWA, 1984; Wilhite, 1990). Such a DRP incorporates not only the sequential actions to be carried out as water shortages threaten, but also all the pre-drought activities necessary to ensure timely implementation of effective action as conditions become drier, and a post-drought review phaseTable 1 Steps in developing a drought response plan Phase Pre-droughtStepTask1Set the overa ll framework and goa ls for the plan : • review past experience during drought • define the overall supply context (system yield and security of supply) • define the overall legal and institutional context • set (quantitative) goals for system operations2Identify and eva lu ate response options: • identify possible demand reduction and supply enhancement measures • evaluate these measures from a technica l and financial viewpoint, the social and environmental impacts, and the institutional/legal requirements and constraints • identify gaps in information3Develop a sequential plan of action for responding to drought: • establish a system for monitoring early warning signs and system status (including the identification of suitable 'triggers' for the various stages of response)' • develop sequential plan for demand reduction/supply ,enhancement • develop a system for monitoring the effectiveness of actions during droughts4Identify and implement necessary pre-drought phase activities arising out of step 3Drought5Plan implementationPost-drought6Post-drought evaluation and revision of planDrought Management Plan for Victoria's Water Resources In late 1989, work began on a drought m anage ment plan fo r the Victorian water sec tor (M oran and Rhodes, 1991). Emphasis was given to improving drought resp ons e in the non-metropolitan urban component of the water sec tor. It was convenient to divide the dro ught planning into two components: • short term planning 1s abou t minimising the impacts of dro ught (on consumers, on the authority, and on the environment) by appropriate management of the situation- i.e. it is about having appropriate 'drought response plans' in place to ensure a timely andresponse plan which is currently being developed for the whole Victorian water sector will provide a coordinated response at State level. In addition to these major products, a history of drought and water shortage in Victoria has been prepared (Keating, 1992) , together with a number of background technical reports on a range of topics relating to short and long term drought planning. Topics relating to short term planning include demand reduction strategies (Semple, 1993a), supply enhancement strategies (Semple, 19936) , water shortage indices (Srikanthan & Stewart, 1992) and an inventory of emergency groundwater bores (Bartley, 1992; Bartley et al, 1992) . Topics relating to long term planning include water supply performance m easures (Rhodes, 1992), risk in headworks planning and management (Rhodes, 1993) and a Low Flow Atlas for Victorian Strea ms (Nathan & Weinmann , 1993).WATER NOVEMBER/DECEMBER 19969WATER • consumer expectations in relation to, and participation in decisions about, security of supply • risk assessment and managementincluding the economic and social impacts of shortfalls in supply, use of modelling, sensitivity of results, appropriate levels of risk. While appropriate levels of risk are Current Australian practice In yleld discussed in general terms in this estimation and security of supply section, desirable limits of risk (security specification. This section describes of supply) for Victorian water supply initiatives by national and state agencies systems are not specified. This is consisto promote appropriate planning tent with the recommendation made by techniques for water supply systems. An the Australian Water Resources Australian Water Resources Council Council (AWRC, 1989) that 'in preferworkshop on risk and reliability in the ence to adopting standard levels of planning and management of water supply reliability, decisions on risk supply systems was held in November should be specifically related to the 1988 (AWRC, 1989). The issues, economic, social- and environmental conclusions and recommendations circumstances and objectives of the arising out of the workshop are particular supply region' . This approach represents a major discussed under four headings: shift from traditional practice in • description of risk and reliability • factors determining decisions on Victoria. In the past, decisions about 'appropriate' levels of security of supply reliability • means of varying consumption have typically been based on subjective judgements made by engineers about between normal and dry years what constitutes 'acceptable' levels of • methods for analysing reliability. Long term planning techniques. risk for urban consumers. The most This section provides information and commonly used forms of security criteria have been based on an analysis of practical guidance on: Long Term Plannlng Guldellnes • data requirements for long term system behaviour during critical periods As noted previously, authorities were planning-including streamflow, climate (usually the worst h1storical drought) slow to adopt sophisticated analyses of and demand data, data extension, data and have involved the provision of some system - performance and security of generation, demand models, environ- 'carry-over' storage. Where more sophisticated simulasupply. Therefore, there was a need to mental flows, bulk entitlements, system tion studies using stochastically-generprovide water planners (authorities and characteristics their consultants) with practical • yield estimation, system performance ated data have been carried out, the guidance on such techniques, along and security of supply-including specification of security criteria can be with techniques that will enable them to definitions of yield and security of extended to include the frequency , make informed trade-offs between long supply, factors affecting yield, use of severity and duration of shortfall term and short term management performance measures, appropriate periods. However, even in these situastrategies. methods for assessing yield and system tions, the actual criteria adopted have The long term planning guidelines performance, the derivation of operat- typically still been based on subjective (DNREb, in prep .) are aimed at provid- ing rule curves and their impact on judgements by engineers about acceptable levels of risk. Little attention has ing this information. They are divided security of supply been given to examining the benefits and costs associated with different levels Table 2 Steps in developing a drought management plan of risk. A framework for considering the Step relative merits of different security Teak criteria is provided in Section III of the 1 Define desirable (quantitative) objec tives for system operations guidelines. 2 to ensure more effective response m future. To assist authorities with their planning, two 'case studies' were carried out for the Stawell and Bright urban systems to illustrate the step-by-step application of the short term planning guidelines in developing DRPs. In the case of Stawell, the DRP involved the development of targe
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