Water Journal December 1985

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Official, Journal of the

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Vol.12, No. 4 December 1985-$3.00

FEDERAL PR ESI DENT A. Lloyd , G.H . & D., GPO Box 668, Brisbane 4001 .

FEDERAL SECRETARY F. J . Carter, Box A232 P.O. Sydney Sth., 2001 .

FEDERAL TREASUR ER J . D. Mol loy, Cl- M.M. B.W. 625 Lt . Coll ins St. , Melbourne, 3000.

BRAN CH SEC RETARIE S Ca nberra, A.C.T. Dr. L. A. Nagy, 8 Belconnen Way, Page, A.C.T. 2614 .

(062 54 1222)

water Offi c ial Journal AUSTRALIAN WATER AND WASTEWATER ASSOCIATION

Vol. 12, No. 4, December 1985

New So uth Wales C. Davis, G.H. & D. P/L, P.O. Box 39, Railway Square 2000 (02 690 7070)

Vic toria J . Park, Water Train i ng Centre, P.O. Box 409, Werribee , 3030. (741 5844)

Quee nsland D. Mackay, P.O. Box 412, West End 4101 . (07 44 3766)

South Au stra li a A. Glatz, State Water Laboratories , E. & W .S. Private Mail Bag , Salisbury, 5108. (259 0319)

CONTENTS Viewpoint - David Philp ACT Federal Councillor . ........ . . .... . . .... . .... .. . . ... . . .

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Association News, Views and Comments . . ... . ... . .. . .. ... . .... . .

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IA WPRC News ........ . . .... ...... .. . .. . . . .. . ......... ... .. . .

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The Role of Science in Water Management - A basis for action or an afterthought?

A Joint Workshop-Report Ed. H. R. Sanders and W. A. Maher . . ... .... . . ... .. . . . . . ... . . .

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Gungahlin Surface Water Management - J. F. Neal .. . ...... . ......... . . ... ... . ... .. . . . ... . ..... .

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Wes tern Au st rali a Dr B. Kavanagh , Water Auth. of W.A. , PO Box 100, Leederv il le 6007 (09) 420 2452

Tas mani a G. Nolan, G.P.O. Box 78A Hobart , 7001 . (002 28 0234)

Northern Te rri t ory M. Lukin , P.O. Box 37283 Winnellie , N.T. 5789.

EDITORIAL & SUB SC RIPTION CORRESPONDEN CE G. A. Goff in, 7 Mossman Dr. , Eaglemont 3084 03 459 4346

Conference Reports: - National Strategies for Managing Hazardous Wastes ........ .

- Hydrology and Water Resources Symposium 1985 - International Association for Hydraulic Research Twenty-first Congress ......... ...... . ... . ... ... . ... .. .

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Professional Training in Water Science - W. Maher, P. Cullen and R. Morris

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Control of Sewage Treatment Pond Odour using Actizyme - R. J. Gilbert . ....... . . ... . ... . ..... .. . .. ... ... . .... . ... .

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Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Conferences - Courses-Events of Interest . . . . . . . . . . . . . . . . . . . . . .

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COVER PICTURE The Telopea Park Storm water Drain, Canberra, comprises a 2-metre wide by 400 mm deep low flow concrete section, located within a 40 metre wide grassed floodway . The photo illustrates the manner in which an urban storm water drain can be used to enhance the urban environment, the use of trees in the flood plain, and the associated open space and recreational uses of the area.

Cover pic ture - courtesy National Development Commission, Canberra .

The statemen ts made or opinions expressed in ' Water' do not necessarily reflect the views of the Australia n Wa ter and Wastewater Association, its Council or commi ttees.

WATER December, 1985

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VIEWPOINT

EDITORIAL Chairman , E. A. Swinton Dr. P. Nadebaum N. T. Palmer F. R. Bishop W. Rees Dr. G. A. Holder A. Gale J . D. Molloy Dr. L. Nagy R. Mc Grath G. Nolan L. Bryceson C. Weeks K. Hartley W. J . Duller Dr. W. Drew Publ isher: Edit or: A.W.W.A. G. R. Gof li n

A MANAGEMENT DILEMMA TECHNICAL EXCELLENCE VERSUS ACCOUNTABILITY

BRANCH CORRESPONDENTS

CANBERRA A.C.T. Dr. L. A. Nagy 8 Belconnen Way Page , A.C.T. 261 4.

062 54 1222

NEW SOUTH WALES W. H. Ree s Prog ramme & Budget Manager M.W.S.&D .Bd .

P.O. Box A53 Sydney South 200 1 02 269 6595

VICTORIA

w. J . Duller 41 Ru sse ll St. Surrey Hills 3127 03 890 8757

QUEENSLAND K. J . Hartle y G.H . & D. G.P.O. Box 668 Brisbane 4001 07 831 7955

SOUTH AUSTRALIA N. T. Palmer Met. Op . Branc h E. & W.S. Dep t.

East Terrace Thebarton 5031 08 216 1585

WESTERN AUSTRALIA A. Gale Binni e & Part . P/L P.O. Box 7050 Cloisters Squ .

Perth 6000 09 322 7700

TASMANIA G. Nolan G.P.O . Box 78A Hobart 7001 002 28 0234

NORTHERN TERRITORY L. Bryceson P.O. Box 37283 Winnell ie 5789

ADVERTISING Mi ss Ann Sykes Appita 191 Royal Parade, Parkville 3052 03 347 2377

PRINTING Exchange Press 10 Syme Street Brun sw ick 3065

In the past five years, considerable attention has been given to restructuring Water Authorities with the primary objective of improving the accountability and responsiveness to the changing needs of the consumers and governments. This has raised the concern that the thrust for better management and accountability has b en at the expense of technical, scientific and operational skills.

In the past, the structure of water authorities has been built on functional and discipline based work groups. Watermains Branch , Sewer Construction Branch and the Structural Design Section are typical examples of these groups. Their individual existence ensured the selection, training and development of the skills of the specialist in each of these groups. However this approach had a tendency to be unresponsive to the consideration of external issues such as environmental protection, corporate financial management, public relations and accountability.

Functionally based organisation structures have been unable to effectively meet the new challenges and there has been a shift or restructuring towards client based organisation structures. This follows changing demands on organisations and increased uncertainty regarding the specific objectives to be achieved by the organisation .

Client based management approaches have involved either a more generalised approach to providing the service or the adoption of matrix type organizations within an authority. In either case the separate focus on specialist technical groups is lost along with the basis for specialist selection, training and development.

The dilemma to be faced by the water industry over the next decade is the trade off between authorities having functionally based organisation structures and their inherent base for technical excellence and the necessity to move towards 'client based management authorities with their ability to provide responsiveness and accountability . This dilemma represents a major challenge to our large professionally based water authorities and their employees. ,,.

The dilemma highlights the importance of searching for the best solutions to managing water authorities. We will need to question the discipline categories within the industry, review the role of corporate planning and examine the techniques of developing the specialist technical professionals.

Whatever organisation is adopted in any water authority, it is essential to remember that the greatest and most valuable resource available to any ~rganization is its employees. The development of their skills, perceptions and motivation will require special attention. Training and career opportunity must be positive and real.

Employees must feel the corporate identity of the water authority . Staff rotation, interchange and the use of outside specialist groups will provide important components of the development programme.

In the future the need for organisation change will increase , rather than decrease , as authorities mu st satisfy an ever increasing range of community and government demands. The important role that the A WWA has to play in this must not be overlooked. Not only can the assocation provide another avenue for professionals to remain in touch with changes and developments in technically based skills but it can also provide the forum to allow a wide ranging discussion to take place in the process of developing the direction for the future to ensure that the Australian water industry has the necessary skills to take it in to the 1990s and beyond .

Victoria

03 380 8194

DAVID PHILP ACT Federal Councillor WATER December, /985 5

The Role of Science in Water Management A Basis for Action¡ or an Afterthought?

A Joint Workshop of the Canberra College of Advanced Education and The Australian Water and Wastewater Association Editors: Norrie R. Sanders and William A. Maher INTRODUCTIO N The water industry in Australia is currently undergoing major structural chan ges. It seems timely to cons ider the nature of thi s restructuring a nd its effects o n the role of scie nce in the management of o ur water resources. The workshop proceedings described here was not on ly an attempt to discuss this theme, but also to bring together a wide range of disciplines for informal int erchange.

In particular, there was an opport unit y fo r those already part of the industry to sha re their views with water scie nce student s who may well shape it s futu re. The A ustra li a n Water a nd Wastewater Association includes engineers, chemi sts, biologists, hydro logists, managers, town planners and students. Allied to the presentations of a number of invited speakers, the works hop provided a forum for the mixing of viewpo ints and t he formulation of new ideas .

SUMMA RY A recurring th eme of th e workshop was that the water indu stry is in

a state of flux, particularly at the ma nagement level. There are a number of forces driving this reorganization . A major o ne is the growing emphasis on improving water q uali ty as new water resources become more scarce. The reorganization is based on functiona l lines rather than the traditional disciplinary groups.

Scientists mu st adjust to the cha ngin g scene whi ch may resul t in less resea rch funding in traditional areas and expa nsion s in a reas which probably received less emphas is, including public participation, economic evaluations of water quality and social aspects of water resources. There may be some boosts to research funding as quality deteriorates a nd problems become more freque nt a nd more 'visible'.

H owever , thi s is by no means certa in .

Strategies for scienti sts to increase participation in ma nageme nt are difficult to define. However, the emphasis will be o n adap tation to new management goals a nd pract ices, communication wit h management, wit h members of other disciplines (sociologists, econom ists) and with th e public.

Debates within the sc ienti fic commun ity abou t concepts such as the ¡ pro mulgatio n o f water quality sta ndards and t he defi niti on of assimilative ca pacity , will co ntinu e. The emphas is may shift from Australia-w ide water qu ali ty crieteria to loca l cr iteria for indi vidua l syste ms.

An aspect of the debate whi ch remained covert was the seemingly fundamental question of the definitions of science and management.

Many of the participants appeared to assume that science did not include enginee rin g technol ogy an d therefore that engineers were not scientists. In fact, there was so me feeling that engineers were the managers, a lt ho ugh ot her viewpoi nt s cast bureaucrats a nd admini strators in t he management role, wit h engineers and scientists . relegated to problem-solving . Discussion of these concepts was not an

No rrie R. Sanders, BSc(ANU) M icrobiologist, Department of Housing and Construction. Currently undertaking an MSc degree at the Water Research Centre, Canberra CAÂŁ. Research interests include nutrient cycling in wetlands and eu trophicalion .

William A. Maher, MAppSc(Melb), PhD(Southhampton) Lecturer in Limnology and Oceanography, Canberra CAE. Research interests include biogeochemical cycling of trace elemen ts and hydrocarbons in marine and f resh water environments.

Th e workshop was conducted at the Water Research Centre, Applied Science School, Canberra Co llege of Advanced Education, 17- 18 May 1985.

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WATER December, /985

explicit aim of the workshop. Participants tended to adopt a more pragmatic sta nce, concentra ting o n what scienti sts have achi eved in the past and what th ey should do in th e future.

In his opening address, David Garman suggested that economic rationali zation, allied to deteriorating quality were primary factors in t he reorganization of sta te water a uth orities. Sc ienti sts may need to change their o utl ook cons id erab ly to avo id being N. Sanders left in t he rush .

Brian Button o utlined the basic compo nents of water resource management from a quantity perspective . He argued that sho rtages and unreliability of water supplies have resulted from in co nsistent a nd ad hoc policy form ul a tion . A more systemati c, integrated and comprehensive approach is ca lled for so that a ll water reso urces , including surface and gro und water, can be managed as part of a single, dynamic physical sys tem.

Ia n Smalls highlighted the importance of W. Maher water qualit y co nsidera ti o ns in management. At the same time as water quality need s to be impro ved in response to pro li ferating standards, the qua lit y of new supplies is deteriorating and non-returnab le costs a re esca lating. He arg ued the case for use of environ menta l quality objectives and emphasized the need fo r scient ists to mainta in an active a nd innovative involveme nt in ma nagement.

Ia n Lawrence presented three case studie1t-which challenged the "accepted" role of science in water management. He clai med that the process of prob lem-solving is not a rational one in that the driving force for change is usuall y poli tical, and t hat scienti sts rarely have the luxury of sufficient time to comp lete the necessa ry research. Co nsequently, th e scie ntifi c met hod has limited predictive capab ility a nd we are forced to adopt engineering 'fixes' as a seco nd best approac h .

Science is restricted to evaluating the efficacy of the solution .

Norm Mackay cha llenged an aspect of the scientific method itself.

The very notion of 'quality' involves a va lue judgement which scientists are not equ ipped to hand le . The concepts of assimi lative capacity and water quality standard s a re futile attem pt s to apply scientific sta ndard s o n a global scale to largely local pro blems.

Dav id Ga rman' s conclusions identified bot h a model for wa ter management in t he future and potential roles for sc ientists withi n thi s framework. He was optim istic that sc ientists cou ld adapt to th e changing work env ironment, and that they had a part to play as managers themselves , rat her than merely as data-providers.

The panel di sc ussion which concluded the proceedings, related to both the uses of scientific data by management and the public role of scientists. There was general agreement that science should be used as a means of defining options and not simply as an afterthought. Scientists them selves need to be actively involved in disse minating information and promoting debate in the public arena.

INDIVIDUAL PRESENT A TIO NS INTRODUCTIO N: DA VID GARMAN

(Head of the Research Branch, Water Quality Section, NSW Water Resources Comm ission) It is an und erstatement that the water indu stry is in a state of

cha nge. In the recent past, with the excepti o n of the Sydney Water Board, all major water authorit ies were managed by engineers . Scienti sts were few in numbers and restricted to serv ice roles.

In the past three years, there have been major re-organisations in S.A., W .A . and Victoria and in the Hu nier Distr ict Water Board in N .S.W. The N.S.W. State Water Aud it has been se t up. All of these changes recognize the importance of science in the management of water resources.

The ' Perspectives to the year 2000' repo rt conta ined 17 consu lta nt reports, ha lf of whi ch related to sc ientific aspec ts of water management. The res t were on traditi ona l quantity assessment, engin eerin g opt ions and so on . One of the recom mendat io ns from the Water 2000 report was that there be State Water Plans - to provide a basis fo r the ratio nali za ti on of expend iture and management in the wa ter indu stry .

A WW A summer school s have had management as major components, there has been a national management sem in ar, and water management was also a major theme of the recent A WW A federa l convent io n in Melbourne.

Why do we have all thi s change?

Economists suggest that t he water economy has matured and rational ization is inevitab le. Some engineers say that most water reso urces have already been developed and now we have to manage the exis tin g o nes better. Other people within the industry suggest that thi s is a case of change for th e sa ke of it.

In this foru m today we must ad dress the question s: e What is th e ro le of sc ienti sts in water management? • How do they fit into thi s state of cha nge?

Eac h of the speakers today has been in vo lved in questioning the status quo. 1n do ing so, they ha ve helped to prov id e some of the motivation whic h has led to this state of change. This is an important on-going role for all scientists.

We must look for the ro les scientists can play in the future - not just in ter ms of a serv ice role or as providers of background information - but what cou ld they be, and where cou ld they prov ide in puts?

In ot her words, we shou ld not onl y define the current roles of scienti sts but map o ut their's and the industry's future in water management.

An add ed difficulty is tha t sc ienti sts as a gro up may not be as co hesive as some of the ot her di sciplin es. There a re no simple answers to these question s, but an attempt will be made to provide some at th e end of thi s work shop.

AN OVE RVIEW OF WATER MANAGEMENT: BRIA N BUTTON

(Senio r Lecturer in Applied Science, Canberra College of Advanced Education) Introdu ction: A statement of the problem

T here is now ge neral co nsensus wit hin the Austra li a n water industry that we are rapid ly approac hing a point where the temporal and spatial vari ab ilit y of available water resources will make it difficult to reso lve the compet ing a nd co nflictin g demands of different uses and use rs. Water shortages a nd decreased reliabi li ties of supply a re alread y a n esta blished fac t of life along highl y regulated tributaries of the Murray- Dar ling Drainage Di visio n which co ntains three quarters of the nation's irrigated ac reage a nd accoun ts for 8 1% of irrigation wa ter use as we ll as two third s of total water use in Australia each year.

A number of significant reports (i nclud ing the Water 2000 Report and preliminary vo lumes of the N.S . W . State Water Plan Task Force) have in terpreted this condit ion as a n indication of the need to move away fro m an era characteri sed by pre-occupation wit h development (for example, capita l headworks a nd infrastructure) and shift towards policies and practices which focus o n the management of o ur scarce water resources.

A popular demand ma nagement mechanism a mo ng water reso urce planners is the use o f increased pricing schedul es to modify th e dema nd s of ex isting use rs a nd to reall ocate entitlements by steerin g the reso urce toward s those who seek it for such hi gh va lu e uses that they are prepared to pay an equ iva lent 'market price '. In thi s regard the recent declaration of a six month free ze on furt her in creases in water charges for irrigators in N .S .W. will probably lead to greater press ure for further increases later on by those who seek max imum economic returns from the use of water .

A number of supply management measures are also being targeted by water supply authorit ies either as alt ern a ti ves to the co nstructio n of

additiona l water conservation storages or as tools for all ocati ng additiona l su pplies from new dams. A case in poi nt is a pr~posal to set the level of additional entit leme nts to be allocated from Spli t Rock Dam on the Manilla Ri ver by manipulating the reli ab ili ty of supply to the point where the nation as a whole is assured of t he maximum econom ic benefi t from the project.

However, if water resou rce manage rs were to rely totally on these ki nds of market forces to allocate resources it would amount to an abd ication of admin ist rative respo nsibi lity a nd could mean committing th e sa me fundamental mistakes which have characterised the majority of rural water suppl y projects in Australia . Indeed , water shortages in irrigation a reas of south-eastern A ustrali a today a re th emselves just a sy mptom of the fai lure by responsible a uth orit ies to adequat ely plan such projects and are the res ult of a piecemeal, ad hoc approach to the comp lex task of water resources management.

The real sc ope of water resources management

T he systems perspective of water resources management presented in Figure I is a concept ual framework for understanding the complex fie ld of water resources management, directed to the problem of a ll ocatin g sca rce resources between compet in g users a nd conflicting uses.

RESOURCE BASE

PLANNING PROCESS

INSTITUTIONAL STRUCTURE

PROJECT OPERATION

Figure 1. Water reso urces management: a system s perspective.

T he schema in Figure I em bodies a systems approach which emphasises interactions and feedback which shou ld occur within a goalseeking arrangement of primary inputs, elements a nd act iviti es compri sin g the water secto r. Accordingl y, water resources management should sati sfy not only economic but social, env ironm ental a nd even political goals through a sequential and deductive planning process in which development s and the use of the natura l reso urce base, according to clear ly defined ope ra ti o na l modes, is regulated by a hi era rchy of funct io na ll y link ed in stitutions .

That is, fo ur essenti al ingredients are necessary for successful water management. They are: a proper planning procedure, an appreciatio n of the multi-source nature of the water) resou rce base, a set of clearly defined objectives and operational proced ures, and an interconnected fun ct ional set of institutional struct ures. ~

The planning process and operation of a project

T he role of the planning process is to for mul ate policies, plans and sc hemes wh ich reflect society's priorities a nd satisfy com munity desires. Water resource plann ers sho uld not predetermine needs but utili se a ny forum, including public comment and community consultatio n on project proposals, to identify, cl arify, articulate and accord priorities to broad goa ls and speci fi c aims. The task of the water resource planner is to crysta lise, synt hes ise a nd translate publi c o pi nion into a hi erac hy of di screte objectives based o n measureable targets and standards against whi ch antic ipated project performance ca n be eva lu ated.

Alternative forms of project implementation and operation should be systemati ca lly and comprehensively eva lu ated according to spec ific criteria so that operatio nal objectives might ultimately be sati sfied with o ut detriment to users or the resource base itself. Final plans should not be selec ted until potential impacts have been assessed in terms of inta ngi bles - such as comm unity well-being , soc ia l justice , improved regional eco no mi c oppo rtunity and preservation of enviro nm ent a l qua lit y - as we ll as pragmati c consid erations of hydrologic perfo rmance and return s on invested capi tal.

Co mpleted projects sho uld be subj ect to o ngo ing appraisal and eva luation so that necessary structural a nd operational adjustments ca n be implemented in accordance with changing economic, environmental and soc ia l circumstances. For example, whereas the Snowy Mo untai ns Scheme was conceived as a water conservation project to maintain irrigation supplies, it now derives its financial via bilit y from electricity generation .

Different operati ng procedures or rules can be used to man age t he WATER December, /985

13

same physical resource sys tem. For exa mple, regio nal ground wa ter ma nagement requires a decision as to wh eth er to ' mine' the reso urce or adopt a 'sa fe yield ' a pproach in whi ch ex traction rates neve r exceed recha rge ra tes in a ny season . Wha t ¡may be mo re preferable for groundwa ter sys tems with a high stor age to flo w rat io (sto rage volum e a t a n y time co mpa red to th e ex traction or recha rge ra te) is a shortterm high rate-o f-use strategy to induce hi gher le vels o f rec ha rge th rough a steepened hydra ulic gradi ent. Wa ter resource systems a re dyna mi c and sho uld be o pera ted accordingly.

Wa ter resource sys tem s a re also ¡cha rac terised by multiple so urces a nd multiple purp oses . Go ne a re the days when a wa ter proj ect ca n be justifi ed o n the basis o f a single set of users a nd uses. The suppl y o f water fo r irriga ti o n sho ul d no t precl ude wetl and preservat ion, the provisio n of water for indu st ry, genera ti o n of hyd ro-electricity o r ma intena nce o f wa terways in a navigable condition. No n-con sumptive in -strea m uses such as rec reati o na l use should receive as much co nsiderat ion as consumpti ve off-strea m uses. H owever, th e user pays principle is ra th er mo re di ffic ul t to en fo rce in the case of in -stream uses .

Institutional structures and the resource base A hierachy of functi o nall y linked in sti t utio ns is necessary to guide the pl a nning process a nd to fac ilitate decision ma kin g so tha t th e in terd ependent water a nd la nd res ource base is ma naged respo nsibl y.

Na tural varia tions in the spati al a nd tempo ra l avail a bility of wa ter fr om different sources need to be ma nipul a ted to minimise eco no mic a nd social hardship caused by wate r sho rt ages a nd surpluses (in cluding fl oods) a nd to prese rve wat er qu ality.

In o rder to accompli sh th ese obj ecti ves th e admini stra ti ve stru cture mu st reso lve d ivers va lu e systems a nd ensure tha t di sparate goals , preferences a nd ini tiatives of indi vidua ls are co mpa tible with those of society in ge neral a nd t he local communi ty in particula r. Represe ntati ve groups comprising indi viduals fr om th e community at la rge as we ll as water users a nd governm ent personnel a re necessa ry to ensure tha t t he democ ra ti c, social, admini strat ive a nd poli tical processes fun cti o n effecti vely.

The administrati ve process is in da nge r of becoming highl y segmented wh en use a nd ma nagement of wa ter reso urces is a pproached o n a so urce specific bas is . Such a n a pproach deni es the physica l in terdependence o f all elements, parti cula rly the run off co mpo nents, of the hydrologic cycle. Equall y wa ter qua li ty co nsid erati ons can not be di vorced fro m decision s regarding rates of use.

Idea ll y, all wate r resou rces, rega rdl ess o f so urce (including river wa ter, ground water, surplus a nd fl ood fl ows, waste water , local run o ff a nd interbasin transfers), sho uld be ma naged within the one integ ra ted administrati ve system using a se ri es o f interdi sciplin a ry, interd epa rtmenta l decision -ma king committees.

Equ all y th ere is a need fo r greater administ rati ve co-opera tio n between agencies with ma nage ment respo nsi bilit y fo r all resources which a ffect th e hyd ro logical res po nse o f a catchm ent. Such an integrated approac h is now being attempted with th e esta blishment of interdepa rtm ent al ad visory committees througho ut N .S. W. under the T ota l Cat c hm en t Ma nage ment Pr og ra mm e (T .C. M .) whi c h recognises the impo rt a nt in terdependencies betwee n the la nd , so ils, fo rests, water a nd fa una within a single catchment whi ch it self co mpri ses a uniqu e asse mblage of sub-catchments.

Th e complex a nd multi-face ted na ture o f water reso urces ma nagement should be recog ni sed by draw ing o n co nt ributio ns fro m a broad ra nge of profess iona ls during th e pla nning a nd operat io nal ph ases of a proj ec t. Th e earl y pl a nning mi sta kes which ch a racteri sed th e development of the Murrumbidgee Irrigati o n Area a nd o th er gove rnm ent sponsored schemes were the result o f undue a ttenti o n being accorded to engineering aspects. T hese pro blems could have been a nticipa ted if not avoid ed had more considera tion been give n to broader iss ues such as the social impact of irrigation, agrono mic a nd environmenta l aspects, so il rela ted problems a nd the economi cs of intensive cro p producti o n a nd ma r keting.

WATER RESOU RCE QU ALITY CHA NGES A N D MA N AGEME NT : IA N SMALLS

(Chief Biologist, Scientific Services Section, Sydn ey Wa ter Board) C han ges facin g the Au stralian Water Industry

In common with much of th e Au strali a n Water Indu stry the Sydn ey 14

WATER December, 1985

Wa ter Boa rd has been undergoin g a reo rga ni sati o n, typified by pla nn ing processes a nd decent ra li sed cont rol wit h a briel to better respond to co mmuni ty a nd custo mer requi rement s.

Thi s process is not uniqu e to Austra lia a nd close ly fo ll ows trends pu rsued by Bri tish Aut ho rities . Indeed a n accep ta nce o f the British model cha racteri sed th e Sydney water supply at th e o ut set; th e Scot ti sh concepts of upl a nd reservo irs with protected ca tchment s grav itating a suppl y which required minima l trea tm ent , was impo rted along with their engineers to fo rm th e bas is of Sout h East A ustra li a n wa terwo rk s.

Fo r the majo rity of the 20th ce ntury th e premi se of Sydn ey's water resource ma nagement was one of service qu a ntit y prov ided with a cos t stru cture accepta bl e to the majority of the customers. Because a raw water source of accepta bl e qua li ty existed for supply a nd a n effecti ve ocean receiving system ex isted for efflu ent disposa l, both dema nding minimal trea tm ent , qua ntity co nsid era ti o ns were para mount. The Sydney Board served the communi ty we ll , both o n _dema nd terms a nd in pro tecting public hea lth. Th e reaso n that we can cohabit in such la rge urb a n ce ntres is fund a menta lly due to the qua lit y a nd qu a ntity of th e wate r resource, a nd th e sepa ra ti o n of huma n efflu ents from th e water supply.

Such a scena ri o undo ubtly bred a compl ace ncy, bo th in the customer.a nd in the orga ni sati o n. In recent yea rs deteri ora tion has set in . Firstly, in th e buri ed assets of th e organisati o n whi ch required replacement o f st ructu res (such as pipelin es) which were prev io usly perceived to have a n in fi nit e li fe. Seco ndly, in term s of both the raw water qua lit y availa ble fo r supply a nd enviro nmental qua lity of the efflu ent receiving systems.

Th e superimposed diffi culty is no t tha t these problems a re insoluble, ra ther that the provisio n o f so luti o ns is no t reve nu e generati ng. In the pas t , supply of t he service , whet her water or sewerage, genera ted income from ra tes . Th e co nsu mer was relucta nt to pay for improvement s in wha t was perceived as a sati sfa cto ry servi ce.

Such difficulties in Brita in ca used a res tru cturing o f the water indust ry. Much o f th a t country's buried assets were nearly a century o ld ; ce ntral business a nd accomm oda ti o n d istri cts were sewe red and water reticul a ted during t he heyday o f city develo pment , made poss ible because of hum a n resource a vailability and the ben efit s o f public hea lth engineering. Repl acement of such services is eco nomi ca lly overwhelm ing. Th is has bee n further compo unded by a n overl ay of water qua lit y sta nda rds which will be developed la ter. H oweve r, two exa mples demonstra te the dilemma. In areas of so (t, plumbo-so lvent waters, lead fittin g will elevate the di ssol ved heavy metal co mpo nents a bove accepta bl e sta nda rds. For cities such as G lasgow, t he repl acement of lead ho useho ld services alo ne will cost hundreds of millio ns o f do lla rs. Secondl y, Britain has traditi o nalty disposed o f its digested sewage sludges to land and this has provided ag ri culture with a va lu a ble, cheap , resource. Now, the evenhandedn ess of Europea n Econo mic Communit y legislat ion is threatening to cu rtail this ad va ntageo us di sposa l o ptio n . T he a ltern a ti ves a re feas ible fro m an engineering standpoint , not perha ps from a fin a ncia l one .

Water quality management issues

Evolving criteria and guidelines Several for ces a re combining to ti ghten th e criteri a a nd guidelines upon whi ch th e Australia n wa ter indu stry bases its poli cy for water qu alit y. Admittedl y, some o pposin g movement ex ists, no t least of whi ch is the avail a bility of funding, but in the maih th e movement is towards a n expansio n of crit eria a nd a more ca reful a ppraisa l of t he levels o f ma terial in water.

Ex pa nsio n o f criteri a has stemmed in pa rt fr o m th e di scovery of biostimula tory or bi o inhibi tory effects o f known ma teria ls, togeth er with th e increasing evo luti o n of chemica ls with hazardous effects . Exa mples a re ma inl y of organi c chemica ls, such as tri a ha lometh a nes , but include some heavy metals. New la borat ory procedures a re ena bling limits of detect ion to be reduced a nd in so me cases ease o f anal ysis has led to tighter guidelines .

Modern society has developed a number of processes which have strict water qu alit y requirements. The spin -rin se cycle of the domes tic washin g machine is a mos t effi cient centrifuge- filt er¡, th e int ervening materials a re th e la undered fa brics whi ch tra p wate r bo rne pa rticula tes . Less co mmon a re the ho me dia lys is mac hin es of kidney patients which have critical requirements with respec t to the a luminium in their wa ter suppl y. These a nd other processes may well differ from

l I

potable water guidelines , especiall y from the earlier standards which required a 'pure and wholesome' supply.

Co mmunity awarness has increased, especiall y wit h the 'ecological' movements of the last decade. Th e grow in g international nature of many environm enta l groups results in rapid introduction of oversea,s concepts into the Austra lian socio-poli tical arena. There are an increasing number of overseas standard setting agencies and an increasing number of standards being set. Notable are the activities of the European Economic Comm unity and their requirements for imported food s ca n influence the water quality need s of loca l exporters.

On the other hand there is a pressure fo r a more libera l approach to standards or cr iteria . New information suggests that drinkin g water ni trate standards may be too restrictive for western countries . Financial restraints may pressure legislators to modify their approach to best avai lable technology, bringing it down to the level of most appropriate technology which see ks to optimise quality under more limited budgets. These pressure admi ni st rato rs to adopt risk management, although the public acceptance of risk for water qualit y is lik ely to be severa l orders of magnitude less than the vo luntary risks accepted, for instance, for road travel.

Surveillance and assurance of water quality Environmenta l protection of both supply and receiving waters demands a planned surveillance programme . Survei llance is itself under constraints as a more rigorous numerical approach is being both demanded and adopted by operating authorities, and approval which has to be provided with in a more careful approach to progra mme budgeting.

Surveillance has two components, the monitoring phase and the control and assurance phase. T here is now an increasing awareness that results will not always reflect the real world ; absol utes a re being discarded increasi ngly in favour of meeting percentiles , alth ough maximum adm iss ible concentrations wi ll cont inued to exist for certa in toxic materials.

So the old approach of sampling a system every seco nd Monday, provided the weather was sui table, is now encountering constraints.

What do the results provide in terms of qua lity ass ura nce and management requirements? Are too many or too few samples being taken?

Do the samp les take int o account the temporal and spatial variab les?

All of these demand that the surveillance laboratory needs an over lay of quality co nt ro l and statistical skills.

Criteria in relation to the environment Water quality management demands compliance with object ives.

Some arg um ent exists as to where cri teria sho uuld be targeted in order to achieve a desirable water quality objective.

I support the concept of Environmental Quality Objectives (EQOs) .

Admitted ly Emission Criteria (ECs) have a role and some advantages; they are legislatively more attractive, they are easy to implement and cont rol, they can ease design and management of control systems. The EQOs however, will take account of the summation of inpu ts and receiving water variables. They relate more closely to water resource usage objectives, whether these be for ecosystem protection or water supply. The EQO approac h encourages alternative basin management relati ons, the high cost of meeting some emission critiria may be replaced by it in sys tem management, such as the use of river polishing zones or water body aeration . Perhaps the ideal approach is to define EQOs which will reflect system individuality, then work back to the setting of emission criteria to meet water resource object ives.

Concluding remarks - 1he role of the water qualify scien1is1 The water scientist is being asked to work in an environment where quality variatio ns can be both large and unpredictable. The scientist is often confronted by a deteriorating resource quality upon whic h more stringent and more complex standards are being imposed. The scienti st must pro vid e a se rvice which meets strict cont rols in terms of quality ass ura nce and performance. This must be provided within the limi tations of financial and operat iona l constraints.

The scient ists must therefore develop flexibility in their respon se.

They must approach their task by defining their own resources and appraising adm inistrators of the options available for quality management, both in defining their potential for success and their cost. In times of industry change this is not easy, but environm en tal resource protection demands scientific inpu t, let us make sure that it is well . done, innovative, and above all , not reticent in nature.

WATER MANAGEMENT IN CANBERRA: IAN LAWRENCE

(Head of the Waler R esource Planning and De"!ign Sec/ion, Na tional Capital Development Commission) This talk is subtitled 'Water Quality Management - Rational Action or Muddling Through'.

The popu lar view of the relationship between engineers and scientists is that the latter generate the knowledge and understanding of the environment and engineers take scientific knowledge and translate it into a set of processes and techniques which meet co mmunity needs .

It is proposed to exp lore this proposition by drawing on three water pollution abatement case studies in the ACT: • Captain's Flat mine pollution abatement.

• Murrumbidgee River Eutrophication abatement.

• Rehabilitation of Lake Burley Griffin.

Ca ptain 's Flat Mine Pollution Abatement

Located on the Molong lo River upstream of Canberra, the Captain's Flat area was worked for metal s between 1874 and 1962. By the 1930s heavy metal pollution of the Molonglo River was noted but little action was taken to resolve the problem . On ly in the 1960s when const ruction of Lake Burley Griffin was about to commence were di scuss ions instigated at the Commonwealth / State level with a view to finding a soluti on to the problem.

In 1973, it was decided to build Googong Dam on a major Molonglo River tributary. Construct ion of the dam world reduce streamflow and exacerbate water quality problems in Lake Burley Griffin. Both the Green bans and EIS Legislation were important factors in prompting agreement on the reso lu tion of the Captain's Flat pollution problem. Remedial works were undertaken between 1974 and 1976.

Macroinvertebrate surveys prior to rehabilitation works showed that the mine discharges were depressing biota in the river. But because of variability of strea mflow and pollutant levels, scientists were unable to arrive at a definition of an acceptable level of pollution or even to characterise the processes by which pollutants were transported to the river and ultimately to the lake.

The engineers adopted conventional sta biliza tion techniques to minimise erosion of the mine waste dumps and transport of material to the river. Scientific st udies suggested that in addit ion, sealing of the dumps was needed to minimise ingress of water and air which were instrumental in regenerati ng su lphates from su lphides. • Consequently, the dumps were graded and covered in clay, and then protected by rock , soil and grass .

Interaction between engin eers, chemi sts, and microbiologists in thi s case had resulted in the adaption of co nventiqnal techniques to incorporate scient ific concerns.

The abatement works were completed in 1976. Subsequently, there were su bstantial reductions in zinc load s discharged to the river.

Biological monitoring in 1977 showed that macroin verteb rate populations had improved. During the 1980-83 drought however, monitoring showed taxa numbers were simil ar to those prior to remedial works due to high concentrations of heavy metals coming from sustained groundwater discharge from the old mines.

There are four conclusions which can be drawn from this case study: • the motivation for resolution of the problem was a threat to a water supply augmentation project; • the impract ica li ty of science to deduce ca use-effect relationships in a scientific study, and the need to reso rt to engin eering techniques for resolution of the prob lem; • the use of scie ntific data to substa ntiate the efficiency of these engineering techniques resulted in adapta tions of the techniques; • the manage ment based nature of the approac h adopted for the reso lu tion of the problem, wh ich comprised a ' fir st best guess' regarding the appropriate techniqu e of co ntrol, fo ll owed by the establi shment of a programme of monitoring to rev iew the need for further abatement works.

Murrumbidgee River eutrop hicat ion

Rapid grnwth of Canberra in the 1960s led to algal grow th in the Murrumbidgee Ri ver downstream of sewage di scharges, and to serious degradation of the aquat ic enviro nment. This was particularly evident during dry periods, such as the 1968 drought. Growing public WATER December, /985

15

• a ma nagement ba sed ap p roach was a ga in ado pted , co mp risin g co ncern regarding eutrop hicati o n, o do u rs and deterge nt foa ms in staged imp le mentati on of actions a nd feed back moai to rin g. loca l waters p roduced a po li t ica l clim ate sy m pa th etic to investm ent in water q ua lity p rotecti o n wor ks.

The decision makin g environment The need fo r a new waste water trea tm ent pla nt was indi cated by . engin ee rin g studi es in the la te 1960s . Th e stu d ies a lso po int ed to the Th e case stu d ies o utlined suggest tha t th e ' kn ow ledge ge nera ti o n by need fo r impro ved effl uen t sta nda rds . Loca l water q ua lit y da ta was scienti sts a nd a p plica ti o n by engin eers' mod el o f the dec isio n ma kin g lack ing , but there was a clear need to redu ce nutrient loadi ngs to the process is not va li d . Scientifi c a nd engin eerin g groups eac h b ring to recei vin g waters to reduce eutrophicat io n. bear their ow n perspec tives a nd see k to press their ow n so luti o ns, ln 197 1, th e co nsul ta nt respo nsibl e fo r th e investiga ti o n of th e new su bsta nt ia ted by cla im s to co mmuni ty int erest. O nl y where preva ilin g sewage treat ment plant reco mm ended th e ad o ptio n o f a fac ilit y inco rengineerin g techniqu es are unde r cha ll enge , a re there op po rtunities pora tin g provisio n fo r p hosph o ru s a nd nitroge n remova l. Scie nti fi c for in co rpo ra ti o n o f sc ienti fi c ad vice. da tum was lac king a t th e tim e for determinin g appro pri ate e fflu ent I suggest th a t the decisio n mak in g enviro nm ents typi ca ll y co mp rise criteri a, a nd for th e rela ti o nship betwee n sewage, urb a n a nd ru ra l t hree broad ca tegor ies : sources of nu trient. Ult im a tely, a so lu tio n wa s reac hed o n the basis of • Estab li shed repertoires : broad a greement ex ists o n a pp ro pri a te the best ava il a ble techno logy rath er tha n scienti fi c crit eri a . tec hni q ues , engin eers optimi ze th e tec hniqu e, a nd th e ro le o f science is A tertiary trea tm ent fac ilit y wa s co nstru cted (Lower Mo lo nglo limited to legit imi sin g th at tec h nique app ropri a te.

Water Qua lit y Co ntr o l Centre) which wa s capa ble o f removing bo th • Co m petin g repert o ire o r uncerta int y rega rd in g the a pprop ri a teness nit roge n a nd ph osph orus fr o m th e efflu ent. A maj o r wa ter q ua li ty of a part icul a r so luti o n ; t here is a grea ter cha nce fo r sc ience a nd stud y was und erta ken in th e peri od 1976 to I 978 to rev iew e fflu ent engineering to interact a nd ad a p t certa in techni q ues . criteria a nd to d etermin e th e o ptimum nutri ent -remo va l o perating • No es ta bli shed reperto ire: this is virtua ll y ope n slat her - whi chever mod es of th e new pla nt. T he $ 1 milli o n stud y co ncluded that , given gro up ca n co me up wit h the mo st co nvincing argum en t p ro vid es th e th e va ria bi lity of strea m fl ow a nd the sub sta ntial in puts o f ph osp ho ru s so luti o n , o r co m pe tin g groups will co mpromi se th eir positi o ns to a rin rura l run off, precise efflu ent crit eri a co uld not be id entified . It sugri ve a t a mut ua ll y accepta ble so lu tio n . gested the ad o pti o n o f a tri a l a nd review a pproac h to pl a n t operat io n .

The decisio n ma kin g process refl ect s bo th th e levels o f a greement Fo ll ow in g co mmi ss io ning o f the pl a nt in 1978, there was su bsta nt ia l rega rdi ng ca usat io n and the level o f agree ment regardin g p referred redu ct io n of a lgal grow th in the ri ve r . T he recovery of Bu rri nju ck o utco mes. If th ere is ex tensive agreement rega rdin g ca usa ti o n , th en Reservo ir was d ela yed due to th e extensive qua ntiti es of ph osp ho rus decisio n ma kin g is co m put at io na l. If there is di sagreement , th en th ere which ha d a ccumul a ted in th e sedim ents . T here are indi ca ti o ns since is mo re cha nce fo r scienti sts a nd engin eers to wor k toge ther . th e recent drought th a t levels o f a lgae in the reservo ir ha ve redu ced In socio logica l terms, bo th engineers a nd scienti sts a re located in the substa nti a ll y. positivist/ deter mini sti c mod e of thinkin g. H owever, the fo rmer tend T he fo ur co nclu sio ns whi ch ca n be d raw n fro m thi s case stud y a re: to use black boxes to so lve prob lems , whereas scient ists tend to wa nt • th e co mmit tment to the wor ks was a re fl ectio n of the need fo r a to un dersta nd th e p rocesses co nta in ed within the blac k box. new wastewater trea tm ent fac ili ty to service a burgeo nin g popul a ti o n In a simil a r way, co mmunity invo lve ment will re fl ect the leve l o f and a refl ect io n of a po litica l climate ext remely sensit ive to enco nfli ct in interests. For ex a mp le, if th ere is li tt le co nflict, engin eers vironm en ta l protect io n ; sim ply go ahea d a nd ad vise on th e ap prop ri a te so luti o n. If there is • in suffi cient da tum was ava il abl e fo r the determina ti o n of much conflict th e decisio n ma y be ma d e by a n elected bod y, a ft er co nscienti fica ll y-based e fflu en t criter ia a nd thi s was st ill the case afte r the sidera tio n o f expert o pini o n . maj or scientifi c stud y, fo ll ow in g co mpleti o n of th e wo rks ; CONCLUS IO NS • a n estim a ted tec hn o logy was adapted to inco rporate provisio n fo r nutri ent remova l; T he case stu dies suggest that th e redu cti o nist, hi ghl y bo un ded • as in th e p revious case stud y, a ma nage ment ba sed a p proach was na ture of th e scient ific meth od limit s it s predi cti ve capab ili ty in th e ad opt ed rega rding a pp ro pri a te techniques of co ntrol , fo ll owed by a case of co mplex na tu ra l systems. The m od ifica ti on o f esta blis hed progra mm e o f mo nito ri ng to review th e need fo r m od ificat io n o f th e techni q ues in the li ght o f scientific findin gs und ert a ken in assoc ia ti o n with mo ni toring progra mmes a ppears to provide a seco nd bes t a nd techniqu e. pract ica l a pproac h to so lving enviro nmenta l prob lems .

-,.

Lake Burley Griffin Rehabilitation Th e la ke was fo rm ed in 1964, a nd sin ce th en has bee n the foc us of increasin g publi c co ncern regardin g degrad a ti o n in recrea ti ona l a nd visua l qu a lity, la rgel y du e to nu isa nce weed a nd a lga l grow th . A number of publi c inquiries have been held o n th e pro blem .

Wa ter qu a lity s tudi es ove r th e per iod 1976 to 198 1 indi ca ted th a t the la ke was eut ro p hic, th a t sewage e fflu ent co nstituted th e majo r sou rce of nut rie nts, a nd th a t substa nti a l qu a ntiti es of phosph o ru s ha d a ccumula ted in the la ke sedim ents .

While the engin eers po ndered th e opt io ns o f di vertin g sewage aro und th e lake or upg rad ing sewage t rea tm ent to in co rpora te nutri en t remo va l, th e scienti sts st ressed the compl exity o f the ecologica l system in vo lved, a nd a rgued the need fo r furth er studi es.

It was ul tim a tely ag reed , in a po liti ca l cl im a te dema nding so me actio n , that reducti on in ph o sph oru s leve ls d ischa rged to the lak e was a necessary first st ep in a ny p rogra mm e of la ke reha bilit a ti o n , a nd th a t remova l o f p hosph o ru s fr o m sewage e fflu ent was th e most practi ca l a nd eco nomic mea ns o f redu cing ph osp ho rus loading o n th e la ke.

Removal o f phosph orus is scheduled to co mmence in late 1985. It is propo sed to cl osely m o nitor the respo nses o f the la ke to determine wha t furth er polluti o n a ba tement acti o ns a re required.

T he fo ur co nclu sio ns which ca n be d raw n fro m thi s case stu dy a re: • th e co mmittment to a n a batement p rogramme in thi s case was th e res ult o f publi c concern ; • th e scientific studies were un a ble to id entify specifi c effl ue nt cri teria or to predict t he likely respo nse of the lak e to cha nge; • th e engin eers foc ussed o n the a ppli cati o n of esta bli shed techni q ue, wit h so me a da p tati o n to refl ec t th e loca l situa ti o n ; 16

IV A T ER Decem ber, 1985

MU RRAY RI VER MANAGEMENT: NORM MACKAY

(Scien1ijic Officer, River M urray Co mmission) wo ul d lik e to pose th e q uesti o n ' is ma nagement o f a na tu ral reso urce po ssibl e?' In th e fi eld o f wa ter qu a lit y th ere is much ta lk about ma nagemen t, bu t success fu l examples are ha rd to find . We have hea rd t hi s a mo ng several success stor ies, here in the A.C. T . a nd with th e Sydn ey water suppl y, but th ese exa mples a re th e excep tio n rat her th a n the rul e; th ere are ma ny mo re exa mples o f ineffecti ve ' ma na gemen t ' , es pecia ll y where the reso urce is sha red between states o r nati o ns.

The destruct io n o f a la ke o r ri ver do es not ha ppe n ove rnight ; it is a gradua l process res u ltin g fro m th e cumul a ti ve effects of a n increasin g number o f min o r inp u ts . Sc ience is poorly equipped to d escribe th ese grad ua l de leteri o us cha nges fo r a number o f reaso ns.

• 'Q ua li ty' is a subj ect ive judgement, which ca n o nl y be mad e relat ive to th e experience o f the o bserver . Science attempts to excl ude va lue j udgement s, o bjecti vity bein g th e co rn ersto ne o f a ll scientific endeavour .

Beca use we ha ve no di rect mean s o f definin g or measurin g wate r. ' qu a li ty' , scienti sts use th e sur rogate o f a tt emp tin g to defin e a nd measure t he characteri sti cs o f wa ter req uired fo r a pa rticula r 'be nefi cia l use' (swimmin g, ir rigati o n , aq uat ic ecosyste m ma in taina nce a nd so o n). T hi s is not as sim ple a ma tt er as is o ft en ass um ed ; in fact there is no simpl e way to qu a ntify o r describe the water characteri sti cs need ed fo r th ese differen t uses, as is show n, fo r exa mple, by the current co nfu sio n over water qu a li ty criter ia for th e relat ive ly stra ightfo rwa rd a nd we ll -studied use o f hum a n co nsumpti o n .

• Science is a co ll ect ive act ivit y. Our geographi ca l pos ition on the periphery of the sc ientific emp ire tend s to make us look to the northern hemisphere for leads in science a nd we often mimic their met hods and approac hes. Thi s is un fortunate because o u r water is · generall y of much hi gher quality than theirs. Un less we are much more cr itica l of overseas approaches than we have been in the past, we wi ll be in th e peculiar situation of advocat in g 'sc ient ifi c' a pproac hes to wate r qua lity management whi ch will guarantee the grad ua l destruct io n of o ur surface waters to the deplorable condition of lakes and rivers in the nort hern hemis ph ere. The notion of 'ass imi lat ive' capac it y was developed a pos1eriori in America a nd England as a just ification for the cheapest method s of sewage disposa l by discharge, untreated, into rivers and lakes. We don't have a ny need to imi tate such obv ious ly dest ruct ive pract ices in Australia.

• Science has bee n repea ted ly used as a placebo in env ironm enta l iss ues, a mea ns of appea rin g to do so mething without taki ng any hard dec isio ns . A cont emporary exa mple is the U.K. decis ion to defer a ny action o n the su lphur em iss ions ca usin g ac id rain and instead to sponso r further research on the subject. But there are numerous examples closer to home. In re la tion to the M urray/ Darl ing system Pro fessor Sa ndford C la rk, a long-time observer of the Austra li a n water scene, has noted that 'research provides a rat iona ll y defens ible and politically positive substitu te for act ion'. · • The grad ua l deter ioration of water qualit y occurs aga inst a background of high variab ili ty in the parameters we commonly meas ure to describe water qu a lit y. Th is hi gh variab ili ty mak es it d iffi cult to est imate the rate of deteri ora tion (or im provement) in wa ter quality and a lso seve rely limit s the practical val ue of ' receiving wa ter standards' based o n water q ua li ty cr iter ia. For exa mple, sa linity in the River Murra y is stro ngly influ enced by fl ow whi ch is highl y va riab le.

Co nfidence limits on current estimates of th e rate of sa li nity in crease in the Ri ver Murray are la rge, so t hat there ca n be no certa int y about th e lik ely future rate of sa li nity increase, o r th e efficacy of mitigat ion work s whi ch may be developed to counteract thi s in creasing sa lin ity.

It seems to me that these wea kn esses or limitat io ns in our contemporary scie nce of water q ual ity need mu ch more ca refu l thought a nd di sc ussion. It is notewort hy th a t the most success ful exa mpl es of water qua li ty ma nage ment - such as those described by Mr. Lawrence ear li er - have deliberately avoided 'sc ientific' approaches in favour of the pragmatic ap proach of attacking the pro blem a t its source.

In Amer ica, the ' sc ientifi c' a pproac h of receiving water standards ba sed on water qua lit y criteria was tried for a decade and fou nd wanting. The C lean Waters Act of I 973 discarded thi s approach in favo ur of a pragmatic po licy of best prac tica l waste treatment a nd a fir m comm ittment to restoring the q ua lit y of A merica n rivers to a 'fishab le, sw immable' co nditi on. While the massive expenditure o n thi s nati o nal clean- u p no do ub t in vo lved some wastage, th ere is eq ua lly no do ubt th a t it was as a direct resu lt of th is best pract ica l treatment approach that river water qua li ty began to improve.

For the Murray Ri ver syste m, we a lso have a policy based o n best pract ica l treat ment a nd a co mmittm ent to improve the ex isting water quality for those parameters (salinity a nd nutri ents for examp le) a lready recognized as ca usin g problems in the river .

T he Mu rray is, by world sta ndards, still a very clea n ri ve r. If we have the maturity to recogni ze the uniqu e advantages we enjoy re lat ive to other developed cou ntri es (l ow pop ulati o n density, li ttle indu st rial deve lopment , ample land a nd a climate favourab le to off-river was te di sposa l) we ca n sustain a nd , where necessary, improve th e qua lit y of Austra lian surface waters.

In order to set up a logica l management framework within which scienti sts cou ld be operat ing, a number of management principles shou ld be adopted: • Spec ify manage ment o bj ect ives a nd chec k management practi ces and efficiency.

• Specify performance criteria. Operatio na l cr iter ia shou ld be decided in te rm s of manage ment obj ec ti ves.

• Ident ify a ll the opt ions - tec hni ca l, engineerin g and other nonengi neering solu tions, for proposa ls (e .g. o n-farm efficiency, lower water usages).

Estab li sh criter ia (econom ic, soc ial,_ environme nt a l) and eva lu ate whether they are met; thi s relates to multi -objective planning . Scientifi c in put prio r to engineer in g so luti o ns can occ ur if pla nnin g is sufficientl y in advance - ot herwise we have to co me up with best possib le sol u tion in a short time.

Scient ists cou ld have a significa nt role in a ll these aspects of ma nage ment.

A water management model

How do we put th is into practice? What so rt of model can we use to implement thi s? T he answer is that we a lready have a model - the hydrologic cycle. Let's m ove managment into o rga ni sing a lo ng th e lin es of the hydra uli c cyc le.

Firstly, we se parate o ut general ad mini stration. What we're concerned about is catchment management , waterway management a nd prov isio n of co nsum er services. These three co mpo nent s a re of co urse int eractive, but broad ly comprise: • Catchment management - dea ls with resou rce assess ment, head work operation land use, operatio n a nd bui lding of dams a nd catc hment ma nage ment itself.

• Waterway management - concerns fl oodp la in and environmenta l management a nd waterway operat io n .

• Co nsum er services - provid e u rba n and rura l water s upply, a nd flood, drought and enviro nm ental protection. Th e environment is seen as a co nsumer. Who pays? - either the d evelopers who benefit from the ca tchment o r th e gove rnment.

The hydrologic cycle mode l includ es a ll the operationa l aspects a nd is a mode l on whi ch organizatio ns can be run . Each organ ization should have its own set of corporate objecti ves, wh ich incorporate priorit ies, goa ls, performance indi cato rs a nd perforfnance revi ew .

Where do scientists fit ?

Traditionally, th ey have been the backr~om boys, invo lved with research a nd investigation and answer in g the difficu lt question s. New areas of ma nagement are involved in : • Water quali ty a nd environmenta l ma nagment whi ch require sc ientifi c input for operation - rapid assessme nt of data fo ll owed by decisio n-mak ing.

• Genera l manage ment: is there a ro le for scienti sts? Wh y not? Scientists have shown that they can move int o manageria l roles. The differe nce between a general manager a nd a scient ist or engin eer is that th e ma nager ca n brin g the s kills of hi s d isciplin e, mould th em to managemen t , be fam iliar with the syste m a nd re late to everyo ne in vo lved in decision making.

We need to ge t away from lin ea r thinking a nd th in k latera ll y, sid eways and upside do wn!

Co nclusions

SC IE NTISTS IN WAT ER MA NAGEMENT - THE FUTURE: DAVID GARMAN (N.S . W. Waler Resources Commission) In co ncluding th e proceedings I suggest that future water management wi ll have to think in terms of conflict resolution . Thi s will invo lve fewe r resources, more dema nd s, new res pon sibili t ies - parti cul arly environm ental ones - and greater public participat ion a nd awa reness . The ques ti o ns whi ch this seminar is attempti ng to reso lve are: • W here scienti sts fit in , o r a re they equipped to fit in at a ll ?

• H ow can they ass ist in terms of determining management goa ls, and their reassess ment by scientific meas urements .

We are movin g in to a new phase - beca use reso urces are beco ming scarcer a nd because of social, economic a nd environm ental press ures .

Genera l rest ru ct uring of the water industry an d new approaches to man age ment are occurring throughout th e co untry. Legi slat ion under which the industry operates is changing a nd attitudes to it s performance a re cha ngin g.

There will be more opportuniti es fo r sc ien ti sts from a wide ra nge o f d iscip li nes including hydro-geo logists, nat ural resource managers, chemists, biologists, microbiologi sts. But , in general management, those sc ienti sts with the ad a ptabilit y to cope with peop le, po li ticians, eco nomi sts and criti cism from other sc ienti sts will be those most ab le to compete wit h ot her di sciplines.

CON TINUED ON PAGE 3/ WATER December, /985

17

Gungahlin Surface Water Management J. F. Neal SUMMARY Downstream constraints in terms of hydraulic capacity and water quality have required special consideration in the planning of Canberra's fourth new town, Gungahlin . The use of stormwater reservations as linear open space systems wi ll result in greater public use of these reservations. Traditional practices for trunk stormwater design have bee n modified in the interest of pub lic safety, amenity and economics.

John Neal graduated from the Swinburne Institute of Technology in 1974 in Civil Engineering and has been employed by the A CT Region of the Department of Housing and Construction since 1975. He has been involved in numerous hydrological and hydraulic projects and various reviews of urban storm water systems. Seconded to the J. F. Neal Nationa l Capital Development Commission in March 1984 for a period of 12 months to provide the hydraulic input for the planning of the new town of Gungahlin, he is now Principal Engineer Storm water Planning, with the Department of Housing and Construction, responsible for stormwater planning in the ACT. He holds a Diploma of Engineering (Civ il) from Swinburne lnstitue of Technology, a Graduate Diploma in Computing Studies from the Canberra College of Advanced Education and a Master of Engineering Science from the University of New South Wales.

t D

•

~~,.-~~ IIU0• - .. •011

NORTH CANBERRA

0

3km

~OIIO I IIIU.IIOATIOIIUlllt

Figure I. Locality plan.

Figure 2. Proposed system.

1. INTRODUCTION Canberra is being developed as a series of 'new towns' separated by the dominant hill/ ridge systems of the local region. Gungahlin, to the north of existing development, will be Canberra's fourth new town. It covers an area of approximately 90 sq uare kilometres and will have an ultimate population of 80 to 90,000 people. Figure I shows the location of Gungahlin in relation to existing Canberra development.

The National Capital Development Commission is responsible for the planning of all new development in Canberra . Higgins and Mills (1975) report that 'because of Government ownership of the land and comprehens ive broad acre development the Commission is well placed to achieve a rational integration of stormwater fac ilities along with the whole range of urban services in modern new towns'.

plains. Soils over much of the site are duplex in nature with sub-soils being moderately to highly dispersive and conseq uently liable to tunnel and piping failure and gully erosion . There are a number of areas of soi l water saturation and seepage in the floors of valleys.

Gully erosion is evident in much of the Gungahlin area. Many of the streams are unstable and actively eroding. In some cases, the stream bed has eroded down to bedrock. However, the majority of streams are eroding either vertically or horizontally, or both.

Figure 2 shows the four major stormwater systems within Gungahlin, namely: • Halls Creek • Ginninderra Creek • Gungaderra Creek • Sullivans Creek

2. SITE DESCRIPTION 3. CONSTRAINTS The terrain of the Gungah lin area comprises ridges and steep hill slopes to the north-west and east, and undulating terrain through , Ginninderra Creek and Gungaderra Creek discharge through exmuch of the central area, in association with collu vial and alluvial isting developments within Belconnen and thence into Lake GinWATER December, 1985

19

nind erra, a ma n-made lak e located close to the Belco nnen Tow n Cen- cha nnels are steep-sid ed and carry flows a t high velocities. A person tre. The G ungahlin compon ents of th e Gin ninderra a nd Gungaderra swept into one of these chan nels in flood wo uld ,..xperience conCreek ca tchment s co nstitute approx im ately 60 per ce nt of the ca tchsiderable di ffic ulty in escaping . As the stormwater reservations are to men t of Lake G innind erra. Sulli va ns C reek di sc ha rges th rough North · form the focu s of the linea r open space system, th e use of large lin ed Ca nb erra , whi ch conta ins so me o f Canberra 's o ld est subur bs, a nd cha nnels, as proposed in the conventi onal system, is considered un sa tisfactory. thence into Lake Bu r ley Griffin.

The Nationa l Ca pi ta l Deve lopme nt Co mmiss ion ( 1985a) requires A so il s survey has ind icated th a t the soils in Gunga hlin are ge nerall y that fl oodways be capable of containi ng flow s up to a n ann ua l ex: dupl ex in nature, with highly di spersive A2 horizons in a number of ceedence probab ility (AEP) of I: I 00 and that a ll bu il d ing blocks be cases . Permea bilit y is low a nd a num ber of seasonall y perched water located above the 100 year fl ood plain . tables a re ev id ent. Any strategy attempting to increase infiltrat ion Ana lysis of loca l da ta indi ca tes th a t urba ni za ti o n res ults in an in - (such as the ' point source retention' sys tem) wou ld simpl y exacerbate crease in pea k fl ow by a factor of up to 7 fo r a l :5 AEP flow and up to a severe limita ti on of the natural soil systems. ln fac t , the limitat io ns 3 fo r a I: I 00 AE P , depend ing o n the degree of urbanization. The in- of the so ils of the area suggest that th e stormwater system sho uld in creased peak flow s as a res ult of th e urba ni zatio n of G unga hlin will co rporate provision for drainage of groundwater. Hence, th e 'poi nt result in areas o n the a bove three streams fai lin g to satisfy these source rete nti on' sys tem is co nsi dered un suita ble for the G unga hlin criteri a unl ess measures are undertaken wit hin Gungah lin to reduce area . peak d ischa rges .

The composite system does not co ntai n th e large cha nnels of the Lake G inninderra currentl y sa tisfies the wa ter qu ality objecti ves of co nvention al system no r does it exacerbate ground water problems inherent in the ' point so urce retention ' system . Of th e three options conchl orphyll 'a' less t ha n 10 microgra ms per lit re. Pre liminary est im a tes indi cate that fu ll urbanization of Gungah lin will result in a 4000Jo in - sid ered , th e co mposite system was the one co nsidered most suitabl e crease in nutri ent export, which wi ll result in t he above o bj ective being for satisfying th e object ives desc ribed in Section 4. exceeded unl ess suitab le measu res a re undertaken to reduce the export of po llut a nt s carri ed by storm water from Gungahlin .

7. ADOPTED SYSTEM

4. OBJECTIVES In develo pin g a strategy for the ma nagement of su rface waters with in Gu ngah li n, th e fo ll o win g six o bject ives were adopted: • to li mit stormwater di scharges such that flow s a re within the downstream hydra uli c chan nel co nstra int s; • to limit th e ex port of sediment , suspended solid s, nutrients a nd bacteria from th e area in order to protect th e environment al amen it y of dow nst ream waters ; • to limi t the la ndt ake associated with storm water systems in order to preserve the neighbourhood int eg rit y; • to provi de a n eco nomical stormwa ter sys tem in ter ms of bo th capi tal costs a nd ope rational a nd maintena nce costs; • to ens ure publi c sa fety a nd amenity; • to enh a nce the urb an land scape a nd recreational opport unit y.

5. OPTIONS CONSIDERED In a n attempt to sati sfy the a bove object ives, three stormwater management strategies were initi all y developed . T hese were: • co nventi onal stormwate r system • po in t so urce rete nti o n sys tem • co mpos ite system .

T he convent io nal stormwater sys tem has two major elements: • An underground pipe sys tem to co nta in flow s with a n AEP of betwee n I :5 and I :20 and overland flow paths to cont ai n excess flow s up to an AEP of I : 100. These overland flow paths may be either road ways o r parkl a nd.

• A lin ed cha nnel (either concrete o r stone-pitched) to co ntain flow s of between I :3 a nd l :5 AEP, with grassed ove rbank s to co ntain excess flow s up to a 1: 100 AE P .

The ' point so urce retent io n' sys tem emp loys met hods for maximi zin g infiltra ti o n , such as the di sc harge of roof drain age o nto lawns a nd gardens, the use of porou s material s fo r paved a reas and retentio n of many of th e ex isting far m dam s. Natura l strea ms are retained o n the maj o r dra in age lin es with on- li ne ponds in associat ion with retardin g basins to impro ve the water, quality o f storm water discharges a nd to reduce peak flows from G ungah lin.

The composi te sys tem utili zes the sa me trunk drainage system as the 'poi nt so urce retention' . Hence nat ura l st reams a re reta ined along the majo r drainage lin es in assoc iati o n with large po nd s a nd retenti on bas ins.

Su b-ca tchment drainage is of a conventional nature with a formal system of in-ground pipes a nd over la nd flo w pat hs (such as roadways and pa r kland) .

6. ASSESSMENT OF OPTIONS La rge lined stormwa ter channe ls, as can be fo und througho ut exist in g Ca nberra development , a re aesth etica ll y unpleasing, tend to d ivid e the la nd scape a nd are a pote nti al threat to public sa fety . The 20

WATER December, 1985

7.1 General The co mposite system was selected as the scheme best suited to sa tisfyin g the defi ned objectives for the management of surface water within Gungah lin . In further developing the scheme, four components of t he sys tem were consid ered separately: • pond s • reta rdin g basins • trunk drain age lin es • neighbour hood drain age.

7 .2 Ponds and Retarding Basins Goyen et al ( 1984) state tha t 'storage of urba n runoff for the purposes of enh a ncing its qu ali ty is an inn ovative step in the ma nagement of urban run o ff' . They conclude 't ha t urba n runoff treatment by detention storage in na tural or engineered pond s is a cost-effective measure whic h wi ll be employed in the fut ure in inla nd Australi an cit ies' . As shown in Figure 2, four po nds are prqposed for the Gunga hlin developm ent. In add iti on to water pollu tion control , these ponds wi ll perfo rm th e fo ll ow in g function s : • Landscape: provide a waterscape, sho reline a nd vegetation of a cha racter which co mplements th e urban landicape.

• Recreation : provide a venue for pass ive (walking, pi cni ck ing, bird watching) and act ive (boating, fi shing) recreation .

• Stormwater Retardation: provide suffi cient temporary storage capacity to atten uate peak sto rmwater fl ows to acceptable levels downstream .

• Water Suppl y: pro vid e a source of second class water suitable for use for the irrigatio n of adj acent open space , go lf courses or sportsgrounds.

The insta ll at ion of three pond s in the Ginninderra C reek catchm ent is considered preferable to one large pond at t he lower end of the catchment for a number of reasons : • the sha ll ower pond s a re superior in res pect to po ll uti o n intercepti o n and retention ; • the adoptio n of upstream po nds increases the potential fo r the retention of na tural cha nn els; • th e uti li zation of three pond s en ha nces the landscape design of th e town .

Th e two major poll ution concern s co nfronting Lake Ginninderra are eutrophi ca tion a nd bacter ia. Rela tionships esta blished between phosphorus and bacteria loading a nd levels or nuisa nce pla nt growth and bacterio logica l qualit y for Canberra 's urban lak es, have been used to determine the accep table va lu es of phosphorus and bacteri a di scharge from G ungahlin consistent with protect ing lake water uses.

Lawrence ( 1984) has develo ped a series of regress io n equat io ns for the reduction in po llutant loadings ac hieved with detention storage . These eq uations have been used to determ ine the required vo lume of the Gu ngahlin ponds.

Flood retardation is required within Gungahlin in order to redu ce peak flows through downstream developm ents in Belconnen a nd North Ca nberra to acceptable levels. (Design criteria of I : I 00 a nnu al exceedence probability). Storage volume is to be in co rporated into-the design of the pond s in the Ginninderra Creek and G ungaderra Creek catchments for reta rdation purposes. A retardation basin is required on Halls Creek to contain peak flow s to their pre-urba n levels in order to protect the down strea m reaches o f th e creek fro m excessive eros io n as a res ult of the developm ent of Gungahlin. Retardation basins a re required on Sulli va ns C reek to co nta in peak fl ows to levels wit hin capacity of the downstream reac hes of the cree k .

The loca ti o ns of th e retardation basins are shown o n Figure 2. In order to avoid excess ive landtake requirements, reta rdation bas in s have either been incorporated into the proposed ponds or have been sited on proposed sports ground s or playing fi elds where inundation of flood waters can be tolerated more frequently th a n a n average of once in I 00 years.

All four proposed po nds a re classified as referable dams under th e guidelines spec ified by the Australian National Co mmitt ee On Large Da ms (I 984). As such, spec ifi c requirements need to be met in relation to : • desig n flood • freeboard • dam survei llance • inund a tion ma ps • eme rgency procedures Whilst the design criteria for pla nning purposes require protection against I: I 00 AEP flow s, stability of da m walls assoc ia ted with the pond s and reta rding basins needs to be ensured during ra rer flo od events. Spillway facilities are to be pro vided to cater for flow s up to an AEP of I: 10 000.

7 .3 Trunk Drainage Lines

7 .3. I Natural Streams A strea m in its natural state offers a more pleas ing and aes thetic aspect to a n urba n environment than does an engineered waterway.

The change from episodic to perennial flow regimes and the increased ava ilability of nutrients as a result of urbani sat ion , entrai ns a significa nt change in ri verine vegetation, with the replacement of grasses by trees, shrubs a nd aquat ic pla nts.

Whil e these changes enhance the landscape a nd recrea tional qualit y of streams, they also reduce the hydraulic effi ciency of stream chan nels, necessitating the provi sion of a larger floodw ay reservation cross section.

The major drainage lin es on Hall s Creek and Su lli vans C reek currently exhibit severe erosion, reflecting prev ious land use cha nges within their catchments from nati ve pasture and forest to graz"ing and crop cultivation. This eros ion has resulted in very deep gu ll yi ng in secti ons and has left the streams hi ghly unstable , with the potential for further erosion. Gungaderra Creek, on the other ha nd , has virtuall y no defined chann el. Storm water is discharged by sheet flow , covering a wide expa nse of flat grassland.

The retention of natural streams in these three situations is not practicable.

The major creek lines in the Ginninderra Creek catchment generall y contain a defined a nd stabl e cha nnel. Some minor instabi lity is evident, such as on the outside of bends where un vegetated vertical ba nks a re being undercut by storm flows. However, these areas of instab ilit y are , in general, only minor in ex tent and occur only in iso lated in sta nces . it is consid ered th a t suitable remedial works could be undertaken to stabilise the banks and hence avoid further erosion. It is in tended to avoid ' ha rd ' engineering solutions and to provide stability by such means as: • shaping of banks to a sta ble batter and re-vegetating ; • planting of trees a short distance from th e banks, enabling the tree roots to extend towards the bank and thereb y provide stabilit y.

The retarda tion basins within the Ginn inderra C reek catc hment will be designed to reduce peak flow s to at least the ir ru ra l valu es . Hence the hydrological regime of the streams downstream of the ponds will be such that the stab ility of the streams is not at ri sk. Consequently, the reaches downstream of the ponds may be left in their natural state, with so me minor remedia l work, where necessary, to ensure a stable system.

Experience wit h ot her natura l strea ms reta ined within th e urban environm ent in Can berra has shown that with th! constant ba e flow, co mbin ed with the excl usio n o f stock grazin g, has res ulted in increased vegeta ti on along these systems. The effect of this is an increase in fl oodway roughness and hence th e ra isin g of flood leve ls.

In deter mini ng the required floodwa y reservation widths for natural st rea ms to be reta in ed within Gu nga hlin , it has th erefo re been necessary to a llow for expected future vegetative growt h as well as any proposed landscaping.

7.3.2 Engineered Waterways On major dra inage lin es where it is not practicable to retain the existing streams in their natural conditi on, enginee red wa terways need to be introdu ced to per form th e required drainage function . While not as efficient as natural st reams in in tercep tin g nutrients, sediment a nd suspended material, engi neered floodways are nevertheless superior to co nventi o na l drains. As prev io usly di scussed the co nventional sys tem of a large open lined chan nel is cons idered un satisfactory.

The proposed a lte rna ti ve is a grassed flood way with a st ru cture designed to contain 'trick le' flow s o nl y a nd as suc h shou ld be expected to have its ca pacit y exceeded severa l times per year. The trick le fl ow structure is required as the sustained flow generated by the urban ca tchments would oth erw ise crea te a number of maintena nce problems .

• the co ntin ua ll y wet ground would make mowing difficult; • th e co nsta nt su pply of water is likel y to result in excessive vegetative growth which wo uld se ri ous ly inhibit the hydra uli c ca pacit y of the sys tem .

Two alternatives for the trick le flow structu re were co nsi dered : a sma ll dia meter pipe or a sma ll co ncrete cha nnel.

Nichols a nd Griffin ( 1983) ex press a preference for a n und ergrou nd pipe. However, a co ncrete cha nnel has been adopted as the preferred op tio n for severa l reaso ns: • a small diameter pipe is lik ely to block easi ly, th us requir in g regular maintena nce; • numerous inlet/ outlet structures wo uld be req uired to direct minor surface flow s into th e pipe ; • as the piped disc harges from residential areas wi ll greatly exceed the capacity of the small pipe, the interface between the residential and trunk systems would require special consideratio n ~ • the co nstant sight of flowing wa ter in an open cha nn el would serve as a reminder to the co mmunit y that these areas a re des igned to carry stor mwater a nd are therefore subject to flooding in times of storm s.

In determining the required dime nsion• of th e engineered waterways, Nichols and Griffin (1983) propose the fo ll owi ng criteria be appli ed to th e I : 100 AEP flo ws: • Maximum average cross-sec ti o n ve locit y of 2 metres per second .

• Max imum depth of fl ow of I metre .

• Maximum product of dep th a nd velocit y of I m2 / s.

Applying these cri teria to the proposed fl oodways with Gungahlin resulted in unaccepta ble floodway widths. Application of these criteria provides a sys tem whereby a non-swi mming adult cou ld safely wade from one side to th e other during a I : 100 AEP floo.d event. The pro vision of this level of protection is not considered wnrra nted give n the excessive landtake involved .

A more practical approach was considered to be the app lication of the criterion of a maximum average cross-sec tion velocity of 2 metres per seco nd together with a maximum cross-fall within the flo odways of I in 6. This sho uld res ults in a situ a tion where a person a ttempting to cross a flooded waterway would quickly se nse the danger of wadi ng into deeper water at the edge, a nd wo uld be able to easi ly withdraw from the da nger. To ensure adequate drainage within th e waterway reservation a minimum cross-fall of I in 50 is proposed. This requirement may be relaxed where sporting fields are incorporated into the floodwa y reservation.

Figure 3 shows two waterway cross-section configura tions. The first, without terrac ing, fu lfi lls th e above requirements, but resul ts in most of the floodwa ys reserve bei ng inundated eve n by more frequently occurring flood events. As the fl oodways are to be utilized as the major open space corridors , it would be desirable to limit the extent of inundation during the more frequent flood events. Th e second crosssection introduce th e co ncep t of a terrace into the floodw ay. The terWATER December, /985

21

1

---~ fil4::"

Cf-~-~~=~-=-=-~-__ __ _ _ F _ 50

' - - Low Flow Channel

1. NO TERRACE

2. WITH TERRACE

Figu re 3. Proposed waterway cross-sections .

or major open space syste ms, cut-off drains have been installed to divert flows away from leased properties.

Many of the cut-off drains previously constructed around Canberra have been installed after development has been completed . As a result, the availability of discharge points has been limited . Hence, existing cut-off drains tend to be excessively lon g. For example, the Mt Taylor cut-off drain, which runs around the back of the suburbs of Pearce and Torrens, is approximately two kilometres in length. This drain carries high flow s and hence failure at any point in the drain could result in a seriou s floodin g.

Failure of a cut-off drain is most likely to occur because of a blockage. Often local residents see these drains as a convenient location for the dumping of tree prunings and grass clippings. In some cases, drains have been blocked by residents forming crossings to enable children to gain access to open space on the opposite side of the drain .

Very little, if any, waterway a rea is provided under these crossings .

In other cases, ch ildren' s play equipment has act ually been set up within the cut-off drains. r.

Within Gungahlin, as with all future developments in Canberra, it is essential that all cut-off drains be integrated into the local municipa l stormwater system.

Cut-off drain lengths are to be kept to a minimum and are to discharge to the nearest existing gully which is to be retained as a floodway reservation. The length of cut-off drains is not to exceed 300 metres.

8. MONITORING race is designed to restrict the width of inundation during more frequent events, say a I :5 AEP flood. This then enables the use of some of the floodwa y for facilities such as sporting ovals which can be at least partially contained within the floodway, but need protection from more frequent flood events.

Traditionally, the planting of trees in flood ways has been discouraged as this results in an increase in flooded area. However, if incorporated into the design of the floodway, the inclusion of trees can actually reduce the flooded area. As described above, the flow velocity is to be restricted to a minimum of 2 mi s. A grassed floodway without tree planting reaches this velocity at a relatively shallow depth and hence requires a wide cross-section. The inclusion of trees allows the design depth to be increased before the maximum velocity is reached, a nd hence the width of the cross-section may be reduced. As the grassed floodway concept has a significantly higher landtake than a conventional lined channel solution, the reduced landtake associated with tree planting in the floodway is of significant hydrau lic advantage as well as being more aesthetically acceptable.

7.4 Neighbourhood Drainage 7.4. l Pipe Systems Stormwater design standards in Canberra require containment of flow s (for a nnual exceedence probability between I :5 and l :20, depending on location) within a formal stormwater system .

Traditional practice has been to utili se pipes until the capacity of three 2100 mm pipes is exceeded. As a result there are numerous large diameter storm water pipes located around the city. These large pipes tend to be an attract ion to children and there have been a number of instances, both locally and interstate, of children becoming trapped in stormwater pipes during storms. In some instances, heavy duty grates have been placed over the downstream ends of these large diameter pipes. These grates are not totally successful in excluding children from the pipes, as access may still be gained via manholes further upstream. Where these grates have been installed, blockages have occured as debris washed down by stormwater flow s is trapped by the grate. This renders the stormwater pipe in effect ive and results in flooding problems further upstream .

In order to overcome these problems in Gungahlin, it is proposed that no stormwater pipes larger than the preferred maximum of 900 mm diameter be installed. Where the capacity of two 900 mm pipes is exceeded, a grassed floodway with concrete invert (as described above) is to be utilised.

7.4.2 Cut-off Drains Within Canberra, where urban development backs onto hill reserves 22

WATER December, /985

At present, two strea mflow gaugin g stations are located within Gungah lin . One is located on a tributa ry of Ginn inderra Creek a nd forms part of a rural/ urban paired catchment study, the urban catchment being in an adjacent developed suburb. The other gauging station is located on Ginninderra Creek approximately one kilometre upstream of the Barton Highway. As such it is ideally located to monitor the effects of the development of Gungahlin on st reamflow quantity and quality. As well as recording streamflow, the station is also equipped with automatic sa mpling equipment to enab le water quality analysis.

9. CONCLUSION Thompson (1984) points out the need for a master drainage strategy to be prepared at the time that future urban development is at the strategic town planning stage. The government ownership of land within the Au stralian Capital Territory and the broad acre development undertaken by the National Capital Development Commission have enabled such a master strategy to be dev!:loped for the new town of Gungahlin .

The development of this strategy has been influenced by external constraints in terms of downstream hydraulic capacity and water quality requirements. The system proposed allows for the use of a number of floodway s and linear landscaped corridors as well as major cyclist and pedestrian links. Public safety and amenity shou ld be considerably improved over more traditional sto rmwater systems.

10. ACKNOWLEDGEMENTS The author wishes to thank the Director of the Department of Housing and Construction and the National Capital Development Commission for permission to publish this pa per .

REFERENCES Australian National Committee on Large Dams (1984), Interim Guidelines on Design Floods for Dams.

GOYEN, A. G., MOODIE, A. R. and NUTALL, P. M. (1985). Treatment of Urban Runoff in Australia . Proc. 1985 International Convention llth Federal Convention. A WWA, Melbourne, pp . 541 -548.

HIGGINS, W. L. and MILLS , J. E. (1975). Trunk Stormwater Design in the ACT. I.E. Aust. Hydrology Symposium, Armidale, pp. 178- 182.

LAWRENCE , A. I. (1984). Outline of ACT Streamflow and Water Quality Models. National Capital Development Commission, December (unpublished).

National Capital Development Commission (1985a). Guidelines on Engineering and Environmental Practices - Hydraulics. January.

CONTINUED ON PA GE 27

CONFERENCE REPORTS NATIONAL STRATEGIES FOR MANAGING HAZARDOUS WASTES O rganised in a rela ti vely short time and staged a t th e Hilto n , Melbourne, November 18-2 1, this Conference attracted some 330 delegates, o ne third fr o m interstate a nd o verseas - a comment upo n the import a nce a nd imm ediacy o f the subj ect a nd th e calibre of the principal speak ers , local a nd overseas .

Th e title of the Conference ma kes clear th e o bj ecti ves . Delegates represented all aspects of interest in th e hazardou s wastes area . Th e spo nso rs, Common wealth Department o f Art s , Heritage and Enviro nment, th e Enviro nment Protection Auth ority (Vic. ) a nd the Melbourne and Metro po lita n Boa rd o f Wor ks, ensured interes t by th e in vita tion of overseas speak ers and communit y in vol vement by the spon soring of representati o n fro m vari o us co nserva tion a nd environmental gro ups .

In o pening the proceedings, th e H o n .

Barry Co hen MP , Commonwealth Minister fo r the Arts, Heritage a nd Environment , stressed th a t th e subj ect o f the Con fe rence is o ne of the most importa nt iss ues of enviro menta l policy in Au st rali a a nd ove rseas.

The prim a ry responsibility is with State and Territo ry Governm ents but the problems a nd their possib le so luti o ns ca n transce nd both State a nd Na ti onal bo und a ri es, hence t he Comm o nwealth conce rn and invo lvement.

The Austra li a n Environmental Coun cil decided to initi ate a na ti o nal consulta ti ve process to achi eve wid er public knowledge a nd pa rticipa ti on . The deve lopm ent of a strategy for Australia has a n intern a tion al dim ensio n . Other a nd adj ace nt countri es have simila r problems requiring similar remed ies a nd the consid erati o n of th e possibilities of sha rin g such is rational.

The iss ue is highl y emoti ve in a ll respects; the creati on of wastes, th e transport of wastes, a nd their disposal. The respo nsibility fo r such in vo lves Sta te a nd Federal Govern ment , bu siness, th e enviro nm ent mo vement and the medi a.

At the Co n fe rence Dinner, the H on . Evan Walke r MLC, Victo ria n Minister for Pla nnin g a nd En viro nm ent, ex plain ed th e Government 's acti ve con cern and interest in the hazardou s waste qu esti o n. He trave rsed the Gove rnment's action s in thi s a rea, the ro les o f th e E PA a nd th e Melbo urne Board of Wor ks, a nd o utlin ed the order of the probl em in Victoria where th e a nnual production o f po tent iall y haza rd ous was tes a pprox ima tes 100 000 cubic metres.

The Conference closing address was given

by Andrew McCutcheon MP , Victorian Mi nister for Wa ter Resources who, ea rlier in the Co nference, iss ued a press sta tement o n reco mm end ation s th a t the Melbo urne Boa rd prepa re pro posa ls fo r a multi -purpose in cinera tor, a nd o n th e release for public comment, o f proposed siting criteri a for o ff-s ite industria l waste treatm ent fac ilities.

Mr McC ut cheon summa ri sed the a ntici pa ted benefits fr o m th e Conve ntion a nd 24

WATER December, 1985

Session : The International Perspective - Panel of international speakers.

Chairman , Ken Paddington.

the va lu e of the presentations, th e -intercha nge of information a nd the resulting di scussio ns.

Th e overall impression fr om the two days of intensive acti vit y was of th e wid es pread con ce rn with hazardous waste containment a nd disposal a nd a pprecia tion t hat th e predo mina nt pro blem a reas are politica l, legal, administra tive a nd co nsulta ti ve, not technica l.

Dur ing the technical sessio ns, 12 prima ry pa pers were presented a nd di scussed . These, with deta il s o f the Auth o rs, a re set o ut in th e rema inder of thi s commenta ry.

Copies of the full proceedings and discussions are available from the Hazardou s Waste Conference Secretariat, M & MBW , 625 Little Collins Street , Melbourne 3000 , Au stralia .

PROGRAM AND SPEAK ERS The Au stralian Scene J eff Wri ght , C ha irma n , Enviro nm ent Protec ti o n Auth o ri ty, Vi ctori a .

The International Perspecti ve H a rvey Ya kow it z, E nvironm ent Progra m , O EC D. Co-operation and Regulation Dun ca n Elli so n , Director Genera l, Dange rou s Goo ds Directorate , Tra nspo rt , Ca nada.

Incineration Mik e Wo rrall , Ma unsell a nd Pa rtn ers P/ L.

Economics of Waste Management Ga ry Dunba r, Se ni o r Vi ce Pres ident, Ca mps, Dresser a nd McKee, USA. Treatment and Disposal Alternatives Willia m A . Ca wley, Deput y Direct or , Hazardo us Waste Engin eer ing Resea rch, Resea rch La borato ry, US - EPA. Defining the C halle~ge - Denmark , an Example to Follow?

Morge ns Pa lm a r k, Proj ec t Man age r, Chem trol AS, Copenh agen , Denm ar k.

Health and Safet y Jim Brassil , C hai rma n , Na ti o na l Occupa ti o na l Hea lth a nd Sa fety Comm ission , Ca nberra .

Risk Anal ys is and Hazard Assessment Joe rg Kubi er , M ini ster of Energy, Water a nd Water/ Recycl ing, Ha mbu rg.

Siting Critiera Steve Hrudey, Professor o f En vironm enta l Engineering, Universit y of Albert a, Ca nada .

Community Iss ues - Hearing the Vi ews Ha ns Kolo , Member Ba va ri a n Sta te P a rli a ment , Munich The Future Direction for Au stralia Repo rter: D . Gasco in e, Dept. Art s, Heritage a nd Environm ent.

EDITOR

HYDROLOGY AND WATER RESOURCES SYMPOSIUM 1985 The 16th Symposium on H ydrology and Water resources under th e auspices of the Insti tution of Engi neers was held at the Uni versity of New So uth Wales, 14th to 16th May , 1985. 276 registrants atten ded and 46 papers were prese nted in a number of technica l sessions. The Hon. Mrs Janice Cros io , NSW Minister for Natural Reso urces, opened the Symposium . She drew attention to the fact that in New So uth Wales no single Minister of th e Crown and no single organ of Government had full responsibilit y for management of the water resources. In fact, the State had the most complex a nd fragmented framework for water administration in Australia. The water Audit Team is now formu lating a strategy to put water management o n a sounder bas is. They are concerned with wate r ow ners hip , catchment ma nagement, agricultura l and urba n water adm in istrati o n , a centra l Government Construction Authority for major water projects a nd Urban a nd Rura l Water pricing .

In the Keynote Address, Associate Professor Dav id Pi lgrim rev iewed some of the strengths and some of th e weaknesses of the Australian National Co mmitt ee on Hydrology and Water Resources. T he in di vidu al Cha racter of Australian hydrology, its diversity, variability , regard for variou s desig n aproaches, management a nd region al differences was most signifi cant.

The most important task was the pub lication of extensively used 'Australian Runoff and Rainfall' (ARR) fir st published in 195 7, with a second edition in 1977, and a new edition in preparation. Although the budget of the Insti tuti on of Engi neers fo r the ARR was on ly $ 150,000, with the efforts of individual

contri bu tors, the Bureau of Meteoro logy and others, a total vo lunta ry effort of more th a n $ I million had been involved. Other strengths mentioned by P rof . P ilgrim were the practical orientation of Australi a n hydrology , graduate teaching research, flood modelling , routine design and emphasis on methods based on observed dat a. Amongst the weaknesses, Prof. Pilgr im counted the lack of communi cation with other grou ps. For example, at the Symposium itself there were many engineers from di vers fields but few , if any, socia l scientists or economists attending.

In th e two para llel T ec hni cal Sessions 46 papers were presented. Irrigation, grou nd water , reservo ir opera ti on, fl ood di sc harge, observa tion and mapping, water resources all ocation an d pollution , rainfall statistics, runoff, urba n and agricultura l hydrology were a mon gst the many subjects covered.

The C rawford Munro Memor ia l Lecture, a feat ure at eac h H ydrology and Water Resources Symposium si nce 1978 , honours the memory of Prof. Crawfo rd Munro. The Memorial Lecture on thi s occasion was given

by D . N. Bod y, Senior Principal Research Scienti st CS IRO , Di vision of Water and Land Reso urces. H e said that C rawford Munro' s interest in water resources was alm os t co mpl etely directed towards engineering hyd rology. H e ac hi eved the transfo rmation from the o rigi na l reliance on empirical formulae estimating flood peaks to better methods and initiated the preparation of the fir st editi on of Austra lian Rainfall and Runoff . Munro's int erest in research stim ulated the estab li shment of the Water Resea rch Foundation of Austra lia a nd he was also responsible for the inclus ion of a

hydrometeorological sec ti on withi n the Bureau of Meteorology . On the other hand th e role perceived by CS IRO in 1968 for the study of water was in the context of biologica l and environment research only while Munro had urged water research over a mu ch wider hori zo n . After a deta iled ana lysis of research activi ty to the presen t day, Body suggests the following central conclusions: Australia needs enhanced water research.

There is a requirement for the estab li shment of centra l bureau co ncern ed with water research. Water research needs to be better foc ussed . Enhan ced research effort cou ld best be achi eved by support of existing agencies and stru ctures.

Water resea rch in CS IRO has now changed from identifi cation of re lationships in the process of the hydrologic cycle to questions of management of water resou rces . P rofessiona l sta ff now numbers 79 and expenditure $2.6 million.

In concludi ng Bod y claimed that the challenge for th e futur e in water research was not so much that we inhabit the driest co ntinent bu t ari ses from the way that we, as a nation, have chosen to use o ur la nd .

A special separate day fo llowing the symposium was devoted to a Preview Workshop of 'Australian Rainfall and Runoff' whi ch is to be pub lished in 1986. This important publi cation is extensively used in th e design of practically all hyd raulic struct ures in Australia.

The Proceedings of the Symposium are ava il abl e from E .A . Books, E ngi neers Australia, PO Box 299, St. Leonards 2065.

H. BA N DLER

INTERNATIONAL ASSOCIATION FOR HYDRAULIC RESEARCH TWENTY-FIRST CONGRESS The Congress, held by the Uni versity of Melbourne , August 19-23 was an historic event in several ways. The twenty- fir st of the Association , the first to be held in Australia and a n attend ance of 376 registrants of whom 195 came from 34 countri es overseas .

The !AHR originated in 1935 a nd the fir st Congress was held in Ber lin in I 937. In the keynote address: ' 5000 years Hydrau lic Engineering - 500 years H ydraulics - 50 years !AHR', signifi cant event s in the history of Hydrology and of the Association were traversed by Prof. Garbrecht of West German y.

A total of 207 papers were presented mostly in three parallel streams including four seminars. Most presen tation s were in English and simu ltaneous translation, E nglish-French or French-Eng lish, was available in some sessions. The standard of papers was very high although perhaps academic in so me cases.

This is not surpri sing as much of the hydraulic research in Austra lia and elsew here is carried out in tertiary inst itu tions. It is relevant that the registration at the Congress included 82 professo rs and I 00 doctors (generally not of medicine).

In addition tu papers presented, poster papers fro m 22 co ntributors were displayed and the Australian a nd State Government agencies a nd authorities featured 'Exa mples of Achievements', a lso manufact urers exhibited eq uipment relevant to the indu stry .

The objective of the Co ngress was to continue the Assoc iat ion's function in the provi sion of regular major meetings, pro vide practical solutions to problems in the areas of interest and enco urage techni cal information exchange and relat ionships.

A ll papers including th e keynote address have been published as Proceedings of the Congress by the In stitution of Engineers, Austra lia in six volum es. Copies of the Proceedings are avai lable from Engineers Australia Books, St. Leonards, NSW.

The I.E. Aust. sponsored the Co ngress and provided a Co nference Manager , Mr Barry Hewish. Professor J ack Lawson and a loca l Organisi ng Committee with the assistance of Correspondin g Members, planned , a rranged and co nducted the Congress.

Parallel with the JA HR Congress and in the same precincts, 'Flomeko '85', the Internatio nal Confere nce on Flow Measurement was held . Thirty- five papers we re presented during 20-23 August 1985. Participation in technica l sessions of both con ferences was open to both Flomeko and !AHR registrants.

This Congress was an important national and internati ona l event in t he sphere of hydraulic research. It brought together in A ustra li a the leading world figures in th is discipline and fulfi lled the objecti ves which had been set.

As part of the activities, a visit was organised to the extensive I 085 ha sewage treatment fa rm of the Melbourne a nd Metropolitan Board of Work s at Werribee. The in spection was fo ll owed by a most enj oyable barbec ue luncheon hosted by the Melbourne Board .

The next !AHR Congress is to be held in Lausanne, Switzerland in 1987. For comment on the 20th Congress see H . Band ier: International Congress on Hydrau lic Research in Moscow, Water, March 1984, p . 27.

H. BANDLER WATER December, /98j

25

Professional Training in Water Science W. Maher, P. Cullen and R. Norris ABSTRACT A water science programm e is offered at the Canberra College of Advanced Educat ion whi ch has been designed to produce graduates capab le of co ping with t he changing needs of the water in dustry . An understanding of the functions of water sys tems within a framework of catchment interactions is provided. The deve lopment of scientific sk ills (problem formulation , data co llection, manipulation and integration) is an essential part of the programme. Teaching strategies are des ign ed to develop autonomous learners who will be ab le to continu e thei r profess ional development throughout their careers.

INTRODUCTION The Australian water industry is undergoing a transition from the histo rica l emp hasis on cap ital works, to a mangement phase emphasising the more efficient use of available water su pplies. The future wi ll see the all ocation of water supplies and water quality becoming even more important management iss ues . The ro le of professional -employees of the water indu stry wi ll chan ge, re fl ectin g thi s shift, and they will need an educatio n that engenders the appropriate know ledge, sk ills and altitudes.

The Canberra College of Advanced Educatio n (CCAE) offers a water science programme to provid e profess iona l training and retrain ing for ind ividuals in the water industry. T he programme has been developed to meet these changing needs o f the water industry.

PROFESSIONAL NEEDS The Water 2000 report ( 1983) has highlighted that land and water reso urces should be managed on a co-ordinated basis and that instream uses shou ld be included in all water resource management decisions . Specifica ll y the a bility to think in term s of sys tems is necessary, and an adeq uate scient i fie understa nd in g by professional staff of th e way aq uat ic systems function is now essentia l.

Shortages a nd variabil ity of the avai lable water reso urces make it diffic ult to resolve competi ng and conflicting demands from different water uses and users. Allocation of water resources has mainly been based on suppl y management, by the allocatio n of water from storages to meet needs. Less capital funding for the development of new water reso urces means tha t ex isting water resources must be bet ter managed, especially to protect a nd imp rove their quality. Whether water quality will be maintained or improved wi ll depend on the use of a scientific resource management approach . Approaches will be multidisciplinary and the ability of employees to find, manage, manipulate and use data wi ll be cru ci al. New graduates recruited to the water indu stry will need to co me from a n ed ucational experience al tuned to t he in vestigationa l and ope ra ti o nal fu nctio ns of the water industry an d with so mewhat less emph asis o n the tech no logies a sociated it h co nstruct ion .

The wat er industry is in a period of change. Employees mu st be capable of adapti ng to a changing work environment, to new tasks and to new areas of activ it y. Leaders must be ab le to perceive and understand changes a nd formulate creative res pon ses to it. Future emp loyees must be ready to lea rn a job , rather than be just ready to perform a job . Thus, education wi ll be seen as a continuing process rat her than an initial und ergraduate preparation for a life-time of work .

WATER SCIENCE PROGRAMME AT THE CCAE In respon e to the industry 's needs for a combined land and water

Dr William Maher, MAppSc(Melb), PhD(S'ton) Lecturer in Limnology and Oceanography - Biogeochemical cycling of trace elements and hydrocarbons in marine and fresh water environments.

Peter Cullen, MAgrSc, DipEd(Melb) Deputy Head, School of Applied Science - Nu trien t dynamics and plant production in aquatic ecosystems, eutrophication and assim ilative capacity.

Dr Richard Norris, BSc(ANU), DipEd(CCAE), PhD(Tas) Lecturer in Aquatic Ecology - • Ecology of f reshwater macroinver1ebrates, biological asse sment of water quality.

26

WATE R Deamber. 1985

W. Maher

P . Cullen

R. Norris

management approach, the Ca nberra Co llege of Advanced Education Water Science programme provides an understanding of the fu nction ing of water systems withi n a framework of total catchment interactions. At the co nclu sion of the programme students should: • be ab le to integrate the physical, chemical and biological aspects of water syste ms in a catc hm ent framework; • have developed a n understa ndin g of spatial a nd tempora l variab ili ty within and between catchments; • have developed an understanding of the concepts of constancy, periodicity and irregularity as app li ed to Australian water systems; • have the knowledge required for t he management and a ll ocation of water reso urces.

The development of scie ntific skills is an essential part of the program me, includ ing skills in problem identification and the subseq uent formation and testing of critical hypothes is. At the undergraduate level extensive use is made of fie ld teac hing to allow student s to gai n exper ience in tak ing sound observations in natural sys tem s and expertise in data coll ection, manipulation and integration.

In view of th e rapid cha nges in the wate r sc iences, it has been decided that student s need to become what is termed a utonomous learners.

Professionals need to be ready to use the bes t ideas and techn iques of the moment, but also need to expect these will be replaced or outmoded by new deve lopments. The cha llenge is to educa'te professionals who can continue to learn, and to grow intellectuall y throughout their li ves, rat her than beli eve the bundle of skills picked up during their first degree wi ll be eq uip them for a li fe long ca reer. l f ed ucation is seen as a n on -going procest, th en one of the cr iti cal skills for a ny professional is to know when to stop learning and get on with the job. We never know everything about a ny topic, and while to some it may be tempting to keep reading, it is esse ntial for a professional to be a ble to judge when enough is known to so lve the prob lem of concern. Other interesting facets of the topics may have to be left for a not her time .

This is not easy for st udents who believe they need to know as much as possible abo ut a topic before being assessed on it. To force st udents to make overt judgements about when to stop, an individuali zed approach to lea rnin g has been used where stud ents work largely at their own pace, a nd have to choose when they are read y to be assessed on a part icular topic, give n the overa ll co nstraint of a certain number of assessments within th e semes ter.

This water sc ience programme commenced in 1973 and is part of a broader Natura l Resou rces progra mme which presently has some I 20 students. The water science programme gradu a tes around 10-15 st udent s eac h year, with a Bachelor of App lied Science degree, who ha ve found emp loyment in a var iety of State and Federa l agencies in vo lved in the water indu stry.

T he Water Sc ience programm e may be undertaken by st ud ents who have completed an approved package of intoductory Applied Sc ience units (Year 1), coveri ng maths/ stats, bio logy, geo logy, chemistry a nd geography. In dividual water science unit s (see study programme) fa ll with in one of two complementary, but integrated strea ms - water quality and water quantity. The first stream emphasized environmenta l aspects of wa ter quality while the second stresses the ava ilability a nd vo lumet ri c use of water resources (units are described below).

Although single units from the fo ll ow ing tab le may be selected by students undertak ing other programmes of stud y, the whole pro-

gramme is encouraged for those see king a professional career within the water industry.

STUDY PROGRAMME Year

S1ream & le vel

2 3

UG•

PGt

Waler Qualify Aquatic Enviro nment Ecochemistry 2 Wa ter Science

cpt

12

Waler Quan1i1y

cpt

Weather & Clim ate Hyd ro logy Appli ed Physica l Geograph y

Water Management PG Water Quali ty Management PG

Studen ts usually do 24 cred it point s per year • UG = undergraduate unit

t PG = postgraduate unit t cp = credit point s

Wafer quality management Thi s unit aims to bring about a n understanding of th e bi o logical , chemical and physica l processes that determine how wat er systems respond to a nd rece ive pollutant inputs; and to provide and criticise tec hniques of assess me nt to estab lish water qualit y criteri a and standards; strategies for managing water qua lit y; and procedures for designing data co ll ection sys tems for water quality ma nagement.

The biological, chemica l a nd physical processes that determ in e water quality in aquatic systems will be exam ined in some deta il. Thi s wi ll include a co nsideration of the ways in which water bod ies respond to pollutant input and loads.

From these consi derations the ways in whi ch quality criteria a nd standards can be es tablished wi ll be co nsidered. Furthermore, the ways in which planning a nd management strateg ies can be developed will be con sidered .

Proced ures for des igning data co ll ection , storag and manipulation systems will be reviewed wit h special attention to the criti ca l need to clearly define the questions that the monitoring programme is required to answer.

Unit descriptions follow.

WATER QUA NTITY WATER QUALITY

Aquaric Environment This unit gives a ge neral introduction at second year level, to the elements, processes and concepts of lim no logy , together with an introdu ction to the physico-chem ical analysis of fre sh waters. The unit will consider from an ecosystem point of view , th e physica l, chemi cal and biologica l processes in inland waters. Emphasis is given to the practical application of various techniques of measurement, identification and ana lys is of the bioti c components of water bodies.

Weather and Climate Th e first half of the unit compri ses a genera l int rod uct io n to the elements, processes and concepts of the at mosphere, so lar radi ation , weather and climate. The second half delves more deepl y into th e co ncepts and phenomena that a re particularl y relevant to the h uman environment and natura l resou rces. The unit is designed for st ud ents who may wish to co mplemen t a major interest in ecology, hyd rology, po llu tion chemi stry , teaching meteorology and climatology, urban planning and landscape a rchitecture, with a better understa nd ing o f th e atmospheric environment.

Ecochemisrry 2 The unit aims to develop both a qualitati ve and a quantitative understa nding of the processes (physical, geological, chemical and biological) that influence, and are influenced by, the chemica l composition of natural waters. Topics to be covered inclu de water cycle and properties; chemica l equi lib ria; chemical features of lentic, lotic and estuarine sys tem s; effect of human activities. Practical work will include field sampling and laboratory instrumental analysis.

Warer Science This unit aims to develop an understanding of processes operating with in aquatic ecosystems and the way these proceses are affected by human activities . The major factors controllin g both primary and secondary productivity in aquatic ecosystems will be examined in so me detail. The emphas is will be on quantitative analys is and prediction. Specific topics that will be covered include land-water interactions, nutrient cycling, eutrophication, estuarine processes, fi sheries, chemical and biological monitorin g, biomanipulation and assim il a tive capacity for pollutants . Th e unit wi ll also examine co mmon approaches to managing aquatic ecosystems including water quality criteria, monitoring, river ' improvement' , and the impact of water storages . A major project is incorporated within thi s unit.

Warer Management The aim of this unit is to ensure that students from divers bac kground s have an adequate understanding of the essential ele ments of inland aquatic ecosystems and of the basic principles of hydrology necessary for water management. Students who have some background in these areas wi ll be encouraged to increase their understanding of selected aspects . Detailed examinat ion of pollutant exports from various land surfaces will lead to a co nsideration of decision- making processes and tools for water resources management in Au stralia. Th is unit will review the biological, chemical and hydrological base for water ma nagement, and exa mine the tran sfer of various pollutants through the soil column and from land surfaces.

The relationship between land use and water quality will be examined in some detail as wi ll specific topi cs such as soil erosion , salin ity and land drainage . The impact of various pollutants on the quality of receiving waters wi ll be considered and the variou s approaches to determining the ca pacity of various water to accept a range of pollut a nts di scussed .

Hydrology The aim of this unit is to introduce students to quantitati ve methods in terrestrial hydro logy, and the a ppli cation of these techniques to catchment studies and the assess ment of water resources. Topi cs include the hydrologic cycle, with emphasis o n gro und wa ter and strea m flow; quantitative interpretation of hydrologic data; introdu ction to mode lling of hydrologic syste ms; examination of some ,problems in the development and manage ment of water resources; and changes in hydrologi c systems indu ced by man's acti vities.

Applied Physical Geography Thi s unit emphasises the co llection, classifi cati on and appra isal of data for the evaluation of water and land resources . Quantit a tive, graphi cal and cartographic tec hniques are used to ana lyse primary and documentary records so that an assessment ca n be made of land use potenti a l within geog raphicall y d iscrete areas. Stress is pl aced o n th e situational effects of terrain , soils, mi cro-climate and surface hydrology. The unit focuses particular a ttention o n the influ ence of meteorological, hydrological a nd geophysica l hazards on the location and di stribution of land use types. A final report is required whi ch will involve a geograp hical assess ment of the physica l suitabilit y of a selected a rea for spec ifi c land uses a nd the likelih ood of impact by a hazardous event.

REFERENCES Water 2000 (1983) . A perspecti ve o n Austra lia 's water reso urces to the year 2000.

Department of Reso urces a nd Energy, pp. 120 .

J. F. NEAL CONTINUED FROM PAGE 22 National Cap ital Development Com mission (1985b) . Gungahl in Su rface Water Management, Pre-Design Report. ( In press).

NICHOLS, P . S. and GRIFF IN, P. C. (t983). Modern Methods of Urban Drainage. I.E. Aus/. Hy drology and Waler Resources Symp osium, Ho ba rt.

No vember. pp. 148- 155.

THOMPSON, D. G . (1984). The One Percent P ro ba bility Flood as a Basic Drainage Design Criterion. Civil Engg. Transac1ions of 1he I.E . Aus/., Vol. CE26, No. 3, August. pp. 197-203.

WATER December, /985

27

CONTROL OF SEWAGE TREATMENT POND ODOUR USING ACTIZYME Technical Note by R. J. Gilbert, City Engineer, Swan Hill* During 1984 the Swan Hill Water Board ach ieved co nsidera ble success in controlling odours from thei r sewage treatment pond s by the use of 'Acti zy me' . t The treatment works were designed to cater for a population of 17,200 co mpared with the present population of 9,100 persons a nd are of relatively recent co nst ruction, being com mi ss ioned in 1978.

Due to the very flat terrain in and around Swan Hill, the sewerage system within the city co nsi sts of gravity mains flowing into a total of 20 sewerage pump stations, which in turn direct the sewage via gravity o r rising mains into a major pumping statio n which discharges the sewage a distance of approximatel y eight ki lometres to the treatment works . A ll but two of these pump station s ·(constructed at an earlier dat e) a re of the subm ersible type.

The treatment works consist of four ponds of which the first is a facultative dual purpose pond with the other three ponds being aerobic. Th e effluent passes from the final treatment pond into a large evaporation basi n . The high salt co ntent of the infiltration water within the city area results in a highl y saline sewage with a sa lt content between 3 and 4.5 thou sand parts per million, which is unacceptab le for use in irriga tion or for di scharge into fre sh water strea ms and therefore the evaporation basin appeared th e only acceptable a lternative.

Swan Hill is very fortunate in that co nditions suit this type of di sposal a nd it must be o ne of the few places in Victoria that has been ab le to adopt such a syste m providing little co nflict with the environment.

The average dail y flow to the treatment plant is 3.3 ML, the sewage consi st in g entirely of domestic, motel and restaurant wastes .

A typ ical analysis is given in Table I . The large number of pumping stat ions co mbin ed with re-pumping and a length y rising main to the treatment plant , res ults in a lengthy retention time and a bui ld up of hydrogen su lphide, particularly at the discharge to the plant.

TABLE 1: TYPICAL ANALYSIS OF RAW SEWAGE pH 8.O.D.5 C.O .D. Suspended Solids Total Filtrable Residue (105 ° C) Sulphate as SO4 Sulphide as S

6.9 190 340 280 3400 370 0.5

From very early it became obvious that the effl uent arriving at the treatment plant was subj ect to occasional odour and had so me peculiarities. One striking phenomenon was

• Mr Gilberl is now Cily Engineer, Sale.

Aclizyme is produced by Soulhern Cross Labora1ories Ply. Lid. , 246 New Line Road, Dural, N.S . W.

t

28

WATER December, 1985

the change in colour of the ponds from a bright green a lgae co lour to pink with an appea ran ce similar to colo ured milk. This phenomena has been fu lly recorded and a lso exists at the Wh ya lla treatment plant and is directly related to the build up of sulphur bacteria in the sewage . In the early stages the occasional odour was thought to be a minor problem which would cure itself after the ponds had been in operation for some time, and with the estab li shment of a normal sludge blanket and the replacement of so me of the fresh water intiall y di scharged to the ponds. However this was not to be so and in fact the odour prob lem gradually worsened.

commercial septic sys tems a nd it has been widely used in a ll States over the past four years - more particularl y, in New Sout h Wales and Queensland. Since its original development, the use of the material has been extended to treatment of effluent and problems in grease traps, abbatoirs, chicken processing works, caravan parks, motels , clubs, res taurants, piggeries and in package treatment plants and digesters.

During the preceedin g three years it was found that the odour problem s at the treat ment works were at their worst during the winter months from the end of May to late August / early September and, despite a ll ef-

TABLE 2: 'ACTIZYME' DOSING SCHEDULE Dose

Main• Pump Station

I. 2.

3.

4.

5.

15 3 2.5 2 2

lnti a l Slu g Dose Secondary Slug Dose Initi al Maintenance Secondary Maint enance General Maintenance

kg kg kg kg kg

Othert Pump Stations IO 3 1.5 I

kg kg kg kg

Period

5 days 9 14 14 11

da ys days days days

Daily Total 25 6 4 3 2

Total Quantity

kg kg kg kg kg

125 kg 54 kg 56 kg 42 kg 22 kg

Total

299 kg

• By automatic feeder t Manually

The Board' s cons ul tants recommended, on a trial basis, massive dosing of the primary treatment pond with ammonium nitrate, to inject more oxygen into the water, and t he blocking off of the discharge lines into the bottom of the primary lagoon to force the sewage to flow freel y over the top of di stribution boxes a nd onto t he surface of the lagoo n. Two I ½ tonne doses were app lied over a five day period which, after two weeks completely removed the odour problem .

However , after a period of time the pond s returned to the ir poor cond iti on and odour problems again developed. Subsequent ammonium nitrate dosing aga in corrected the problem . When problems again arose during the winter month s May-August, the a mmonium nitrate dosing proved unsuccess ful and had no effect on the odour problem and alternatives had to be investigated.

One recommendation was the installation of aerators on the ponds at a capita l cost of $ 100,000 . With operation and maintenance, ann ual cos t s would have approac h ed $25, 000-$30,000 . Following a recommendation from the Board 's Engineer, as an a lternative, the Board accepted an offer from Sout hern Cross Laboratories Pty. Ltd. to experiment with 'Acti zyme' over a seven week period . Thi s product is used in Bendigo to control odour and fa t problems caused by abbatoir wastes and it was thought it may offer economic advantages in Swan Hill.

'Actizyme' is a biological comp lex of selected micro organi sms, enzymes, nutri ent and buffer in a stabi li zed pellet form similar to chicken pell ets in appearance. It was originally developed for use in household and

forts, no substantiaI° results in odour contro l were ach ieved during this period. 'Actizyme' dosing commenced early in August, in accordance with the schedule summarised in Table 2, and at a time when the ponds were in extremel y poor condition.

Following the intial slug dosing of pump stations throughout J he city, it was obviou s, from the increase in small fat nodules at the main pump station, that the Actizyme was having the effect of cleaning out the mains .

Eighteen days after the initial slug dosing, the lagoons showed some sign s of improvement and over a period of the next four days the odour comp letely disappeared and th e pond s continued to operate extremely satisfactorily without any odours during the dosing period.

As past experience indicated that the treatment pond s tend to operate satisfactorily without specia l attention during the warmer su mmer months and t hat dosing would not be necessary on a 12 month basis, the feedin g of 'Actizyme' into the sewerage system was stopped late in September. However, two weeks later odour problems aga in returned to the primary lagoon, and dosing of the system was resumed on a basis of 12 kg on the first day and 2 kg per day for the next seve n days.

This brought very quick response a nd the odour problems at the primary lagoon disappeard again within five days. Dosing was again discontinued for a period of two weeks, ho wever slight odours agai n occurred in the primary lagoon area and a further dosin g of 3 kg per day over an eight day period was commenced at the beginning of November.

Within· I 2 days a ll lagoons returned to good

operat iona l condition and the odour again di sappeared. Sli ght o dour problems aga in became ev ident in mid Dece mber and furth er dosin g was carried out for IO days. No dos in g was necessa ry durin g th e fo ll owing eight weeks.

The initial dosing program in vol ved 300 kg of the Ac tizyme a nd the quantities purchased by the Water Boa rd were a t a specia l rate of $ 13.80 per ki logra m. In addit ion it was necessa ry to hire a n Actifeeder for the dosing period . The all -up cost for the seven week dosin g program was $4,23 0. If it is necessary to maint a in a ge neral maint ena nce dosing fo r the other I 9 weeks of the wi nter period a t,

say , 2 kg per day, a further 266 kg may be required resulting in a n add iti ona l cost, wit h hire of the Actifeeder, of approxima tely $4000. .

All ow ing fo r so me minor dos in g during the summer period a nd continual dosing during the winter month s, it is est im ated that the total annual cos t of the Actizyme dosing progra m will not exceed $ I 0,000. This cost ca n be compared wit h the alternative of installation of a n aerato r on th e pond, the capital cos t, power cos ts a nd mai ntena nce cos ts of which wo uld result in an a nnual cost of between $25,000 and $30,000 .

January 26-30, Florida, USA Geotechnical App lications of Remote Sensing Transmission February 6-8 , New Delhi , India 4th Groundwater Congress February 16-23, Adelaide, SA 8th Aust. Geological Co nvention February 22-27, Monte Carlo, Monaco Mediterranean Water Technology Ex hibiti o n and Conference.

February 27-March 1, Singapore Water and Wastewater Management in Asia March ? , Melbourne, Vic. Environmenta l Engineering March 27-28, Florida, USA 6th Internationa l Sym pos ium on Environmental Pollution I April 1-4, Hangzhou, China 2nd Internatio nal Co nfere nce on Small Hydro April 7-8 , Edmonton , Canada 2nd National Co nference o n Drinking Water (Treatment for Organic Conta mina nts) April 9-11, Dubrovnik, Yugoslavia International Symposium on Comparison of Urban Drainage Models with Real Catchment Data April 9-11, London, UK Measuring Techniques for Hydraulic Phenomena April 14-18, Adelaide , SA Engineering Conference, IE Aust April 16-18, Southampton , UK H ydrau lic Design in Water Resources Engineering

Experimental dosi ng of t he sewerage sys tem with 'Actizyme ' has proved successful in controll in g an odo ur problem at the Swan Hill Treatm ent plant at a cost less than est im ated for mecha nical aerati on, a nd has also proved beneficia l in helping clean sewer mains and co ntrol localised odo ur probl ems at pumping stations. Further in vestigation a nd ex perim enta ti on is now required to determine the nomin al dai ly dosage rate necessary, after the slug dosi ng, to control odour problems during th e worst six month s of the yea r. It is a nticipat ed that the ponds will need litt le o r no treatment during the six warmer month s.

August 17-22, Rio de Janeiro, Brazil 13th IA WP RC Biennial Conference

CALENDAR 1986-87 January 18-28 , Co nference - Pollution Monitoring and Contro l

Co nclu sion

April 21-24 , Pennsylvania, USA Environment al Geotechn ology

A ugust 24-30 , Canberra , ACT Sed iments Down-Under

April 22-25 , Ostend , Belgium 4th World Fil trat ion Co ngress

August 25-27 , Rio de Janeiro, Brazil Marin e Di posal of Wastewater IAWPRC

April 28-May 3, Perth , Western Australia A WRC National Work shop on Urban Water Management May 11-16 , Brisbane , Qld International Conference Systems Under Stress

Ground water

May 14-15, Lo ndon , UK Sewerage - Va lue for Money May 14-16, Brighton , UK Water for Energy May 15-16 , Madeira, Portugal 7th Europea n Co n ference o n Envi ronmental Protect ion May 21-23, Brighton , UK Condition Monitoring May 28-30, Paris , France Management of Water and Sa lin a tio n Network s June , Jerusalem, Israel Ecology and Environmental Quali ty June 3-6, Basie, Switze rland Pro Aqua - Pro Vita June 10-13, Bournemouth, UK Water Qua li ty Modelling in the Inland Natural Env ironment June 15-26, Beijing, China Inter-Basin Water Transfer

September 7-10 , Minneapolis, USA Distri bution System Symposi um Septe mber 8-15, Karlovy Vary, Czechoslovakia 19 Co ngress International Association of H ydrogeologists Se ptember 9-11, Durham, UK Jet C utting Technology September 15-19, A mste rdam , Holland Anaerobic Trea tm ent - A Grown Up Technology ' September 22-24, Hanover, W. Germany Press ure Surges 1'

November, Bris bane, Qld Hydrology Co nference November 19-26 , Sydney , NSW 56th Anzaas Co ngress ovember 25-27, Griffith Un, Brisbane , Qld River Basin Management December 6-10 , Baltimore, USA Water Quality Technology Co nference

1987 January 14-16, Khon Kaen, Thailand Rain Water Systems March 23-28 , Adelaide, South Australia

July 2-10, Budapest, Hungary 2nd IAHS Scientific General Assy July 14-17 , London, UK World Water '86

A WW A 12th Biennial Co nventi on

April 6-10 , Rome, Italy H ydrology in Perspective

July 17-1 8, London, UK Famine and Drought

May 26-29, San Juan , Porto Rico Water and Sa nitation in Develo ping Coun tries

August 11-13, Adelaide, SA Expansive Soi ls Conference

June 22-25 , Lisbon , Portugal Waste Stabilization Ponds WATE R December, 1985

29

CONFERENCES • COURSES • EVENTS OF INt"EREST NATIONAL WORKSHOP

URBAN WATER DEMAND MANAGEMENT WAWRC AND WAC Perth, April 29-May 1, '86 The Western Australian Water Resources Council and the Australian Water Resources Council are sponsoring a threeday workshop as first stage of an on-going national program directed to planning for efficient use in eac h state.

First day will be plenary sessions with ad dresses by prominent international and Australian speakers. Days 2 and 3 will be workshop sessions directed to issues, strategies and demand management . Rapporteurs will summarize and AWRC will publish papers and proceedings.

The venue will be the Alexander Library in Perth. Details from: Executive Officer, Western Australian Water Resources Council, PO Box 100, Leederville, WA 6007

FIP 10th INTERNATIONAL CONGRESS New Delhi, February 16-20, '86

The International Federtion of Prestressed Concrete expects an attendance of some 3500 at the Congress which will feature the theme 'Structural Concrete in the Developing World '.

Further information: Concrete Institute of Australia, 25 Berry St, Nth Sydney, 2060.

CENTRE FOR ENVIRONMENTAL TOXICOLOGY - NSW

AUSTRALIAN WATER RESEARCH ADVISORY COUNCIL

November saw the official opening of Australia's first specialist ce ntre dedicated to protection of the environment by reseach into the toxicity of chemicals. The opening coincided with the proclamation of the Environmentall y Hazardous Chemi cals Act. The centre, located at Gore Hill Campus of the NSW Institute of Technology was set up as a joint venture between the State Pollution Control Commission and the NSW Institute of Technology. Scientists at the centre will conduct laboratory tests on aquatic organisms and terrestial plants to assess the hazards posed by chemicals and chemical wastes.

The official opening was performed on November 2 by the Planning and Environment Minister, NSW, Mr Bob Carr. The opening coincided with the proclamation of the Environmentally Hazardous Chemicals Act which will control the effect of chemicals and chemical wastes upon the environment. The Centre is essential to th e operation of the Act . In the past , th e State and Australia has been largely dependent upon overseas resources which have not always been relevant to local conditions.

The new Centre will rectify the situation.

The official opening coincided with a symposium on environmental toxicology which linked government responsibility for regulating hazardous chemicals with the need to develop the science of environmental toxicology.

The Centre and the information it produces will be of great importance in assisting the Control Commission in the evaluation of hazardous chemicals and th e provision of expert advice to government and industry.

The Council announced by the Minister, Senator Evans, under Mr K. W. Lewis as Chairman , co mprises: Dr A. T. Arthington Reader School of Australian Environmental Studies, Griffith Univers ity, Old .

Mr D. W. Beattie, Commissioner Queensland Water Resources Commi ssion, Old. Mr M. Bennett , Chairman NSW lrrigator's Council , NSW Dr P. J . Crawford , General Manager Metropolitan Water Sewerage and Drainage Board , Sydney, NSW. Dr B. T. Hart , Director Water Studies Centre Chisholm In st itute of Tech nology, Vic. Mr J. C. McColl , Director-General Department of Agric ulture, SA. Prof. N. F. Millis, MBE Professor of Microbiology University of Melbourne, Vic. Prof. W. F. Musgrave Professor of Agricultu ra l Economics Universi ty of New England , NSW. Dr J . P. Paterson, Director-General Department of Water Resources, Vic. Mr C. F. Porter, Director Department of Conservation and Environment, WA . and executive member Mr A. Manderson First Assistant Secretary Water and Development Division Department of Resources and Energy, 1ACT.

N. R. SANDERS & W. A. MAHER CONTINUED FROM PAGE 17 I see a great future for scienti sts in the water industry in thi s country, because there isn't going to be much of a water industry without good scientists. In the near future, I would like to see scientists taking a major role in deciding where the water industry goes in Aust ralia .

PUBLIC ROLE OF THE SCIENTIST

SCIENCE IN WATER MANAGEMENT

Scientis ts must emerge fro m their laboratories a nd play an a tive role in advising co nsum ers of the co nsequences of ma nagement activities. Scientists should recogni ze that fin a ncial restrictions a nd changing comm unit y va lu es will result in more publi c debate on iss ues previou sly left to scientists and engin ee rs.

There is also a role for scienti sts in increasing pub li c awa ren ess and encourage debate by th e appropriate publication of sc ienti fie information. The information should be presented in a readil y intelligible form and as objectivel y as poss ible.

The use of sc ience in water management to date has frequ entl y been as an afterthought or as a means of optimi zing or modifying prevailing techniques. The present shift towards more efficient use of existing resources should necessitate a greater scien tifi c input into water quality iss ues.

Water resources are complex and va riable systems, to which all encompassing water quality criteria are not applicable. Scientific invest igation s can define the important system inputs, determine the effects of va riou s uses and help frame th e pla ns of management.

At the conclusion of th e workshop the support of th e Ca nber ra Branch of th e A WW A a nd of the App lied Science Schoo l of the Canberra CAE were gratefu ll y acknowledged together with the at.tendance of th e invited spea kers and th e contribution of Ian Lawrence to the original concepts of th e project a nd of Frank Krik owa, Laslo Nagy and several CCAE students to va rious aspects of the organisa tion.

PANEL DISCUSSION

Two issues emerged from the panel discussion . They related to the use of science in water management and the public role of scientists.

ACKNOWLEDGEMENTS

WATER December, /985

31