Page 1


Volume 27 No 6 November/ December 2000 Journal of the Australian Wate r Association

CONTENTS

Editorial Board F R Bishop, Chairman 13 N Anderson, P Draayers, W J Dulfcr. G Finlayson. G A Holder, M Kirk , 13 Labza . M Muncisov, N Orr, P Nadcbatm1, J I) Parker, M Pascoe, A J Priestley, J llissman. F R.oddick , E A Swinton , lllatcr is a refereed journa l. This symbol indicates that a paper has been refereed.

From the Federal President ........................... ... .... ....... .. .... .. .. .... ... .. ...... ...... ... 2 From the Executive Director ................ ..................... .. .. .. .................. ............ 4 INDUSTRY

Interview: Rod Welford ... ..................... .. ......... ....... .. .. ..... ............... .............. ..... 6 MY

Submissions Submissiom should be made co E A (!Job) Swinco,1, Featu res Editor (sec below for details).

General Editor P et e r Stirling PO Box 8-l, 1-la111pt011 Vic 3 I88 T cl (03) 9530 8900 Fax (03) 9530 89 I I

Features Editor E A (Bob) Swinton -l Plcasam View Crcs, Wheelers H ill Vic 3 150 Tel/ Fax (03) 9560 4752 Email: bswinton@bigpond.net.au

AWA Head Office PO 13ox 388, Arrnnnon, NSW 1570 T cl +6 I 2 9-l 13 1288 E111ail: i11fo@awa.as11.au

Water Advertising & Production Hall 111ark Editiom PO 13ox 84. Hampton, Vic 3188 Lt·vcl I, 99 13ay Street, !Jrighton. Vic 3 186 Tel (OJ) 9530 8900 Fax (03) 9530 89 I I Email: hal l111ark@ halledic.con1.au Advertising coordination: Fiona Second Graphic design: Mitz i Mann

Water (ISSN 0310 - 0367) is published in January. March. May, J u ly, Sc-ptc111ber and November.

Australian Water Association Inc A11..13N 05-l 253 066

Federal President Alle n G ale

Executive Director C hris Davis

AWA

tfj

AU STRALIAN WATER ASSOCIATION

PEOPLE

POINT

OF

VIEW

Permanent Water Restrictions: A Tangible Step To Ecological Sustainability .. ... ... ... .... ... .. ...... ..... .... ........................ ... .. ..... ... ..... ... ... .. ... .... .... 12 J Crockett CRC

FOR

CATCHMENT

HYDROLOGY

Integrated Hydro logic Prediction for Catchments .......... ...... ................. .. 14 R. M ein The Impacts of Afforestation on Water Yield: Predictions using MAYA .... .... .. .... ......... ..... ..... .... ..... ..... ... ... ..... .. ............................... .......... 16 R Vertessy, J R ahman , Y Bessard and L Z hang The Impact of Logging and Fire on Water Yield: Predicting the Thompson Catchment by Macaque ....... .... ... .. ... .... ........... .. ............... ..... .. ..... 20 M Peel, F Wa tso n and R. Vertessy Forecasting Rainfall for the Olympic Games .. ........... .. ... .. .... .. ........ .. ... .. ... 26 A Seed and T Keenan Improving Urban Stormwater Quality - From Theory to Implementation ................................................................ ........ ....... .. ... .... .... ..... 28 T H F W ong Communication for Adoption of our Research .... ..... .... .. .. ............ .... .... .... 32 D Perry WATER ·, Optimisation of Filter Function Using Particle Counting .. .. .... .. ...... . 33 M Colwe ll and P R L M asse Drinking-Water Management In New Zealand ... .... .. ... ... ... ... .... .. .. .... .... .. .. 36 M EU Taylo r WASTEWATER Effluent Reuse by Crops in Queensland ............ .... .. ... .... ..... .... ...... ... ...... 41 T Gardner and H G ibson ENVIRONMENT

Australian Water Association (AW A) assume, no responsibility for opinions or statcmcms of faces expressed by contributors or advertise,~. Editorials do noc necessarily represent official AW A policy. Advcnimnc-nts a1-e included as an infonmtion service to readers and arc reviewed before publication co c n~urc r elev;111Lt' to the w:ite r environment and objectives of AW A. All material in IVa1<·r is copyright and should not be reproduced wholly or in part without the written perm ission of the General Editor.

·, South East Queensland Regional Water Quality Management Strategy ..... ... ... ... .. .. ... ... .. ...... ....... ....................... .......... .. .. ... .. .. ... .. .. ... .. ..... ..... .. 42 T Lloyd, P M cM ahon, B Gibbcs, C Collie r

Subscriptions

Aquaphemera .. .. ..... .. .. ..... .. .. ....... .. .. ....... .. .. .. .. ..... .. .. .. .. ....... .. .. .. ..... .. .. .. ... .... .. .. ... .. 2 Water Environment Federation News .... ..................... ......... ................ .. .... ... 10 Water Industry E-commerce ... ................. ... .. ..... ... .. .... .. ..... .. ... ..... .. ... .... ...... ... 11 Membership .. ....... ... ...... .................... ............. ............... ... .... .... ..... .... ...... ..... ..... 51 Meetings .................. ......... ...... ......... .... .... .... ... ......................... ....... .. ............... . 52

I l'i11,·r is s,·nc to all AWA m,·mbcrs six times a ye.1r. It is also avai lable via subscription.

BUSINESS •, Water Account for Australia: The Analysis of Water Usage Data .. 48 C J ac kson DEPARTMENTS

Visit the Australian Water Association and access news, calendars. bookshop and over 100 pages of Information at

OUR COVER: Cool, clear 111ater, {ro111 a /im!sf catc/1111e111. Tlris iss11e, a11d tire 011e {ol/0111i11g, .fcat11res artirlesf,·0111 tire CRC.for Ca 1~/1111e11t 1-Jydrolo,~y. T11cir progra111 ai111s I<; predict liydrolo,izic belravio11r 011 a 111liole-cfratcl1111e11t scale. Photo courtesy of A udre Taylor, B risbane City Council.


FROM

THE

PRESIDENT

PASSING THE BATON As I w rite th is colu mn , l am mindful of the fact that our members will soon be meeting to consider a change of structure, one result of which will be a d ifferent cycle of leadership rotation. Assuming the changes are adopted, m y term of office w ill be ending in April next year, in stead o f th e usual November. As this move has been planned fo r so m e time, l have always been min dful of having to achieve my goals in a tight timetable. In that context, I am especially pleased to note that two of th e objectives I had flagged (Water Nov-Dec 99, p2) have been realised . Both relate to relationships and spill over into profile - two of the areas m entio ned in chat first co lumn of mine. Firstly, we have created the Australian Water Industry Forum, an informal affil iatio n between AWA, the Irrigati on Association of Australia (LAA) and the Australian National Comm ittee o n Irrigation and Drainage (ANC ID ), wh ich is effectively th e ind ustry association for irrigation water supply agencies and companies. T he Forum is likely to expand as other key, na tion al associations take part, and th e influential Water Services Association (WSAA), as A WA 's 'sustaining m ember' already has a watc hing brief in th e Forum through us. The Water Industry Foru m is th us a d iverse group, with a large constituency (ie pretty much all the water o rganisations in the cou ntry, plus several thousand ind ividuals there are som e overlaps amo ng the participants' members). It is capable of actin g as the voice for the broad water industry on issues and as a so unding board fo r Government w he n it needs to consult w ith the industry at large . One of its first actions w ill be to produce an expanded issue of th e A11srralia11 Water DirccroryjcJr 200 1, hig hlighting the role of th e Water Indu stry Fo rum, and to ensure that there is a stron g water po licy thread through our Ozwater Convention next year, Water Odysse)' 2001 (1 - 4 April , in Can berra). N ext, it w ill be taking up the cudgels on broad, nationa l water policy questi ons that arise in Canberra, and puttin g the industry viewpoint effecti vely . I am confident chat the Water Industry Forum w ill, th rough its eclectic make-up and large constituency, build a strong rep utation as the water industry's voice; helping all the associations improve their profile and that of water as a c1itical resource in Australia's natural resou rce management scene. Makin g that relationship work is, fo r us, a milestone. Th e next goal we have brought to fruition is on the international front. AW A has signed an agreement with m embers of !WA (the International Water Association) in Australia, making the local comm ittee fo r those m embers a part of AW A. The new co m mittee w ill be called the Austra lian nationa l 2

WATER NOVEMBER/ DECEMBER 2000

Allen Gale

committee oflWA, or AIWA (to addjust one more acronym to our already heavily initialed fi eld!) and AIWA will be the link betwee n Australia and IW A on the world stage. Local IW A m embers w ill be holding a general meeting later in N ovember, to agree on pooli ng funds w ith AW A, elect a new committee and elect a member to sit o n the Board of A WA w hen it becomes a compan y limited by guarantee (assuming that resolutio n is adopted at o ur special general meeting o n Friday 10 N ovember). The Board ofl WA w ill have a representative from Australia, through AWA. This IWA connectio n is a useful one, since Australia , despite its relatively small populatio n, actually has the fourth largest counny m embership group in IW A. Australian members are well represented in the IW A lea dership , especially among its man y special interest groups. A key point about LWA is that we wi ll be hosting the 2002 !WA World Water Congress in M elbou rne, from 7 to 12 April t hat year, combined w ith th e Enviro 2002 co nference and exhibition. Tha t combined event is likely to break records for attendan ce, with target numbers o f tho usands, not hun dreds of delegates. A stron g relationship betwee n AW A and IW A is a sine qua non for that vital event, so the recent agreement was important for all of us. Of course, relationships of th is sort are very li ke m arriages, capable of being made in haste and regretted at leisure. The o nus is on us all co ensure cha t we make the most o f the rela tionships. I will be able to pass the Presidential baton to my successor before too lo ng, but all m embers need a sense of ownership in the o utco mes , so w e ca n produce the best possible resu lts for AW A and our partn ers.

A llen Gale

Aquaphemera Do Australian water e ngin eers face the problem of a declining image ? I have just read the recently published book, R111111ing D o11111 Water i11 a Cha11gi11g Land, by M ary White, an author w h o, over the past fifteen years, has produced a series of beautifully crafted and stimulating books o n the origins and developm ent of the Australian landscape. This book has hund reds o f coloured photos, maps and illustrations and , du e to some generous sponsors, it is pri ced at less than $ 50 .00. T his is a bargain and a must for Christmas presents to, and fro m , all those associated w ith water industry . However, at eve1y stage and fo r eve1y State and Territ01y the sto1y of Eu ropean modification of the riverine system is portrayed as o n e of mi stakes, misund e rstanding and mismanagem ent. Ma1y W hite is an advocate for the 1ivers, she states quite clearly (a nd frequ e ntly) that " ... the seriousness of the consequences of failing to understand the natme of o ur water and what is required to fo ster their sustainable m anagem ent cannot be overestimated" . Further, that" ... respo nsible stewardship of land and water resources - ou r life-support systems - is our indi vidual and national duty". The monograph is not directly an in dictme n t of wate r e n gineers. Techni cally, the e ngineering was generally w orld class - it is the effect, and lack of unde rstand ing of th e results of the engineering that is serio usly questio ne d. The reco gn ition of the past errors of engineeringo c ract i c soluti o n s is e m e rgin g elsewhere. In the last few wee ks, we h ave the decision to return some 25% of the flow to the Snowy River and a sem inar at P arliament House on the possible rem.oval of dams to improve the fluvial environme nt. This questioning of past wa ter engineerin g in A ust ralia is g rowing apace, t h e image is becomin g tarnished. Will we see a situation w here water engineers j oin po liti c ians and use d-ca r sal es m e n as propping u p th e table of th e less tmstworthy professions? What should the AWA do co save o ur image? R egardless of its g reen image, Rmwing Daum has no eq ual o n Australian bookshelves. Bu y it and see w hat it says about yo ur region .

â&#x20AC;˘ Running Down - Water in a Changing Land. Mary E. White . Kangaroo Press: Roseville NSW. $49.95 ISBN O 7318 0904 1.

Dingle Smith


WATER

INDUSTRY

E-COMMERCE

ELECTRONIC PORTAL OPENS FOR WATER T he South Austral ian Water Industry Alliance, the umbrella orga nisation that showcases the capabili ties of companies involved in the state's water industry, has launched a Web Portal as part of its global m arketing strategy. D escribed by Malcolm Colegate, executi ve di rector, as " the pe rfect channel for tapping into world markets," th e Porta l was officially 'logged on' by the S A Ministe r fo r Government Enterprises and Information Economy, D r M ichael Armitage. M ore than 120 Alliance members can now demonstrate their specialist capabilities, products and services through the Po rtal. It has comprehensive public information areas plus extensive members only sections which outline busiuess opportuni ties along with the strategies by whjch compan ies operating either independently or in collaboration with others can w in contracts interstate and overseas. "The site , at www.waterindustry . com. au is an industry ini tiative that ven tu res way beyo nd the co nventional website and directory . Th ere's really nothing lik e it in the Austra lian water i ndustry, "said Mr Colegate.

"On oue hand the Po rtal is the public interface by which potential customers globally can instan tl y learn alJ about the innovative way South Australian based water companies do business, what they have to offer to export markets and how the All iance itself operates to the advantage of both customers and members. "On the other, it is the tool which can be used to give ou r mem bers a competitive edge. Tt will speed commun icati on between member companies, give them a much needed research fac ili ty and enable them to make fast, b ut well in form ed decisions on how to approach a potential project . " In essence, the Portal can be used as a virtual reality boardroom in which the business interests of o ur members can be canvassed in complete secu rity while publi c visito rs includ ing potential customers browse the members' database for profi les on companies of interest. " Th e Water Industry Alliance was fo rm ed in 1998 as a direct co nsequence of the o utsou rcing of wate r and wastewater operations in Adelaide to U nited Water and the awarding ofa Build Own Operate Transfer contract for water treat-

men t plan ts in ru ral South Australia to R ive rland Water. T hese projects brought international water compan ies to Adelaide and established the climate which allowed the unique ski lls and capabilities of local companies to become focused on exports. T he Alliance came into being as an incorporated body after the formatio n of a water industry cluste r grou p and is now maki ng its presence fe lt on the internatio nal stage. R ecent successes have included the export of co mposite reinforced plastic tanks from Murray Bridge to Sin gapore where they form part of a $400 m illio n aquacul tu re proj ect, the sale of South Austra lian ma n ufactured desalination eq uipment to Scotland and the first ever shjpment to Japan of spec ial ist plastic water fittin gs fo r use in connecting ho useho lds to the mai ns water supp ly. Fur t h e r informati o n: M alco lm Colcgatc, Execu tive Director, Water Industry AIJia nce, 08 8204 1892 o r Sta n Boath, Publi city Consul tant, 04 19 698 998.

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WATER NOVEMBER/ DECEMBER 2000

11


MY

POINT

OF

VIEW

PERMANENT WATER RESTRICTIONS: A TANGIBLE STEP TO ECOLOGICAL SUSTAINABILITY My first point is that there are real and tan gib le be ne fits from having w ate r restri ctio ns. So , w hy not make them permanent and tighten them progressively ove r th e next d ecade? Rules cou ld include: hoses o nly hand-h eld on ce per wee k initi ally, no fi xed sprinklers o r automatic wa tering system s, phase out of w ater- using applian ces other th an low water- use cloth es washers, e ncouragem ent of grey water use on th e garde n and a switch to composting toi lets. In future we could introduce a " by permit only" syste m for hoses and perhaps ho usehold batch m eterin g to li mit the supply to houses to say around 500 to 600 L/ d. Suc h action w ould have a num ber of far-reaching benefits: reducin g demand o n our wate r resources by o ver half, extending the life of o ur capital-intensive dams, borefields, trunk mains and treatment faciliti es, redu cing fossil fu e l energy use (including e ne rgy used to make con cre te , pip es, c hemi cal s a nd fue l fo r la wn mowers), providing in creased flow s in rivers to maintain ecosyste ms, reducing the time w e spend on establishing, wa tering and maintainin g ga rde ns w hich are inappropriate fo r our cl imate and reducing the cost of w ater supply. P eople w ould ge t m ore exercise cartin g wa te ring cans and buckets. Sew erage syste m costs vvould similarly reduc e and even th e quality of urban runoff may improve because th e ground becom es less saturated. H e's nuts! som e readers w ill be saying by now: totally impractical, politically suicidal, disregardin g of public health and the practi calities of w ater and sewerage systems. Some may even sa y wh y bother, the drought is broken. However, for many residents of tow ns outside our capital cities, this level of restriction on water supply use, and m ore, is comm o n. Even in wellw atere d southeas t cities su ch as Geelo ng the re have bee n bans on hoses for a year or more . Where I live near the small tow n o f G isborn e 60 km n o rth w es t of M elbourne, the surface water storage until rece nt rain w as under 10% o f capacity for almost a yea r. I ha ve n't used a hose for two summ ers. Ama zingly the garde n has survive d. Thu s m y second point is that many already live under sim.ilar restrictions and have not found it too bad. In other words, it is not un acceptable and the majority of people w ill pull toge ther.

12

Jo11atha11 Crockett s111died Chen1ical and Biochemical Engineering and started work in 111ater engi11eering i11 1973. H e j oined CHD i11 1975. Wit/1 CHD lie has held tlie positio11s of Ma 11ager, Water Tecli110/oly a11d latterly Manger, Enviro11111c11tal E11gi11eNi11g. His curre111 i11terests i11c/11de implica1io11s of ,no11i11g toward Ecological S11srai11ability. He is a past Viaorian Stare Bra11ch Preside111 <if A WA.

M y third point is that there w ill be a spin-off be ne fi t from permanent wa ter restrictions. l t w ill pro vide a practical example of ho w w e can reduce consumption of resources and still lead comfortable and healthy lives. A practical example is far more powerful than the campaigns and advertising w e currently spend money on. Th e example provided by halving water con sumption , if effectively monitored , re porte d and co mmu n icate d to th e co mmunity w ill provid e a basis for the even more necessary and greater re du ctions we must achieve in fossil fu el use. It will show us w e can change . M y fourth and fin al point is even more fundam ental. W e need to change th e direction of our co nsumption- driven economy. Our economic system currently relies on ever-increasing consumption , be it consumptio n o f water, consumption of e nergy, consumpti on of manufactured goods, con sumption of food and be verage item s. Ou r consumption - d ri ve n economy is consuming our e nvironment and nobody beli eves it can continue. Why shouldn ' t th e wa ter industry be the leade r' Why shouldn ' t our industry say: " No , you , th e community, cannot expect to consume what you have in the past and

WATER NOVEMBER/DECEMBER 2000

to co ntinu e to pay low p rices for it. W e are goin g to pro vide you w ith water of adequate qua li ty in adequ ate quantities. W e are goin g to do it effi ciently and sustainably and we are going to do it using th e asse ts w e have w hich we are go ing to make last longe r by prop erly maintainin g th e m ." Th e re will be prac ti cal diffic ulties with maintaining permanent water restrictions. Lower flows in sewe rage syste ms may necessitate som e modification s and flushin g w ith sto rm water until inevi table popul ati on inc rease in our c iti es increases flows. We will ha ve to modify our public and private gardens a little. T here w ill also be politi cal problems. Wate r price per unit will need to rise in order to cover fix ed costs with a lesser volume deli vered. Manufacturers of home irrigatio n systems, garde n hoses, spa bath s and swimming pools will have to move into oth e r busin ess . C apital w orks will redu ce in th e water supply sec tor and nurseries will have to change the typ es of plants they se ll. However, the reside nts of non-metropolitan areas have already shown w e can adapt to restric tio ns. Suc h a proposal w ill be unp opular w ith many . P opularly-e lec te d decision - makers will need to risk being ou sted. Visionary and fearless lead ers are needed to take such a politically risky decision but they will be rewarded in the end by be ing able to say they contributed in a tangible way to m ovin g to ecologi call y sustainable deve lopm e nt. I have been w atching th e CS IR.O Urban Wate r Program w ork on assessing future water managem e nt opti ons. I have not yet seen anything to convince me that this w o rk will do more than make marginal changes in how w e consum e and dispose of w ater. I w o uld like to see a scenario such as I have described added to th e options bein g in vesti gated . Ac hieving a major drop in urban water consumption by radically changing our expectation s of what w e use water for and how much w e use will be fa r more sustain able than purely techni cal solutions. Du al re ticulation and massive water re use sc hem es in fac t dri ve more c on sumption o f agricultural products. Slick advertising campaigns for water-savin g make th e adve rtisers feel good but do they achi e ve reall y significant results?


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CATCHMENT

The first of th.is special two-part fea ture ou tl ines some of the latest resea rch into catchm ent hydrology, the study of waterdriven processes at a catc hment scale. Th e CR.C fo r Catchment H ydrology is a cooperati ve venture i n public good researc h aimjng to assess th e hydrologic impact of land and water managem ent decisions at whole- of-catc hment scale . The organ isatio n represen ts a close collabora ti o n between resea rc h and industry organisations: • B risbane C ity Cou ncil • Bureau of M eteorology • CS!RO Land and Water • D e partme n t of Land and Wate r Conserva tion , NSW • D epartm ent of Natural R eso urces and Environment, Vic toria • Departme nt of Natu ral R esou rces, Queensland

HYDROLOGY

Coul burn- M urray Water • Griffith Unive rsity • Melbourne Wate r • Monash University • Murray- Darling Basin Comm ission • Southe rn R ural Water • T he U niversity of M elbourne

ou tpu ts o f the cooperative resea rch approac h, where research and industry participants com bine in proj ect form ulation , conduct, and delivery. They typify the resea rc h outputs, knowledge, and skills that form the building blocks for the program of t he new CRC. c oo, e1... 11vt U U ARC. H CtN TRf fQl

• W immera MaJJee Water T here are also stro ng coope rative linkages with associated organisations who collaborate in particular CRC proj ects of in terest. T he CRC Associates are : • State Forests of NSW • SA Water • H YDRO (Tasmania) T hese articles, spread between the Nove m ber and J an ua ry ed itions of 'vllnter', derive mostly from the work of t h e i n i tial C R C for Catc h ment H ydrology. T hey show some of the

CATCHMENT HYDROLOGY

CRC for Catchment Hydrology Centre Office V irginia Verrelli CRC for Ca tchm ent H ydrology Departm ent of Civil Engi neering PO BOX 60, Monash Un iversity 3800 T e l (03) 9905 2704 Fax (03) 9905 5033 em ail virgin ia.verrelli @ eng.monash .edu .au

Integrated Hydrologic Prediction for Catchments R Mein The C R C fo r Catchme nt H ydrology was successful in its bid for a seco nd seven -year term of fund ing with quite a diffe re nt foc us - pred ictin g hydro logic behavio ur at whole-of-catchment scal e. Issues fac in g the wa ter indu stry over the next decade, and the part a new CRC for Catc hm e nt H ydrol ogy co uld play in providing th e knowledge base and tools to help dea l w ith the m , were iden tified in a se ri es of scoping workshops with land /wate r manage rs: • water allocati o n (sustainable allocation of resources and more efficient water use) • land- use im pac ts o n rive rs (addressing the con sequences of histo ri ca l la nd use)

14

• climate variability (the po te ntial to redu ce hydrologic risk) • urban run off quality (th e o pportunity to impro ve city ri vers and bays) • rive r restoratio n (to halt and reverse the degradation of stream s and wa terways) . These are national issues, involving land and w ater interactions on catchments of all sizes. T he mission of the current C R C is: T o deliver to resource man age rs the capability to assess the hyd rologic illlpact of land and water 111amgc111cnt decisions ,lt w hole-of-catchlllent scale. The central goa l is to produ ce a new decisio n support system able to predi ct the mo ve me n t of water, sedim e nt , and

WATER NOVEMB ER /DEC EMBER 2000

solutes fro m land to rivers, linking the impact of climate va riability, vegetation , soi l, and w ate r manage me nt together in an in tegrated pac kage. For catchm e nt and wate r managers, this system w ill e nab le the m to fully evaluate the short- and lo ngterm o utcom es o f po licy decisions at regional scales.

CRC Research Programs W e ha ve established six them atic programs of resea rch w it h a nu mber o f projec t areas, summari sed as follows. 1. Predicting catchment behaviour

• development o f a ca tchm e nt mode lling toolki t


CATCHMENT

• scaling of h ydrologic processes for catchments 2. Land-use impacts on rivers

• sed im ent movement, water quality and physical hab ita t in large river syste m s • pollutant delivery from u pland catchments • effects of land-use change on yield and sa linity • nitrogen and carbo n dynamics in riparian zones 3. Sustainable water allocation • in tegratio n of water ba lance and econo mi c m odels • socio-economic ana lysis of procedures fo r w ate r trading 4 . Urban stormwater quality

• sto rmwater pollu tant sources, path ways, and im pacts • storm water best management practices 5. Climate variability • mode llin g and forecasti ng c limat ic va riables in space and time • stoc hastic climate and strea mfl ow mode ls 6. River restoration

• scre am restoration p rocedures and eva lua tion • improved desig n of cools fo r scream res to ratio n T h e r esea r ch projects fo rm an integrated sec and there arc also close links co ocher C R. Cs ( Fres h water Ecology, Coastal Zone) co in crease t h e scope an d integra tion of discip lin es. T he co mbined aim is a co re modelli ng fra mework, com patible w ith geograp hic and h ydrologic databases, w ith key h ydro logic, econo mi c, and eco log ical processes buil t into it. C limate w ill be a key m o del inpu t (spacial an d temporal); land cover and ma nage m ent options are ocher inputs of impo rtance.

Communication and Adoption, Education and Training Programs The maj o r performance ind icator fo r th e CRC is the leve l of adoption of research o utcom es; o u r Commu nication a nd Adoption Program takes the lead in ch is respect. The use of foc us catc hments, w ith the direct involve m ent of ca tchment managers and co mn1un iLy gro u p~ in the research at these sites, is fac ilitating linkages and (ultimatel y) adoptio n. In th is r ega rd , th e soc ia l and econo mi c con straints, w hi ch c urrentl y limit the app lication of ca tchm ent technology, are spec ifically addressed. T o in crease the skill and knowled ge-base in catchment-scale h ydrology, an Education and Training

HYDROLOGY

Program, linked co the research , incl udes school and community education, training of profess io nal staff, and en riched pose-graduate studies.

CRC Participants T he capac ity of this C R C is, we believe, much en hanced through combinin g the strengths an d com mitm ents of: • seven key rural land and water managers in t he eastern m ainland scares of Australia • two ofche largest urban water au thorities in Au stralia • the m aj o r CS IRO di visio n coverin g land and water research • th ree u niversities with strong water research a nd teaching programs • Austral ia's national 111e teorologica l and h yd ro logical bod y. The 14 Parties in o u r C l<..C brin g a w ide range of mu lti-disciplinary ski lls co it. With three new participants joining the o ri g in al eleve n , we have been able co build o n the success and experie nce of the ini ti al Centre. Coope rati ve li nks established in the initial C R C have been strengthened w it h the membersh ip of the n ew Queensland l~arcics, in addition to the w ide r geographi ca l variety, and scope of issues, being presented.

Outputs and Outcomes T he resea rch program is both an imp o rtant and ambit io us one; we expect it w ill take most of the remaining six years of o ur term co com plete th e m o de lli ng cool-kit, and train people co use it. During t h is period, there w ill be man y test versions of cool- kit software, and research outputs cha t w ill have va lue in the ir own righ t. Cooperati ng w ith land and water man agers to faci litate adoption of these o utcomes w ill be an impo rtant step co ou r m ai n goa l, ie. to ach ieve the 'big picture' m ission. If we can m ake pred ictio n at catchment sca le a reali ty, we w ilJ be w ith in reach of: • more efficie nt wa ter use, with large economic and environmenta l gains • sustainable ca tc hm en t m anagement • reduced hydrological risk from extremes of clim ate • cleaner urban strea ms, beaches, and bays • hea lth ier rivers

The Author Russell Mein is Director ofchc C l<...C for Catchm ent H ydrology, and Professo r in the Departme nt of Civ il Engineering at Monash Uni ve rsity. H e has had m o re than 35 years of experi ence in h ydrologic research , w ith a kee n interest throughout his academic career in m eetin g user needs . WATER NOVEMBER/ DECEMBER 2000

15


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The Impacts of Afforestation on Water Yield: Predictions using MAYA R Vertessy, J Rahman, Y Bessard and L Zhang Introduction The affo restation of agricultural areas, if conducted on a b road eno ugh scale, w il l exert profound influ ences on the hyd rology of catchme n ts. P rincipal amon gst these w ill be redu ced w ate r yie lds and re du ced grou nd wate r rec ha rge, t ho ug h maj o r changes in the seaso nal distributi on of runo ff, the tim in g and m agni tude of pea k flo ws, and t he pe rsiste nce o f low flows, can also be expected . Prude nt water reso u rce managem e nt de m ands th at we are able to anticipate the tim ing an d m agnitude of t hese effects. T here are maj o r effo rts unde rway to treble the area o f ti m ber plantation s in Australia by the year 2020 (D l) ]E I 997). This w ould raise the plantatio n area in Austra lia to o ver 3 m illi o n hectares, w ith mu c h of the ne w area d isplacin g w hat is curren cl y pastu re . T here are signifi cant en vironm e ntal dri vers for pla n tatio n expansio n in Australia. For instan ce, widespread tree planting is rega rded as the ke y to t he fi ght against ou r country's biggest enviro nm e ntal proble m , dryland sali n ity. K ey sub-ca tchm ents w it hin the Murray-D arli ng Basin are now in the process of setti ng 'e n d of vall ey targe ts' fo r salt load red uction, and catc hm ent m anage rs regard tree planting as a key option for achi eving th ese . Plantatio n expansion is also see n as a pivotal strategy in o ur management of gree nhouse gas em issio ns. T he carbo n sequ estratio n be nefits con ferred by tree planting are stimu lating sign ifi cant in vestm ent fro m en e rgy providers, w ho also perce ive o ppo rtunities in bio-e nergy prod uction and activated ca rbo n and essential o il m anufacture from plantatio n pr9ducts. Other o ft- m ooted bene fits of tree plantin g include the enhan ce m en t of aest hetic and bio-diversity values and th e provision of wi ndbreaks.

The link between land cover and eva potranspirat ion T he term evapo transp irati o n co nnotes the su m of evapo rative losses from· the la ndscape, including evapo ration o f int~r-:cep te d rain fa ll fr o m plant ca no pies', transpiration o f w ater through the leaves o f trees, evapo ratio n o f w ater from o pe ,i wate r bodies, and evapo ration from th e soil. It is we ll esta blished cha t evapocranspiracion (ET) races in native forests and

16

plan tations exceed t hose 1600 in pas tures (C o rn ish , e HSR 1989; R. u p rec ht and g C -· · · Zhang S c h o f i e Id , 1989 ; g 1200 (!! Sc h o fi e ld , 1996) . l n -~ south ern Australia , mean ~ & 800 annual E T is usua lly less "' i\ than 650 111111 in grass.; :, C lands, but can exceed 400 C "' C 1300 m m in for es ts "' ::;; " (Vertessy, 1999; Z ha ng o+-----~----+-----------< et al., 1999, C ornish and 500 1000 1500 2000 2500 Vercessy, subm itted). ET Mean annual rainfall (mm) te nds to increase w ith Figure 1. Relationship between land cover, mean m ean a nnu al ra in fa ll, annual rainfall and mean annual runoff, as predicted by p ri m ari ly bec au se o f the Holmes and Sinclair (1986) relat ionships and th e in creases in th e rain fa ll Zhang et al. (1999) model. in terception co m po ne nt, m ean annual rainfall exceeded 1200 111111 but also o w ing to in creased t ran spi ration (Figure 1). T he Z hang et al. (1999) model pro mo ted by highe r plant prod ucti vity in predicts that mean annual fo rest ET sho uld we tter cli mates. rise to abo ut 1400 m m at wet sites, Th e Holmes a nd Sin clair ( 1986) wh ereas the H o lm es and Sincla ir ( 1986) relatio nship ill ustrates t h e c ombin ed mode l predicts an ET pea k o f about 11 50 effects of vegetatio n cover and m ea n mm. Z hang ct al. (1999) teste d thei r annual rainfall o n m ea n annu al ET. It is model o n ove r 250 catc hm ents fro m based o n lon g term annual rainfall/ ru noff aro u nd th e world and obtai ned a very re lationsh ips fo r 19 large catch m e nts good fit to fi eld data. Th ey have sho w n situated across Victoria, w ith mean an nual that th eir ET curves are very similar to rainfalls ran ging be twee n 500 an d 2500 like cu rves develope d by T urn er (1991) 111111 , and varyin g m ixtures of grass an d for 68 C al ifo rnian ca tchme nts o f varying native e ucalypt fo rest cover. H olm es an d land co ver. Sin cl air (1986) de monst rated that there were cl ear diffe re nces betw een ET rates Neit he r H olm es and Si ncla ir (1986) nor Z hang et al. (1999) discriminated fo r grassland and e ucalypt forest catchm e nts, and ill ustrate d th is w ith a pair of between di ffe re n t types of fo rest cove r. curves that denoted the d iffere nces along H owever, there is signifi can t evidence to a rainfall g radie nt (Figu re 1) . Acco rding indicate that ET ra tes differ between pin e to th ese curves , a full y forested eucalypt plan tatio ns and eucalypt forests. M ost catc hm e nt vvould evapo rate 40, 90, 2·15, South African stud ies indicate tha t planta240 and 250 m m m o re pe r yea r than a tio n eu calypt ET rates exceed those for fu lly grassed catchment w ith m ean an nual pine plantatio ns (Bosc h ·1979, Van Wyk rainfa lls of 600, 800, 1300, 1500 and 1800 1987, Smith and Scott 1992, D ye 1996, mm , respec ti vely. It is important to no te Sco tt and Sm ith 1997) . Presumably this that these curves de fin e an ' en velo pe' fo r is beca use e ucalypt plantatio ns g ro w ET rates under differe nt land co vers and m uch bette r in South Afri ca than in fie ld conditio ns, im plyin g that t he fo res t Australia , d ue to reduced levels o f insec t curve is an uppe r estimate and that t he predatio n. On the o th er hand, se veral grassland curve is a lower estim ate of likely Au stralian studies have sho,vn t hat ET ET rates fo r t hese land cove rs. rates are greater in pine p lantations than in native eu calypt forests, p rim arily M ore recentl y, Z hang et al. (1999) becau se o f differen ces in rainfall inte rdeve lo ped a sim ple process-based m odel ceptio n rates (S mith et al. 1974, Fell er to p red ict m ea n an nual ET as a fu nctio n 1981, P ilgrim et al. 1982, Du nin and o f land cove r, m ean annual rain fall and M ac ka y 1982). U nfo rtun ate ly, there are mean annual potential evapotranspira tio n. no p ublishe d studies fr o m Australia Th eir m ode l yielded ve ry sim ilar ET com parin g th e wate r balance o f inte nc urves to those proposed by H o lm es and sive ly m anaged e ucalypt plan tatio ns and Sincla ir (1986), d iffe ri ng o nly in terms o f pin e plantatio ns. the ET estimates for for est cove r w he re

WATER NOVEMBER/ DECEMBER 20 0 0


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CATCHMENT

HYDROLOGY

signifi cantly in terms of their ca tchment under pines. For areas size, mean annual rainfall and land cover w ith me an a nnual rainfall of 1200 mm , the mixtures. Th ese results confirm that - - - open eucalypt woodland 800 water yield m ean annual even tho ugh t he MAY A analysis does not ----closed eucalypt forest E pine plantations reductions ma y be as account fo r seemin gly important catch0C: 600 great as 265 and 350 m e nt prop e rties like soil t yp e and 2 111111. Again , we note topograph y, it is suffi cient to predict m ean t iii :, C: that the estimated yield annual water yie ld and how th is might be 400 C: "'C: redu cti o ns are probably affected by land cover change. More "' maximal o nes, owing co facto rs would need to be represe nte d in ::;; 200 the fa c t that they are the model to faithfully predict inter-ann ual derived from the 'ET or intra-annual variability in water yield. 0 +--""'----=r--~--""..,......c:c.-..,....-~..,....-~..,....-----l e nvelo pe ' of H ol m es MAY A can be used to perform a spatial 400 600 800 1000 1200 1400 1600 an d Sinclair ( 198 6) . analysis o f afforestation impacts across large Mean annual rainfall (mm) Depending on the actual ca tc hments on a p ixel by pi xel basis, an plan tation produ ctivity Figure 2. Mean annual water yie ld curves for different example of which is given in Figure 4. achieved, the percen t land covers, after Vertessy and Bessard (1999). Figure 4a shows the Middl e and Upper area afforested a nd the Mu rrumbidgee catch m e nt segm ent of a Predicting mean annual yield sil vic ultural regim e adopted, t he effects pl a nt at i o n capability assess m en t , may be less. However, in particularly wet from catchments using MAYA co nduc ted by Booth and Jova n ovic years, wa ter yield reductio ns may exceed (199 1) for th e sout hern Murray Darling R esea r c h e r s in th e C R C for these m ean annual change es timates. Basin. It de fines 17% of th e ca tchment as Catc hment H ydrology ha ve developed Superimposed on Fig ure 3 are fi eld having 'high' capabil ity fo r affor estatio n, several different kinds of m odels to a furth er 20% as ha ving '1n edium' capab ilo bse rvatio ns of m ea n annual w ate r yield pre dict the impacts of lan d cover change ity, and 1% as ha ving 'low ' capability. reducti ons following pine afforestati on o f on catchm ent runoff (sec for insta nce the MA YA was used to pre dict t he conseat two N ew Zealand sites grassland paper by Peel ct nl., this volume). Below, quences of establishing pine plantations in (G le ndhu an d Waiwhiu ) sourced from w e describe one of these m odels, MAY A , all of th e 'high ' capability areas, closed Fahey and J ackson (1997) and Ro we and designed to predict mean annual yield at eucal ypt forest in all of the ' m edium' J ac kson (1997), and one Australian site the region al sca le . capability areas, an d open woodland in all (Tu mut) so urced from unpublished data MA YA (a n acronym for M ean Annual of the 'low' capability areas. Th e MAY A gath ered. T he observ ed w ater yie ld Yield Analysis) is a very simple but robust analysis was performed on 250 x 250 m reductions from these three expe rimenanalytical tool that can be used to predict pix els, each having a designated mean tal sites accord reason ably well with the changes in mean ann ual water yield that annual rain fa ll and land cover. Figure 4 6 MAY A model estimates. W ater yield might ensue from pin e and eucalypt shows that th e prop osed afforestation reduc tions at the Tumu t site are lower atforestation of grasslands. MAY A is based sce nario would result in m ean annual than predic ted by MAY A, presumably on a series of four c urves re lating m ea n water yield reductions ranging mostly beca use the plantation is still young (data annual water yield to mean annual rainfall between 30 and 300 111111 , w ith a m edian shown are for age 6-10 years) and yet to and land cover (Figure 2) . Th ese are reductio n of 120 mm. Annual reductio ns realise its maximum ET rates. Th e reducderived from the H olmes and Sinclair greater than 190 111111 w ould affect abou t tions at W aiw hiu are slig htly greater than ( 1986) relationships described above, and 10% of the proposed area planted. estimated by MAY A, suppo rtin g th e case published estimates o f ET fo r e ucalypt It is unlikely that such a large area as for adoption of the Z hang er n/. (1999) fo rests and pine plantations (see C ornish, shown in Figure 4 wou ld be afforested in model fo r wetter fo rest sites. T he G lendh u 1989 and Vertessy and Bessard , 1999 for the basin, particularly at an y one time . observations match th e MAY A model further details). The land covers represented H ence the scenario desc ribed above in MAY A include pin e plantations, closed estimates we ll. eucalypt forest, ope n euca lypt w oodland We ha ve used and grassland. These are broad ca tegories MA YA to predict 500 of land cover intended to span th e w ide + the hydrolog i c E range of land covers that exist in t he impacts of afforesta400 C: landscape. Addition al rules are impl etion in the middle 0 '.§ m e nted in MAY A fo r dealing w ith rain and upper Murrum::, 'O 300 ~ falli ng on water bodies and urban areas. bidgee Basin, N ew 0 From the c urves show n in Figure 2, Sout h W ales and C: 2 200 it is possible to deduce the like ly redu cfou nd that the m odel iii - - eucalypt forest :, C: tion in mean ann ual w ater yield that was able to explain - - - - · pine forest C: o Tumut "'C: 100 would result fro m pine and eucalypt 82% of th e variation • Glendhu "' afforestation of g rassland (Fig ure 3) . 1n m ea n a nnu a l ::;; + Waiwhiu Fig ure 3 shows that reduc tions in m ea n w ater yield in 28 0 annual water yield will be greatest in high sub -catchm ents o f 600 800 1000 1200 1400 1600 rainfall areas and tha t pin e afforestation th e basin over the Mean annual rainfall (mm) will ha ve a greater impact than euca lypt period 1986- 1995 afforestation. For areas w ith 800 111111 mean Figure 3 . Potential reduction in mean annual water yield (Ve rt essy and annual rainfall , m ean an nual water yie ld B essa rd , 1 9 99) . estimated to resu lt from afforestation of grasslands with Th ese sub -catc h ma y reduce by up to 165 111111 und er eucalypts and pines. Also shown (as symbols) are field cucalypt plantati on s and up to 220 111111 men ts va ri ed observations from three separate field experiments. 1000

- - grass

.s

..

.s

..

18

WATER NOVEMBER/DEC EMBER 2000


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HYDROLOGY

(b)

:: I

i:lnnual yield (mm)

150 100

50 0

Figure 4 . (a) Plantation ca pabil ity in cleared areas of the Middle and Upper Mu rrumbidgee catchment, adapted from the analysis of Booth and Jovanovic (1991). (b) MAYA model prediction of mean annual yie ld reductions after afforestati on of areas denoted as 'high ', 'medium' and ' low' in (a). shou ld no t be regarded as a likely o ne for the M u rrumbidgee Basin. It is simply inte nded to show the range of water yield impa cts lik ely to occu r with in a large region.

NSW D epartment of Land and Wate r Conservation and State Forests New South Wal es for providing data fo r th is study. W e tha n k Da n Figuc io for drafting o ur diagra ms.

Summary

References

T here are m an y sound reason s fo r in creasing the area of plan tations in Au st ra lia. However, ca tc hm e nt mana ge rs should care fulJ y assess th e water use requ irements of downstrea m use rs and the aquatic e nvironment befo re co mmitti ng to any m ajor affo restation initiative t hat is co nce ntrated ge ograph icall y. MAY A ca n assist catc h m ent plan ne rs in thi s regard , in so far as it is an easy-to-apply model that can forecast likely impa cts on m ean annu al water yie ld. It should be regarded as an adju nct to o th er fo rms of hydrologic analysis suited to estimating the like ly changes in flow regim e that ma y resu lt from afforestatio n. Changes to pa rticular flow m agnitudes and their pe rsistence may be more probl ematic fo r catc hment managers than changes to m ean an nual yield , and arc the fo cus of curre nt resea rc h in t he C RC for Catch m e nt H ydrology. The impacts o f afforestatio n o n mean ann ual yie ld ca n be m in imised by establish ing plantations in low-interm ediate rai nfall zo nes, and by planting parts of catchmen ts o nly. Shou ld widesp read affores tati o n be plann ed for catchm e nts w he re flows are al ready h ighl y all oc;ited to users, plantation establishm e nt shou ld be accompanied by rational wate r trad ing arra ngem e nts.

Booth , T. H . and Jovan o vic, T. ( 199 1) ldentific:nion of land capable for private plantati on dcvdopmcnt. r~eport to N ational Plantat ions Advisory Committee. CS m .O Division of Forestry, C anbe rra. 13osch,J.M. ( 1979) Trearmem effects o n annual and d,y period srream flows at Cathedral Peak . South African Forestry Jo urnal, 108: 29-38 . C ornish , P.M. and Vertessy, R .A. (subm itted) Forest age induced changes in cvapotranspirat ion and water yield in a eucalypt forest. Jo urnal of H ydrolo gy, su bmitted. Cornish, P.M. (1989) The effect of radiata plantatio n establish me nt and management on streamflows and water quality-a review. Forestry Commission of NSW, Technical Paper N o. 49, 53 pp. Dunin , F.X. and S .M. M ackay ( 1982) Evaporation by eucalypt and coniferous plant communities. In T he First Nat ional Symposium on Forest H ydrology, Melbourne. 11-13 M ay, I 982 . The Institute of Engi neers, Australia. Preprints of papers. pp I8-25. DP I E ( 1997) Th e 2020 Vision Sratrn1ent. Department of Primary Industri es an d Energy. Dye. P.J. (1996) C limate, fo rest and stream flow relationships in South Afiican afforested catchments. Commonweal th Forestry P... eview, 75(1): 31-38. Fahey, 13. And I<... Jackson ( I 997) H ydrological impacts of converting narive fo rests and grasslands to pine planrations, South Island, N ew Zealand. Agricultural and Fore,c Meteorology, 84 : 69-82 . Feller, M.C. (1981) Water balances in Eucalyptus regnans, E. obliqua and Pinus radiata forests in Victoria. Australian Forestiy, 44: 153-161. H olmes,J.W. and j.A. Sinclair C\986) Streamflow from some afforested catchments in Victoria. H ydrology and Water Resources Symposium, Gr iffi t h University, Bri sba ne, 25-27 N ovembe r 1986. The Institute of Engineers,

Acknowledgments W e gratefully acknowledge th e Bureau of Rural Sciences, Murray Darling Basin Commission, Bu rea u of Meteoro logy,

Australia, l're prinrs of papers, pp. 214-218. Pilgrim, D. H .. D.G. Doran, I. A. Rowbottom, S.M. Mackay and J. Tjendana (1982) Water balance and runoff characteristics of matu re and cleared pine and eucalypt carchmen rs at Lidsdale. N.S. W. In The First N ational Symposium on Forest H ydrology. 11-13 May, 1982. Melbourne. The Insrirnte of Engineers, Australia. Preprints of papers, pp. 103-110. Rowe, L.K. and J ackson, R.J. (1997) The influence of afforestation by Pinus radiata o n stream/lows available for municipal and irrigation uses. In: Proceedings of the 24t h Hydrology and Water l<..esources Symposium, New Zealand, 1997. Ruprech t, J. K. and N.J. Schofield ( 1989) Analysis o f stream fl ow generatio n following deforesrarion in south-west Western Australia. J ourna l of H ydrology, 105: 1-1 7. Schofield , N .J. ( I 996) Forest management impacts o n water valu es. l<..ecent l<..cscarch Developments in H ydro logy, 1: 1-20. Scott, D.F. and R .E. Smith ( 1997) Preliminary empirical models to predict reductions in total and low flows resulti ng from afforestatio n. Water South Africa, 23(2): 135- 140. Smith, M. K., I<.I<. Warson and D.H. Pilgrim ( 1974) A com parative srudy of the hydrolo gy of radiata pine and eucalypt forests at Lidsdale, N.S.W. The Institute of Engineers, Australia, C ivil Engineering Transactions, CE 16( 1): 82- 86. Smith, R.E. and D. F. Scott ( 1992) T he effects of afforestation on low flows in various regions ofSourh Africa. Water South Africa, 18(3): 185-194. T urne r, K.M. ( 199 I) Annual evapo transpiration of native vegetation in a M edite rranean-type climate. Water l<..esources 13ulletin, 27( I): I -

6. Van W yk, D.B. ( 1987) Some effects of afforestation on srreamflow in the West ern Cape Province. South Africa. Water South Africa, 13:31-36. Vertessy, R .A. ( 1999) The impacts o f forestry on stream/lows: A review. In: J. Croke and P. Lane (eds), Forest M anagement for the protection o f water quality and quantity. Proceedi ngs of the 2nd Erosion in Forests Meeting, Warburton, 4-6 May 1999, Cooperative R esearch Centre for Catchmen t H ydrology, rl..eport 99/6, pp. 93- 109. Verressy, \<...A. and Bessard, Y. (1999) Anticipating the negat ive hydrologic effects of pla ntation expansion : R esults from a G IS-based analysis on the Murrumbidgee Basin. ln: J. Croke and P. Lane (eds), Forest Management fo r the protectio n of water quality and qua11tity. Proceedings of the 2nd Erosion in Forests M eeting, Warburton, 4-6 M ay 1999, Cooperative R esearch Centre for Catchment H ydrology, R eport 99/6, pp. 69-73. Z hang, L., Dawes, W.R. and W alker. G .R . (1999) Predicting the effect of vegetation changes on catchment average water balance. Cooperative R esearch Centre fo r Catchment H ydrology, T echn ical R eport 99/ 12, 35 pp.

The Authors Rob Vertessy, Joel Rahman, Yves Bessard and Lu Zhang are based at CS IRO Land and Water, GP O Box 1666, Canberra, 2601.

WATER NOVEMBER/ DECEMBER 200 0

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The Impact of Logging and Fire on Water Yield: Predicting the Thompson Catchment by Macaque M Peel, F Watson, R Vertessy Introduction

two layers of vegetation are reprecanopy and unde rstorey. sented: Th e Th omson rese rvoir catchPrecipitation fa lls through these ment area is one of few M elbourne laye rs and can be intercepted by water supply catchments where forest them. R adiation is also propagated harvesting is pe rmitted. The region through, and absorbed by these is also at risk of bush- fire. Macaqu e, la yers. The P e nma n-Monte ith a large-scale , lon g-term , physicall y equatio n (M onteith and Unsworth, based, water balance m odel devel1990) is used to calculate evapooped by Watson (1999) and Watson transpiration (ET) from each of the et al. (1998 & 1999) w as applied to laye rs, as we ll as evaporation from the Thomso n ca tchm ent in order to the soil. predict th e impact of profound Each ESU has two soil zones, vegetation disturban ce on water re prese nting unsaturat ed and yield (Peel et al. , 2000) in a project C.uchrn~rit sa turated soil respectively. The co- funded b y the CRC fo r interface between these is the Catc hment H ydrology, the Victorian Figure 1 . Vertical and spatial structure of the water tabl e, which moves up and D epartment o f Natural R esources Macaque model (hydrology-only vers ion). Symbols: down in response to vertical water and Environment and Melbourne P = precipitation, TF = throughfall, E = evaporation, move ment, and horizontal water Water. Th e results from th is project T = transpiration, R = recharge, SF= saturation move me nt be tween ESUs within will be u sed in t h e Victorian excess flow, BF= baseflow, Unsat = unsaturated the hillslope. Department of Natural R esources soil moisture store, Sat = saturated soil moisture A de tailed clima te sub- mod el is 'and En vironm ent decision support store. used to conve rt prec ipitation and system for the Thomso n catchment temperature range inputs into (Lau et al., 1999) . Model structure other climate variabl es such as radiation In this paper, th e structure of Macaque and humidity. is briefly ou tl ined. Some resu lts from the Macaqu e is a complex model and a Changes in forest type and age are recently completed in vestigation into the comple te description ca n be fo und in re presented by changes in leaf area index maximum impa ct of vegetation disturWatson ( 1999) . R ece nt developments to (LA I) and leaf cond uctance to water bance on w ate r yi eld for th e T homson Ma caque are describe d in P eel et al. vapour. These are specifi ed to the model catchment arc presented, and future (2000) . Important operati onal feat ures of as a series of LA I/age an d conducappli cation s of th e model are discussed. M acaque are briefly summarized below.

750

900 1050 1200 1350

1500

N,

1650

1800 1950

2100

-

0

2

4

6 km

Figure 2 . Map of synthetic mean annual precip itation (in mm) for the Thomson catchment.

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WATER NOVEMBER/DECEMBER 2000

A schema ti c diagram of the model structure is displayed in Fi gure 1. The model s p l it s catc hm ents spatia lly into hillslopes, and hill slopes int o sma ll er areas ca lled elem enta1y spatial units (ESUs). Each ESU is mod elled separat ely and linked together by subsurface water flow pathways . Hill slopes are linked together by a stream n etwor k. Total catchme nt flow is t he sum of all hillslope flo ws. The mode l run s o n a daily tim estep and requires a daily time se ries of pr ec ipitation and maximum and minimum temperature for input. Within each ESU ,

-JOO 130

360

590

820 1050 1280 15 10 1740 1970

N 0

2

4

6 km

Figure 3. Simulated annual average water yie ld (in mm) from old growth vegetation for the Thomson catchment, using an average synthetic climate.


CATCHMENT

HYDROLOGY

strea mflo w . T his is gene rall y consisten t verifi ed over a fo rty-seven year w ith t he V ictoria n regio nal cha rac teri~aperiod (no t including the period tion o f relationships bet wee n m ean used fo r calibratio n) and th e annual yie ld versus precipitatio n made by resultant coeffic ient of effi ciency H olmes and Sinclair (1986) and fu rth er was 0. 7 4, w hi c h is co nsidered deve lop ed by Ve rtessy and Bessard to be satisfa c tory (C hiew er 11/. , (1999), whic h predict ze ro yields for areas 1993) . M acaqu e w as calibrated of similar elevatio n w ith prec ipitation and th e calibratio n verified for below 750 mm . D iffere nces between th e seve ra l sub-ca tc hments o f th e m ode l predictions and values deri ved Tho m s o n a nd ge n e r al l y from the Ve rtessy and Bessard equation s perfo rmed satisfac torily . could be because LA I estim ates for In o rder to o bse rve th e lowl and mi xed spec ies fo rest ma ybe maximum impact of vegetation high (Peel et 11/. , 2000), or because slightly o n water yield over a lo ng th e mode l is calibrate d to op erate best in period , th e effec ts o f climate th e w e tter clim ate o f th e hi g her-elevavari ab ility have to be re m oved tio n Ash forest. Th e Thom son reservoir first (Watson, 1999) . C limate itself is predicted to have nega ti ve yie ld. variab ility was re moved by the - 100 80 This is due to there bein g mo re simulated use o f a synth e ti c climate, with 260 440 evapo ration from th e rese rvo ir surfa ce no inte r- annual variability, as 620 than prec ipitation on an an nual basis. th e clima ti c inpu t to th e ~~ N 1160 Th e rate of forest rege n eration , after Maca q u e mode l. Th e dai ly 1340 1520 compl ete c learing, is presently de fin ed climate series fo r an average year 0 2 4 6 km using th e LAI/age and leaf-condu cwas repeated to crea te t he Figure 4. Simulated minimum annual water yield tance/age curves develo ped for each fo rest long- term synthetic climate. A (in mm) from re-growth vegetation for the Thomson type by W atson et 11/. (W atson , 1999 ; map of the synthetic mean catch ment , using an average synthetic climate. W atson and Ve rtessy, 1996; Watso n et annual precipitation is prese nted 11/. , 1999) . Du e to hig h LA I and high leafin Fig ure 2 . conductance in youn g euca lypt forests, tan ce/age curves for each fo rest type (e .g . In the foll owing m aps o f w ater yield , annual for es t w at er use re ac hed a M o untain Ash , Mixed Species, Scru b). th e re arc ofte n odd-shaped ho moge nou s ma ximum , and ann ual streamflow yie ld areas, separated by hard bo un dari es. T he Maximum impact of vegetation reache d a m inimum a short time aft er hard bo u ndari es are cau sed by th e m odel disturbance on water yield in regeneration began. Figure 4 shows a map ass ig ning differe nt vege tati o n types to the Thomson catchment o f th e minimum yield simulated in all neighbouring ESU 's (sec Peel et 11/. (2000) parts of the ca tchment. M ost of the catchfor a compl ete explanation). T he T ho m son R eservoir has a catc hm e nt dri es to a m inimum a nnu a l m en t area o f 487km 2 . The terrain is steep . A map of ma ximum wate r yie ld and mountaino us, ranging from 300111 to impact·, ca used by vegetation 1520111 above sea level. M ean annual di stur ban ce, is c rea te d by prec ip itatio n ranges from 700mm to su btra cting a m ap of minimum 2500111 111 across th e catchme nt. The wa ter yi eld (a fte r di st urban ce) c atc h m e nt is c o mpl e t e ly for es ted , from a m ap o f old g rowth predom inantly by Mountain Ash (E. water yield (pre d istu rbance) . ln re,(.!111111s), Alpin e Ash (E. dele,(!11/e11sis), Snow order to ge ne rate these maps the Gum (£. p1111c!flom) and m ixe d spe cies synth etic clim ate w as applie d fo rest (in cluding £. obliq1111). ove r a 300-yca r pe riod. Old grow th water yield was modelled Maps of daily prec ipitation fo r th e for the first 50 years (vegetatio n catchme nt w e re estim ated using a nove l age rangin g fro m 200-250 years), approac h base d on three lon g- te rm th e n t h e c atchm e nt was records o f dai ly prec ipitation , mul tiple. comple te ly c le ared a nd relinear regression and a 3- D spline surfa ce. growth was mode lled for th e M aps o f daily maximum and m inimum remaining 250 yea rs. T he annual temperature for th e catchme nt w ere yield fro m each ESU was o utput estimated usin g a single long-term record from Maca qu e. of daily maximum and minimu m te m per0 ature and a lapse rate of -0.006°Cm- 1 for A m ap o f sim u lated o ld 160 320 both m ax imum. and minimum temperag rowth water yield is presente d 480 640 ture . in Figure 3. As expected, high est 820 980 N Maca qu e was successfu lly calibrated yi elds arise fro m the areas that 1140 1300 receive th e hig hest precipitatio n. over a seven-year period against m o nthly1460 6 km 0 2 4 Sl o pes drain ing into the upper reco rded streamflow. The coeffici ent of Thom so n r ese rvoir e x hibit e ffi c iency (Nash and Sutcliffe, 1970) was Figure 5. Simulated maximum annual water yie ld relati ve ly low prec ipitati o n 0 .8 2 with a maximum possibl e val u e of impact (in mm) from vegetation disturbance for (<850111111) and , subsequently, 1. 0. This is ge n erall y con side red an the Thomson catch ment, using an average arc predi cted by the mode l to acceptable ca libration (C hiew el 11/., synthetic cli mate. yie ld ve ry little, o r even zero 1993) . T he calibration of th e model was

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WATER NOVEMBER/DECEMBER 2000

21


CATCHMENT

HYDROLOGY

2600-r------------ - - ------~6 ~- -------------- -- - -------

T w o as h fo rest types "pea k then declin e" prog ression of LAI were invest i ga t e d , holds fo r Alpine Ash. The Alpine Ash 2400 Moun ta in A sh a nd fo rest in Figure 7 w as situated at 1180 111 - -Annual Prcc~,i1a11on e 2200 A lpine A sh. on the no rthern slo pe of the Baw Baw sC: LAI plateau. It was estimated as h aving a mean Th e impacts of clearj 2000 ·a. annual precipitatio n o f 2220 mm , and a ing and regeneration on -~ 1800 pre- disturbance yield of 11 25mm . These the w ater yi eld and LAI Q. 1 - - - ---ll , . - - - - - - - - - - - - ------! 5 1800 ; valu es are higher th an th ose for the o f Mountain Ash are 2 1400 - ~~ - - - - - - - - - - - Mountain Ash forest examined ea rlier, as prese nte d in Fig ure 6. Th e m e an a nnual is the impact on yie ld , 739 mm , w hen 1200 I comparing pre-disturbance and mi nimum pre ci pit a tion wa s 1000 .___ _ __ __ _ _ _ _ __ _ _ _ _ __ .., 0 values. 1933mm (elevation 887 50 100 150 200 250 300 m ), w hi ch led to a T wo non -as h fo rest typ es we re invesYears stream flo w yie ld of 692 tigated ; Sno w Gum and th e assoc iatio n Figure 6. Time series of annual water yield and LAI for 111111 unde r old-grow th known as " mixed species" w hich typically an ESU with 1933mm of annual precipit ation and conditions. M o untain comprises dry sclerophyll species su ch as Mountain Ash vegetation. A s h f o r ests we r e E. obliqua. streamflow yield of 200 mm or less during simulate d as exhibiting a complex longA Snow Gum fo rest (Figure 8) was the rege neration pe riod, largely irrespecterm LAI progressio n estimated fro m field selected from the cold , sub-alpine slopes ti ve of forest type o r precipitation. This work and satellite data by Watson (1999) of th e Baw Baw plateau at an eleva tion suggests that, at peak performance, these and W atso n & V ertessy (1996) . LAI was o f 1427 m. The site had a m ea n annual forests are able to m ake use of almost all predicted to start at zero, and rapidly rise precipitati o n of 2475 111111, yie lding an w ater falling as precipita tion. It is likely to nearly 6. 0 in the first 5 to 10 years o f estima ted 1546 mm as strea mflo w under that some wa ter li1niting o f re-grow th forest developm e nt, after which it would old-growth conditio ns. Like other nonoccurs in these for ests. C onversely, in the graduall y decl ine to a steady o ld-growth ash fo rest types, Snow Gum was simulated south w est on t he high elevations of th e value o f 3 .5. Similarly, m axi mum leaf to ha ve a very simpl e LAI curve . At age Baw Baw plateau, mjnimum yields do not conductance w as predicted to undergo an ze ro (year 50 in Figure 7) , LAI was zero , fall below 1000 111111. These areas receive expone ntial decline from a hi gh point at aft er w hich it rapidly increased o ver 5 to over 2000 mm of precipitation and exhibit age zero , to a value about three times 10 years to a stable long-term value of 2 .5. lo w - produ cti vity vegetation such as lower for the leaves o f old-gro wth This curve accounts for the early p eak in Snow Gum fores t and alpin e m eado w. forests. With these curves as the primary simulated yield follo w in g clearing, but is Tran spirati o n is cold tempe rature and inputs driving long- term trends, the quite unrealistic. A much slower re-estabradi ation limited , and th erefor e will not model pre dic ted the w ater yield c urve lishment w o uld be exp ec ted in the cold continue rising w ith increased precipitasho wn in Figure 6 . Th e fi g ure shows that climes experie n ced by Sno w Gums , tion. clearin g and regeneration in thjs forest had ho w ever, little is known o f the true lo ng The maximum water yield impact map a dramati c effect. Within 5 to lO years, te rm LAI d ynamics of non-ash eucalypts. is presente d in Figure 5. T he g reatest simulated annual w ater yield declined H e nce , th e LAI curves used he re are impact is predicted to occu r in the ashfro m 692 111 111 to almost zero . Thereafter, simply awaiting future researc h . Like all fo rested, mid-elevation band between the it rapidly, and then more g radually, o th er fo rest types, Snow Gum w as low elevation areas in the northeast, w here in creased back to o ld-growth le vels aft er simulated to exhibit a lon g-term decline transpiratio n is water-]jmjted, and the high abo ut 150 to 200 years. Th e "impact", in maximum leaf conduc tance. This elevation areas in th e w est, where transpior difference between pre-disturbance acco unts fo r the continuing long-te rm ration is cold temperature limited. Areas old-grow th yield and minimum p ostin crease in yield with forest age shown that are not ash- forested w ere predi cted disturban ce yield , was 662 mm. in Figure 8. The plo t of wa ter yi eld to be m inimally impa cted, in absolute Similar results (Figure 7) w ere recorded impact shows that the maxjmum e ffect on terms, by forest clearin g. This is because fo r Alpine Ash, w hi ch are found on water yield caused by regen erating this LAI was ass ume d to be constant in the hig her, colder, and wetter slo p es than Snow G um fores t is a decline in yield of lon g term fo r non-ash fo res t typ es . The M o untain A s h. only reason th ey sho w any impact at all 2400 , - - - - - - - - - - -- - - - - - - - - - - r 6 Ph ysio logical data o n is beca use, upon the evidence of R o berts 2200 Alpin e Ash are sparse, Yield er al. (2000) , they were simulated as having 2000 althou gh it is generally - -Annual Pracipnatlon e ..... , LAI the sam e proportional long-term reduc.§_ 1800 recognized that they tion in leaf conductance as the ash- forests. are less productive· than .2 1600 Tim e series o f annual wa ter yie ld and Mountain Ash. This is 1 1400 - t - - -~ LAI are presented in Figures 6 to 9 for suppo rted by satellite 1200 1 - - - - 1 four locations in the Thomson catchment, d a t a fr o m W a rson l5 1000 g:, 800 cove red by four diffe re nt species of (1999) that suggested a: vegetatio n . The annual water yield versus that the LAI o f Alpin e 600 forest age curves are analogo us to the Ash at Maroondah w as 400 catchm ent average curves presented by about 0 .3 lo w er than 200 ' - - - -- - -- - - - - -- - - -- - ~ 0 50 100 150 200 Kuczera (1987) . In the follo w ing time 250 300 that of M o untain Ash . Years seri es figur es there is a four-year periodIt was assumed char this icity, whic h is an artefa ct of the w ay in was the only difference Figure 7. Time series of annual water yield and LAI for an w hi ch leap years w e re handled in th e b e tw ee n th e tw o ESU with 2220mm of annual precipitation and Alpine Ash synth etic climate data . spec ies, and that the vegetation.

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CATCHMENT

2600 ~ - - - - - - - - - - - - - - -· · - - - 2400

I §

~- ------- - - - -- ------------

6

-Yield 2200

- - Anrual Prodp,lal""1

LAI

2000

1i

J ls

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= 0

§ 1-400 a: 1200 1000 ~ -- - - - - - - - - - - - - - - - - - - - ' 0 50 100 150 200 250 300 Years

Figure 8. Time series of annual water yield and LAI for an ESU with 2475mm of annual precipitation and Snow Gum vegetation.

237 111111 per year w hen the forest is abo ut fiv e years old. C lea rl y, this "res ult" would change if more were kn own abo ut LAI tre nds in snow g um forests. A result that would 1101 change, however, is t hat, du e to the cold cl imate and low LAI of Snow Gum forest, water use by the fo rest was less than 1000 111111, despite the occurrence of nearly 2500 mm of precipitation. Plants in alpin e and sub-a lpine environm e nts pl ay a sma ll e r ro le in the water balance than those on lower slo pes. A "mixed species" forest (Fi gure 9) was selec ted on the dry, eastern slo pes of the catchment at 820 111 e levation. The m ea n annual preci pitation for this ESU was 11 84111111, and t he average predisturbance yield was 238mm. A simple LA I curve, similar to that described fo r Snow Gum was prescribed. In future, this will be improved based o n fie ld data in dry scl ero ph yll forests su c h as that described by R o berts el nl. (2000). In this dry fo rest, there is plenty of warmth and radiation , and so the evapotranspiration acco unts for m ost of the precipitation. Sho rtly after regeneration, th e fo rest has rega ined its old-growth leaf area, but w ith h ighly conductive leaves. Fig ure 9 shows that maximum fo rest water use leaves as little as 40 111111 of water fo r annua l streamfl ow. Th e maximum water yield impa ct is 192 mm , whi ch is similar to t he val ue fo r Snow Gum fo rest at the tem peratu relimited e nd of the spectru m. Conclusio ns from the mode lling work cond ucted in the Th om son catchm ent about the maximum impact o n water yield of fo rest c lea ring are: • The m ost prod uc tive forests have the g reatest leaf area index and use the most water. • The refore, th e greatest change in water use, and he nce, the grea test impact o n water yield , wi ll generally result from clearing and re-growth of the m ost produ ctive forests.

24

HYDROLOGY

• The areas w ith the greatest impa cts w ill ge nerall y be the areas where the m ost productive, never water or tempe rature limited, fo rests g row. Th e mo del h as suggested th e locatio n of these areas. Our results indicate that M acaqu e de m onstrates sign ificant utility in ide ntifying regions o f hi gh water y iel d impa c t from for est disturbance.

Future applications of Macaque A project fund ed by the Laun ceston City Council is currently in progress. This proj ect is an in vestiga tion into the impact of vegetati on disturbance o n summer low flo ws in the North Esk R.iver. Vegetation d isturba nce in th e North Esk catchm ent prese ntly includes loggin g in State forests and the conversio n of sheep grazing properti es into tree farm s.

References

Lau J.A., Watson I. S., Sutton M.W. & R hodes 13.G. 2000, Predicting the water yield impacts of forest disturbance in the Maroondah and Thomson catchnu,nts using the Macaque model. Cooperntive ls.esearch Ce n t r e for Catchme n t Hydro logy. Melbourne. Report in prep. Roberts, S.L., Vertessy, R.A. , Grayson, R .G ., in press. T ranspiration from Eucalyptus sieberi (L. Johnson) fores ts of different age. For. Ecol. Manage., in press. Watson F.G.R. I 999, Large scale, long term moddling of the effects of land cover change on fo rest water yield. Ph I) thesis, Dept. of C ivil and Environmental Eng., Th e University of Melbourne, Au~tralia. Watson F.G. R. . & Vertessy l's. .A. 1996, Estimating leaf area index fro m stem d iameter measurements in Mountain Ash forest. Cooperative Research Centre for Catchment H ydrology . M elbourne . Report 96/7, November 1996, I 02pp. Watson F. G .R., Grayson R.B. , Vertessy R.A . & McMahon T.A . 1998. Large- scale distribution modelling and the utility of detailed ground data . Hydrological Processes, 12:873888. Watson F.G.R., Vertessy R .A. & Grayson R. 13. 1999, Large-scale modelling of fo rest hydrological processes and their long-term effect on water yield. H ydrological Processes, 13:689- 700. Vcrtessy ls..A . & Bessard Y. 1999, Anticipating the negative hydrologic effocts o f plantation expansion: R esults from a G IS-based analysis on the Murrumbidgee basin. Proceedings of the second Forest Erosion Workshop, May, 1999, Cooperative Research Centre for Catchment Hydrology l's.epo rt 99/ 6, pp: 69-

Chiew F.H.S., Stewa rdson M.J. & McMahon T.A. 1993, Comparison of six rainfallrunoff modelling approaches. Jo urnal of Hydrology, 1-17: 1-36 . Holmes J. W. & Sincbir J.A. I 986, Water yield from some afforested catchments in Victoria. In Proceedings of the H ydro logy and W ater 74 . R esources Symposium, The lnstitt1tion of Engineers, Au st ra lia , Brisbane, 25-27 Authors N ovember, pp: 21-1-218. Murray Peel is w ith t he Department Kuczera G. I 987. Prediction o f water yield of Civil and En vironmenta l Engineering, red11ctions follow ing a bush fire in ashmixed species euca lypt forest. J ournal of U niversity of Melbourne. Fred Watson Hydrology, 9-1:215-236. gained h is PhD at M elbou rn e and is now Lau J.A., Vandenberg W.G., Willig R.U . wi th Earth Systems Science and Policy. 1999, Linking different scales of planni ng Ca lifornia State Uni versity Monterey using an integrated forest planning approach Bay, CA, USA . Rob Vertessy is w ith (Victoria, Australia). Proceedings of the IUFRO working party S-1. 12.00 workshop CS IRO Land and Water, Canberra. assessment methods of forest ecosystem status 1'00 , - - - -- - - - - - - - -- - -- - -- ~ 6 a nd sustainab ility . 1200 __. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Krasnoyarsk, Russia . Monteith J . L. & Yle'd Unsworth M. H. 1990. ~ 1000 - - Annual Prociphalion Prin c ipl es of Environmental Physics 800 1 - - -- - , _ _ _ _ _ __ ._.._.._·~'-- - - - - - - ~ (2nd ed.). Routledge, 3 3 0.. 600 :! C ha pman & H al l. l5 New York. 291 pp. 400 Nash J.E. & Sutcliffe JV. ~ 1970, Ri ve r fl o w 200 forecast in g through conceptual models, I . A d iscussion of pri nci100 50 150 200 250 300 ples. Journal of Yeara H yd rology, 10:282Figure 9. Time series of annual water yie ld and LAI for an 290. ESU with 1184mm of annual precipitation and mixed P eel M.C .. Watson F.G.R., Vertcssy ls..A., species vegetation.

WATER NOVEMBER/DECEMBER 2000

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CATCHMENT

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Forecasting Rainfall for the Olympic Games A Seed and T Keenan Introduction The Sydney 2000 Oly111pic Games is the sort of major international event where severe weather can have a major impact on a nu111ber of o utdoor activities. T he Bureau o f M eteorology (BOM) was responsible for the provision of an operational service tha t issued forecas ts at 1-3 hourly intervals providing infor111atio11 on te mperature, humidity, wind and rain for eac h of the ni ne pri111e Oly111pic venues. During sto rms and seve re w ea th e r , ' nowcasts' (1-hour fo recasts) would be issued at 15- m inutc inte rvals for eac h O lym pic venue . Th e Bureau depl oyed three weather rada rs, another able to m easure the wind profile through th e at111osphcre, a network of automatic weather stations in strategic locations, and in creased the frequency of upper ai r soundings as part of th eir co m mitm e nt to provide a world class service to the Games.

Forecasting weather T h e Wor ld W eather R.ese a rc h Programme {WW R P) is a progra111111c of the World Meteorological O rga nisation (WMO) to develop improved forecasts of the sort of weather w hi ch affec ts qu ality of life, is disruptive, or is li fe threatening. A com po nent of the WWR.P is to de monstrate th e capability of 111odcrn forecast systems and to quantify the associated ben efits in the delivery of a real-time short te rm for ecast in g (nowcas ti n g) se rvice. Th e WW RP w ill take adva ntage of th e en hanced observation network in Sydn ey over th e Olympic Gam es to demonstrate how state- of-the-art nowcasting (0-6 hr forecas t) syste ms can be used

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26

in an operational setting. T he proj ect runs fro m 1 September to 30 November 2000. While the products ge nerated by these system s wi ll be used to provide nowcasts fo r the O lym pic Gam es, the weather elemen ts being fo recast are also of conside rable i nte rest fo r a w ide range o f appl ications inclu ding aviation and flash fl ood warnings. A WMO workshop has been planned at t he cud of the observation period to allow interested pa rties to observe the operatio nal syste ms.

'Nowcasting' Six nowcast syste 111s are to participate in an operational fram ework providing real- time forecas ts to users. Th e United States Warning Decisio n Support Syste m fr o m th e Nationa l Seve re Sto r m s Laboratory and the National Center for Atmosphe ric R esearch Autonowcaste r; N IM R OD fro m th e Un ited Ki ngdom M eteorological Office (UKMO) and th e Generatin g Ad vanced N owcasts for Dep loym ent in O p erational Land-surface Forecasts system from the University of Salford and the UKM O in the UK; the Canadian Ra dar Decisio n Support System and the Aust ra lian Spectra l PR.OGnosis (S_PR OG) system !described below!. These systems e mploy obse rvational tec hniques, numerica l wea the r prediction and a combination of both. The nowcasts w ill be generated automa tically and made avai lable to the Bureau fo recasters responsibl e fo r issuing O lympic, specia list user, and other fo recasts.

Evaluation of alternative systems At the e nd of th e proj ect period, an independe nt international veri fi cation and impact study tea ms w ill com pare and benc hmark th e WW RP nowcasts and assess them for added valu e and impact re lative t o c urre n t (o ffi c ial) B OM products. Each syste m has a differe nt se t of forecast elements (rain fa ll , wind fie ld, and identification o f severe weather incl uding hail , tornados, gust fronts, and down bursts) ove r a ra nge o f forecas t periods. Th e diversity of products and display systems makes it diffic ult to rank th e syste ms re lative to eac h other overall since eac h syste m w ill be applicable in some situations and applications and not in others. Th erefo re, t he aim of the proj ect is not a com petition to fi nd the best nowcast syste m , b ut rather a de monstrati on of the

WATER NOVEMBER/DECEMB ER 2000

utility of such systems .i n a range of situations and applications.

CRC and BOM collaboration (the S_PROG model) BOM as a party to th e Cooperative R esearc h Cen tr e for Cat c hment Hydrology (C RCCH ) has been actively researc hing the use of weather radar data in hydrologica l appli cations sin ce 1997. Th is work has seen the developm ent of a stochastic space and time model of rainfall (Motivate) (Seed e l al. , 1999); cu rre nt work incl udes a proj ect on m ode llin g and forecas ting the space and time c haracteristics of rainfall. Motivate has been further developed into the S_PR.OG m odel fo r nowcasti ng as part of this proj ec t, and th e wo rk ing prototype installed in Sydney as a contributio n to the WWRP proj e c t de sc ribed above. S_P I\.OG is also being e va luated in New Zealand by the National Institu te ofWater and Atmosphere (N IWA) as the nowcasting com ponent of a flash flood warning system currently bei ng developed by NIWA. C onsiderable empirica l evide nce has accumulated over the past decade to suggest that rainfie lds are not o rganised as a co llection o f ind ividual cells , eac h with a characteristic scale, but rather as a continuum or hierarchy of structu res over all scales from l 00 111 to 200 km at least. R ecent researc h has been conducted o n metho ds to explo it this sca li ng behaviou r in nowcasting appli cations; the fu ndam en tal observatio n is that the lifet im e of a tu rbu le nt stru cture has a power law depende nce o n the scale of the structu re. The promise o f these new m ethods is their

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CATCHMENT

+

HYDROLOGY

isation can be used to id e n t i fy t h e t y p e of hydrometeor (hail, snow, rain drops) and to measure the rainfall inte nsity in areas o f ground clu tter and blockage.

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Th e Bureau of 1 1 .1 M e teorology R ese arc h C entre (BMRC) has been 11.1 operating a dual-polarisa4, p, _ 20 ~ km ~ R1Gar Q S.a!nQ V4nut tion ra dar in D a rwin i_ R~nSOMf S 1 000m lo 1m which has been relo cated a A\oli'S eJ 500m Figure 4. A 60-minute forecast 4' HN-'WS e AWG (\'\'lodon~ to Syd ney fo r a year in produced by S_PROG support of th e WWRP to Figure 3. A 30-minute forecast produced by S_PROG. work togeth e r w it h a Not e that the forecast field has less sm all-sca le det ail Reference c onv e n tional a n d a than the input radar field. Seed, A.W. , R.. Srikanthan, and M. Menabde, Doppler radar. H aving th e 1999, A spare mu/ ti111e 111odel for dcsf.~11 stor111 abi lity to recogn ise th e rate at wh ich the th ree rada rs in the Sydney area provides rni,ifn/1. J. Geophys. R es., vol. l 04 (0 24) fi eld is evolving as a fu nc tion of scale in the opportu nity to undertake research 3 1623-3 1630. real- ti me. Th is information is used to in to evaluating the relative performance p rodu ce fore casts w he re th e small-scale The Authors of the three radar systems fo r quanci tad e tail is all owed to dissipate in a structi ve radar rainfa ll es tim at io n for Alan Seed is a member of the t u red way as the fo recast lead- time is hydrological applications w hich is planned H ydrology Unit and T om K eenan of the in creased. to be u nd ertake n , building on previous R esearch Ce n tre at t h e Bu reau of O ne way to generate a rainfall fie ld is research by the CR C and BMR.C. M e teoro logy. to assume they are the product of a hierarc hy of correlated rando m fie lds, w here the c o rre lation length o f the fi eld is th e scale re prese nted at that level, and the variance of th e field decreases as a power la w with "TODAYS TECHNOLOGY PROTECTING TOMORROWS ENVIRONMENr' th is scale. This approach can be used to ge ne rate n ow casts if t he m easure d rai nfi elds can be used to in fe r the model parame te rs. R ainfall is related to radar re flectivity through a power law, the radar re adin gs are used for th is purpose in the S_ PI~OG mode l. T ypical ou tput fro m S_ PROG as it is se t up for th e WWRP is shown in Figures 2 to 4 .

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The Hybrid Toilet System

Errors in forecasts One of the most signi ficant sources of e rrors in nowcasts based o n radar data is in th e real-ti me co nversion of radar reflectivi ty, which is measured at some height ab ove the ground, into estimates ofrain faU intensity o n the ground . T his is particularly problematic in situa tions w ith severe local thunderstorms since onl y a few of the rai n gauges deployed for real-time radar calibratio n will m easure rainfall and the undetected presence of hail w iLI lead to a signi ficant over-estimatio n of rainfall intensity. R ecen t developm e nts in radar technology have been in the use of dualpola risation where t he radar transmi ts p ulses that are polarised alternately in th e vertical and horizontal. The differences in th e phase and powe r of th e signal re tu rned by ho rizontal and vertical polar-

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27


CATCHMENT

HYDROLOGY

Improving Urban Stormwater Quality From Theory to Implementation TH FWong Introduction Increasingly over recen t years, initiatives to protect the aquatic en vironment o f urban areas have been a fo cus of many federal, state and local government organisa tions and co mmunity groups. Man y of th eir actio ns have successfully reduced poin t source pollutio n such as from sewage discharge and industrial effl uent. Urban storm wa ter and its role in conveying pollutants to our urban waterways is now recognised as the next major issue to tackle. However, the sources of urba n poll u tan ts are d iffuse and inheren tly more difficult to manage. C on ve ntion al u rba n sto rm wa te r management has fo cused on providing highly efficient drainage systems to collect and rem ove sto rmwater runoff, using a com bi nation of underground pipes an d li near "engineered" o verland £lo w paths. Th e treatmen t of this stormwater runo ff is possible , but canno t be considered in isolation to the broader p lanning and design of th e contributing urban area. R ather, stormwater management needs to be co nsidered at all stages of the urban plann ing and design process to ensure that th e site plann ing, arch itecture, landscape archjtecture and engineering infrastructure is all provided in a manner th at is sympathetic to th e stormwater trea tment system . T he concept of W ater Sensitive U rban D esign (WS U D) is based on form ulating developm ent plans that incorporate m ultip le storm water m anagem ent obj ecti ves. It involves a pro-active process wh ich recognises the oppo rtu n ities for integrating urban design, landscape architecture and stormwater mana gem ent infrastructu re . At th e bui ldin g d es ign leve l, innovative m eans for recyclin g stormw ate r fo r n o n - potab l e usage ca n significan tly reduce pressure placed o n

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Figure 1 . Typi ca l stormwater quality improvement measures, the ir target pollutant size and hydraulic operating range (Wong et al. , 1999)

water resources development and drainage infrastructure by urban development. T he concept ofWSU D is gen eric, and shou ld apply at a local , regional and catchment level. It provides the basis for a holistic app roac h to storm water m anagem ent , using techniques that are capabl e of delivering a wide ra nge of beneficial outcomes. U rban planning provides the pro-active elem ent in the process to facilitate the utilisation of stormwater best management techn iques. Th e selection of appropriate Best Man agem ent P ractices (BMPs) at a specific site in vo lves an assessm ent made within a variety of disciplin es (drainage en gin ee ring, la ndscap e arch itect ure , ecology etc) . Strategies fo r the man agem ent o f non-point source po llu tants in vo lve using a catchment- wide com bination of structu ral and no n-stru ctural m easures in se ries or concu rrently as an in tegrated treatmen t tra in approac h. Fundamental to the success o f this holistic approach to storm water managemen t 1s th e approp ri ate prio ritisatio n and p os i t i o nin g of app r o pria t e storm water management measures .

Managing Stormwater for Multiple Objectives

Figure 2. The use of vegetat ed median strips for management of car-park stormwater runoff.

28

Hydr a ulic Loading

WATER NOVEMBER / DECEMBER 2000

As with most multi- obj ective exercises, the management of urban storm water in volves th e consideratio n of a ran ge o f m easures that can appear to be mutuall y excl usi ve . Fo r exa mpl e, the rapid conveyance of storm water requ ires h ydrau li ca ll y effi cient sys te m s; contrary to conditions conducive to the effec tive removal of fi ne partic-

ulates, o il, gri t and grease fro m the sto rm wa ter. T he practicaliti es of urban sto rmwater management often require fl o od protecti o n, pub lic safe ty an d drain age econom.ics issues to be addressed before consideratio n of stormwater quality improvements. H oweve r, th e obj ectives of storm wa ter q uan ti ty an d quality managemen t are not always mu tually exc lu sive, esp ec iall y if sto rm w ate r management strategies are fo rmu lated du ring th e ea rly stages o f catchment plannin g and development. M any water quality managem ent and ecological pro tection stra tegies require a co m b inatio n of water quantity and quality control measures. For example, the protecti on of ecological h ealth of urban wa terways requires both water quantity and quality issues to be addressed , with the fo rmer o ften the main ca usal factor o f diminished ecosystem h ealth in urban waterways . T he in creased m agnitudes of sto rm wa te r disch arges influe nce the frequency of ec osystem disturbance, in turn in flu encin g the diversity o f faun a in th e ecosystem . Many measures designed fo r storm w ater quantity control have inheren t wa ter q uality manage m en t functio ns, while others can b e retrofitted to serve the dual functions of stormwater qu antity and q ualit y mana ge m en t. Similarly, source co ntrol fo r storm water quality improvem ent can be utilised fo r £low reductio n and atten uatio n, with beneficial outcomes incl uding the reductio n in th e frequ ency o f aquatic habitat disturbances and storm water recycling. The operatio n range an d ta rget po llutant chara cteristics fo r a n umber of


Figure 3. Well-planned streetscapes can promote local amenity values while having stormwater quality improvement attributes. common ly adopted storm water quality improvement fac iliti es are illustrated in Figure I.

The CRC'S Stormwater Management Decision Support System The Urban Storm wate r Quality R.. esearch Program of the CRC a ims to deve lop a toolkit of m odels for predicti n g th e performance and to aid th e des ign of storm wate r managem ent practices. T he integration of th ese m odels w ill fo rm a Decision Support System (DSS), en abling practitio ners to deve lop cost-effec tive storm wa ter manageme n t strateg ies, and co mpare the costs and benefits o f di ffe re nt d esigns. Lt will also pro vide a q uantitative basis fo r predi cting the perfo rm ance of storm water manageme nt m easures an d de fin e thei r optimal design standards. The D SS wi ll be deve loped in modu lar for m , us111g a Geographi c In fo rm ation Syste m (G IS) platform to lin k models as required. Consequ en tly, develop ment of th e DSS w i II allow the la test techno logies in storm water qu ality manageme nt to be util ised at a number of leve ls, from d e tailed des ig n of individual faci lities to the deve lop m e nt o f catc hment stormwater managem ent st rategies. Th e DSS w ill simulate the pe rform ance of storm w ate r m a nagem en t m easures o n an event o r continu ous basis, allowin g rigoro us analysis of t he m erit of proposed st rategies over the short o r long- term. Time series of rainfall (fro m th e CRC's C lim ate Variability Pro gram) w ill be availabl e as input to the m odel. Similarly, aq uatic ecosystem responses to interm itten t and stochastic loading of urba n pollutants, de ri ved fro m researc h by th e C R.C fo r Freshwater Eco logy, w il l also be incorporated into the DSS. T o m eet in du stry needs, the D SS w ill have th e capabi lity to o perate at a range of temporal and spatial scale, suitable for catc hm ent areas from 100 km 2 to 0.0 1 km 2 .

Figure 4. Grass swales in place of the conventional ke rb and channel system for management of road ru noff can promote both wate r quality improvement and flow attenuation.


CATCHMENT

HYDROLOGY

the case prior to urbanisation). Infiltratio n attenuation and water quality improvesystems ha ve not enjoyed w ide-accepment has been advocated fo r many tance, mainly as a result of po o r years, although past experiences with maintenance practices (clogging being the grass swale have no t been always most common reason for poor perforpositive. The main problem stems from mances) and inadequate pre-treatm ent of inappropriate design , with system s the stormwater runoff. that are either too steep (causing loca lised erosion) or too flat (poor Vegetated infiltrat io n systems (o r construction leading to long ponding bi o filters) m ay overcome som e of the times following a storm event) , poor problems associated with clogging w ith mai ntenance and a general lack of the use of th e roots of vegetation to " ownership" by adj oining property main tain the porosity of the infiltration Figure 5 . Con struction of a bioretention owners. Many of these issues can, and media. An extension of th is concept is the system in t he median strip of a divided have been, resolved through expe ribioretentio n system recently adopted in street in t he Lynbrook Estate for both water ence. For example, flat terrain may the Lynbrook Estate, a m edium density quality im provement and flow attenuation. require a system that promotes infilresidential development in the outer tration and sub-surface drainage as well To underpin the DSS, the CRC is suburbs of Melbourn e (Figure 5). as flow conveyan ce thro ugh a vegetated u ndertaki ng research to define stormRetrofitting urban stormwater channel. water pollutant sources, pathways and infrastructure impacts, and to predict the performance Encouraging local ownership has often of traditio na.l and innovati ve storm water been overlooked in past swale systems and C onsideration of treatment methods q uality improvem ent facilities to meet th is can be addressed thro ugh better based on retrofitting existin g storm water user-specified water quality targets. integration into the streetscape. A number drainage infrastructure is o f particular relevance and requires m atching the of streetscape design concepts can be Integrated managem ent of storm water utilised to provide enhanced local am enicapabilities and site requirements of requires definition of pollutant loads ties as well as promote better management stormwater managemen t techniques to the ge nerated in an urban catch ment, to of sto rmwater quantity and quali ty. conditions of the site. R eplacement of form ulate an integrated water managem en t strategy involving th e use of D esign considerations oflocal public open underground stormwater pipes with more space, housing layou t, road layout, ecologically sensitive systems is not often structural and non-stru ctural m easures. It streetscap e, parking space managem ent p r acti ca l or t ec hn i ca ll y feasible . also requ ires an understanding of aquatic and reduction of run off can all contribute Retrofitting opportunities in the past have ecosystem responses to alteration in therefore been confined to the applicato the better management of storm water hydrology and water qua}jty resulting from runoff for the multiple obj ecti ves listed. tion of m ethods for ren10val of gross catchment urbanisation to set objectives for flow and water quality targets. T he pollutants. Car-parks are high source areas for a CRC research is addressing th ese ne eds. w ide range of poll utant types, rangi ng Pilot field experiments to quantify the from gross poll utants to fin e particulates role o f vegetation in wetland systems, The adoption of WSUD principles in undertaken by the CRC for Catchment and h ydrocarbons. Th ere are ofte n stormwater management and urban design Hydrology during 1999 (Figures 8 and 9), is currently hampered by the lack of competing requirements in selectin g the appropriate m easures for the removal of co nfirm the scalability of curren t knowlquantitative data on the performance and edge on the performance of constructed these pollutants. Options include the use costs o f structural and non-structural stormwater wetlands to small con fi ned of non-stru ct u ral m easu res for the stom1water quality improvement practices. areas. Th e CRC is now examin ing how To ensure the DSS m eets the needs of management of gross pollutants (ie . street the concept of w etland systems as source sweeping), and a grassed swale fo r the industry, we are researching key knowlcontrols can be incorporated into densely removal of sedim en t and associated edge gaps such as processes involved in built- up urban landscapes. contam inants (Figu re 2). the removal of stormwater pollutan ts, the Residential stre etscape design, such effectiveness of vegetation in the removal Conclusion as that illustrated in Figure 3 , can signifand transformation of storm water polluUrban storm w ater ru noff, and its tants, and effectiveness of infiltration/ icantly enhance th e amen ity (and thus en vironm ental impact on u rban aquatic value) of the local area, whil e havin g adsorption systems for storm water quality ecosystems, is a catchment-wide issue; it storm w at e r qu a lit y imp r oveme n t improvem ent. Research will include the requires a holistic approach in formu laeattributes. T he use of grassed swales (as development of operation and mainteillustrated in Figure 4) in place of nan ce practices fo r these system s. the conventional kerb and channel In addition to these fundamental stormwater drainage system, can resea rch activities, the CRC will be effectively im prove road runoff monitoring a number of stormwater quality and flow attenuation. quality improvem ent facilities in Brisbane Infiltratio n systems used for and Melbourne, and assessing the effecstormwater q uantity managem ent tiveness of non-structural stormwater may include aqu ifer storage and management measures. recharge technologies for stormSome Source Control Measures water recycling. T hese systems in WSUD essentiall y reduce the equ iva lent impervious areas of a catchment by Incorporating Stormwater Management Figure 6 . Ephemeral wetl and system for allowing runoff to be d ischarged Measures into Streetscape into the surrounding soils (as was treatment of road runoff The use of grass swales to promote flow

30

WATER NOVEMBER/ DECEMBER 2 0 0 0


CATCHMENT

in g strategies for its man age m ent. Measures to improve the qu ality of sto rm water can make an in val uable contribu tion to the man ageme nt of non p o int source pollu tants, and can fac ilitate the management of stormwater as a resou rce. There are clearly evolving technologies for effective water quali ty im.provement targeting a wide range of pollutant types. The re are many best management practi ces available to us fo r implem en ting WSUD. Many of them are no t well tested in the field and dem onstration proj ects are needed . T his has hampered progress and unde rstanding of their longterm ope ration in actu al fi eld conditions. A major impedime nt to imp le me ntati o n is the existing regu latory fram ework fo r u rban design. Wong and Eadie (2000) reco mmend that state and local govern m.e nt pla nning authorities make a firm co mmitme nt to take WSUD beyond just a p olicy o r strategic inte nt, by makin g it a conditio n of developm e nt through amendments to th eir regulatory pla nning instrumen ts and relevant urban planni ng and design gui delin es. To ensure lo ng term susta inability of WSUD ele ments, co mmuni ties will need to be empowered with a sense of owner-

HYDROLOGY

ship of the local storm water assets; the assets will be maintain ed by the commu nity reducing the reliance on recurrent fundi ng from state or loca l government. This will only be achieved through designi ng urban stormwater systems to be features within the urban landscape and by promotin g the inh erent values of storm water (ecological, aesthetic, recreation , educati on). T here remains a need for further research and development to improve methods of storm water management under t h e g uidin g prin cipl es o f WSUD. Improving th e level of understanding of the processes by w hich indi vidual storm water management methods conttibute to achieving multiple objecti ves of stormwater management is essential for the fu ll valu e of WSUD to be realised. In additio n, there exists a need to provide robust, but flex ible, decisio n support tools to improve the process by w hic h urban stormwater management systems are developed and implemen ted. T he C R C for Catchment H ydrology's Urban Stormwater Quality Program is addressing these needs

Urban D evelopment of Western Australia, ISilN O 64615 468 0, 1994. Wong, T.H .F. (1997), 01,erview ef sol11rio11s to proble111s caused by urban stor111water, invited paper, Proceedings of the Urban Sror111111arer Manage111e11t vVorks/10p, 17th Co11ve11tio11 ef the A11stmlia11 vJlater mid Wastewater Associatio11, Me/bo11r11e, M arch. Wong, T. H .F., Breen, P.F. and Lloyd, S.D. (1999), R etrefitti11.~ Urbm, Drainage Syste111s for bll~~mted Stonnwater iVlm1a,~e111e11t, proceedings of the 1st South Pacific Confere nce o n Com prehensive Stormwater and Aquatic Ecosystem Management, Auckland, New Zealand, 22-26 February 1999, Vol.1 , pp. 271-279. Wong, T. H.F., Ilrecn, P.F., Seymour, B.S. and C hesterfi eld, C (1999), Plm111i11.~ mid Desig11 of Srormwat cr M anage111 e11r Measures, Shorccourse N otes, D epartm ent of C ivil Engineering and Cooperative Research Centre for Catchment H ydrology, Monash University. Wong, T H F and Eadie, M L (2000), Water Se11siti1,e Urbm, Desig11 - A Pamd(~111 Shift i11 Urbm, Des(e11, proceedings lin C D- ROM I of the 10th World Water Congress, Melbourne, I 2-16 March 2000.

References

The Author

Whelans and H alpern G lick Mau nsell (1994) , Plm111i11,~ a11d Mmwgi'111wr C11idcli11esfor Water Se11siri1,e Urbm, (Rcsidmria/) Dcs(~11, report prepared for the Department of Planning and

Associate Professor Tony H F Wong of M onash Un iversity is Program Leade r - Urban Stormwate r Qual ity.

An Exciting Joint Universities' Postgraduate Program in One-Year Masters Program A 12-month J o int U niversities' M asters program by cou rsework and research project leading to a Master of Engineering in H ydrology and Water R esources is offered to both Australian and Intern ational stude nts. Applicati ons must be lodged by Wednesday, 31 January 2001.

What is unique ab out this Program? • Integration of science, engineerin g and techno logy management foc using on real appli cations. • T he exp ertise and collabo ratio n of five research/edu cational institutio ns. • It is designed to be completed in three sem.esters over 12 m o nths. • lt provides knowledge and skills for total water resou rce ma nagement. • Water resource managers are among the lecturing staff This postgraduate program will be of particular interest to professionals w ho are working, or planning to work, in the field of wate r reso urces managem ent and development in governmen t agencies, consultin g fi n11s or academi c institu tions . Admission is in the fi rst semester of the academ ic yea r.

Graduate Diploma and Graduate Certificate courses are also offe red. Fo r application and fee details and other enquiries, please contac t Ire ne Spong, Program Coordinator, J U MP, D ivision of Information Technology, Engineering and the Environment, Un iversity of South Australia, M awson Lakes Cam pus, M awson Lakes, SA 5095, telepho ne (08) 8302 3207, facsimile (08) 8302 3609, email iren e .spong@un isa.edu. au Web address http:/www. unisa. edu.au/ h vdroloQ'V/ CRC for Water Quality and Treatment

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of Adelaide

University of South Austral/a

The Flinders University of South Austral/a

--·

Centre for Groundwater Studies

Q WATER NOVEMBER/ DECEMBER 2000

31


CATCHMENT

HYDROLOGY

Communication for Adoption of our Research D Perry Introduction N£WSU:TTfR

A key performance indicator of the CRC fo r Catc hm ent H yd rology is the level of adoption of its research. In practice, this m eans that our C R C is committed to delivering knowledge, activities, tools and publications that meet the needs of land and water managers. T he in vo lvem en t of industry end-users and stakeholders in the imple me ntation of o ur research is just as important as their involvement in the formu latio n and conduct of th e research.

OF

TH £

COOPERATIVE

RESEARCH

CENTRE

F-OR

models, avail abl e for downloadin g directly from the site or for a modest cost from the Centre Office. U nder links, there are man y valuable web addresses from aroun d the world , and emai l li sts relevant to those in the land and water managem ent industry. They are grouped in categori es and are regu larly updated .

CATCHMENT HYDROLOGY

CATCHWORD

Obtaining knowledge from our research The articles in th is special feature o n our C R C provide excell ent exampl es of the range of products and appl ications that develop from our research . Th ere are many easy ways to find out about o ur research outcomes and keep in touch w ith new developments: • O ur high-qua li ty newsle tter Cntc/i111ord is distributed fre e to over 11 00 rec ipie nts each m onth , both electronically an d in hard- copy • T he Centre Office has a wide range of publications available for sale including tech n ical reports, sem inar videos and reade r friendly industry reports • T h e C R. C h as a learn in g-based program of fie ld tours and demonstrations of research products, tailored to the needs of pra ctitioners, co mmunity gro ups, and landholders • R egu lar professional e du c at ion workshops and short co urses • C R.C researchers often contribute to groups of featu re arti cles (tail ored to p ractitio ne rs) in trade journa ls; for example in this edition of, Water • T hrou gh our website, as detailed below For your information www.catchment.crc.org.au

Th e C R.C's website is th e best place to start w he n seeking informati on about catc hme nt hydrology our resea rch, produ cts, activities and staff. This site has be en design ed fo r land and water managers w ho need reliab le information quickly; and has a number of'qu ick clicks' that go strai ght to the page required. T he pa ges are updated regularly (o fte n daily)

32

and provide a range of practica l in formation an d services. CRC Publications on-line

Our newsletter Catchword and our Publications List (providing details of over 100 reports, CD - R OMs and videos available) can be qu ickly downloaded. AJ1 of ou r cu rrent C R C pu blications sin ce Jul y 1999 are also published as web pages under th e publications 'quick click'. Each technical and industry report has a preface and abstract available and, in some cases, the conclusion. There are also instructio ns o n how to order our reports and to subscribe to Ca tch word on-l ine . Events calendar on-line Our CRC eve nt calendar is updated regularly ; many organisati ons use it to advertise their activiti es. W e in tend this ca lendar to be a key source of information about hydrology-based activiti es suitable for land and w ate r managers aro und Austra lia. D etails of se minars, works hops, field trips and oth e r forums are listed in a monthly fo rmat . If yo ur organisation has an event that you would like listed on our calendar then please send de tails to us (see be low) and we w ill add it, o ften o n the sa me day .

For those w ho like to be notified by em ail of upcom ing events and other activities as they are arranged, there is an event noti ficatio n service. Ove r 650 peop le around Australia are currently registered. E nter yo ur nam e and e mail address and select th e C RC programs of interest to yo u , then press t he submit button. This sends us an e mai l w ith yo ur spec ific details, whic h we add to our communi cation database. CRC researchers and research In fo rm ation on the researc h programs from both the initial and current C R C are also on- line . T he ini tia l CRC ach ievem ents, and de tails of our current research proj ects, are listed by project (see the R esea rc h 1993-1999 and R esea rc h 1999-2006 links). T he site also has a ' M ode ls' page with deta ils of C R C

WATER NOVEMBER/D ECEMBER 2000

If you have a question about the CRC 's research

The website now has an on-line forum fo r communi cation betwee n practi tione rs and researchers. The forum page is designed to allow you to ask gene ral or specific questions of CR. C staff about our research, its applicatio n and other related activities by posting your question or request on our website. T he Forum page may be accessed from the hom e page by a 'quick click' at the top right. From there yo u arc give n th e choice of w hi ch CRC program is most relevant to you r question or the information required . T here is also a forum for qu eries of a gen era l nature . We hope that, in time, the forum page w iU be a commonly used source of informati on about hydrologic resea rch and its app lica tion . If you are not su re where to fi nd in fo rmation about a particular issue, you could use the site's search e ngine. lt is a valuable tool to qui ckly find out w hethe r the C R.C's research can assist you w ith the in formation you are seeking. A CR C staff contacts database is also on-line allowing yo u to contact our researchers direc tly. Th e staff database can be accessed fro m t he home page (cl ick on 'Contactin g the CRC') and searched using a range of criteria (eg. location, nam e, research program etc). The C R.C for Catchment H yd rology has m ade a significa nt investm en t in its website at www.catchment.crc.org.au. If you have suggestions or comments about it, please drop us a lin e. T he on ly reason the website is th e re is for yo ur in for matio n!

Author David Perry is leader o f the Communicati on and Adoption Program. T e l: 03 9905 %00 Fax: 03 9905 5033. e mai l: david.pe rry@eng.monash .cdu .au


B

WATER

OPTIMISATION OF FILTER FUNCTION USING PARTICLE COUNTING M Colwell and P R L Mosse Abstract The use of a portable particl e counter to m o nitor and optimise th e perfo rmance

o f a sm all water treatment pla n t is described. Valve ramping speeds, event se quen c in g, backwa sh interva l an d du ration , and plant run times were altered to achieve a sig nifi ca nt reduc tion in filt ered water particl e counts in th e 21 5Âľ111 size range . Maj o r c hanges to the initial plant desig n have bee n undertake n in light of particle cou nt results. Pa rticle co unts of <200/ mL were ac hi eved in,mediatel y afte r bac kwash and <40/ mL du ring normal fil te r ru n tim es. Filte r rip e nmg pe riods were less than ten m inutes.

Introduction Particle counters are increasingly being use d to assess and o ptimise Wate r Tre atment Plant o peration. They are also be in g used in th e eve ry day o peration of WTP's and in the moni toring of product water gu ali ty from WTP 's. Gippsland W ate r ope rates sixtee n WTP 's ranging in size from 0.5 ML/ d to 27 ML/ d. As part of an active program to im prove treated \Nate r guality at al l plants, one plan t was c hosen to serve as pilo t fo r the applicati o n o f pa rticl e co u ntin g to the optimisation of th e treatm e nt process.

The Plant The H eyfi eld WTP was built for Gi p psland Water in 'I 998, under a desig n a nd const ru c t c ontrac t , b y Wa te r T re atment So luti o ns P/ L. The plant is a sta n d-alone package plant co nsisting of two 1.5 ML/d m o dules (Figure 1) . The modules were fab ricated offs ite in stainless steel and consist of in- line che mi ca l dos ing, a flo cc ulatio n tank, primary filt er a nd secon da ry fi lte r. Th e m o dular constru ctio n :illows for flex ibility of operation and th e abil ity to respo nd to c ha n gin g po pu lation by the add ition or re moval of modules. The plant was designed w ith a primary filt e r rathe r than a co nventio nal clarifi er /sedim enta tion tank co allow greater flexibility in the face of varying raw water

Figure 1. Heyfield Water Treatment Plant

qu ality. Rain fa ll events in the H eyfi eld W TP ca tchment can lead to rapid deterio ration o f river wate r qua lity. So urce wa ter for th e plane is predomi nantly co.llected from state fo rest. Approximately fi ve pe rce nt of total ca tchment area is assoc iated w ith cattl e grazi ng. Trea te d water passes to an o pe n basin and the n to a c hl o ri ne co ntact tank.

screen. Data tre nding availabl e on site includes raw and product water turbidity, sludge tank levels, dosed wate r pH , plant flo ws, fil ter le vels, backwash tan k level and c he mi cal storage tan k levels. At prese nt c he mica l do sing is operator controlled based on j ar testing, however future plans are to include a capabili ty to respond to changes in in comi ng raw water quality base d on histo rical data.

Trea tm ent residuals are ini tiall y settled in a primary slu dge ta nk un de r th e actio n Influ e nt water is dosed w it h PFS of gravity. The seede d solids are m ixed (po lym e rised Ferric Su lphate, 12% Fe w ith po lym er and pu m ped to a seco nd w / w) . T ypi cal doses range betwee n 2.5 small er tan k . T he clarifi e d sup ernatant - 5.0 m g/L Fe. Durin g a rece nt di rty from both tanks is re turn ed to the head water eve nt th e dose w as increased to of the plant. The th ic ke ned product is 7 m g/ L. There is no pre dose pH correcca rte d offsite and added co sewage in a tio n and t he flo e tan k typi ca lly operates large sewe rage syste m. T he combin ed arou nd a pH of 5.4 . Po lym e r 11 15 (Be tz bi osolids and water treatmen t res id uals D earborn polyacrylamide) is added prio r are subseq u e ntl y m a n age d at t h e PFS Backwash Sewage T reatment dosing Primary Filter tank Filter 1 point Floe f Pl a n t. D ir ec t tank1 --;---, disposa l to sewer is not a cost effe c tive - - - Storage basin optio n at chis site. Floe ~ Primary Filter tank 2 Filter 2 - 1---,.~ A sc h ema ti c

J

l

rep resentatio n o f the H eyfie ld WTP a s ori g in a ll y cons tru c t ed i s sho wn in Figure 2. T h e plant is PLC controll ed vi a a s mall touc h

J

t.

â&#x20AC;˘i

Normal water flow Dirty backwash water out of filters

Supernatant return

Primary sludge tank

7.

Figure 2 . Schematic of Heyfield WTP as originally constructed. WATER NOVEMBER/ DECEMBER 2000

33


WATER

Table 1. Filter Characteristics

Nozzles

Primary FIiter

Secondary Filter

Plastic Nozzles 1.5 mm slots

PCDM Ceramic tiles

3-6

Gravel

100 mm

Sand 2.6-1.5

Pumice

1000 mm

3-6

100 mm

18/40 (1.0-0.7 ) 30/60 (0.7-0.25)

300 mm

2.6-1.5

500 mm 900 mm

1100mm

Media depth Filtration Rate

18 m/ hr

Backwash Rate

20 m I hr

to the primary filt er at a dose rate of around 0. 08 mg/ L. Filter design fea tures are p rovid ed in Table 1. The plant w as designed so that upon initiation of a backwash , in either of the m odules, inflow to the plant was halved. The prin ciple being de veloped is to operate the primary filte r in su ch a way tha t the seco ndary filte r receives a uniform quality of water and its run times remain relatively co nstant. Durin g high raw water turbidity events primary filt er run times are redu ced. The initial post-commissioning operating conditions are listed in T able 2 . At this time the plant ran fo r appro ximately six hours at a time at the design flo w rate of 28 Lisee.

Use of Particle Counting for Process Optimisation After completion of the initial perfo rmance trials at the H eyfi eld W T P , a portable particle counter (PMS LiQuilazE20) was se t up (Figure 3). The purpose of the particle counter was to monitor existing conditions, and assess the effect that normal plant op eratio n had on particle counts. Particle counts were m easured in the product water from each filter unit. The overall objective was to optimise the particle removal pe rfo rman ce of the plant. The p arti cle counter at H eyfield has been set up to m easure the total numb er of particles in the 2- 15~m1 size range. This size range was selected as it includes particles in the size range for Cryptosporidi11111 oocysts (4-6µm ) and C iardia cysts (812µm ) (NHMRC 1996) .

Murray (1995) states that while 20 particles/ mL can be achieved w ith high quality raw wate r, a more rea dily achievable figure of 200 particles/ mL for 95% of sa mples sho uld be possible even during periods of poor raw water quality. Th e aim of this optimisation process was to consistently achieve better than the 200 p articles/mL and durin g normal operation to approach the 20 particles/mL suggested by Murray .

Initial Particle Counts Typical particle co unts achi eved pri or to any pro cess modifications are shown in Figure 4. Figu re 4 shows a marked deterio ration in wate r quality immediately foll o wing the combined backwash of a primary and secondary filter, with particle counts rising to as high as 5000 particles/ mL from th e " normal" operating level of betwee n 40 and 60 particles/ mL. These particle spikes also happened o n pl ant start up . T he figure also shows that particle spikes fro m filter 2 were almost tw ice that o f filter 1. In itial filter rip ening curves were of exte nded h eight and duration . The ripening times w ere defin ed, for the purposes o f this work , as the time that it took from the unit coming ba ck on line after a bac kwash until the counts dropp ed to the pre backwash levels. For filter 1, counts o f > 1000 particles/ ml occurred for approximately 55 ni.inutes, with a peak o f approximatel y 3000 particles/ ml. For filt er 2, co unts of > 1000 particles/ml

Table 2. Initial operating conditions of the Heyfield Water Treatment Plant Primary Filter

Secondary Filter

Run Time

300 mins

700 mins

Air Scour

60 secs

60 secs

160 secs

210 secs

Back Wash

34

occurred fo r appro ximately 45 minutes, with a p eak count o f approximately 5000 particles/ mL. Visual observation o f w ate r pass in g fro m primary filter 2 to secondary filt er 2 sugges ted greater so lids carryo ver w hich was consistent with the instrumental observations and suggested that the primary filte r for tha t modul e was performing w o rse than the primary filter of module 1. Inspection of primary fil ter 2 revealed that a significant loss of media had occurred. So me m edi a has bee n lost during backwash bu t this appears to have occ urred equally in both filte rs. Th e reason for this apparent loss is not clear. Approximately 20cm was added lead ing to an immediate improvem ent . In an atte mpt to improve th e performance of bo th m odul es th e foll owin g changes were progressively made and the effects observed . • th e storage basin level w as allo wed to drop lower before triggering th e plant start , th e re by allo win g th e plant to run fo r lo nger pe ri ods each day, • rapid c hanges in fl ow were prevented by slowing down the opening and cl osing speeds of th e filte r inl et and outlet valves, • backwash times were inc reased, • primary filter run tim es w ere redu ced to reduce th e load carried ove r to th e secondary filte rs, and • sec ond ar y filt e r run times we r e increased. Th e optimi se d c ondition s are summarised in T able 3. As a result of all the changes, a marked redu cti o n in particle co unts from each of the filt ers was obse rved (Figure 5) .

2.4 m x 2.4 m

2.4 m x 2.4 m

Filter Area

Figure 3. Portable particle counter

WATER NOVEMBER/DECEMBER 2000

~

'"~- ahd Sec< ndary I ilter

-

5000

"·----·f ... -

. FJ

l, .. . , - -

, , v ...

and econdaty_Fllter

4000 3000

j

~

I

J wi.

.....

r Plai toff"

2000

I

I\ ~

:!:

~

J..

io---7

~

g'

g

i:i

0 ,o

...

!

~

iii

~- .;~ ~: ~

I

., 0 0

g

IL 8 ~

g

~

~ ~ ~' ~ ~ ~ Figure 4. Heyf1eld WTP Particle Counts before process modifications.

II I

~

~

~-

~~

!~


WATER

1100 M

I

~

I

I ~ IC2B ckw sh

60

~o

i C1 Bllckw , h I

1

~

w--g

~ ~ Wffl/9'1

Fi or1 aack i,,ash 0-4 n ns> hoo, oak

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~

Filtt 2B ckw sh - 4 ~ins 100 1 •

•• ,

I

lsoo

I

-""'

'~ ~

~

I

outlet of each of the primary filte rs. The aim i~ to se lect and ~et a primary filter o utle t turbidity that will trigger the backwash of the prima1y filte r. In this way part ia ll y filtere d water passing to the seco ndary fi lter will be of a relatively consisten t quality the re by all owing th e secondary filter to m aintain a constant run time . The prima1y fi lter on the ocher hand will o p erate on d iffe re nt run times depe nding on th e incomin g raw water qua lity. In this way the pla nt will also be able to automatica ll y respond to d irty water eve nts in the catchm ent .

I

Plan star -F!lt11 1 - IB mi, s>1 Kl, p, ak< ~ Fllte 2- min,: 10 , pe, k< 1,kl

0 C

8

~

~

~-

_.

\ J

g

g

g

~

~

~

llM ~ ;::;

~

0

~

0 C

g

~

a

~

p

C

~

C

'?.

imJ

Figure 5. Heyfield WTP Particle Counts after process modifications. (Note the

ch ange in vertical scale from Figure 4 emphasising the improved performance.) Filter ripening pe riods were sign ificantly improved . In filte r I , counts of 100 parcicles/mL were excee ded fo r approximate ly 8 minutes, w ith a peak of approx imately 200 pa rcicles/ mL. In filter 2, coun ts g reater than 100 particles/111 L we re obse rved fo r approximately 2 minutes, with a pea k of 150 particl es/ ml. D u ri ng norma l o peratio n partic le co unts we re co nsistently <-W particles/ml. Although th e modific atio ns described above resu lted in a signifi cant improvem e nt in the removal o f particles, fu rth er improve m e m was limited by the capacities of th e backwash water tank and t he pri ma ry sludge tank . B o th of these e ffect ively limited th e duration o f backwash possibl e and in part the interval between su ccessive ba ckwashes. Diffi culties were also exp e ri enced w ith programming interlocks in the PLC. The P LC was in itially program m ed to backwas h the seco ndary filter eve ry s c co n d t i 111 e the pr i 111 a r y fi I t e r ba c kwashed. Thi s logic sequ e nce was desig ned to minim ise production down time w he n a unit w as off line d ue to ba c k wash ing, and e nsured th at th e primary sludge tank had suffic ient capa city to accept t he dirty ba ckwash w ater. Unfortunately, changes to the bac kwashing intervals resulted in filte r e lem e nts q u e uing fo r backwash. This q ue uing was cau sed by th e inabi lity to ret urn superna tant fro m the primary sludge tank qu i c kl y e nou g h to a llo w the n ex t was hwater volume to e nte r th e primary sludge tank (refe r to Fig ure 2). This

Conclusions

res ulted in decreased produc tio n, and detrimentally affected the condition of the secondary filters. Under these conditions t he seconda ry fi lters w e re running for lo nger but the backwashes w ere not being proportionall y in creased to compensate for th e in creased load.

Particl e counting has proven to be a va luable tool in the optimisa tion o f the op eration of th e H eyfi e ld WTP. Process modifi cations le d to signifi ca nt improvem e nt in typical and ma xi mum pa rticle counts in the filtered w ater. Consequently th e ri sk of water supply contam ination asso ciated with pathogens has been further red uced.

T he ex istin g plant has bee n furt her modified by th e add ition of another bac kwash tank and anot h er prima ry sludge tan k, th ereby inc reas ing both the ba ckwas h capac ity, and th e do w nstrea m washwater hand ling capacity. The changes are shown d iagrammatica lly in Fig ure 6. In add ition a la rger ca pacity supern atant retu rn p um p was installe d to ensure that the backwash water receiving volum e was made ava il able as soon as possible. T he su pe rnatan t re turn is up to I 0% of plan t flow. This rate of return to date has req u ired no modifi cation of dose rate and has had no m eas urable effect on product wate r qua lity. Modi ficat io ns currently in progress will allow t h e pla nt to be backwashed for almost twi ce as long as befo re and fo r the dirty bac kwash water to be dive rted into the primary sludge tank that ha s t h e lowest level. Modificatio ns to th e PLC w ill all ow the filters to be back was hed ind ependently of eac h o t he r. Th is will pro vide greater fl ex ibilit y o f PFS operation. dosing Primary On 1in e turbidity m ete rs will a l so b e insta lled o n the

l

point

Floe tank 1

n

..r

Filter

Acknowledgments Th e authors w ish to thank B ru ce M urra y of C ity Water T ech nology fo r c ritical review of the manu sc ript.

References NHMR.C and ARMCANZ. (1996) . Australian Drinkin g W ater Guidelines. Commonwealth of Australia. Murray. 13. A. ( I 995). Particle Counting W ater Treatmen t. Warer, 22:37--10.

Authors Michelle Colwell (c olwellm@ gippswater.com.au) is a Water T reatm ent Tec h nologist an d Dr Peter Mosse (mossep @gip p swate r. c om .au) is th e Water T rea tment Manage r at Gippsland Water, PO Box 348, Traralgon , V ictoria

3844.

I

Backwash tank

Filter 1

- -+-- - ,

Floe ....r+ Primary tank 2 Filter

Table 3 . Final operating conditions of the Heyfield

J

Jr-..__--+ Storage basin

Filter

2

-'i

-1---,,-~ Normal water flow Dirty backwash water out of filters

Water Treatment Plant

New

Primary Filter

Secondary Filter

240 mins

- 900 mins

Air Scour

60 secs

60 secs

Back Wash

240 secs

330 secs

Run Time

111

Primary sludge tank Supernatant return

7.

secondary sludge tank

_r

~ vkj

Figure 6. Heyfield WTP schematic after major modifications WATER NOVEMBER/DECEMBER 2000

35


WATER

lJJ~JJ\JJ~JJ\Ji:J~ ~YJ-i-J EJ~ JyJ; iJ\J; ifJEJYJEJ\J-1 JJ\J u\JE ~y 1EJ-ilJiJ\~D ... ·-· 1..:-J--- - - -~ - -- -----..=--:..;.:: : Overview Before discussing the role of E. coli in the microbiologica l monitoring of drinkin g-water in N ew Z ealand it may he lp to give a brief overvie w o f th e reasons behind the N ew Z ealand approach to managing th e public health aspec ts of drinking-wate r. In 1992 the public health o versight o f drinking- w ater 1nanagem ent in N ew Z ealand was in disarra y afte r seven years of central and local government restructuring and re tren chm ent. Th e (the n) D epartment of H ealth was receivin g little informatio n abo ut the quality o f publi c drinking-wate r suppli es I but an independent 1989 survey 2 had shown that at least 45-50 percent of water supplies did not monitor the ir ch lorine dosage satisfac torily, 28 pe rce nt n e ve r te sted th e bacteriological quality of water after it e ntered the reti culation and anothe r 30 percent tested only fou r times per year. After the D epartme nt of H ealth was restructured into th e Min istry o f H ealth in 1993, an initial appraisal 1• 3 of the public health safe ty managem e nt o f th e drin kin g-water industry was carried out. Th e opportunity w as take n to fund ame ntally review and restru cture the pro cess o f publi c health manage me nt o f drinkingwater. There were also a n umber of major governance and structural issues surrounding the wate r industry that might be nefit fro m revie w but respo nsibility fo r th ese lies outside th e hea lth portfolio. The Ministry of H ealth , therefore, concen trated on th e p ublic health infrastru cture, alth o ugh it has co ntributed where possi36

ble to various govern ance and stru ctu ral re view s carried out by oth e r agen cies. In New Z ealand som e 85 percent of the total popu lation is servi ced by a mere 103 drinking- water supplies. Each of these is a m edium to large supply , servi cin g m ore than 5,000 people . The re ma inin g 15 perce nt of the populatio n is serviced by over 1800 supplies that each supply few er than 5,000 people . 98.4 p ercent of the supplies that failed to comply w ith the b acte rio lo gica l requirem e n ts of t he

Driuking- Water S tandardsfo r Ne111 Zeala11d 1995 in 1998 fell into this lo wer 15 percentile. 6 • 7 · 17 Many o f these are in poor, dispersed rural communities that not only do not have ready access to laborato ty facilities but also have relatively high per capita costs for both treatment and monitoring compared to their larger urban counterparts. The existing le gislative fram ework for drink ing- wate r is fr agmenta ry and o utdate d, refl ectin g its roo ts in English legislation from the 1800s and th e redistribution o f po rtion s of the h ealth portfolio among a multiplicity of agencies in 1987- 199 3 . Conseq u e ntly th e Minist1y of H ealt h has had to deve lop manageme nt proce du res based o n nonregulato ry interve ntion.

The management approach To improve the public health managem ent of drin king-wate r supplies, the Ministry has developed an in tegrated managem ent system in whic h the vario us compone nts not o nl y complem ent but mutually re inforce eac h oth er. Th e management programmes are designed to

WATER NOVEMBER /DECEM BER 2000

p ro mote m ax im um interac tion and mutual support b etween the various stakeholders; the public and th e media; the drinking-wate r supplier; and the public health officer. Emphasis is on using risk manage m ent plannin g tec hniqu es to promote a quality assurance app roach. This is complemented by a monitoring programme used as a final quality control w hich also acts as a fee dbac k loop and provides a tri gger for re medial action w he re this is necessary. The prin cipal public health managem ent tools used are : • the Dri11killg- Water Sta11dards fo r Ne111 Z ealand 1995, (DWSNZ 1995)4 • monitorin g by wate r suppli ers of complian ce with th e DWSNZ, with surveillance by health protection officers designated by th e Ministry of H ealth • public health gradin g of community drinking-wate r supplies5 • the Register ef Com1111111ity Dri11king- Water Supplies i11 New Zeala11d6 w hich lists the location o f all drinking-water suppli es in N ew Zealand , th e populati o n served , the publi c health grading of th e drinkingwate r supply and the prese nce of any determinands wh ose conce ntra tion exceeds 50 percent o f th e MA V • an A 111wal report 011 the 111icrobiologica l

quality of drillki11g-wafer supplies i11 N ew Zeala11d7, which advises the public how w ell th e ir supply has complied w ith th e m icrobio lo gical require m ents o f th e DWSNZ; the likelihood that th eir water supply has been faecally contam.inated; and analyses the causes of proble ms

• Guidelines fo r D ri11killg- Water Quality


kla11agc111c11t i11 Nc111 Zcala,u/ 8 which provide information and advice on managing drinking-water supplies • the requirement'+ that only laboratories approved for the purpose by the Ministry of Health may carry out compliance testing for the DWSNZ • a national electronic drinking-water information base WINZ, shared with Public Health Services and drinking-water supply authorities. WINZ collates compliance and quality assurance data, automatically checks that sampling and analytical protocols have been complied with and is used in the verification of compliance and the public health grading of drinking-water supplies.

The public health grading of drinking-water supplies The principal driver of improvement in the quality of drinking-water in New Zealand since l 993 has been the public health grading of drinking-water supplies by public health officers. This provides an impartial assessment of the performance of a supply and is published so that the public can evaluate the service they arc receiving. The resulting improvements have been gratifying. The purpose of grading a drinkingwater supply is to provide a public statement of the extent to which the supply achieves, and can ensure, a consistently safe product. The protection of the source and the adequacy of the treatment arc graded on a scale A = good to E = completely unsatisfactory, based on the competence of the operators, the extent of treatment (e.g. coagulation - filtration - disinfection) and the degree to which the supply complies with the DWSNZ. Similarly each distribution zone in the network reticulation is graded from 'a'= good to 'c' = completely unsatisfactory, depending upon the condition and management of the distribution system. The public awareness stimulated by the grading is supplemented by the publication of the A111111al report 011 the 111icrobiological quality cf dri11ki11g-water supplies which arouses considerable local media interest in districts in which the drinking-water supplies is unsatisfactory.

Drinking-water standards The DWSNZ l 995 prescribe maximum acceptable values [MAVsj for determinands of public health significance and provide a yardstick against which drinking-water quality is measured. The DWSNZ specify minimum frequencies of monitoring that will give 95 percent confidence that a drinkingwater supply is complying with the Standards for 95 percent of the time. This applies to the small supplies. Larger supplies arc required to monitor more frequently. In 2000 the DWSNZ 1995 were revised to produce Dri11kii1g-l,Jlatcr Stmulardsfor New Zcalm1d 2000 (DWSNZ 2000) which come into effect on I January 2001. DWSNZ 1995 used 'classical' statistics to derive the necessary monitoring frequencies, but DWSNZ 2000 takes advantage of recent advances in the use of statistics 15 in which monitoring frequencies arc derived from the Bayesian approach. This requires fewer samples for the same degree of confidence and has the potential to enable the performance record of the supply to be taken into account in determining the appropriate sampling protocols 1<i. The DWSNZ also: • specify referee methods against which the methods used by individual laboratories have to be calibrated • require that laboratories carrying out compliance testing be approved for the purpose by the Ministry of Health • specify minimum remedial :1ction that has to be taken in the event of the standards being breached The purpose of the referee methods is to overcome the problem that different analytical methods can give different results. The referee method provides a benchmark in case of disagreements. Laboratories can use any method that has sufficient precision and sensitivity, but the conformance assessment agency that accredits them is required to certify that the methods the lab is accredited for have been calibrated against the referee method. To minimise the number of detenninands that have to be monitored routinely in any specific drinking-water supply but still maintain adequate safeguards to

public health, in the DWSNZ the determinands of public health concern are grouped into four priority classes. Priority I is given to the indicators of faecal contamination and to indicators of the efficacy of treatment processes in inactivating protozoa. Rapid response and remedial action is required for all determinands that indicate the potential presence of pathogens. All drinking-water suppliers are required to monitor Priority I determinands. Priority 2 dcterminands are chemicals that have been shown to be present at more than 50 percent of the MA V in a particular supply or, in the case of pathogenic micro-organisms, where the Medical Officer ofl-lealth considers that the circumstances require that they be monitored. The requirement to monitor Priority 2 (P2) dcterminands is specific to the supply concerned. The Ministiy of Health has carried out a survey of all drinking-water supplies serving more than 500 people, to identify the presence of P2 detcrminancls in order to determine monitoring requirements. Priority 3 and Priority 4 detcrminands include all other detcrminands of public health concern for which there is no evidence that they arc present in the water supply in significant concentrations. Monitoring for these is at the discretion of the drinking-water supplier. It can be seen that the top priority is given to identifying potential causes of infectious disease outbreaks. In an ideal world we would use a screening test that provides instant identification of the presence of pathogenic organisms in drinking-water. At present, no such test exists. Until better tests have been developed, New Zealand, like the rest of the world, has to fall back on the use of indicator organisms to identify the probability that the water has been contaminated by excrement and, therefore, the possibility that pathogenic bacteria or viruses arc present. Because of the practical difltculties in routinely enumerating infectious protozoa in drinking-water, surrogate methods have had to be used, based on checking that the water has received is from a safe source or has received a level of treatment that has a high probability of removing protozoan organisms.

WATER NOVEMBER/DECEMBER 2000

37


WATER

Microbiological standards Tn DWSNZ 2000, E. coli has been chosen as the indicator organism for faecal contamination, instea d of the faecal coliforms used in DWSNZ 1995. The choice of E. coli is, to some extent, arbitrary. E. roli, Enterococci and sundry oth er organism s all ha ve their propone nts for use as ind icator orga nisms and , in differe nt situations, a d iffere nt o ne may be supe rior. H owever, E. coli appears to be th e most gene rally applica bl e. U ntil evidence to the c ontrary becom es available, E. coli has bee n chosen fo r use in N ew Z ea land. Furth er evid e n ce is currently bei ng sought in a year-long inte ragency study9 at 20 represe ntati ve sites that w ill evaluate relationships between pathogens and indi cator organisms in New Zealand natural waters. This should provide furth er evidence about the most appropriate choice. The referee method chose n for E . coli is AP H A 9223 B 10 (M PN fo rmat), th e E nzyme Substrate Coliform T est, in preference to th e older fermentation and m embrane filter m eth ods. This test has b een calibrated against the fermentation method 11 and is available commercially as pre-packaged ki ts, making it more accessible to smaller organjsations. Protocols fo r usin g the kits have been develope d 12 . A furth er advantage of En zyme Substrate tests for small organisations is th at testing may be pe rform ed at different levels of rigour, rangi ng fro m presence/absence testing for total coliforms to full e numeration of E. coli. When the M PN version of th e test is used , use of exa ct enumeration tab les derived from occu pancy theory 13- 14 w ill be e ncouraged . There remains th e probl em of achievin g consistency between laboratori es . To some extent this can be achieved by interlaboratory co mparison, but in mo st cases the inter- laboratory protocols use freeze dried organisms and do not adequately test the considerable va riance that is due to sam ple handling procedures. T his problem has not ye t been sa tisfactoril y resolved . No supplem enta1y monitoring of other organisms is required by DWSN Z 2000. Any furth e r develop ment of mi crobiologica l surveillance is intended to arise from the use of risk management prin ciples. Th e extent o f risk managem ent and the level of surveillance is linked to the degree of risk to the public health safety of the supply. Thus the greater the number of barriers to in fection that erist, the lo wer the freque ncy of compliance mon itoring tha t is req uired. For exampl e for drinking-water supplies derived fro m secure aquifers or w ith a demonstrated adequate

38

disinfection residu al the frequency of E. coli monitorin g is less than for a su rface water w ithout residual disin fec ti o n.

Public health risk management plans The development of publi c hea lth risk managem ent plans by drinking-water suppliers is enco uraged by the Ministry and is proposed to becom e a statutory requirem ent. N o difficulti es are an tic ipated w ith the la rger supplies, but a substantial proportion of the smalle r supplies will not have the resources to achi eve th is. To assist suppliers to develop a nd implement public health risk management plans, th e M in is try of H ea lth is developing model plans that cover the major critical po in ts of raw water quality protection. Th ese models w ill provide the basis fo r the development of specific public health risk management plans for individual supplies. A matrix approach is used wh ich uses a se t of modules fo r eac h ind ividu al stage of a general ised drinkin g-wate r su pply system, such as: • ca tchm ent manage ment • raw water storage reservoir nunagement

WATER NOVEMBER/DECEMBER 2000

• each of the vario us treatment processes • the network reticulation • service reservoirs. For each process in a water supply there w ill be m odul es cove rin g: • risk assessment • risk ca uses • poten tial preve nta ti ve m easures and con trols • comparative level of risk • corrective action • indica tors o f perfo rman ce in preventati ve measure contro ls and corrective actions • process manage ment • contingency plans. Each drinkin g-water supplier w ill th en be able to adapt the modules t hat apply to th ei r parti cular circumstances to develop a risk m anagement plan for the w hole of their suppl y that ide ntifi es the risks and the associated controls, enablin g the management pri orities for th e supply to b e established , taking into account the overall be ne fits and costs. Gu idance fo r this stage in the development of the public health risk management for t he supply is provided in an overview docume nt. The draft public health risk management

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plans w ill go th ro ugh a three m o nth public co nsultati on process be fore be in g fin alised.

Legislative developments Th e effec t of the no n- regulatory interventi o ns in drinkin g-wate r m anagem e nt pra ctice that have been intro du ced sin ce 1993 has been to improve the situati o n fro m that re po rted in 1989 2 to the present situatio n w here 8 1 perce nt o f the populatio n recei ve drinking-water that is fulJy compliant w ith th e DWSN Z 1995. 7 · 17 C omplian ce requirem ents are stri ct. A supply fails to comply w ith th e Standards

if: • MA Vs arc exceede d more freque ntly t han is permitted by th e Standards • th e numbe r of samples analysed is few er th an that re qu ired by the Standards • th e labo ratory used for the analyses has not bee n approved by th e Min istry o f H ea lth • t he presc ribed re medial actio n is not ca1-ried o ut w he n a MA V has bee n ex ceeded. T o conso lidate thi s pro gress, in Nove mbe r 2000 th e Min istry of H ealth w ill reco mm end to governm e nt an am e ndm ent to th e H ealth Act w hich will provide a statu tory fram ew o rk fo r th e non - regu latory interve ntio ns that are presently operating. The am endme nt will stre ngth en and improve the existin g legislation by: • pl acin g duti es on drinkin g-w a te r suppli ers to take all practicabl e ste ps to comp ly with drinkin g- wate r standards (a nd vari ous oth er duti es and po wers an c illary to that) • providing a statu to1y framew ork fo r the promulgation of drinking-water standards • putti ng duti es on th e general public not to contamin ate drinkin g-wa te r suppl ies • r equ irin g drinkin g-wa ter su pplie rs to intrnducc and impl em ent public hea lth ris k manage me nt plans • provide fo r offi cers designate d by the Ministry to ac t as assessors to ve rify: - comp liance with the Standards - the standard and impl em entati on o f publi c health risk managem ent pl ans - th e competence o f w ate r suppl y staff c a rrying out process and fi eld analyses • r e quiring designated assessors to have

BOOK REVIEWS Water Supply 5th edition Compiled by Twort, Ratnayaka & Brandt. IWA P11blishing. 2000. ISBN 0- 34072018-2 RRP $185. 00 (GST i11cl11sive). Enquiries by tel (02) 9413 1288 or available f rom AWA Bookshop on bookshop@ a.wa.asn.au Th.is new edition of a well-respected title provides a compre hensive and thorough overview of water supply and water engineering aimed at professional engineers, university students, and consultants. U suall y, the maj o rity of teclmical in formation available in Austral ia tends to fo llow American practice principally because of the similari ties betv,een distan ces covere d, geo logical variability, populations serviced per utility and the range of climates expe rienced here and in USA. H ence this reader was esp ec ia ll y interested to see how th e contributing authors handled the issu e of water qualj ty sta ndards as apply in Britain and many Europea n cou ntri es. Not unexpectedly the authors strongly suppo rte d t he notion of standards versus gu ideEn es fo r ma intaining w ater quality and safety through th e distributio n sys tem m ea ni ng that t h e e mphasis te nds to be a bit presc riptive . The wea kest part o f th e book is th e sec tio n dealin g with microbiological contam inants - chat on viruses and coliforms is very disappointing because there is much ne w material that could have been included. While p rotozoa arc mentioned again, mo re rece nt data and experie nce in their managem ent in water su pply is lacking . These minor issues apart, the book is a n exce llent re fere nce fo r t he e nginee r and w ater su pply ope rator: an d it is re asonably priced for a hard cover. Flow kinetics, distribution systems and design issues are all covered in cluding qu ite a bit of detail on piping and valves u nder vario us conditions There is quite a large section deaEng with dam s, reservo irs and sto rage systems.

Water Law by Professor D.E. Fisher ISBN 0-455-21 726- 2 . RRP $120. Published by LBC Itifortnation Services. Available from A WA bookshop@ awa .asn.a11 or by fax to (02) 9413 1047 T his is a practi cal as welJ as a use ful guide to th e logic and mi nd-set of those c harged with the duties o f w riting the legislation governing the quality of our water and ou r associa ted responsibili ti es including rights to access and use water. W hile some people may blanch at a legal topic and expect it to be dry, Professor Fisher surprises us. To begin, h e takes an historical focus w ith Govern or Philli p's problems and the early settlem ent of Sydney. Chapter 2 rapidly moves to the modem age and an international perspective. Ini tially this appea rs a somewhat puzzling move, given that Australia is an island co ntine nt. The reader might expect Australian wa ter laws to have evolved from early history and to be somewhat inde pendent of the concerns of oth er co un tries which might wish to share or claim j miscliction. However, the international perspective provides the global an d resources based framework on w hich current Australian water law is developed. Profess or Fisher shows how the most recent Australian legislation attempts to merge existing state laws and provide a consistent and updated statement, but also one encompassing philosophical ideals and goals. T he result is a w ell researched book o ffering the first comprehensive outline ofstate and commonwealth legislation. While individual laws are not detailed and e;,rplained in depth , they are placed in the overall context and historical evolution of a natio nal set of laws governin g water in Australia. An excellent addition to the reference bookshelf.

Dr Diane Wiesner, Snr Scientist, A WA Federal Office.

WATER NOVEMBER/ DECEMBER 2000

39


WATER

21st Century" The Second Annual A IC Water 11...eso urces Annual Conferen ce. Auckland. NZ, July 1993. 4. Ministry of H ealth New Z ealand, Dri11ki11g-

the ir competence accredited by an internation ally recognise d co nformanc e accreditation agency • providing for appropriate reco rd keeping and publication of inform ation about the compl iance o f the supply with the Act. Once the public health risk managemen t plans are operational th e criteria used for public health grading of drinkin g- water supplies wi ll b e revised to take advantage of the new opportunities fo r performance assessment that the plans wiU provide. In conj u nction with the information processing capabiliti es of W I NZ, this will enable annual or quarterly review of the pu bli c health grades to be carried out for each supply. The plan ned reorgan isation of the pub lic h ealth managem ent of drinking-water in New Zealand will th en have been completed.

Water Sta11dards for Ne111 Zeala11d 1995 November 1995 Wel li ngton New Zealand. 5. Departm ent of H ealth N ew Zealand, War er Supply Cmdi11g Explm1arory Notes March 1993 W ellington New Zealand. 6. Ministry of H ealth New Zealand, Register ,J( Co11111u111iry Dri11ki11.~- vVater Supplies i11 Ne111 Zea /a11d !annual! latest e diti o n , 2000 W ellington N ew Z ealand. 7. Ministry of H ealth New Z ealand, A 111nial

Report 011 the Microbiological Quality of Drinki11gWat er Snpplies i11 Ne111 Zeala11d I 999 Iannual I latest edition, 2000 W ellington N ew Zealand. 8 . Minist ry of H ealth New Zealand, G uidelines for Drinki11g-Water Q11alir y Managen1mt i11 Ne111 Zeala11d Dccembe r 1995 Wellington N ew Z ealand. 9. Ministry of Agriculture and Forestry, Ministry for the Environment and Ministry of Health , New Z ealand, Fresln,,ater Microbiolo.~ical Research Progra111111e Project Dc•sig11 Ma111ral /i11

prep/.

References

I 0. American Public Healt h Associatio n Standard

Methods for rhe Exm11inatio11 cl{ Water mid Wastewater. 20th Edition , 1998.

·1. Taylor , M . E.U. , "r~cview of t h e Management of Drink in g Wa ter Quality in N ew Zealand" NZ Water and Wastes Association Annual Conference, September 1993. 2. New Zealand Water and Wast es Associat ion N e wsletter, 20, 24th Se ptember 1989. 3 . Taylor, M.E.U. , " Drinking-Wat er for the

11. Finlay, RI<, M illar,JA & Whyte, l\j. ( 1995). Deterrio11 of'toral colifor111s a11d Eschcrir/,ia coli i11

~r

drinki11,Q-l/Jalers: co111pariso11 a .,ta11dard 11111/tiple 111befem1mrario11 111cthod wir/1 Coli /err® t111d Colis11re®. ESR contract report t o Ministry of H ealth FW95/ 20.

12. Whyte, l\j. ( I 996). Protocol fo r drinkingwater mo nitoring programmes based on rapid rest systems such as Colilert?/Colisure'. ERS co ntra ct report to Ministr y of H ealth FW95 / 28. 13 . T illett, H .O.. C oleman , 11.... , Estimated numbers of bacteria from non- homogeneous bodies of water,Jo11r11al <)'Applied Baaeriolo,~y, 59 381-388, 1985 . 14 M cBride, G .B. Exact MPN tables 11Si11,~

om1pm1ry rheory /pers . co,11111/. I 5. M cl3ride, G.B., and Ellis, J.C. Co1ifidC11ce of ro111plim1re: A Ba)wsia,1 approach for perce11tile starisrics. Wat er R esearch (submitted 2000). 16. M cBride, G.13. Q11a11tifyin,Q rnns11111er's aud

s11pplier's risks.for assessi11g co111p/imice with a 95 perm 1tile dri11ki11,Q-water standard. Contract report to t he M inist ry of H ealt h Wellington, N ew Zealand, April 2000. 17 . Ministry of H ealth h1itiari1Jes ro l111pro1Je the Qnality of Dri11ki11g-Warer i11 Ne111 Zeala11d, Discussion Paper for Local Gove rnme nt New Zealand, Wellington, New Zeala nd, 2 May 2000 .

Author Dr. Michael Taylor is the Contracted Senior Adviser, Environment, Ministry of Health, N ew Zeala nd . Dr Taylor was awarded th e New Zealand Water and Wastes Association Medal in September 2000. H e addressed the A WA "Total Coli fo rms Debate" in Melbourne in May, 2000, giving an overview of dri nkingwater management in New Z eala nd, and was invited to su m marise his talk for publication 1 11 vll ater. Email Mi chael_T aylor@ moh.govt.nz.

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Published by the Department of Human Services, Victoria. 104 pages, A4. ISBN 073 110 703. Freefrom Stephen Ma eb11s, 03 96167777. This handbook p rovides information and gui delines for the operation of p ublic swimming pools. It has been developed by a committee chaired by th e Vi c tori an Aquatic In dustry Council, and is based on the Pool Water Guide 1995. It lists the current Acts, Regulations and other legislative requirements, then deals with hygiene, water treatment, monitoring, physical management of the water, including filtration and heating and ventilation systems, and a brief chapter on maintenance and winterisation. The handbook is clearly written, well-illustrated and has a bibliography for more detailed information, a glo ssary and index. EA (Bob) Srvinton


WASTEWATER

EFFLUENT REUSE BY CROPS IN QUEENSLAND T Gardner and H Gibson Qu eensland produces of o ver 340,000 ML of treated sewage effiuenr each year and about 11 % (38,000M L) of this is recycled , largel y for irriga tion pu rposes (about 75%) . Whi lst t hi s recyc ling percen tage is sm all, it is co mparable to o r exceeds the reuse percentages for o ther Australian states. The primary irrigatio n users are golf courses, spo rting fields, and parks and gardens w ith abo u t 15% used for agricu lture . Of the 5,700 ML/year (ie 15%) used in agriculture, the maj o rity use is o n pastu re sys te ms with about 2,300 ML year used for vineyards, orc hards and processed crop s, in cluding sugar ca ne . Sugar ca ne irrigation is the major agri c ultu re use r with th e best known sch e m e being H ervey Ba y where 7 farmers share 1,600 ML/year irrigating 400 ha of sugar can e. Th e total cos t of the sc h e m e was S5.5M , w ith cost sharing largel y between the local , state and co mmonwealth governments. The Maryborough City Council , in partn ership w ith the Maryboro ug h Sugar Co mpany and local ca negrowers arc abo u t to co m missio n a 14 farme r, 2 ,900 ML/year scheme irrigating 740 ha of sugar can e w ith an average expected yield in c re ase of 40 tonnes sugar cane/ hectare . Total o ff fa rm cost of th e sc heme is S6 M , with the maj ority of th is funded by th e lo ca l and state governm ents. A m o re informal re use sc h e me ope rates in the Burdc kin R ive r Irrigatio n Area where about 900 ML/year of effi ue nt from th e town s of Ayr and Home H ill is fu rrow irrigated on to sugar can e. By far th e larges t and most thoro ug hly investigated scheme is the Gold Coast C ity Council's N orthern W aste W ater Strategy where initiall y 2,900 ML/year will be irriga ted o n 600 ha of suga r can e in the R oc ky Point M ill area between Southport and Bee n leigh. With popu lation growth in th e area, plu s piping tertiary treated eillu e nt from th e so uth ern sew age treatm en t plants, th e re are plans co irrigate almost 4 ,000 ha o f ca ne by 2020. The current sc he me has the added interest of suppl ying 4M/day of tertiary trea ted

eilluent for cooling water at the 30MWatt cogene ratio n (gree n power) sugar m ill at R o cky Po int. The potential for suga r ca ne irrigation in Qu ee nsland is su bsta ntia l, as 60,000 M L/yea r of e illu cn t available fro m suga r towns cou ld be transform e d into abou t 720,000 tonnes of sugar cane, worth about S28M pe r year. T he eco nomics of transpare ntly partition ing the costs and bene6ts of th ese sc hemes has been assisted by the recent release o f the SUGA R. C OST spreadsheet model (Ga rdner et nl 2000) . H ealth issues are always paramount with irrigating food crops, and sugar has so me special advantages beca use of its h ighl y processed nature involving periods of high (>60°C) tempe rature treatment. Moreover the large wet weathe r sto rages required to even out irrigation supply and d e mand in the Quee nsla nd climate pro vides a substan ti al opportunity for natu ral disinfection processes to take place. This will be important from a public hea lth viewpoint, as the seco ndary treated effl uent leav ing t h e m ajority o f Qu eensland coasta l sewage trea tm en t plants fail many of the microbiological guidelines fo r above gro u nd irrigation (Thom as el nl 2000) . One of the m ore visionary sc hem es undergoing de tailed feasi bility studies is pumping Brisban e and Ipswich's sewage e illu ent west to the Lockyer Vall ey fo r use as vegetable crop irrigation . Potential vol um es range from 20 ,0 00 ML to 70,000ML per year, with an o peration & mainten ance cost of about s ·150/ ML reflec ting the high treatment level, and the

larg e pumpi n g d is tan ces (80 km ) and st ati c head s involved (200111). A variation of th e scheme involves lifting the eill uent another 400111 and using it for (primarily) non-food crop irrigation on th e Da rli ng Downs, a further 40km west of the Lockyer (the Darli ng Downs Vision 2000 sch eme). Substantial private fund ing is a major co mponent of both sche mes, but th e Lord M ayor of B risba ne has expressed h is c ity 's in - prin cip le fi nancial support for either schem e, subj ect to certai n conditions. (R ene we d Water Sem inar 1999). There is an e merging view i n Queensland that if we are to re-establish the once strong nexus between urban and rural commu nities, th en recoupLing t he consu mption of natural resources with the recycli ng of wastes for beneficial p urposes is an eminently sensible step towards achieving sustai nable commu nities.

References E.A. Gardner, L. E. 13rennan, S.N . Lisson and A.M. Vieritz (2000) "Effiuent irrigation of sugar cane - w ho pays, who gains'" W ater 27 (3) 46-51. Renewed Water fo r Agricultu re - Proceedings ofa seminar. Gatton 21 Oct 1999. C D- R O M from Lockyer Ca tchm ent Centre (07) 5465 4400. R.J . Thomas, E.A. Gardner, G .A. Barry, H.N. C hinivasagam , P.E. Green, A.V. Klieve, P.J. 13bckall. G.W. Bl ight and B.J . Bl aney (2000) . " Indicator orga nism levels in effiuent from Queensland coastal STPS" vVnter 27 (2) 38-45.

Authors Ted Gardner is a Principal Scientist with the Qu eensland D epartme nt of Natural R eso urces at lndooroop illy, Brisbane. Email: ga rdnet@dn r. qld .gov .au Howa rd Gibson is an executive e ngin eer with the Queensland D epartment of Natural Reso u rces, Brisbane and is Direc tor of th e Q u e e nsla n d Waste Wat e r R ecyc li n g Strategy. Email: H oward.G ibson@ dn r.qld.gov.au

• T his article rmfo rt11nn tely missed the re-11se Jent1-1re in the September issue.

WATER NOVEMBER/ DECEMBER 2000

41


Ill

ENVIRONMENT

Abstract South-east Queensland's coastal regio ns and waterways, including M o reton Bay, represent unique and compl ex ecosystems that supp o rt healthy po pulatio ns of dugongs an d turtl es, migratory wading birds and 111ajor recreational and co111mercial fisheries . The agricu ltural districts of the regio n co ntribute significantly to the loca l and regional econom y and in turn arc heavily reliant on the availability of good quality water suppli es and the protection of productive soils to maintain econo 111ically viable yields. Projected popu latio n in creases in south-east Qu eensland have the potential to seriously impact on th e ecologica l and econo111ic health of the regions w aterways and land catchm ents. In response to th ese threats, govern m e nc, indu st ry and community stakeholders are currently working in close coopera tion to develop a regional wa ter quality 111anagem ent strategy to protect and en hance the social, econ omi c and en vironmental valu es of the region . Th e

reviewed ava ilable information and delivered a m o del fo r Strategy deve lo pme nt. Stage 2 ( 1996 to 1998) focused on urban areas in the lower catc hm ent, marin e and estuarin e areas of the M oreton region and was developed by six local co un ci ls, the Qu eensland E nvironm ental P rotectio n Agency (E PA) and other State agencies, industry and comm un ity. Stage 3 (1999 to 2001) of the Strategy is foc ussin g on the freshwate r catch m ent areas of the Moreton region and incorporates the north (Noosa, Maroochy and Mooloolah catch111ents) and south (Logan , Albert and Gold Coast catchm ent) sub-regions.

South East Queeusla11d R egional Water Quality Mauage111e11t Strategy (the Strategy), form s part of the South East Queensland R eg i on al Frame¡work fo r Growth Manage111en t 1998 (RFGM). Under the RFGM , the Environme ntal P ro tection Agency (E PA) and lo cal governments in south -east Queensland have j oint responsibility fo r the development and i111ple111entati on of a regional water quality ma nagement strategy . Stage 1 ( 1993 to 1995) of the Scr:itegy

42

Figure 1. Geographical scope based on sub-catchments of the South East Queensland Regional Water Quality Strategy.

WATER NOVEMBER/ DECEMBER 2000

This collabo rati ve approach has been a key characte ristic of Strategy develop111e nt to dace. Based on strong local political leadership and ad vocacy, it has allowed the development of an effective , "whole of community" o rga nisation al approac h to preparation of an action plan to protect and en hance water qu ality and ecological/ eco n om ic sustai nability in the region .

Introduction Th e South East Q11ernsla11d Rc,Qioual Water Quality Ma11a,ec111c11t Srmte,~y, (the Strategy), is a joint federa l, state, local go vernm e nt and co mmunity initiati ve cove rin g t he south -east Queensland region , in cludin g coastal wa ters, estu aries an d freshwater streams from Noosa to the Gold Coast and west to the Great Dividing R ange. The Strategy cove rs 15 major catc hm ents w it h a combined catc hm e n t area of approx im a t e ly 22,352 km 2 and includes 19 local govern111ent areas . The Strategy is a technica l handbook providing a framewo rk fo r managing wate r qua li ty in south - east Q uee nsland designed for use by govern m ent and council o ffi cers, industry, catchment, landcare gro ups and interested commu ni ty groups and in d ividuals. It allows th ese groups to develop a "bluep1in t" for water quality management in th eir own area, w ith a view to improvin g and conservi ng ecological hea lth t hroughout the w hole regi on. The Strategy forms part of an on -go m g program of:


ENVIRONMENT

M o r eton Ba y a nd other wate rways and ca tch m e nts in so uthe a s t Que e n s l and. N utrients (particularly nitrog e n ) f i ne sed im en ts and, to a lesser extent, toxicants (pesticides and heavy m e taJs) had previously be e n id e ntifie d as • Old Fruit & Y•g. • Brl1ba,e C1ty causes of significa nt . UOIA • D1lry lrKfuctry c.tchmcnts recommended . EalrKt. hi du.try • C1Nlcmon'1AJGA • Pumko&lono / CRICM bf,'BAMG , OCf"O • GralnQl"OWlt'1 • Pine Al~• Cetchmene e nvironmental lndltonous • A\'fWA • CU»IJl' OIIIIWC • BfOrror Cachmonl Rckttncc , Food loch. Accn • lrrl9a1orc • Lockyw Catchmenl probl em s. Grwp ·Al ? • Pr.1'Wn f arm.r, •Vppor Brfsb.Jno/Klleoy • QCCt • Pork Producora · Logan/Nerang Pr i or to t h e • Chkkcn Produc:eri • Gold Con t • OFF • Ma-oochy/MoolOcl.lh Strategy, water q uali ty • No°'a manage m e nt in th is Figure 2 . Arrangements to deli ve r t he South East region co nsisted of: Queensl and Regional Wate r Qu ality Management Strategy • various m easu res 111 by 2001 state and lo cal govern• u nderstanding the waterways and catchm ent regu lation s, pol icies, prac t ices, m e nts; and catch m e nt managem ent p la ns • deve lo pme nt of spec ifi c mana ge ment • c ity and shire develop111e nt p lans; and ac t ions with agreed fu nding and ti111elines • co m mun ity action and political and to address water quality main te na nce and socia l comm itments eco logica l health needs. While these were positive measures in Its aim is to provide a coordi11ated process improvi ng water q ua lity, t hey ge ne ra ll y for t he develo pme nt of m anagem en t te nded to be uncoord inated and often actions to deal w ith water qua lity (includlacked scientifi c information o n w hich to in g habitat, wild life and ecological hea lth) make fu t ure manage m e nt d ec isions. im pacts fro m acti viti es and point and non The refo re, developm ent of a coord in ated point pollu t io n so urces in th e regio n. strategy became a priority in o rder to protect an d en hance t he social, econ o m ic Ba ckground and environmental va lues of the area. The maj o r drivers for improved w ater In response to these pressures, governq u a lit y m a nage m e nt in so u th -east m e n t , i ndustry and co m m u n i t y Q u eens land are: stakeho lders are currently working in close • d ecl ining water quality and ecosyste m coope ration to develop a R egio nal Water hea lth in fr es h and tid al wate rways, Q u ality M a nageme nt Strat egy. Th e esp ec ially M o reton Bay (loss o f dugong Strategy is a combinatio n of con tinu ing and seagrass, in creased alga l bl ooms, lo cal initiati ves and ne w m anagement threats to fisheries) actions dete r111i ned by stakeho lders based • i ncrea sing co mm u n ity exp ec tatio ns on good sc ientifi c information. about improving waterway quality, access an d uses The Vision

.•.

• lack of sec ure water supply (quality and q uantity) for agri cultural pro d uc tion , ind ustry and urban growth; and • pote ntial and ac tua l loss of industry via b ility for touri s111, fishi ng and agricu lture South east Qu eensland's natura l systems have undergone profound m o difi cat io ns si n ce Europea n settl em ent, parti cularly in areas of intense human /eco nom ic activity . T he river estuaries are now highly turbid and the lower B risbane River docs no t curre ntly m eet nationa l standards for pr i ma ry contact activities such as sw imming. In the early 1990s it becam e apparent t hat projec ted population increases ove r the next 30 years had th e pote ntia l to se i·io usly impact on th e e nvironme nt of

An importa nt aspect o f the Strategy has been the develop ment a nd agreement by all stake holde rs, at an early stage in the process, of a singl e, clear cohe rent visio n for the futu re health of th e region's waterways. Th is common vision has been referred back to man y times during deve lopm ent of the Strategy to assist reso lution of issues re lating to the identificati o n, prioti tisation and scoping of technical investigatio ns and the develo pment of agreement of managem ent actions. T he vision is: S011//,-east Q11ee11sla1//l's rntc/1111e11ts a11d l/)fl/er111ays will, by 2020, be l,ea/tl,y livi11g emsyste111s s11pporti11g tl,e live/i/,oods a11d l[festyles people ill s011//,-east Q11eeusla11d m,d 111il/ be 111a11aged 1/mmg/1 collabomtio11 be/l/)ee11

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WATER NOVEMBER/ DECEMBER 20 00

43


ENVIRONMENT

as content (issu es, fac tual scientific in formation and actio ns) . A staged approach also implies time and patience is given in the Strategy development process. The in tegrated app roa ch has blurred the boundari es be tween acti vities and tasks, rat her than b ecoming isolated from each other, each activity has info rmed the other resu lting in co nstant ite ration s and exc hanges of info rmati on at all levels.

Funding

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The vision is outcome based. H ow the outco me is achieved is th rough numerou s exist in g n etwo rk s of l oca l , sub-catchment and regional initiatives . For example, ach ieving th e vision w ill no t only be successful where groups and individual s are w orking cooperati vely toge the r but also across in tegrated levels of activity: • Lo cal level - prope rty management planning, landcare , waterwatch, individual acti ons • Sub-ca tc h m e n t level - catc hm e nt ma nagement plans, partne rships • R egions - strategies, plans, regulatio ns

able bi te sizes of issues and geography in a staged approach over tim e has facilitated earl y stake holder in volvement, coll ective learn ing about involvement process as well

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Development of the Strategy The Strategy is based on the National Water Quality Managem ent Strategy approach in that stakeholders across communi ty, industry and government determine: • Environm ental va lues to reflec t the Vision - co mmunity driven processes • Water quality obj ecti ves to protect valu es - initiall y science/ inform ation dri ve n processes • Tec hni cal feasibili ty, economic and soc ial impacts - consider cost and be nefit actio n/ inaction • Managem ent actions and priori ties to ac h ieve obj ectives - all participan ts working togeth e r towards consensus • M.ethods to monitor, review and adap t - evaluation of actions and reportin g of outco mes Staged and in tegrated approaches have bee n key factors in th e success of Strategy development to date. Addressing manage-

44

T he d evelopment o f the Strategy has been supported financiall y by all levels of government since inception . Stage 1 comme n ce d unde r a jo in t fundin g arrangement betwee n Brisban e C ity Coun cil and the EP A. Stage 2 was funded e qually by the federa l, state and local governments, under th e previous National Land care Partnerships Program. Th e local govern ment fu nding component was provided by the six initial parti c ipating coun cils o n a population basis. At the e nd of Stage 2 the proj ect came under the (then) new N atural H eritage Trust (NHT) Lan dcare Program . Total proj ect funding to th e end of Stage 2 was SS .25 mil lion . Stage 3 is fund e d through a range of

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sources. T h e core , o r "seed " fun d ing, is provided by the Federal N H T Ri vercare Prog ram (25%), a Seate m atching co mpone n t (35%) and local gove rnmen t (40%) . Aga in the coun cils shared fu ndin g o n a popu lation basis. This "seed " Fede ral NHT Rivercare fundin g has allo vve d develop111 en t of a m o re exte nsive and co mpre he nsive progra111 . Th is has bee n ac hieved th rough the addition o ffundi ng fr o m a ran ge o f o th e r sources, inc ludin g th e Fe de ral NHT C oast a nd Clea n Seas Program , state age ncy fundin g (predomin a ntly EPA) and coo rdinatio n with o n -going resea rch programs (e.g. So uth Ea st Q ueenslan d W ater corporatio n). R esearch fundin g o btain ed by th e Uni versity of Qu eensland and Griffith Un i ve rsity t h rou g h the Au s tral ian R esearch C oun cil Str,1 tegic Partne rships in R esearch and T echnology Program has al so been incorpo rated in to th e Strategy. Suppo rt fro m the C oo perati ve R esea rch Ce n tres fo r Coastal Zone, Estuary and W a terway Man age me nt and Catc hm ent H y drology and additiona l inputs fro111 a number o f th e counci ls has also providin g funds to co ver researc h gaps and o n - go in g m onitorin g. Total cash and in ki nd fundi ng fo r Stage 3 is approxim ately $20 milli on.

Stakeholder ownership

the Strategy. This was ac hieved th rough (refer Fig u re 2): • Man agem ent Commi ttee of elected offic ials fro m the spo nsoring council s and senior o ffi cers fro m the spo nso rin g State Go vernme nt departme nts • T ec hnical Ad visory G ro up of tec hn ica l offi cers fro m State Governm e nt departments and local governm ents; and • Ind ustry and Co m munity Advisory Group of non-govern m ent representatives ft-0 111 ind ustry, fishin g, co nserva tion and indi genous gro ups Co nsultation w ith the wider co m111unity was also undertaken. In 1997 a Public Involvem ent Progra111 was established to provide th e ge ne ral publi c and spec ial interest gro ups w ith an o ppo rtun ity to contri bute to t he deve lo p111e nt o f th e Strategy. Con t ribu tio ns we re so ught thro ugh : • newspap e r adve rtise men ts • worksho ps w ith stakeho ld er groups • public m eetings and pub lic in fo rmatio n sessio ns O ngoin g co nt ributio ns fro111 t he ge ne ral pu blic and specia l inte rest stak eholde rs arc e ncouraged by:

• d iscussio ns and workshops w ith stakeho lde r groups • a series of public in fo rmatio n sessio ns th rougho m th e Strategy area , in conjuncti o n w it h c ou n c il s sp o n so rin g t he Strategy; and • rev iewin g respon ses to di sc uss io n pa pe rs, public m eeti ngs and info rm atio n sessio ns

Strengths of the Strategy T he maj or strengths o f th e Strategy are: • Loca l gove rnm en t lead e rsh ip an d advo cacy wo rkin g coo perati vely across t he regio n • Effec t i ve co llab o ra ti o n b e tw ee n go ve rn m ent, industry and com m unity in decision - m aking • Collabo rative and coordinated approach to th e scoping, gat he ring and co mm u nicating of sc ie ntific inform atio n • Providin g stake ho lde rs w ith informati o n as it co m es to hand • C on sid e ri n g soc ia l, c ul tu ra l a nd econom ic impacts of environ mental choices • Un ifie d H ea lth y W ate rw ays cam paig n • Integration w it h region al planning and statuto ry processes

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Th e Strategy is develo ped di rectly by stake holders. T his collabo rative app roach is a key characte ristic of the process. Based o n stro ng local political leadership and ad vocacy , it has all owed the deve lo pment of an effecti ve , "who le of co mm un ity" approach to deve lop111 ent and agreem ent of t h e 111anagem e nt actions co nta in ed in WATER NOVEMBER/ DECEM BER 2000

45


ENVIRONMENT

• W hole-of-comm un ity moni torin g & feedback

Major achievements to date Important achievements of the Strategy to date include: • a much better understandin g of ecosyste m processes and effects of po ll utants • new ecological health indicators, such as seagrass depth range, sediment nutrient fluxes, denitrification effi cien cy, an d phytoplankton productivity and abundance • en viron mental valu es, goals and water quality objectives defined for marine and estuarine waterways • sustainable point sou rce nitrogen loads determined for differe nt waterways•new tec hnology to track sewage • a framework for sewage management fo r the next 20 years; and • conti nuing determination of sustainable stormwater loads and a fram ework for stormwater management The most important Strategy results are "on- the-gro und " management actions that w ill achieve th e vision. Th ese managem e n t actio ns were develop ed directly by stakeho lders in response to consistent scientific inform ation . These actions were agreed by consensus through a "peer pressu re" / "peer support" process within the management structure outlined earlier, rath er than through a more traditional "co mm a n d-type" r egul a tory approach . Importantly, actions were agreed to be implemented in specified time periods and to agreed performance sta ndards. In additio n, stakeholders, gene ral public and sc hools have been informed of the Strntegy's current scientific findi ngs and m anageme n t actio ns through 2 uni que pub lications. The Cre111 Me11 1/Jer's Guide to t!tc Hcalt!t if 011r W aterways takes the sc ience to the people in an easy to understand, interesting a nd co lou rful format. It p rese nts informatio n to move people into action and enco urages readers to become part of the ' H ealth y Waterways' crew to help our waterways. The second publication and co mpan ion book to the Crew Guide is the Moreton Bay Study - Scieut[fic Basis for t!tc J-Jca/1/1y Warc,ways Ca111pa(rz11 . Th is book provides the highlights of the scientifi c data collected, in terpretation of results and the main fi ndings about water quality wi thin th e M oreton Bay catch men t. Both pub lications ha ve had n ota ble success and rema in for sale from va rious outlets in cluding the Strategy Office. A new C re111 Me111/Jer 1s Gu ide for the entire south east Queensland region is currentl y in developm en t and w ill include detai ls resu ltin g from Stage 3.

46

Key lessons In addition, a number of key lessons have been learnt thro ugh the project . T hese are summarised below: • la rge scale planning process can often take time, includin g an initial "gestation" period , during w hi ch few " tangibl e" results appear. This pe riod often involves ge tting the scope of the project right and building the co mmun ity in volvem ent processes necessary for later success (which ofte n then come with a rush). Patience during these early stages is important, as is grasping firml y consequent opportunities for delivery • it is n ecessa ry to develop an effective process fo r inter-agency interaction. ft is important to never give up on this issue • local political leadership ca n p la y a key role in obtaining and maintainin g support and fu nding and in dealing w ith the bu rea ucratic issues • the Federal Government can also play a key role in provid ing the "seed" fun ding and political / social " imprimatur" to get pa rties togethe r e.g. Natural H e ritage Trust o r other suc h funding so urces • it is crucial to get scientists, industry and

community re presentatives on decisionmaking committees where th ey can intera ct directly with politicians and state governm en t officers • the project must be "grou nded" within th e establis hed regional planning framework, ideally through a catc hm en t-based approach • a common vision must be developed early in the process to ma intain foc us and m omentum; and • th ere is no substitute for the deli very o f good information by scie ntists sp ea king effectively with "one vo ice" and the co mmunity confi den ce that resu lts from gettin g this process right

Conclusion The South East Queensland R egional Water Quality Management Strategy is an example of a successful regional planning process, in volvin g a broad stake holder base. The Strategy's success is due to: • effective collaborati on and cooperation between gove rnme n t, in du stry an d community • pr ov iding co nsiste n t info r m ation direc tly to stak e holde rs, includin g scientific findin gs, co mpute r nrndelling predi ctions, impacts and costs o f va rious

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m a nage me nt actions and impacts and costs of doing nothi ng • develop ing H e,1 lthy Wate rways as a u nified identity and vision that can be used by all stakeho ld ers; and • stakeho lders agreeing to own and im ple ment " on-th e-ground " managem ent actions to achieve th e vision

Acknowledgments

• Tech11ical Advisory Croup, i\ll rJi111 Fel/li11gs, E1111iro11111e11tal Proleclio11 Agency - Chair. • illd11stry and Co111111u11ily Adviso,11 Croup, Mr Joh n Bishop, Qld Far111ers Federalio11 represe11/alive • D enniso n, W & Abal , E . (1999) The More/011 Bay S1udy: A Scic11t[fic Basis fo r !he H ea lthy Wa/erways Campa(<!_ 11 • SEQR. WQMS (1999) Ecological Health J\llo11ilori11,'.! Pro,'.!m111 Newsletter • SE QR. WQM S ( 1999) Sou1h Eas l Queeuslaud /,Vater Qualit y Ma11a,f!_ e111e11/ Slra legy, Drafi • SEQR WQM S ( 1998) Th e C re," Me111ber's G uide to !he Heal//, 1![ Our vVaterways • SEQR WQMS ( 199 8) More/011 Bay C atclu11e111 J;Valcr Qualif y 1\lla11a,'.!e111en/ Slrategy

The Strategy (and th is paper) is the res ult of the work and co n tri bu tio ns of nu merous people - fa r too many to m e ntion by name . H owever, the auth ors wi sh to thank all the me m be rs of the foll owing groups: • South East Qu ce115laud R.egio11al Water Q11ali1y Ma11age111en/ Co11u11itlee, Cr J olu1 N 11,f!_e111, Mayor <!f lpsu1ich C ity Co 1111cil Cl,air • S tralegy J\l/a1,age111eu/ Tea111, !Vlr Barry • For furt/rer i1ifor111atio11. 011 t/re South Ball, Ma11ager Walerwa ys, Brisbm1e C ily Ea st Qu ee11-sla11.d R egiona l Water C ou11cil - Direc/or. Quality Ma11ageme11t Strategy, or to • 1Scie111[fic Ma11age111e111 Services, Pn!fessor order publications please co11ta ct the Paul C ree,!field, Depuly Vice- Cha11cellor, Strategy office 011 tel +61 7 3403 4206, R esearch, Uuilll'l"Sil y <!f Quce11sla11d - Chair fax +61 7 3403 6879,

BOOK REVIEW Water Technology A n Introd11ctio11 for Environme ntal Scientists and Eng ineers . NF Gray. B11tterivorth H eiiiema,rn publishers. ISBN 047 023632 9, 1999 edition A vailable from: AWA Bookshop, PO Box 388, A rtanno11 NSW1570. Email: booksl1op@ arva.as11.a11 or Jax (02) 9413 1047 RRP $89. 95 K ey concepts of hydrobiology, water & w astewater trea tm ent & supply are the fo cus of this concise text but with a slightly diffe ren t fo cus. Bes ides j ust pro viding an introduction to its targe t audience, this text looks at th e technologies in use or developm ent and their application. This means that the author is able to diverge fro m th e dty facts w hich provide the basic tools to n ew entran ts to the industry. B y way o f example: Of parti cular interest to this reader was the approach taken in two of the early chapters. First, the C hapter on MicroOrganisms and Poll ution Control. Rather than simply providin g basic biological info rmation on species fo und & used in wate r and wastewater treatm ent processes, Dr G ray looks at their bi ochemistty, their n utti ent requirement, metabolism and the yields. This approach has value beca use it is the poten tial of aerobic and anaerobic sp eci es to optimise wa te r & wastewater trea tment processes that th e operator needs to understand and capitalise on at the plant level not j ust simply know that the best substrate is "x" and that contaminant " y" i~ likel y ~low the rate of th rough-put. Seco nd, the C hapter on Water Quality Assessmellt whe re the author deals with the issue o f biological ind ices a useful and practical tool. Essentially, raw biological data exist as lists o f species (o r taxa) names and abundance. T his is difficult for non-biologists to inte rpre t in order to compare the water quality either between sites or at the sam e sites over tim e. One of the best ways to reduce or condense the bulk of m atelial co lJected from river surveys and represent it clea rly and concisely is to use a co mparati ve index. T he two types commo nly used are pollution indices and diversity indices. An informed and practical description of these indices is provided plus examples of their use in the field . Th ere is a lot more valu able info rmatio n i n t h is ve r y u seful bo o k. R ecommended, Dr Diane Wiesner, Snr Scientist, A WA Federal Office.

WATER NOVEMBER/ DECEM BER 2000

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B

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WATER ACCOUNT FOR AUSTRALIA: THE ANALYSIS OF WATER USAGE DATA C Jackson Abstract Water accounts record which industries take water from the environment and how much they use themselves, how m uc h is provided to (and used by) other industries and how much is reused o r returned to the e nvironment. The Australian Bureau of Statistics (ABS) developed the Water Acco1111t for A11strnlin, '1993-94 to 1996-97 (ABS, 2000) as part of its environmental accounting program. Environmental accounts provide a mec han ism to link together environm ental and economic information in a consistent framework. Du ring 1998 and 1999 the ABS collected and analysed data fron-1 a range of organisations on how much water was being supplied and used ac ross Australia for the 1993-94 to 199697 finan cial years . Gaps in the data existed and information from other ABS surveys were ut ilised to mode l and impute miss ing data. This paper describes the met hods used to estimate water usage by sector.

What is the Water Account? Water accounts record which industries ta ke water from the environment (surface and groundwater), how much th ey use themselves, how much is provided to (and used by) other industries and how m uch is reused o r returned to the environmen t. T he vf/11/cr AffOl/1/( _/<n A11stl'l1li11, 1993-94 lo 1996-97 (A BS, 2000) was recently published as part of the Australian Bureau of Statistics environme nta] accounti ng program. Work on physical e nvironmenta l acco unting has arisen from the desire to assess the sustainability of eco nomic activit ies and their interaction o n the depiction and degradation of natural resources. Environmen tal accounting provides an integrated information system to link environmenta l and reso u rce issues to economic data se ts such as Australia's National Accounts w hich can enable a broader assessment of the co nsequences of econ omic grow th , A major compon ent of the Water Account project was th e development o f

48

su pply and use tables for water. These tables will be d iscussed in detail.

Data Collection for the Supply and Use Tables The aim of the data collection activities for the supp ly and use tabl es was not to duplicate existing data collectio n activities but to tic together regional and state water resource data into a single system of the eco nomy w ide impact of water resource managem ent and usage across Australia. Traditionall y supply and use tables are compon en ts of an econom ic fram ework used widely in th e field of economics known as in put-o utput tabl es (A BS, 1997) . Th e water supply and use tabl es indicate the physical am ou nt of water suppli ed from the environment and w ater authorities for use by industry, households, gove rnment and the amount ava ilable for re turn flow to the environment. T he suppl y table illustrates w ho is supplying water fo r use and the use table shows w ho is using wate r (refer T able 1).

Collecting Supply and Use Data in Australia The sup ply and use tab les presented in

l,Vater A cco1111f fo r A11stmli11, 1993-94 to '/996-97 (ABS, 2000) inte grated ad hoc admi n istrative data from a range of sources. T he project aim ed to measure all water supply and usage of surface and g roundwater in Austral ia. Th e following water users were approached for informat ion:

• individuals and companies that extracted water for their own use (eg domestic, industrial, commercia l o r rural use); • w ate r providers w ho extracted and supplied water onto customers for use (eg domestic, industrial, commercia l, rural o r bulk use); • sewera ge t reatment plant ope rarors which treated water and released it from the sewage treatm ent plants back into the e n viro n ment (land, river o r ocean disposal) . T hese operators also provided a wate r re use service w hich e nabled som e of their treated wa ter to be m ade available for reuse by som e of t heir custom ers ; • other large organisations which treated water and m ade it ava ilable for subsequent re use. • other large organisat i ons whi c h discharged water direc tl y to the envi ron ment. (eg power sta tions, min es) ; and • major in -stream water users, for example aquaculture, h ydro-electri city generatio n , w here this information was available. The type of data requested in order to determine wate r su ppl y and usage included: • water intake (so urce and volume); • distribution of supp ly to various use rs (vo lum e and type of use and details of major water consumers); • ave rage an n ual domestic usage; • losses from the supply syste m (whi c h often was not separate ly available); • treated and untreated eilluent discharges (volume and locatio n); and • volume of treated eilluent transferred to

Table 1 . Basic structure for the supply or use tables Category!•) Megalitres (ML)

Supply from/ Use by

Self-extracted

M ains water

Effluent reuse Regulated discharge

Environment lndustry<bl Households Total supply/use (a) Definitions for each category vary depending on whether the table is illustrating use or supply. (b) In ABS (2000) industry was split into 37 categories.

WATER NOVEMBER/DECEMBER 2000


BUSINESS

oth er users fo r re use (volum e and type of use). In Australia a large compo nent of water is self-extracted pri va te ly by o rganisati o ns and individuals no t co vered by regulato ry water amhoriti es. This information was co llec ted fro m state governme nt li censing informatio n or directl y from large water using industries w hich self-extracted th e ir own water supply from surface water o r groundwater sources.

Analysing the Collected Data Th e data were aggregated to a State level fo r co nfidentiality reasons. Wate r suppliers and users were defined and classifie d to the 1993 Australian and N ew Zealand Standard Industrial C lassifi cation (ANZS IC) . Supply data was well known , espec ially w h e n this inform ation w as co llected fro m the wate r supply industry. The usage of wa ter w as no t so w e ll un de rstood, esp ec ially in regions where m eterin g did no t occ ur. To ensure consisten cy and coverage of all wa ter u se d a nd suppli e d ac ross A u st ralia , a numbe r of es tim at io n tec hniqu es we re used to fill in the gaps fo r missin g data. In the abse nce of de tailed wate r use data fo r so m e sec tors o f the eco no m y, w ater usage coeffic ien ts we re develop ed. Th ese w ere based o n avai labl e w ater usage and suppl y data and linked w ith popul atio n, e mplo ym e nt, turno ve r o r produ ction sta tistics. Water supply W a t e r su pp l y informati o n w as re quested from approximately -WO compani es and g o ve rnm e nt orga nisa tion s involved in water suppl y and usage . Survey forms were no t rece ived from all , howeve r th e maj o ri ty of supply and use we re cove red in the responses that were received. For example in Qu eensland 85 o ut of a total of 125 loca l govern m e nts responded to the survey; th e mi ssin g co mpon ent represen te d o nl y 2% of the Q u eensland po pulatio n . Miss in g suppl y da ca was es timate d using a ML/ person coefficient that w as based o n know n w ater use fo r simil ar local government areas and population statisti cs within t he same State . Water use

Th e coll ected water usage in fo rm ation included total water usage, as well as usage foi¡ agricultural, mining and dom estic purposes and for each of the major wate r consum ers. Wate r consumption by som e 6,300 businesses was known and t hese w e re used as a basis fo r developing case

st udies of co mm e rcial and ind ustrial water usage. Th e re m aining vol um e fo r w hi ch water usage was unkn own w as c at ego r ised as ' una ss ign e d ' . T h e ' unassigned ' ca tegory incl ud ed wa ter used in the industrial and co mmercial secto rs. T abl e 2 sum mari es th e meth ods used to calculate mi ssing water usage for

alJ sectors (at t he 4-digit ANZS IC level). For employment coefftciellls, ABS labo u r fo rce num bers were multiplied by the ML/e mployee coeffic ien t to estimate the water used for a parti cular industry. Th e M L/S turnover coe ffici e nts were mu ltiplied by industry tu rnover in eac h

Table 2 . Methods used t o derive water usage by industry sector Sector

Method

Agricu lture<â&#x20AC;˘l

The s upply of water was known. Hectare area coefficients were based on the ABS Agricultural Census 1996 97 and irrigation data were derived to apportion water usage by crop type.

Services to agriculture; hu nting and trapping, forestry and fishing

ML/employed persons

Coal mining, Oil and gas extraction, Metal ore mining, Min ing n.e.c.

ML/unit of production for each mineral commodity.

Construction material mining, Services to mining

ML/ employed persons

Manufacturing!bl

ML/$ turnover

Wood & paper product mfg, Petroleum & chemical products mfg, Non-metallic mineral product mfg.<cJ

ML/employed persons

Mi scellaneous Manufacturing<dl

ML/ $ turnover

Construction<el

ML/ employed persons

Electricity and gas, water supply; sewerage and drainage services coefficient.

Majority of the water use was known and the rest was imputed using a ML/employed person

Finance; property and business services, Government adm inistration<1l ML/ employed persons Wholesale and retail trade Accommodation, cafes and restaurant s; Transport and storage, Education, Health & community services ; Cultural. recreational & personal services Zoological & botanical gardens, Recreational parks & gardens<gJ

ML/employed persons ML/ hectare

Horse and dog racing, Sports grounds & facilities n.e.c.

In WA the proportion of water used for sporting activities had been estimated. The same rate was used in the rest of Australia (approx 1.58% of total consumption).

Household

Average domestic usage coefficients in the State were used to derive ML/ person coefficients.

(a) Water consumption of rice and cotton were known. The percentages of 'area sown ' (from the ABS Agricultural Census) for pastures; vegetables ; fruit; and grapevines were compared with the percentage irrigated data from NSW lrrigators ¡ Council (1998). In South Australia a different method was used based on total irrigation water in Thomson (1997). The ratio of water consumption by various crops was then applied to the known total water usage in the re ference. (b) Developed for 143 ANZSIC groups. (c) Used for manufacturing sectors with insufficient information available to lin k water usage with turnover data or where an industry was dominated by a few large establishments. Used for 18 ANZSIC groups. (d) Coefficient based on all the available data in the manufacturing sector. (e) Many contractors work in the construction industry and a surrogate measure of employed persons was used based on ABS Construction Industry Survey data (= persons employed x average employment). (f) Excludes property developers (e.g. shopping centre owners) to avoid double counting. Includes Defence which could have a higher water usage per employee due to the variable nature of their activities (hospitals, offices, housing, airports etc. ). (g) Based on the ABS survey of the zoos, parks and gardens industry. n.e.c not elsewhere classified

WATER NOVEMBER/ DECEMBER 2000

49


BUSINESS

state . The coefficients were refin ed after the rem ova l of outliers (those businesses with very high water consumption). T he rati onale behind th is was tha t major water consumers data had been coll ec ted and these were not representative of the industty across Australia. Coefficients calculated fo r one year were applied to all four refere nce years of the study. W he n estimated water usage was derived for each industry, it was compared ·with the actual consumption data obtained fro m water providers. Once water use was determined fo r all industries, a proportion o f the 'unassign ed' water was allocated accordingly, based on known water use and the industry profile of the releva nt State/ Territory.

Table 3. Net water consumption Australia, 1996-97 (ABS, 2000) Net Water Use 1996-97

Sector<•>

Gigalitres Livestock, pasture, grains and other agriculture

635 1,236

Sugar

704

Fruit

649

Grapevines Cotton

1,841

Rice

1 ,643

Services to agriculture; hunting and trappi ng and Forestry and fishing

Th e majority of the reuse data was obtained from the water industry. Some ma nu facturing and nuning water reuse \Vas also known, however this was not comprehensive, as a number of manufacturers reuse water on-site and it would have been time-consuming to collect such data. M ost of the reuse data co llected included custom er usage information on who was re u sing treated effl u e nt. However, some respondents only gave total amo unt of water w hich was reu sed. This was ca tegorised as 'unassigned' reuse w hi ch included water suppli ed from th e sewerage sector of the industry and o ften used for irrigation . Informati on from the 1996-97 Agricultural Census was used co determine w hat typ e of crops the reuse wa ter was used o n. Some responde nts vvere unable to quantify the volum e of treated effluent reused. T here was no sec pattern for utilising eilluenc re use and it was dec ided not co impute reuse for chose responde nts unable co provide a volum e of eillue nc supplied for reuse. R euse ma,y occur on a more extensive basis wiclu n the manufactu ri ng and mining sector than has been

$/ML

2000

1500

1000

570

Food, beverage and tobacco manufacturing

137 76

Textile , clothing, footwear and leather manufacturing Wood and paper product manufacturing, printing and publishing

182 65

Metal product manufacturing Electricity and gas

1,308 1,707

Sugarcane for crushing I ncludes livestock, grains (except for rice) and 01her agriculture.

Collon lint (includes value of couon seed).

522

Other business services

1,829

Household Totai!bl

22,186

(a) Greater level of detail for manufacturing and business services available in ABS (2000). (b) Discrepancy between total and components due to rounding.

quantified in th e Water Acco1111tfor Australia (ABS, 2000). le wou ld be necessary co survey th e w hole manufacturing and mining industry to obta in a clearer picture. The constant recirculation of water within a busi ness was not quantifi ed. Regulated discharge

The volume of water discharged from sewage treatment plants (STPs) was no t pro vided by all respo nde nts. A STP disc harge coe ffi cient was derived on a ML/ person basis by co mparing discharge and population data for similar areas within the same State. T he usage of water by the aquacu lture industry and the hyd ro-e lectri c power gene ration secto r was assumed to occur ·100% inscream and was acco unted fo r as a sup pl y and discha rge by the same industry .

Fruit Grapevines Pastures(b) Cotton(c) Rice Industry

(a)

49

Water supply; sewerage and drainage services

Results

(c)

197

Machinery, equ ipment & miscellaneous manufacturing

0

(b)

24

Non-metallic mineral products

500

Figure 1.. Gross value per ML water used, Agricu lture 1996-97.

50

19

Mining

Petroleum, coal, chemical and associated product manufacturing

Effluent reuse

Vegetables Sugar(a)

8,795

Vegetables

WATER NOVEMBER/DECEMBER 2000

On ce the suppl y and use tables were developed, net wate r use tables and linkages to socio-econonuc in fo rmation were develo ped. T able 3 and Fi gure

1 are some examples of the information de ri ved. More de tail informa tion is available in ABS (2000) .

References ABS 1997, A11s1ralia11 N ario11al Acro1111ts: /11p11r0,11p111 Table.i, Cat. No. 5209.0, Australian 13ureau of Statistics. Canberra. ABS 2000, Waler Amn111t Ji,,. A11srralia 1993-94 w 1996-97, Cat. No . 46 10 .0 Australian 13meau of Statistics, Canberra. NSW lrrigators· Council 1998, lrr(eatio11-.f<wd mrd .film' .f<n· a semre, wri11,e a11d s11sMi11able 11,or/d, NSW lrrigators' Cou ncil , Sydney. Thomson. Tony 1997, /rr(eario11 i11 S0111/J A11S1ralia, Primary Industries and R.esources South Australia, Lenswood.

Author Christina Jackson gain ed her H ono urs degree in geography from th e Uni versi ty of Tasm ania, and worked for the N SW Departm ent of Agriculture and Environment Australia before her appointmen t as Senio r R esea rc h Statistician , Environmen t and Energy Section, in th e Australian Bureau of Statistics, PO Box 10, Delco nnen ACT 2616 . Pho n e: (02) 6252 7876. Fax: (02) 6252 5335 . Email: c hriscina.jackso n @ abs.gov.au

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Water Journal November - December 2000  

Water Journal November - December 2000