Australian Guidelines for Urban Stormwater Management

Natinal Watr Quality Managmnt Stratgy Australian Guidlins fr Urban Strmwatr Managmnt 2000 Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil

Cpis f this publicatin may b btaind frm: Australian Watr Assciatin PO Bx 388 ARTARMON NSW 2064 Tlphn (02) 9413 1288 Facsimil (02) 9413 1047 r: Cmmnwalth Gvrnmnt Auslnf bkshps in th Stats and Trritris r: AFFA Shpfrnt Edmund Bartn Building BARTON ACT 2601 Tlphn TOLL FREE 1800 020 157 r: ANZECC Scrtariat GPO Bx 787 CANBERRA ACT 2601 Tlphn (02) 62741428 Facsimil (02) 62741858 Fr furthr infrmatin, cntact: Th Scrtary Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland Dpartmnt f Agricultur, Fishris and Frstry GPO Bx 858 CANBERRA ACT 2600 Tl: (02) 6272 5216 Fax: (02) 6272 4772 r Th Scrtary Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil GPO Bx 787 CANBERRA ACT 2600 Tl: (02) 6274 1428 Fax: (02) 62741858 Cmmnwalth f Australia ISBN 0 642 24465 0 ISSN 10387072 Printd n rcycld papr. Cvr pht: Mlburn Watr Printd in Australia fr th Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, and th Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil.

TABLE OF CONTENTS PREAMBLE... 1 NATIONAL WATER QUALITY MANAGEMENT STRATEGY...... 1 Acknwldgmnts... 2 1 INTRODUCTION... 4 1.1 URBAN STORMWATER....4 1.2 PURPOSE OF THESE GUIDELINES.......4 1.3 IMPACTS OF URBANISATION... 5 2 STORMWATERMANAGEMENTFRAMEWORK... 7 2.1 What d w want t achiv in Strmwatr Managmnt?... "... "... 7 2.2 Intgratd Catchmnt Managmnt... 7 2.3 Eclgically Sustainabl Dvlpmnt... 8 2.4 Ecsystm Halth Managmnt... 8 2.5 Watr quality bjctivs... 8 2.6 Rivr flw bjctivs (watr fr th nvirnmnt}... 9 2.7 Public halth and safty... 9 2.8 Intgratd Watr Cycl Managmnt... 9 2.9 Urban strmwatr as a rsurc.......... 10 2.10 Cmmunity valus and participatin...... 10 2.11 Ecnmic Sustainability... 11 3 STORMWATER MANAGEMENT TECHNIQUES... 12 3.1 THE MANAGEMENT HIERARCHY... 12 3.2 RUNOFF MANAGEMENT... 14 3.2.1 Flw managmnt gals... 14 3.2.2 Run ffsurc cntrls... 14 3.2.3 Structural Cntrls... 15 3.3 WATER QUALITY MANAGEMENT... 15 3.3.1 Strmwatr quality managmnt gals... 15 3.3.2 Cnstructin sit stnnwatr quality managmnt... 16 3.3.3 Surc cntrls - xisting urban aras... "... 16 3.3.4 Stnnwatr Tratmnt ~ Existing urban aras...... 20 3.4 RIPARIAN VEGETATION MANAGEMENT... 22 3.5 WATERCOURSE AND AQUA TIC HABITAT MANAGEMENT... 23 3.6 URBAN BUSHLAND MANAGEMENT....23 3.7 BRIDGES AND CULVERTS ACROSS WATERWAYS... 24 3.8 WATER SENSITIVE URBAN DESIGN... 24 4 CHALLENGES TO IMPROVING STORMWATER MANAGEMENT........,........... 26 4.1 INSTITUTIONAL ARRANGEMENTS... 26 4.2 FUNDING CONSTRAINTS... 26 4.3 MANAGEMENT SKILLS... 27 4.4 UNCERTAINTY... 27 4.5 PUBLIC INVOLVEMENT... 28 4.6 CHANGING MANAGEMENT FRAMEWORK... 29 4.7 URBAN GROWTH IMPACTS....29 5 CATCHMENT MANAGEMENT FRAMEWORK... 30 5.1 CATCHMENT MANAGEMENT PLANS... 30 5.1.1 Primary bjctiv f catchmnt planning... 30 i

5.1.2 Scp f Catchmnt Managmnt Plan cnsidratins... 30 5.1.3 Administrativ framwrk... 31 6 STORMWATER MANAGEMENT PLANS... 32 6.1 OVERVIEW... 32 6.2 BEST PRACTICE... 32 6.3 ADAPTATION TO LOCAL CIRCUMSTANCES... 33 6.4 MANAGEMENT OBJECTIVES... 34 6.5 MANAGEMENT HIERARCHY... 34 6.6 SCOPE... :... 35 7 DEVELOPING STORMWATER MANAGEMENT PLANS... 36 7.1 PROCESS... 36 7.2 ESSENTIAL ELEMENTS IN DEVELOPING PLAN... 37 7.2.1 Establish framwrk... 37 7.2.2 Idntify stakhldrs and partnrship mchanisms....37 7.2.3 Idntify activitis and cnditins... 38 7.2.4 Idntify valus and bjctivs... :.39 7.2.5 Idntify thrats t valus. cnditins and bjctivs....40 7.2.6 Idntify managmnt stratgis... 40 7.3 LOCAL AREA DEVELOPMENT PLANS....41 7.3.1 Dvlpmnt bjctivs... 42 7.3.2 Administrativ framwrk... 42 7.4 ASSESSING ALTERNATIVES AND SELECTING PREFERRED OPTIONS....43 7.4.1 Dvlping actins... 43 7.5 IMPLEMENTING STORMWATER MANAGEMENT PLANS....43 8 PERFORMANCE REVIEW... 45 9 A VIEW TO THE FUTURE... 46 APPENDIX 1: NWQMS GUIDELINE DOCUMENTS... 49 APPENDIX 2: IMPACTS OF URBANISATION ON THE STORMWATER ENVIRONMENT... 50 APPENDIX 3: STORMWATER ISSUES... 58 APPENDIX 4: DESIGN OF MONITORING PROGRAMS... 58 APPENDIX 5: BIBLIOGRAPHY... 60 APPENDIX 6: GLOSSARY AND COMMON TERMS... 65 ii

PREAMBLE Ths guidlins ar n f th suit f dcumnts f th Natinal Watr Quality Managmnt Stratgy (th Stratgy r NWQMS). Accrdingly, th mphasis f ths guidlins is n quality managmnt rathr than quantity managmnt. Th guidlins and dcumnts which frm part f th Stratgy ar dtaild in Appndix I. Natinal Watr Quality Managmnt Stratgy Th Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil (ANZECC) and th Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland (ARMCANZ) ar wrking tgthr t dvlp th Stratgy. Th Natinal Halth and Mdical Rsarch Cuncil is invlvd in aspcts f th Stratgy which affct public halth. Th main bjctiv f th Stratgy is: 'T achiv sustainabl us f th natin's watr rsurcs by prtcting and nhancing thir quality whil maintaining cnmic and scial dvlpmnt'. Th Stratgy mphasiss th imprtanc f th fllwing principls in watr quality managmnt: c c c clgically sustainabl dvlpmnt; intgratd (r ttal) catchmnt managmnt; bst managmnt practics, including th us f accptabl mdm tchnlgy and wast minimisatin and utilisatin; and th rl f cnmic masurs, and applicatin f th usr pays and pllutr pays principls. As watr rsurc managmnt is mainly a stat and trritry rspnsibility, implmntatin f th Stratgy invlvs: natinal guidlins dvlpd undr th Stratgy; stat and trritry watr plicis; cmmunity prfrncs n th us and valus f lcal watrs; th currnt watr quality f lcal watrs; and th cnmic and scial impacts f maintaining currnt watr quality r f mting nw lcal watr quality gals. Implmntatin f th Stratgy shuld includ: catchmnt, grundwatr and castal watr quality managmnt plans; an apprpriat lvl f srvic prvidd by watr authritis fr watr and swrag srvics; and furthr dvlpmnt f rgulatry and markt framwrks. Cmmunity viws frm a crucial part f th Stratgy and public cmmnt is sught during its dvlpmnt and implmntatin.

Natinal Guidlins Ths paprs prvid guidanc n many aspcts f th watr cycl including ambint and drinking watr quality, mnitring, grundwatr, rural land and watr, urban strmwatr, swrag systms and fflunt managmnt fr spcific industris. Furthr infrmatin can b fund n th Stratgy wbsit at http://www.affa.gv.au/nwqms. Th NWQMS Australian and Nw Zaland Guidlins fr Frsh and Marin Watr Quality (ANZECC & ARMCANZ, 2000a) and th NWQMS Australian Guidlinsfr Watr Quality Mnitring and Rprting (ANZECC & ARMCANZ, 2000b) ar ky dcumnts f th Stratgy. PRINCIPLES T achiv sustainabl us f natin's walr rsurcs by prtcting and nhancing thir quality whil maintaining cnmic and scial dvlpmnt rl N,,'",' PU'" r-- PROCESS t- and Principls I "" ~ I!iI> Natinal Guidlins ~ IMPLEMENTATION AT STATE REGIONAL AND LOCAL LEVEL Stal watr I I Currnt walr ~ I quality plicis quality Cmmunity dsirs fr particular walr bdis II PRODUCT Sustainabl Watr I Rsurcs I Mnitr and rviw th ffcts f actin plan,. Natinal Watr Quality Managmn! Stratgy Rviw Dsignat th nvirnmntal E!l!- valus t Evaluat th scial, cnmic and r;,pa~ts nvirnmntal impacts ' accptabl Impacts OK t.1 Implmnt actin plans St Slat, rginal and lcal gals and dvlp acun plans I Acknwldgmnts Figur 1 - Natinal Watr Qualify Managmnt Stratgy Th prparatin f ths guidlins was initiatd by th Watr Rsurcs Managmnt Cmmitt f th Australian Watr Rsurcs Cuncil (nw th Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland). Prparatin f 1996 Draft fr Public Cmmnt Mmbrs f th wrking grup wr Mssrs Kwam Asumadu (DPIE), Pat Grg (WA WA), Nigl AlxandrlMax Giblin (Dpt Primary Industry & Fishris), Ian Lawrnc (ACTPA), Grdn McIntsh (EWSD), Prfssr Gff OLughlin (Sydny Univrsity f Tchnlgy), Richard Pck (Mlb Watr), Rlf Rs (WRC Qld), & Linl Wd (DIE). Fllwing th dcisin that th 2

guidlins shuld b a jint ANZECC and ARMCANZ dcumnt, Mr Digby Habl (EPA Canbrra) jind th wrking grup as th ANZECC rprsntativ. Th supprt f watr rsurc agncis natinally in cmmnting n prgrssiv drafts, and in rsurcing th drafting by th wrking grup, is gratfully acknwldgd. Prparatin f Rvisd Draft, 1999-2000 In July 1999, Envirnmnt Australia tk th lad in finalising th draft guidlins. Envirnmnt Australia gratfully acknwldgs th cntributins f Chris Chstrfild (Mlburn Watr), Ian Lawrnc (CRC fr Frshwatr Eclgy), Mik Sharpin (NSW EPA) and Jant Murnn, Mgan Sctt and Tara Hwitt (Envirnmnt Australia) thrughut th rvisin prcss. 3

1 INTRODUCTION 1.1 Urban strmwatr Urban strmwatr is runff frm urban aras, including th majr flws during and fllwing rain as wll as dry wathr flws. Dry wathr drainag flws gnrally riginat frm grundwatr, gardn watring, washdwn, laking watr pips, and illgal dischargs. In mst systms, vrflws frm swrag systms r sptic tanks may als bcm part f strmwatr flws during wt and dry wathr. Managmnt f sullag in small twns can als prsnt a prblm, as sm prprtis hav inadquat prvisin fr n-sit tratmnt and discharg dirctly t strmwatr systms (NWQMS Guidlins fr Swrag Systms - Swrag Systm Ovrflws ar currntly undr dvlpmnt, s Appndix I). In many Australian citis strmwatr runff is sn as a nuisanc t b dispsd f as quickly as pssibl. Urban drainag systms hav ftn bn dvlpd t minimis th risk f flding, withut du cnsidratin f thr imprtant valus such as rsurc cnsrvatin, nvirnmntal quality, public safty, and amnity. It is nw clar that a nw apprach t strmwatr managmnt is ndd - an apprach that addrsss issus f strm watr quality and aquatic csystm halth, as wll as strmwatr quantity. W nd an apprach that rcgniss th nvirnmntal impacts f urbanisatin, th linkags btwn land and watr managmnt, and th imprtanc f cmmunity valus and invlvmnt. Urban strmwatr prsnts a managmnt challng in trms f quantity (fld and drainag managmnt, strmwatr rus), quality (littr, nutrints, chmicals, sdimnts) and aquatic csystm halth (aquatic habitats, riparian vgtatin, stram stability and nvirnmntal flws). 1.2 Purps f ths guidlins Ths guidlins aim t prvid a natinally cnsistnt apprach fr managing urban strmwatr in an clgically sustainabl mannr. Th apprachs utlind in this dcumnt rprsnt currnt bst practic in strmwatr planning and managmnt in Australia. In particular, ths guidlins will hlp managrs t idntify bjctivs fr strmwatr managmnt (including prtcting scial, nvirnmntal and cnmic valus) and t intgrat managmnt activitis at th catchmnt, watrway, and lcal dvlpmnt lvl. Th tls and apprachs in ths Guidlins will assist managrs t undrtak intgratd strm watr managmnt planning in accrdanc with th valus and cnditins f th lcal nvirnmnt, whil intgrating ths activitis int th catchmnt cntxt. Th Guidlins als utlin: G G why w nd t manag ur strmwatr; what ar th challngs; hw t invlv th cmmunity; 4

th managmnt tls availabl; and prparing, implmnting and mnitring Strmwatr Managmnt Plans. It is imprtant t rcgnis that diffrnt jurisdictins may hav diffrnt lgislativ and rsurc managmnt rquirmnts rlating t strmwatr managmnt. Many Stat, lcal and rginal gvrnmnts hav dvlpd cmprhnsiv tchnical guidlins n spcific strmwatr managmnt tchniqus and practics, many f which ar rfrrd t in ths guidlins. Managrs shuld apprach thir rlvant stat, trritry r rginal agncy fr infrmatin n any spcific rquirmnts than nd t b mt, r tchnical infrmatin that may assist in thir stnnwatr planning and managmnt activitis. 1.3 Impacts f urbanisatin With prgrssiv changs in th Australian landscap frm frst r thr indignus vgtatin t rural r urban nvirnmnts, th natural mvmnt f watr has changd dramatically. Th grwth f urbanisatin has ld t a substitutin f vgtatd grund with land cvrd by larg imprvius surfacs such as rfing and paving. Tpgraphy has als radically changd thrugh land lvlling and grading, and natural watrcurss hav bn rplacd with guttrs, pips and channls. It is difficult t mak gnralisatins abut what impacts urbanisatin will hav n aquatic csystm halth. Gnrally, rducd watr quality and a lwr divrsity f aquatic flra and fauna can b xpctd. Th cmpsitin f clgical cmmunitis may als b altrd, r th rlativ abundanc f spcis tlrant t th altrd cnditins may incras. Lft unmanagd, ths impacts may nt nly b dtrimntal t th nvirnmntal valus f urban watrways, but may als ps a risk t public halth and rstrict ptntial pprtunitis fr th cmmunity t bnfit frm th watrway. A dtaild discussin f th impacts f urbanisatin n th strmwatr nvirnmnt is prvidd in Appndix 2. Ths includ changs in: G c c G catchmnt hydrlgy - incrasd frquncy and intnsity f runff and flding vnts, highr runff vlums and pak flws, mr rapid paking f strm flws, and rducd bas flws in watrcurss. watr quality - lvatd lvls f suspndd slids, nutrints, micr-rganisms, havy mtals and rganic matrials. watrway channls - channl frm may b changd by incrasd rsiv frc f flws, rmval f riparian vgtatin, and sdimntatin. riparian vgtatin - rmval f riparian vgtatin and rplacmnt with xtic spcis can lad t, fr xampl, highr watr tmpraturs, lss f aquatic and trrstrial habitats, and dcrasd bank stability. aquatic habitats - aquatic habitats may b lst thrugh changs in th bd matrial and bd shap f watrways, rmval f in-stram bjcts such as snags and aquatic plants, and drainag f wtlands and fldplains. watrcurs barrirs and cnstrictins - structurs such as bridgs and culvrts may altr flw pattrns, fauna mvmnt, and sdimnt transprt pattrns. Th magnitud and natur f ths impacts will b spcific t individual catchmnts. Thy may als b influncd by thr factrs such as pr-dvlpmnt land uss. 5

Frm a managmnt prspctiv, thr ar tw ky pints that shuld b ntd: actins shuld b tailrd t tb catchmnt - gnric slutins ar nt apprpriat; and changs t runff pattrns shuld b minimisd. This rducs a rang f thr nvirnmntal impacts. 6

2 STORMWATER MANAGEMENT FRAMEWORK 2.1 What d w want t achiv in Strmwatr Managmnt? Thr is n singl bjctiv that is apprpriat fr th managmnt f all urban strmwatr systms. A multipl bjctiv apprach shuld b adptd, cnsidring bjctivs such as: G csystm halth, bth aquatic and trrstrial; flding and drainag cntrl; public halth and safty; cnmic cnsidratins; rcratinal pprtunitis; scial cnsidratins; and asthtic valus. Ths bjctivs ftn nd t b addrssd in tw cntxts: rstring xisting strm watr systms; and minimising th impacts f strm watr frm nw dvlpmnts. In stablishd urban aras, th first cntxt will b th mst cmmn. Thr will, hwvr, b th nd t apprpriatly manag th impacts f rdvlpmnt prjcts and sk pprtunitis fr rstratin and upgrading. In urban grwth aras, th scnd cntxt will b dminant. This is an imprtant rspnsibility fr strm watr managrs in ths aras. It is gnrally mr cnmical and ffctiv t minimis th impacts f nw dvlpmnts than it is t mitigat ths impacts frm cmpltd dvlpmnts. Th applicability f many strm watr managmnt tchniqus will dpnd n whthr rstratin, rhabilitatin and/r prvntin ar th gals. In many xisting aras, cnstraints such as xisting prprtis, hritag classifid watrways and bridgs may prvnt managmnt bjctivs frm bing fully ralisd. 2.2 Intgratd Catchmnt Managmnt Intgratd Catchmnt Managmnt (ICM) r Ttal Catchmnt Managmnt (TCM) rcgniss th catchmnt-wid rlatinships btwn rsurc us and managmnt. It als addrsss th nd fr cmmunity invlvmnt in idntifying issus and managmnt slutins. It has bn adptd in a numbr f Stats and Trritris and mbracs: a hlistic apprach t natural rsurc managmnt within catchmnts, marin nvirnmnts and aquifrs, with linkags btwn watr rsurcs, vgtatin, land us, and thr natural rsurcs rcgnisd; intgratin f scial, cnmic and nvirnmntal issus; c-rdinatin f all th agncis, lvls f gvrnmnt and intrst grups within th catchmnt; and cmmunity cnsultatin and participatin. 7

Intgratd Catchmnt Managmnt is incrasingly bcming th 'umbrlla' fr sustainabl rsurc managmnt. 2.3 Eclgically Sustainabl Dvlpmnt Eclgically Sustainabl Dvlpmnt (ESD) rprsnts n f th gratst challngs facing Australia's gvrnmnts, industry, businss and cmmunity in th cming yars. Whil thr is n univrsally accptd dfinitin f ESD, in 1990 th Cmmnwalth Gvrnmnt suggstd th fllwing dfinitin fr ESD in Australia: 'using, cnsrving and nhancing th cmmunity's rsurcs s that clgical prcsss, n which lif dpnds, ar maintaind, and th ttal quality f lif, nw and in th futur, can b incrasd. ' Put mr simply, ESD is dvlpmnt which aims t mt th nds f Australians tday, whil cnsrving ur csystms fr th bnfit f futur gnratins. T d this, w nd t dvlp ways f using ths nvirnmntal rsurcs, which frm th basis f ur cnmy in a way which maintains and, whr pssibl, imprvs thir rang, varity and quality. At th sam tim w nd t utilis ths rsurcs t dvlp industry and gnrat mplymnt. Th 1992 Natinal Stratgy fr ESD idntifis cr bjctivs and guiding principls dsignd t achiv dvlpmnt that imprvs th ttal quality f lif in a way that maintains th clgical prcsss n which lif dpnds. Th ptincipls f ESD ar: (a) Th prcautinary principl. Namly, that if thr ar thrats f srius r irrvrsibl nvirnmntal damag, lack f full scintific crtainty shuld nt b usd as a rasn fr pstpning masurs t prvnt nvirnmntal dgradatin. (b) Intr-gnratinal quity. Th prsnt gnratin shuld nsur that th halth, divrsity and prductivity f th nvirnmnt ar maintaind r nhancd fr th bnfit f futur gnratins. (c) Cnsrvatin f bilgical divrsity and clgical intgtity. Cnsrvatin f bilgical divrsity and clgical intgrity shuld b a fundamntal cnsidratin. (d) Imprvd valuatin, pricing and incntiv mchanisms. Envirnmntal factrs shuld b includd in th valuatin f assts and srvics. Th challng in ESD is t dvlp and manag in an intgratd way, th quality and quantity f surfac and grundwatr rsurcs and t dvlp mchanisms fr watr rsurc managmnt which maintain clgical systms whil mting cnmic, scial and cmmunity nds. 2.4 Ecsystm Halth Managmnt Strm watr managmnt is currntly undrging a paradigm shift. Th traditinal fcus n fld managmnt is bing bradnd t addrss strmwatr quality cnsidratins. A furthr shift is mrging, whr strmwatr managrs ar addrssing aquatic csystm r rivr halth. This invlvs th managmnt f all aspcts f th watr nvirnmnt t achiv th bst utcm fr 8

th halth f watrcurss, laks, stuaris and th marin nvirnmnt. Stramflw, watr quality, aquatic habitats and riparian vgtatin ar all cnsidrd whn managmnt dcisins ar mad. 2.5 Watr quality bjctivs Ambint watr quality bjctivs hav bn, r ar in th prcss f bing, stablishd fr watrways in many Stats, Trritris and rgins. Ths bjctivs can prvid a gal fr urban strm watr managmnt. This is, hwvr, cmplicatd by: & G watr quality bing affctd by thr pllutin surcs, such as pint surcs, agricultural runff and swr vrflws; and difficultis in stablishing rlatinships btwn ambint watr quality cncntratins and wt wathr strmwatr dischargs. Guidlins fr frsh and marin watr quality hav bn prpard by ANZECC and ARMCANZ (ANZECC & ARMCANZ, 2000a) t prvid gvrnmnts and tb cmmunity, particularly catchmnt/watr managrs, rgulatrs, industry and cmmunity grups, a sund st f tls fr assssing and managing ambint watr quality. Als svral NWQMS Guidlins rlating t swrag systms and fflunt managmnt hav bn, r ar in th prcss f bing, dvlpd (s Appndix 1). 2.6 Rivr flw bjctivs (watr fr th nvirnmnt) Objctivs fr rivr r nvirnmntal flws ar bing dvlpd in sm Stats, Trritris and rgins. Ths bjctivs rcgnis that watrway halth is influncd by th flw rgim, which may b affctd by landus chang and watr xtractin. Rivr flw bjctivs can als prvid a framwrk fr urban strmwatr managmnt, althugh in many larg catchmnts, urban aras may b nly a small cmpnnt f th catchmnt. Th Natinal Principlsfr th Prvisin f Watr fr Ecsystms (Sustainabl Land and Watr Rsurcs Managmnt Cmmitt Subcmmitt n Watr Rsurcs 1996) prvids sm guidanc fr rivr flw bjctivs. 2.7 Public halth and safty Managmnt bjctivs t minimis public halth and safty risks can includ: G dsigning structural cntrls and watrways t minimis th risk f trapping ppl caught in watrways during flds; minimis th risk f injury t th public and maintnanc staff frm structural cntrls; and minimising public risks assciatd with vctrs such as msquits frm cnstructd wtlands. 2.8 Intgratd Watr Cycl Managmnt Traditinally, strm watr, watr supply and swag hav bn managd sparatly. Thr ar, hwvr, pprtunitis availabl t intgrat ths aspcts f th watr cycl in a way that imprvs nvirnmntal and cmmunity utcms, smtims at rducd cst. Frm a strmwatr prspctiv, th mst cmmn apprach is strmwatr rus, gnrally fr nn-ptabl purpss. This rducs th dmand n th ptabl watr supply and rducs runff vlums and flw rats. Schms hav als bn dvlpd that rus bth strmwatr and tratd fflunt. ' 9

Cntmprary apprachs t strmwatr managmnt als includ nsuring that watr supply systms allw fr nvirnmntal flws in strams blw xtractin pints, th sustainabl managmnt f xtractins fr irrigatin, and mimicking natural flw rgims in managd strams. Ths apprachs rcgnis that strmwatr managmnt nds t idntify bth th nvirnmntal valus f strams as wll as th pprtunitis t utilis strmwatr as it passs its way thrugh th urban watr cycl. 2.9 Urban strmwatr as a rsurc In th past, th main aim f urban strmwatr managmnt was cllcting and rmving xcss runff as quickly and chaply as pssibl. This was t avid flding during majr rains and t prvid gnral amnity drainag. As grwing urban cmmunitis apprach r xcd th cnmically viabl limits f watr supplis, pprtunitis assciatd with us f lcal watr surcs such as urban strmwatr and grundwatr ar bing rcgnisd. Bttr managmnt f th watr cycl at th rsidntial blck nds t b achivd t rduc dmand fr dmstic irrigatin. Whr urban aras ar lcatd vr r adjacnt t grundwatr aquifrs, thr is ptntial fr strmwatr t b usd t rcharg aquifrs prvidd th watr quality is prtctd. This rquirs vry carful managmnt as ptntial issus includ rising watr tabls, salt prblms and grundwatr xtractin rights. Th quality f urban pn spac has ftn bn cmprmisd by th lss f natural urban strams t rstrictd hard nginring drainag structurs. This can b du t pr planning f th urban frm as part f th riginal urban dvlpmnt and th rquirmnt t nsur a crtain fld immunity and drainag standard. Th lss f natural urban strams can advrsly affct th amnity f surrunding aras, clgical halth and watr quality. In nw dvlpmnts it is ssntial that strmwatr is rcgnisd as a rsurc prir t alltmnt layuts bing finalisd. Lng trm scial, nvirnmntal and cnmic bnfits can b achivd fr pn spac drainag crridrs thrugh planning and dsign apprachs which rcgnis urban strmwatr and strams as valuabl rsurcs. Opprtunitis t rtrfit pllutin cntrl dvics and r-stablish an asthtically appaling nvirnmnt t dgradd drainag crridrs by habitat rstratin shuld als b invstigatd. 2.10 Cmmunity valus and participatin Managing strm watr nly fr fld prtctin is n lngr an adquat rspns t changing cmmunity valus which nw rflct cncrn fr prtcting th nvirnmnt, clgically sustainabl dvlpmnt, and imprvd accss t pn spac and rcratinal facilitis. Mst urban dwllrs njy a vry high lvl f fld prtctin du t th wrks dn in th past. Ths nd maintnanc and, at tims, upgrading. Dmand shuld nw fcus qually n imprvd nvirnmntal quality and rcratinal pprtunitis. Th NWQMS papr, Plicis and Principls - A Rfrnc Dcumnt (1994), sks t rspnd t ths cmmunity valus by adpting th bjctiv f 'achiving sustainabl us f th natin's watr rsurcs by prtcting and nhancing thir quality whil maintaining cnmic and scial dvlpmnt'. 10

Cmmunity participatin hlps t: G G idntify stratgis which ar rspnsiv t cmmunity cncrns; xplr prblms, issus, cmmunity valus and altrnativ stratgis pnly; incras public wnrship and accptanc f prpsd slutins; gnrat bradr dcisin making prspctivs nt limitd t past practics r intrsts; and rflct th cmmunity's lif styl valus and priritis. 2.11 Ecnmic Sustainability A wid rang f strmwatr managmnt practics is availabl. Th capital and nging pratins and maintnanc csts f ths practics ar highly variabl. It is imprtant fr strmwatr managrs t adpt slutins that ar cnmically sustainabl. This is particularly rlvant whn.chsing structural watr quality cntrls. Th annual prating and maintnanc csts f ths dvics may rprsnt a larg prcntag f, r xcd, thir initial capital cst. Managmnt authritis may find this cst difficult t affrd n an nging basis. This may thn cmprmis th ffctivnss f th dvic in mting its tratmnt bjctivs. 11

3 STORMWATER MANAGEMENT TECHNIQUES 3.1 Th managmnt hirarchy A cmplx intractin xists btwn th hydrlgical (stramflw), watr quality, channl frm, aquatic habitat and riparian vgtatin charactristics f a watrcurs. Ths intractins will als impact n human halth, rcratin and asthtic cnsidratins. T maintain th lng-trm intgrity f ths valus a hlistic apprach is ncssary. Similarly, managing nly n aspct f a strmwatr systm is unlikly t addrss all f th rlvant cnsidratins. Strmwatr managmnt shuld cnsidr th hydrlgical, gmrphlgical, clgical, sil, land us and cultural charactristics f a catchmnt and its watrcurs ntwrk. If th intractins ntd abv ar nt rcgnisd, thr is th ptntial fr wll-intndd managmnt tchniqus t hav a gratr nvirnmntal impact than unmitigatd strm watr runff. A st f brad and hlistic principls that can b fllwd fr ffctiv strmwatr nvirnmnt managmnt ar: hydrlgical: minimising th impacts f urbanisatin n th hydrlgical charactristics f a catchmnt, including wt wathr and lw flws. If th pr-dvlpmnt land us rsultd in an inapprpriat stramflw rgim (g runff frm an agricultural catchmnt causing rsin), this shuld b mitigatd whr practical; watr quality: minimising th amunt f pllutin ntring th strm watr systm and rmving an apprpriat amunt f any rsidual pllutin by implmnting strmwatr managmnt practics; vgtatin: maximising th valu f indignus riparian, fldplain and frshr vgtatin; and aquatic habitat: maximising th valu f physical habitats t aquatic fauna within th strmwatr systm. Whil ths principls ar strpgly intr-rlatd, thir rlativ imprtanc can vary within and btwn catchmnts. It may b ncssary t cmprmis btwn ths principls at any particular sit t achiv a balancd utcm that maximiss vrall nvirnmntal, scial and cnmic bnfits. Hwvr, givn that runff rats and vlums ftn, dirctly r indirctly, caus many ptntial scial, cnmic and nvirnmntal impacts in urban aras, managing ths spcific runff charactristics is imprativ. 12

A stnnwatr managmnt hirarchy can b idntifid t dfin prfrrd stnnwatr managmnt practics (Figur 2). This is: 1. Rtain and rstr (r rhabilitat) valuabl csystms: rtaining r rstring (if dgradd) xisting valuabl lmnts f th stnnwatr systm, such as natural channls, wtlands and riparian vgtatin; 2. Surc cntrl: nn-structural masurs: nn-structural tchniqus fr limiting changs t th quantity and quality f stnnwatr at th surc; 3. Surc cntrl: structural masurs: cnstructd managmnt tchniqus installd at r nar th surc t manag stnnwatr quantity and quality; and 4. In-systm managmnt masurs: cnstructd managmnt tchniqus installd within stnnwatr systms t manag stnnwatr quantity and quality prir t discharg int rciving watrs. Rtain and rstr valuabl csystms Surc cntrl: nn-structural masurs Surc cntrl: structural masurs In-systm managmnt masurs Figur 2 - Strm watr Managmnt Hirarchy This apprach fcuss n pllutin prvntin in accrdanc with th principls f ESD. Ths stps firstly sk t prsrv th valuabl faturs f th watr nvirnmnt, thn prmt cstffctiv strmwatr managmnt by minimising and cntrlling strrnwatr pllutin at th surc, and nly prps managmnt masurs within strmwatr systms fr th rsidual impacts that cannt b cst-ffctivly mitigatd by surc r nar-surc cntrls. Th NWQMS Australian and Nw Zaland Guidlins Watr Quality Guidlins fr Frsh and Marin Watrs (ANZECC & ARCANZ, 2000a) adpt thr lvls f prtctin in rspct t csystms: Pristin t slightly mdifid systms - prtctin; Slightly t mdratly mdifid systms - rstratin pprtunitis; and Highly mdifid systms - lcal idntificatin f th valus t b scurd. 13

Th bulk f stnnwatr rlatd csystms will fall int th third catgry. Thr may hwvr b a numbr f aras whr ithr th lvl f accptabl chang is cnfind t th slightly t mdratly disturbd lvl, r whr rasnabl pprtunitis xist t rstr impactd csystms t th slightly t mdratly disturbd lvl. 3.2 Runff managmnt 3.2.1 Flw managmnt gals Th traditinal apprach t managing th impacts f urbanisatin n flw pattrns has fcusd n mitigating th ffcts f incrasd pak flws frm infrqunt vnts (g th IOO-yar avrag rcurrnc intrval vnt). This apprach has bn basd n rducing human halth risks and damag t prprty and infrastructur. Frm an nvirnmntal managmnt prspctiv, mphasis nds t b placd n th managmnt f flws frm frqunt vnts f rlativly small magnitud. This is primarily bcaus in urban nvirnmnts, th mst significant changs t th hydrlgical rgim ccur in th frquncy and magnitud f th smallr, mr frqunt runff vnts. 3.2.2 Run-ff surc cntrls Runff surc cntrls gnrally includ infiltratin tchniqus r strmwatr rus practics. Infiltratin tchniqus rang frm ths implmntd n individual husing blcks t ths incrpratd within th stnnwatr systm. Ths includ: infiltratin trnchs, pits, wlls and sakaways fr infiltratin f rf runff; dircting rf runff t pnding aras in back yards fr infiltratin; grassd swals; prvius stnnwatr pips; prus pavmnts; and infiltratin trnchs and basins (installd within th drainag systm). Ths systms ar suitabl fr infiltrating runff with lw sdimnt lvls in aras with rlativly high pnnability sils. Grassd swals hav th advantag f slwing flw vlcitis and can b usd instad f krbs and guttrs. Prus pavmnts hav a rlativly high failur rat. T b ffctiv in th lng tnn, infiltratin tchniqus nd t b apprpriatly dsignd, usd in lwtraffickd aras and infiltrat stnnwatr with ngligibl sdimnt lvls. In slcting th mst apprpriat infiltratin tchniqu, managrs shuld cnsidr whthr prtratmnt f th runff is rquird t nsur ths tchniqus cntinu t functin in th lng tnn. Any ptntial fr grundwatr pllutin r aggravatin f urban salinity prblms is als an imprtant cnsidratin. Managrs shuld als cnsidr th masurs that can b takn t imprv managmnt f sptic tank systms, sullag dischargs and swrag systm vrflws. Stnnwatr rus can prvid an ffctiv runff cntrl apprach, with th furthr bnfit f prviding an additinal watr rsurc. Rus masurs can b undrtakn at ithr individual blck 14

lvl r n a catchmnt r sub-catchmnt basis. Ths may includ rainwatr tanks r similar dvics fr cllcting rf runff, and wt basins r cnstructd wtlands. Th watr cllctd can b usd fr nn-ptabl purpss, including industrial prcsss, irrigatin, gardn watring and tilt flushing. As th vlum f watr strd in ths dvics will vary, thy shuld nt b usd as a substitut fr anyn-sit dtntin rquirmnts ndd fr fld mitigatin. Th strags can, hwvr, b dsignd fr multipl bjctivs. Strag culd b prvidd fr bth strmwatr rus and flw attnuatin. 3.2.3 Structural Cntrls In larg and infrqunt strm vnts, infiltratin is likly t b minimal. Pak flws can b rducd by tmprary strag t minimis public halth risks, prprty damag, aquatic habitat disturbanc and channl rsin. Rtarding (r rtntin) basins ar cmmnly usd t mitigat flws frm infrqunt vnts, such as th loo-yar avrag rcurrnc intrval fld, in th catchmnt. In individual dvlpmnts, n-sit dtntin can als b usd t rduc flw paks. Rtarding basins can als b dsignd t attnuat th pak flws f mr frqunt vnts, such as th 1-2 yar avrag rcurrnc intrval vnt. This can rsult in n incras in th frquncy f ccurrnc f th bank-full flw aftr urbanisatin. It ds, hwvr, rsul t in th lngthning f th flw hydrgraph. This may rsult in channl rsin. Ths basins nd t b carfully dsignd t ptimis thir prfrmanc. Dsigning rtarding basins t mt mr than n discharg critrin can prvid bnficial utcms fr clgical managmnt withut cmprmising drainag and fld prtctin rquirmnts. 3.3 Watr quality managmnt 3.3.1 Strmwatr quality managmnt gals Th gratst chang in pllutant lads dischargd t watrways frm urban aras ccurs during th mr frqunt strm vnts. Nn-urban aquatic csystms ar gnrally nt subjct t runff frm smallr and frqunt strm vnts, du t thir ability t infiltrat rainfall far bttr than urban nvirnmnts. Rducing runff vlums frm ths strm vnts will assist in rducing pllutant lads. Th ASCE & WEF (1993) nt th fllwing rgarding this apprach: 'Th dsign runffslctdfr sizing watr quality cntrls is cnsidrably diffrnt frm that usdfr th dsign f drainag facilitis. Th damag dn t a rciving watr csystm by uncntrlld pllutant runff in th 50 yar ARI vnt is incnsquntial cmpard t th hydraulic damag that rsults naturally t aquatic habitats frm such an vnt: (a) drainag systms ar dsignd fr larg infrqunt runff vnts [10,25,50 r 100 yar ARI]; (b) dsign vnts fr runff quality cntrl ar small frqunt vnts [smallr than th 1 yar ARI runff vnt].' A significant prprtin f th lng-trm (g annual) runff vlum frm urban catchmnts ccurs frm frqunt, smallr fld vnts and frm a prprtin f largr vnts. Cmmnly in urban aras, apprximatly 90-95% f th man annual runff vlum ccurs at flws lss than th 3-15

mnth avrag rcurrnc intrval vnt (apprximatly 25-50% fth I-yar flw in tmprat aras). Ths frqunt vnts ar th targt f mst strmwatr quality cntrls. Strmwatr quality cntrls shuld b implmntd during bth th cnstructin and pstcnstructin phass f urban dvlpmnt. Bth surc cntrl and "nd-f-pip" managmnt practics ar apprpriat. 3.3.2 Cnstructin sit strmwatr quality managmnt Watr quality managmnt frm cnstructin sits falls int tw catgris: rsin and sdimnt cntrl; and managmnt f wasts, chmicals and ful. Th gnral managmnt principls fr rsin and sdimnt cntrl invlv: minimising th xtnt f disturbd aras; rapidly rvgtating disturbd aras; divrting runff frm undisturbd catchmnts arund wrk aras; and trapping rdd sdimnt frm disturbd sits as cls t th surc as practical by, fr xampl, sdimnt fncs, traps and basins. Ths principls apply t cnstructin sits f all sizs, frm majr urban dvlpmnts and frways t singl hus cnstructin. Th succss f this apprach is havily dpndnt n: apprpriat planning prir t th cmmncmnt f cnstructin activitis; apprpriat mnitring and maintnanc f th managmnt practics; and ducatin and dilignc f cntractrs, cnsultants and cuncil fficrs in th planning and managmnt f ths tchniqus. Th managmnt f wasts and chmicals at a cnstructin sit gnrally rlats t apprpriat strag, handling and dispsal practics. Th practics shuld nsur: chmicals and fuls shuld b strd and handld in a mannr which nsurs that n pllutants ar dischargd t strmwatr; wastwatr frm building activitis (such as washdwn watr frm cncrt trucks r cling watr frm brick cutting) shuld b cntaind n-sit; and littr frm building pratins shuld b adquatly strd and dispsd f. 3.3.3 Surc cntrls - xisting urban aras What is surc cntrl? Surc cntrl f strmwatr pllutin frm stablishd urban aras aims t minimis th amunt f pllutin ntring th drainag systm. It is basd n th prmis that it is gnrally asir and mr cst-ffctiv t cntrl pllutin at th surc, rathr than subsquntly rmving pllutin frm within th drainag systm. Furthr, strmwatr tratmnt masurs may nt b abl t rduc pllutant lads t dsird lvls in th lng trm. In many cass, a cmbinatin f surc and insystm managmnt tchniqus may b ncssary. 16

Surc cntrl tchniqus can b catgrisd int: nn-structural surc cntrl: tchniqus that aim t chang human bhaviur t rduc th amunt f pllutants that ntr strmwatr systms (pllutin prvntin); and structural surc-cntrl: tchniqus that aim t rduc th quantity and imprv th quality f strmwatr at r nar its surc by using infrastructur r natural physical rsurcs. Nn-structural surc cntrl can includ cmmunity ducatin, cuncil managmnt, pratins and maintnanc activitis, and land us and sit planning. Th main advantags f using nn-structural surc cntrls ar: lng trm sustainabilty; cst-ffctivnss; minimisatin r prvntin fcus; " rducd nging pratin r maintnanc liability (cmpard with structural cntrls); and.. ffctiv us f all rsurcs - including th cmmunity. Cmmunity ducatin Cmmunity ducatin can playa significant rl in th imprvmnt f strmwatr quality. Strmwatr pllutin frm rsidntial, industrial and cmmrcial aras is th rsult f many actins at varius lcatins within a catchmnt. Th impact f allwing a can t lak il, washing paint brushs int drains, nt claning up aftr dgs r inapprpriat us f hushld chmicals may sm rlativly minr. Hwvr, whn th individual impacts ar addd acrss th catchmnt, ths actins bcm a significant surc f pllutin ntring watrways. In additin t strmwatr pllutin, thr impacts f cmmunity activitis n th halth f watrways includ: G incrasd runff rats causd by incrasd imprvius aras (such as rads, rfs and paving); rmval f riparian vgtatin adjacnt t watrcurss and thr watrbdis; and dgradatin f aquatic habitats such as pls and rapids in crks and wtlands. Ppl ar ftn unawar that thir activitis at wrk, whil travlling r at hm can impact n strmwatr. Onc thy ar awar and hav larnt simpl slutins t rduc r avid causing strmwatr pllutin, changs t thir bhaviur ar mr likly. Thr is a valuabl rl fr lcal cmmunity ntwrks, lcal cuncils and stat gvrnmnt agncis t assist cmmunitis t playa cnstructiv rl in strmwatr managmnt. Educatin prgrams may nt rsult in an immdiat chang as thy ar nt th nly factr that influnc a prsn's bhaviur - particularly in th shrt trm. A prsn's bhaviur is als influncd by: th scial valus and standards passd n in th hm, at schl, thrugh scial grups and th mdia; " ag, gndr, thnicity, incm and ccupatin; " rcnt vnts; " laws, rgulatins and plicis - and hw ths ar mnitrd, implmntd and nfrcd; 17

G th availability f tchnlgy, prducts and srvics; and cnmic factrs such as financial incntivs r disincntivs. Educatin prgrams ar mr likly t shw rsults if thy ar plannd and implmntd as n f a numbr f cmplmntary apprachs that addrss issus arising frm ppl's bhaviur. Cmplmntary apprachs t cnsidr ar: G Enfrcmnt: making bttr us f plicy, lgislatin and rgulatin. " Ecnmics: xamining markt incntivs and disincntivs fr changing bhaviur. & Enginring, scinc and tchnlgy: prmting and assisting dvlpmnt f nw tchnlgis and srvics. Evaluatin, mnitring and rsarch: xamining th barrirs and infrmatin nds t facilitat chang. Cmmunity ducatin is a prcss usd t: G G crat awarnss f issus; nhanc ppl's knwldg, undrstanding and skills; " influnc ppl's valus and attituds; and " ncurag mr rspnsibl bhaviur. Th fllwing stps culd b adptd in dvlping an ducatin prgram: l. Analys th issu r prblm - Find ut what's causing cncrn and brak th issu dwn int its cmpnnts. Find ut hw much is alrady knwn abut th prblm by prfssinals wrking in th ara and th cmmunity mmbrs wh ar assciatd with th issu r prblm lcatin. 2. Idntify stakhldrs - Idntify th stakhldrs, invlv thm and find ut whr thy stand in rlatin t th issu and lk fr cmmn grund whr th stakhldrs may b abl t wrk tgthr t slv th issu. 3. Knw yur targt grup - Idntify, gt t knw and invlv yur targt grup arly in th prjct. 4. Objctiv and utcms - Dtrmin th rsult yu want frm yur cmmunity ducatin prjct. 5. Dsign yur mthds - Invstigat th mthds, tls and tchniqus yu culd us t achiv yur gal, bjctivs and utcms. 6. Cnsidr funding - Idntify pssibl funding surcs and th bnfits fr ptntial funding rganisatins. 7. Mak an actin plan and implmnt it - Prpar an actin plan t nsur that yu achiv yur prjct's gal and bjctivs. 8. Mnitr and valnat - Mnitr and valuat th prjct and tll ppl abut it. 18

Auditing f cmmrcial and industrial prmiss Audits can b undrtakn f cmmrcial and industrial prmiss within catchmnts, targting prmiss with th ptntial fr strmwatr pllutin. It is ftn mr ffctiv fr this t b. undrtakn initially by an indpndnt party, rathr than a rgulatr. This is likly t rsult in a gratr dgr f cpratin with th managmnt f th prmiss. Th audits can b cnsidrd as part f a cmmunity ducatin prgram. Prmiss undrtaking activitis likly t caus strmwatr pllutin can b ncuragd t rctify thm and, fr largr prmiss, prpar an nvirnmntal managmnt plan. Fllw up visits can b undrtakn. If th managmnt f a prmiss is uncprativ and it is suspctd that activitis with a ptntial fr strm watr pllutin ar bing undrtakn, this culd b rfrrd t a rgulatry authrity. Cuncil managmnt activitis Lcal cuncils can influnc th quality f strmwatr within a catchmnt whn planning and managing cnstructin and maintnanc activitis and during day t day managmnt dcisins. It is als imprtant fr cuncils t b sn t b stting th right xampl fr th cmmunity and thr rganisatins t fllw. Tabl 1 nts sm cuncil managmnt activitis that hav a dirct r indirct influnc n strmwatr managmnt. It is imprtant that ths influncs n strmwatr managmnt b rcgnisd and cnsidrd. Managmnt activitis undrtakn by cuncil that can usd b t maximis cuncils ffrt in managing strmwatr pllutin includ: " cnducting intrnal rviws; prfrmanc mnitring; intrnal training and ducatin; " intrnal cmmunicatin; " financial managmnt; " dvlpmnt and building apprvals; and " nfrcmnt f sit cntrls. Simpl maintnanc activitis that can b implmntd at minimal cst can als achiv significant imprvmnt in th quality f strmwatr run'ff. Prpr planning f pratinal prcdurs fr ach activity is th ky lmnt t succss in minimising th impact ach may hav n th strmwatr quality. Activitis whr this can b undrtakn includ: " Maintnanc f rads, ftpaths and bridgs; " Maintnanc f strmwatr systms and watrways; " Opn spac managmnt; Dpt pratins; and Wast cllctin. 19

Tabl 1 - Cuncil activitis and ptntial influnc n strmwatr Cuncil activitis EnvirnmntallLand Us Planning - Stratgic planning EnvirnmntallLand Us Planning - Dvlpmnt cntrl Building apprvals and inspctin Envirnmntal Halth Parks and Gardns Rad Maintnanc Drainag systm maintnanc Wast cllctin Rad and drainag dsign Financ Library Ptntial influnc n strmwatr Urban capability assssmnt G Dvlpr cntributin plans fr strmwatr managmnt Strmwatr managmnt practics fr nw dvlpmnts Sil and watr managmnt fr building sits Trad wast, dischargs t strmwatr Maintnanc activitis (g tr planting, frtilisr applicatin, grass cutting) G Varius maintnanc activitis Varius maintnanc activitis Littr managmnt Rad rut slctin, drainag systm dsign Budgts fr strm watr managmnt Cmmunity ducatin Urban capability assssmnt Urban (r land) capability can b cnsidrd as th capacity f an ara t sustain a prpsd land us withut having a significant impact n th halth f aquatic csystms r xcding th physical capability f th land t supprt th dvlpmnt. Urban capability assssmnt is an imprtant part f strmwatr managmnt. If an assssmnt is nt carrid ut fr a nw dvlpmnt, th pprtunity t mitigat many f th impacts may b lst r may nly b vrcm at significant cst t th dvlpr r th cmmunity. It is imprtant that ach dvlpmnt is tailrd t th charactristics f th dvlpmnt sit. Th ptimal tim fr assssing urban capability in th dvlpmnt prcss is at th land us planning stag. Th rsults f an urban capability assssmnt can b prsntd in a Cnstraints and Opprtunitis Map. Ths maps indicat th faturs f th watr nvirnmnt and any limitatins impsd by th nvirnmntal and physical charactristics f th sit. Th maps may b prsntd as a sris f vrlays, ach cntaining a diffrnt suit f faturs r limitatins. 3.3.4 Strmwatr Tratmnt - Existing urban aras Diffrnt strmwatr tratmnt masurs fr managing strmwatr quality frm urban aras pstcnstructin will prvid diffrnt lvls f tratmnt (Figur 3). In sm cass, a particular tratmnt masur may vrlap tw r mr tratmnt lvls dpnding n its spcific dsign faturs. In mst situatins, hwvr, a cmbinatin f diffrnt tratmnt masurs that rduc pllutants thrugh diffrnt prcsss will prvid th bst vrall tratmnt. Ths tratmnt masurs nd t b apprpriatly slctd, plannd, dsignd and maintaind if thir pllutant rtntin bjctivs ar t b mt in th lng trm. 20

Primary lvl tratmnt c Scrning f grss pllutants Sdimntatin f cars particls Scndary lvl tratmnt Sdimntatin f finr particulats Filtratin "- Trtiary lvl tratmnt Enhancd sdimntatin and filtratin Bilgical uptak " Adsrptin n t sdimnts Figur 3 Lvls f strm watr tratmnt Primary tratmnt masurs gnrally targt littr and thr grss pllutants, and cars sdimnts. Exampls cmmnly usd includ: littr baskt - a baskt installd in an inlt pit t cllct rubbish dirctly ntring th strmwatr systm frm rad surfacs; littr (cntrl) pit - a baskt lcatd in a strmwatr pit, whr it cllcts littr frm th upstram drainag systm; littr (trash) rack - a rack installd within a strmwatr channl, r at th dwnstram nd f a sdimnt trap; sdimnt trap - a frmal 'tank' r a lss frmal pnd structur fr trapping cars sdimnt., grss pllutant trap - a sdimnt trap with a littr rack; and littr bm - flating dvic installd in channls and watrways t cllct flating littr and il. Many prpritary primary tratmnt dvics hav bn dvlpd. Scndary tratmnt masurs gnrally targt sdimnts, with sm rmval f nutrints and bactria. Cmmnly usd xampls includ: G filtr strips (als knwn as buffr zns r buffr strips) - grassd r vgtatd aras that trat vrland flw, ftn adjacnt t watrcurss; grass swals - grass-lind channls fr cnvying runff frm rads and thr imprvius surfacs; xtndd dtntin (dry) basins - basins that str runff fr 1-2 days and drain t an ssntially dry cnditin btwn strm vnts. Ths diffr frm cnvntinal dry rtarding basins, which gnrally str runff fr up t a fw hurs; sand filtrs - bds f sand (r thr similar mdia) thrugh which runff is passd. Th filtrd runff is thn cllctd by an undrdrain systm; 21

G G infiltratin trnchs - shallw, xcavatd trnchs filld with gravl (r any high prsity matrial, including prpritary units) int which runff, f an apprpriat quality, drains t grundwatr; infiltratin basins - pn xcavatd basins dsignd t infiltrat runff thrugh thir flrs; and prus pavmnts - pavmnts that allw runff t drain thrugh a cars gradd cncrt/asphalt pavmnt r pn paving blcks, subsquntly t infiltrat t th undrlying sil (rfr t th nts n prus pavmnts in Runff Managmnt). Infiltratin shuld nly b adptd fr rlativly "clan" runff (g rf watr). Runff cntaining high lvls f nutrints and micr-rganisms shuld nt b infiltratd. Trtiary tratmnt tchniqus aim t rmv nutrints, bactria, fin sdimnts and havy mtals. Th mst cmmn tchniqu is th cnstructd wtland systm. This cmpriss: G @ a pnd (r dp watr zn): pn watr that might hav submrgd plants, but with mrgnt macrphyts ccurring arund th fring (littral macrphyts), and a wtland: an ara vgtatd with mrgnt plants, with varius vgtatin zns bing distinguishd by dpth, frquncy and duratin f inundatin. A pnd can als b trmd a watr pllutin cntrl pnd, a wt basin r a dp watr zn. Pnds ar cmmnly cnstructd upstram f a wtland, and can b cntiguus within a wtland systm. Th pnd and wtland may, hwvr, b cnstructd sparatly t prfrm diffrnt functins Sand filtrs may b cnstructd t includ a mdia layr with an adsrptin capacity (g pat r humus). Ths culd als b classifid as a trtiary tratmnt masur. Strmwatr tratmnt masurs and rtarding basins shuld b lcatd as cls t th surc as practical. This maximiss th ffct f managing strmwatr quality and quantity thrughut th lngth f th watrway, maximising bnfits t dwnstram aquatic csystms, channl frm and riparian vgtatin. This apprach will als liminat th advrs nvirnmntal impacts that cmmnly ccur whn strmwatr tratmnt masurs ar cnstructd n watrcurss in th lwr rachs f catchmnts. Th risk f xcssiv pllutant ladings t rciving watrs will als b rducd by this apprach. If a singl, larg tratmnt masur is rlid n t achiv th dsird rductin in pllutant lading, any failur will incras pllutant ladings. If a numbr f small tratmnt masurs ar distributd thrughut th catchmnt, th failur f an individual tratmnt masur is unlikly t cmprmis th catchmnt's targt pllutin rtntin. Furthr, unlss upstram flw and watr quality cntrls ar prvidd, rstrd aquatic habitats may rquir nging rstratin. 3.4 Riparian vgtatin managmnt Th principal apprachs t managing riparian vgtatin ar rtntin and rplanting with apprpriat indignus spcis. It is, hwvr, imprtant that th causs f th initial dgradatin b addrssd prir t undrtaking rplanting. This particularly applis t flw and watr quality managmnt and th pssibl nd fr structural bank prtctin wrks fr rding channls. Altrnativly, th rplanting culd b dsignd t suit ths changd cnditins. 22

3.5 Watrcurs and aquatic habitat managmnt Watrcurs and aquatic habitat managmnt activitis includ: maintaining xisting valuabl watrcurss, rhabilitatin f physically dgradd watrways and dsigning "natural" channls in liu f mr cnvntinal lind channls. Ths activitis can imprv th clgical cnditins f th watrway, and nhanc rcratin and asthtic pprtunitis. As ntd abv, th causs f any dgradatin shuld b invstigatd and managd t minimis th impact f th caus prir t undrtaking rstratin, r th rstratin shuld b dsignd fr ths changd cnditins. A rang f tchniqus is availabl which can nhanc th habitat charactristics f dgradd watrcurss fr aquatic fauna. Ths tchniqus includ: bank stabilisatin, bank/armuring prtctin, and th installatin f habitat structurs (g snags). Th dsign f "natural" channls is an xtnsin f stram rstratin. It invlvs th cratin f channls with th attributs f natural watrcurss, including: G a mandring plan frm in dynamic quilibrium with sit charactristics; a main channl with a fldplain (principally in middl and lwr rachs);.. a sris f pls and riffl zns (rapids); and G riparian and fldplain vgtatin. Th lcatin f strmwatr discharg pints t aquatic nvirnmnts shuld als b carfully cnsidrd. Strmwatr pips discharging t tidal wtlands and stuarin nvirnmnts with sagrasss can altr th salinity pattrns by th discharg f "frsh" watr. Thy can als ffctivly rprsnt a "pint surc" f pllutin t ths aras. A similar situatin can aris in snsitiv frshwatr nvirnmnts such as wtlands. Apprpriat nrgy dissipatin shuld b undrtakn fr any strm watr pips discharging t natural watrcurss. This is t avid a "jt" f strmwatr.. causmg rsion. Maintnanc f natural watrcurss shuld b undrtakn in a mannr that is snsitiv t th natural nvirnmnt. This can includ timing f maintnanc activitis t avid th sasnal mvmnt f any aquatic fauna. 3.6 Urban bushland managmnt Aras f urban bushland ar frquntly affctd by th discharg f urban strm watr. This impact is causd by incrasd and mr frqunt strm watr flws, incrasd nutrint lvls and wd sds and prpaguls, lading t rsin f drainag lins and th stablishing f wds within bushland aras. T minimis ths impacts, strmwatr managrs shuld: " minimis th cratin f nw strm watr flw paths; cntrl th vlcity f strmwatr flws ntring bushland; and rduc th lvls f strmwatr pllutants dischargd int bushland aras. 23

3.7 Bridgs and culvrts acrss watrways A numbr f issus shuld b cnsidrd whn dsigning bridgs r culvrt crssings f watrcurss r stuaris t nsur thir impacts ar minimisd. Ths includ: dsigning th structur t nabl any significant upstram and dwnstram mvmnt f fish, aquatic inscts and trrstrial fauna t ccur; minimising scur dwnstram f th bridg r culvrt. Highr dwnstram flw vlcitis may scur th channl, causing rsin and habitat lss; acknwldging that watrcurss ar in a stat f "dynamic quilibrium" and can chang thir lcatin and frm undr natural cnditins. Watrway crssings may rstrict this dynamic prcss r th crssing may b undrmind; and prviding an apprpriat watrway ara and gmtry fr stuary crssings, t minimis th impact n upstram tidal cnditins. Fr xampl, bx culvrts can prvid bttr flushing charactristics undr ths cnditins than pip culvrts. 3.8 Watr Snsitiv Urban Dsign Nw urban dvlpmnts shuld b basd n watr snsitiv urban dsign principls. Ths principls ar basd n minimising th impacts f dvlpmnt n th ttal watr cycl and maximising th multipl us bnfits f a strmwatr systm. Th vrall gals f watr snsitiv urban dsign ar: prsrvatin f xisting tpgraphic and natural faturs, including watrcurss and wtlands; prtctin f surfac watr and grundwatr rsurcs; and intgratin f public pn spac with strmwatr drainag crridrs, maximising public accss, passiv rcratinal activitis and visual amnity. Th brad principls f watr snsitiv urban dsign includ: minimising imprvius aras; minimising us f frmal drainag systms (g pips); ncuraging infiltratin (whr apprpriat); and ncuraging strm watr rus. Watr snsitiv urban dsign principls can b adptd at a rang f dvlpmnt scals, including: th vrall xtnt f prpsd dvlpmnt aras; th rad and blck layut within a dvlpmnt; and dvlpmnt frms n individual blcks. Ptntial watr snsitiv dsign tchniqus includ: inclusin f natural habitats (g watrcurss) within th dvlpmnt ara, primarily within pn spac aras. This includs th prvisin f buffr zns adjacnt t watrcurss and thr watrbdis; 24

c intgratin f majr (abv grund) strmwatr systms as psitiv faturs within th urban dsign rathr than purly functinal lmnts t b 'hiddn' (g aviding back fncs adjacnt t drainag rsrvs); adptin f watr snsitiv rad dvlpmnt standards. Ths can includ rducd pavmnt widths and th us f grass swals in plac f krb and guttr and. pipd strmwatr drains; us f cmpact dvlpmnt frms. Fr xampl, rducing individual blck sizs and incrasing cmmunal pn spac (and strmwatr drainag) aras t achiv th sam dnsity as a standard rsidntial dvlpmnt; and watr snsitiv car park dsign. This can includ substituts fr imprvius surfacs such as pavrs r rinfrcd grass, particularly in infrquntly usd parking aras. Runff can als b managd by grass swals instad f krb and guttr and pipd drainag systms. Infiltratin f runff can als b cnsidrd. 25

4 CHALLENGES TO IMPROVING STORMWATER MANAGEMENT Thr ar a rang f financial, institutinal, tchnical and managmnt challngs that strmwatr managrs may nd t rcgnis and addrss if th strm watr managmnt bjctivs ntd abv ar t b satisfid. 4.1 Institutinal arrangmnts Strmwatr managmnt is rarly th rspnsibility f n rganisatin within a catchmnt. Organisatins that may playa rl can includ: a lcal cuncil; a watr authrity; a rad authrity; a rail authrity; catchmnt managmnt bdis; a stat r trritry nvirnmnt prtctin authrity; a stat r trritry natural rsurcs managmnt authrity; a stat r trritry planning authrity; a natinal parks managmnt authrity; and land r prprty dvlprs and buildrs. Th rls f sm f ths authritis may b undrtakn by th privat sctr. Ths rganisatins cmmnly hav sparat rls, rspnsibilitis and managmnt priritis. Strmwatr managmnt may b a cr activity f nly a fw, if any f ths rganisatins. Past xprincs may influnc th way that ths strmwatr managrs mak dcisins. Achiving a cmmn visin fr all strmwatr managrs within a catchmnt can b a challng. Th prparatin f a Catchmnt Managmnt Plan n a cprativ basis by all strmwatr managrs within a catchmnt can hlp addrss ths institutinal issus. Th implmntatin f th plan culd b guidd by a string cmmitt, with rprsntativs frm all rlvant managrs. A catchmnt managmnt bdy culd als tak a guiding rl. An additinal challng can ccur in nw dvlpmnts. Land dvlprs can install apprpriat watr quality cntrls during th cnstructin phas f a dvlpmnt. Ths may thn b rmvd whn th rspnsibility fr th land and strm watr systms is handd vr t th lcal cuncil. Oftn th building phas is nt cmplt at this tim, rsulting in lvatd pllutin lads until building is cmplt. This highlights th nd fr apprpriat managmnt f th building phas by bth buildrs and th lcal cuncil. 4.2 Funding cnstraints Funding fr strm watr managmnt by strmwatr managmnt authritis has ftn fcusd n th installatin and maintnanc f drainag infrastructur. Funding t bradn th currnt apprach 26

t strmwatr managmnt, and adpt a mr nvirnmntally-snsitiv and ESD-basd apprach may nt b radily availabl frm xisting rvnu surcs. Structural strmwatr managmnt cntrls tnd t b rlativly xpnsiv, bth in capital and prating csts. Nn structural surc cntrls tnd t b lwr cst. Anthr funding challng can aris whn a dwnstram strm watr managr is rquird t pay fr managmnt practics that ar ncssary t manag th high flws and/r pllutant lads frm upstram aras undr th cntrl f thr strmwatr managrs. Thr ar tw brad apprachs that can b adptd t addrss this issu, sparatly r tgthr: incras rvnu, pssibly by additinal rats r lvis. Ths ar mr likly t gain cmmunity supprt if th cmmunity has bn clsly invlvd in th strmwatr planning prcss and can s whr thir mny will b spnt. Grant funding is an altrnativ incm surc; and r-allcatin f xisting funding. Lcal cuncils and thr strmwatr managrs may hav sparat budgts that rlat t bradr strmwatr managmnt. Ths can includ wast managmnt, rad maintnanc, parks and gardn maintnanc, and cmmunity rlatins. A multi-disciplinary apprach t strm watr managmnt can draw n rsurcs frm ths and thr surcs. Imprvd strmwatr managmnt practics can ftn b cmbind with xisting prgrams at minimal cst. Any spcial strmwatr rats r lvis culd b basd n a "gnratr pays" principl. Highr rats culd apply t landhldrs gnrating highr runff vlums r pllutant lads. This culd b basd n th imprvius aras n a blck f land. Rbats culd b prvidd fr th installatin f rainwatr tanks r blcks that minimis imprvius aras cnnctd t th drainag systm. Th distributin f csts shuld b quitabl and lgally sund. Othr ptins may includ th dvlpmnt f catchmnt-basd r rginal strmwatr managmnt prgrams. This may includ ducatin campaigns r catchmnt audits f industrial r cmmrcial prmiss. This can rduc th cst t th individual stnnwatr managrs invlvd. A catchmnt managmnt frum and fcus can hlp hr. It is unprductiv t hav n grup rpair th damag anthr grup is causing as this ds nt lad t chang in pr practics. Prparing Strmwatr Managmnt Plans n a catchmnt basis thrugh a c-prativ prcss, invlving all strmwatr managrs, can rsult in th idntificatin f th mst cst-ffctiv and quitabl managmnt practics bing implmntd. It can nabl a surc cntrl apprach t b adptd, whr strmwatr is managd as cls t th surc as pssibl, rducing impacts n dwnstram managrs. 4.3 Managmnt skills Th shift t a mr nvirnmntally snsitiv and intgratd catchmnt apprach has ncssitatd nw and bradr skills fr managrs, as strmwatr managmnt bcms an incrasingly multidisciplinary fild. Sm cuncils and thr strmwatr managrs may nt hav th skill bas, in bth tchnical and managrial trms, t idntify and succssfully implmnt multipl-bjctiv strmwatr managmnt prgrams. Cntinuing ducatin, th us f cnsultants, th us f thr rsurcs within a cuncil (g nvirnmntal and cmmunity rlatins fficrs), r sharing f tchnical rsurcs btwn strmwatr managrs can hlp addrss this issu. 27

4.4 Uncrtainty A dgr f uncrtainty xists with many aspcts f stnnwatr managmnt, including: G pllutant gnratin frm diffrnt land uss; th rspns f watrways t pllutant ladings; aquatic csystm rspnss t changd watr quality, flw and thr cnditins; th rspns f channl mrphlgy t changd flw rgims; th ffctivnss f stnnwatr tratmnt masurs, cmmunity ducatin prgrams and thr managmnt practics; watr quality and hydrlgical mdlling; uncrtainty in stimating infrqunt flds usd in fld mitigatin and any crrspnding risk analysis; watr quality mnitring (accurat and rprsntativ mnitring can b xpnsiv, particularly as pllutant cncntratins can vary vr tim); and climatic and sasnal variability. Dspit this uncrtainty, thr is ampl vidnc that urbanisatin rsults in ngativ impacts n aquatic csystms. Th currnt difficultis in quantifying ths impacts shuld nt prvnt actins bing implmntd t minimis ths impacts, in accrdanc with th prcautinary principl f ESD. It is imprtant that this uncrtainty is accmmdatd within th stnnwatr managmnt planning prcss. Apprachs t addrss this challng may includ: fllwing an adaptiv nvirnmntal managmnt apprach. This may invlv implmnting th bst knwn slutin t a prblm, mnitring th ffctivnss f th slutin and rfining it if ncssary; undrtaking r ncuraging indpndnt mnitring f stnnwatr tratmnt dvics and dissminating th mnitring rsults; and including a mnitring cmpnnt in stnnwatr prjcts. This can apply t bth structural slutins and cmmunity ducatin prgrams. Th NWQMS Guidlins such as th Australian and Nw Zaland Watr Quality Guidlins fr Frsh and Marin Watrs (2000) and Guidlinsfr Watr Quality Mnitring and Rprting (2000) can assist in dfining ths aspcts. 4.5 Public invlvmnt Cmmunity invlvmnt in stnnwatr managmnt is imprtant t nabl th cmmunity t hav "wnrship" f bth th issus and th slutins. An apprach whr managmnt slutins ar dvlpd in islatin frm th cmmunity and thn impsd "frm abv" is unlikly t b succssful r sustainabl. Achiving ffctiv cmmunity cnsultatin in th strmwatr managmnt planning prcss can b a challng. Hlding a structurd public mting may b inffctiv in raching a significant sctin f th cmmunity. Mr "n-grund" cnsultatin prcsss may b rquird (rfr t th Cmmunity Educatin part f sctin 3.3 fr furthr infnnatin). 28

Raising th prfil f strm watr issus in th cmmunity is likly t> ncurag gratr invlvmnt in strmwatr planning. Prgrams such as 'adpt-a-drain' fr industris and schls r cmmunity invlvmnt in simpl strmwatr mnitring prgrams can hlp in this rgard. Thr ar als many situatins whr urban cmmunitis hav bn th primary surc f th visin and imptus in rcvring urban watrway valus. Strmwatr managmnt agncis hav prvidd an imprtant tchnical infrmatin prvisin rl in ths situatins. 4.6 Changing managmnt framwrk Th managmnt framwrk in which strmwatr managrs mak dcisins ftn changs vr tim. Th plicy and lgal framwrk can chang, as can cmmunity xpctatins. It is imprtant that strmwatr managrs rcgnis this and adpt an adaptiv appr>ach t strmwatr managmnt. 4.7 Urban grwth impacts Grwth f urban aras, incrasd urban dnsity, industrial dvlpm.nt, and failur f aging swrs hav cmmnly ld t incrasd urban strmwatr pllutin f lcal and dwnstram csystms. Inadquat prvisin fr strmwatr drainag has ld t flding prblms frm incrasd pak flws, gratr flw vlums and altrd flw pattrns. It is imprtant that th impacts f urban dvlpmnt b assssd as part f th land us planning prcss. This will nabl th planning authrity t mak a mr infrmd dcisin n th bnfits and nvirnmntal csts f a prpsd dvlpmnt. Th Grn Citis - Stratgy Papr #3 (May 1995), publishd by th Dpartmnt f Husing and Rginal Dvlpmnt, discusss urban watr quality prblms and sm dirctins fr th futur. Incrasd nutrint and cntaminant ladings lad t mr apparnt changs in csystm cmpsitin and structur. Cumulativ lading f pllutants frm catchmnts shuld b rducd t lvls cnsistnt with dwnstram sustainability. Dvlpmnt shuld b guidd by a c-rdinatd apprach assciatd with: c catchmnt basd planning and managmnt; intgratd urban land us planning; intgratd watr cycl managmnt; and infrastructur prvisin and managmnt practics which rflct scial, cnmic and nvirnmntal valus. 29

5 CATCHMENT MANAGEMENT FRAMEWORK 5.1 Catchmnt managmnt plans Rarly ds urban land us ccupy th ntir catchmnt. Cnsquntly, thr is a nd t cnsidr th rl f diffus dischargs frm a rang f land us sctrs, tgthr with municipal, industrial and agricultural wastwatr pint surc dischargs, in scuring th prtctin r rstratin f dwnstram watr quality and nvirnmntal valus. This planning framwrk thn prvids th catchmnt cntxt fr th managmnt f individual land us sctrs, including urban land us, acrss th catchmnt. 5.1.1 Primary bjctiv f catchmnt planning Th ky bjctiv f catchmnt planning is t achiv clgically sustainabl us and managmnt f watr and land rsurcs acrss th catchmnt, and scuring th physical, cnmic and scial wll bing f cmmunitis within th catchmnt. Th us f Catchmnt Managmnt Plans hav bn adptd as a vhicl fr: G G G partnrship f stakhldrs in rsurc managmnt dcisins and actin; intgratd planning and managmnt f watr and rlatd land rsurcs; scuring agrmnt n nvirnmntal and us valus f watrways t b prtctd; and idntificatin f cllctiv actins rquird t mt a rang f cmmunity physical, scial and cnmic nds in a mannr cnsistnt with th prtctin f th agrd nvirnmntal and us valus. Th dvlpmnt f Catchmnt Managmnt Stratgy Plans is ncuragd undr th NWQMS Implmntatin Guidlins(ANZECC & ARMCANZ, 1998) and th Cuncil f Australian Gvrnmnts Watr Rfrms (Cuncil f Australian Gvrnmnts Cmmuniqu n Watr Rsurc Plicy, 1994). 5.1.2 Scp f Catchmnt Managmnt Plan cnsidratins Catchmnt Managmnt Plans d nt rplac th rl f Lcal and Rginal Plans in implmnting a numbr f th stratgis cntaind within th Catchmnt Managmnt Plan. It is th basis fr nabling stakhldrs t cllabrat in th idntificatin f: G G th rang f nvirnmntal and us valus f watrways acrss th catchmnt t b prtctd (Sctin 7.2.4); th currnt flw and pllutin issus and th managmnt implicatins, acrss th rang f land us sctrs (including urban land us); th intgratd catchmnt wid actin ncssary t scur a rang f nvirnmntal, scial and cnmic bnfits in rspct t watrs acrss th catchmnt; and th principls guiding th implmntatin f th catchmnt actins rlativ t ach f th land us sctrs (including urban aras) and pint surc discharg catgris acrss th catchmnt. Dcisins n land us, dvlpmnt frm, landscaping, pn spac prvisin and lcatin, and rcratin facilitis hav a strng baring n urban watr managmnt pprtunitis and cnstraints. 30

Cnsquntly, in an intgratd land and watr basd catchmnt apprach, thr ar pprtunitis t scur substantial scial, nvirnmntal and cnmic bnfits as cmpard t a sparat cnsidratin f land and watr aspcts. A Catchmnt Managmnt Plan can prvid th instrumnt fr this intgratin. Plan dvlpmnt will fcus n whl f catchmnt issus, cmpris a brad rang f bjctivs, and invlv xtnsiv cmmunity participatin. 5.1.3 Administrativ framwrk Stat gvrnmnts hav adptd a rang f administrativ framwrks nabling th dvlpmnt f Catchmnt Managmnt Plans, frm lgislatin stablishing catchmnt basd watr managmnt agncis, t lgislativ r administrativ rquirmnts (and funding) fr dvlpmnt f plans by lcal gvrnmnt authritis sharing catchmnts, t administrativ prvisins fr stablishmnt f catchmnt managmnt advisry cmmitts. In additin, thr ar many xampls whr a lcal gvrnmnt authrity, ithr indpndntly in situatins f sl ccupatin f a catchmnt, r in cllabratin with adjining authritis whr a catchmnt is shard, has undrtakn th dvlpmnt f Catchmnt Managmnt Plans and bst managmnt practic guidlins. Fr xampl: Mrtn Bay catchmnt, Prt Phillip Bay catchmnt, Uppr Murrumbidg catchmnt (ACT and sub-rgin), castal stuaris, Mtrplitan Adlaid urban catchmnts, and Swan Canning and stuary catchmnt. 31

6 STORMWATER MANAGEMENT PLANS 6.1 Ovrviw Th primary purps f Strmwatr Managmnt Plans is t idntify actins that will imprv th nvirnmntal managmnt f urban strm watr and prtct th nvirnmntal valus f rciving watrs. Urban strm watr is just n f a hst f cmplx urban planning issus having brad scial, cnmic and nvirnmntal implicatins fr urban cmmunitis. Substantial urban planning, lgislativ and administrativ framwrks ar alrady in plac, including cmmunity cnsultatin, t dal with ths issus. Thr is a nd t intgrat urban strmwatr managmnt stratgis int this urban planning and managmnt framwrk. Th rcnt grwth in cncrns abut th prvisin and quality f urban pn spac, including drainag crridrs, tgthr with cmmunity cncrns abut th watr quality impacts f urban strmwatr, hav highlightd th imprtanc f urban strmwatr stratgis as part f urban planning. Th Australian Mdl Cd fr Rsidntial Dvlpmnt dals with strmwatr as an intgral part f urban dsign. Th issus f urban watr quality ar dscribd in th Dpartmnt f Husing and Rginal Dvlpmnt's Grn citis - Stratgy papr #3 (1995). Th planning and prvisin f urban strmwatr infrastructur is largly th rspnsibility f lcal gvrnmnt. At tims, ths urban srvics ar prvidd by th privat sctr. Planning cntrls, nginring standards and sub-catchmnt basd drainag schms ar th principal instrumnts guiding th prvisin f ths srvics. Implmnting urban Strmwatr Managmnt Plans is th ky t imprvd quality f stnnwatr particularly in xisting urban aras. Ths plans rly n th applicatin f bst managmnt practics and th Watr Quality Guidlins and th Guidlins fr Mnitring and Rprting (2000) shuld infnn thir dvlpmnt. 6.2 Bst practic Strmwatr Managmnt Plans ar a way f hlping cuncils and thr lcal authritis rcgnis th impacts f activitis within thir bundaris, and t dvlp bst practic managmnt stratgis and prgrams. Stnnwatr Managmnt Plans rflct th bligatin f vry authrity t adpt a bst practic apprach t th nvirnmntal managmnt f urban strmwatr. Th achivmnt f bst practic shuld nsur that (a) dcisins in rlatin t nw dvlpmnt (including rdvlpmnt) ar mad with th implicatins fr strm watr impacts n rciving watrs takn int accunt rathr than vrlkd, and (b) rmdial masurs (bth structural and nn-structural) ar undrtakn in a cstffctiv, intgratd and crdinatd mannr. Bst practic nvirnmntal managmnt f urban strmwatr rquirs th intgratin f a rang f masurs within a dfind prgram, as picturd in Figur 4. 32

Land and Watrus Planning Rgulatin Urban dsign LandMgmt Enfrcmnt Educatin and awarnss Strmwatr tratmnt FtwMgmt Plicy, Planning and Dsign Surc Cntrls In-Systm Managmnt Masurs Bst Practic Strm watr Managmnt Figur 4 - Bst practic nvirnmntal managmnt f strm watr rquirs intgratin f a rang f masurs (Adaptd/rm Victrian Strm watr Cmmitt (1999)) Ths masurs shuld incras th liklihd that: G thr is clar cmmitmnt t imprvd strmwatr managmnt; strm watr managmnt bjctivs ar incrpratd int th statutry planning framwrk and thr rlvant plans, stratgis and plicis affcting land us and land managmnt dcisins; nw urban infrastructur mts nvirnmntal prfrmanc bjctivs cnsistnt with agrd sustainabl lad/cncntratin targts; rlatinships btwn agncis and lcal authritis ar strngthnd t dlivr crdinatd prgrams and nsur cnsistnt priritis; th cmmunity is invlvd in strmwatr managmnt; and prfrmanc mnitring allws fr fdback and imprvmnt f th plan. 6.3 Adaptatin t lcal circumstancs Thr is grat variability in th physical, chmical and clgical prcsss which ccur within and btwn catchmnts. Rspnsibl authritis must dal with a rang f managmnt bjctivs, prblms, issus and cmmunity xpctatins within catchmnts. Dvlpmnt and implmntatin f Strmwatr Managmnt Plans must accmmdat ths circumstancs as wll as lcal lgislativ and administrativ arrangmnts. Each authrity must mak its wn judgmnts abut balancing priritis, cnflicting bjctivs and allcating rsurcs. Strmwatr Managmnt Plans shuld prvid a framwrk fr making ths judgmnts, rcgnising th cnsquncs f dcisins and bing accuntabl fr prfrmanc. 33

6.4 Managmnt bjctivs Th ky bjctiv in strmwatr managmnt is t idntify a rang f bst practics fr imprving th nvirnmntal prfrmanc f urban strmwatr systms that will assist in prtcting th nvirnmntal valus and bnficial uss f watrways and castal watrs. This bjctiv may b scurd by applicatin f a rang f actins, including: G raising cmmunity awarnss rgarding strmwatr managmnt pprtunitis and bnfits, and th prvisin f tchnical infrmatin guiding imprvd practic; th intgratd planning, dvlpmnt and managmnt f watr and urban land n a catchmnt r sub-catcnmnt basis;.. th partnrship f stakhldrs in rsurc managmnt dcisins and actin; and G idntificatin f cllctiv actins rquird t mt a rang f cmmunity physical, scial and cnmic nds in a mannr cnsistnt with th prtctin r rstratin f th agrd nvirnmntal and us valus, induding th us f rgulatin and th prvisin f strmwatr managmnt infrastructur. Whr urban land us is th majr land us acrss th catchmnt, th dvlpmnt f th Strmwatr Managmnt Plan may b undrtakn intgrally with th dvlpmnt f th Catchmnt Managmnt Plan. 6.5 Managmnt hirarchy As ntd in Sctin 3.1, strmwatr managmnt planning shuld b basd n th fllwing hirarchy: 1. Rtain and rstr valuabl csystms: rtaining r rstring (if dgradd) xisting valuabl lmnts f th strmwatr systm, such as natural channls, wtlands and riparian vgtatin; 2. Surc cntrl: nn-structural masurs: nn-structural tchniqus fr limiting changs t th quantity and quality f strmwatr at th surc; 3. Surc cntrl: structural masurs: cnstructd managmnt tchniqus installd at r nar th surc t manag strmwatr quantity and quality; and 4. In-systm managmnt masurs: cnstructd managmnt tchniqus installd within strmwatr systms t manag strm watr quantity and quality prir t discharg int rciving watrs. Bst practic ncurags an intgratd apprach incrprating ths principls. Surc cntrls can idally prvnt many f th pllutants frm raching th strmwatr systm, hwvr, in practic a cmbinatin f surc and structural cntrls ar usually rquird t achiv an imprvmnt in strmwatr quality. Prtcting r rstring th valus and uss f urban watr nvirnmnts rquirs an intgratd apprach dirctd at managing th vlnm and rat f catchmnt run-ff, th qnality f th runff, and th habitats ncssary fr supprting a halthy aquatic cmmunity. 34

Fld prvntin and public safty rmain as fundamntal bjctivs f strmwatr systm planning and dsign. Strm watr quality masurs shuld in n way cmprmis ths bjctivs. In fact, many masurs dsignd fr strmwatr quality cntrl hav inhrnt watr quantity managmnt functins (and vic vrsa). 6.6 Scp Strmwatr Managmnt Plans shuld prvid an intgratd urban land us and drainag managmnt stratgy n a catchmnt r sub-catchmnt basis, which: Q G dscribs th catchmnt r sub-catchmnt ara idntifis stakhldrs and partnrship mchanisms utlins agrd valus, issus and managmnt bjctivs idntifis managmnt stratgis fr: land and watr us and practics land us and frm addrsss implmntatin instrumnts and prgrams, including: ducatin and training planning infrastructur prvisin pratin and maintnanc rgulatin cnmic incntivs addrsss assssmnt and prfrmanc rviw, including: mnitring f valus and cnditins mnitring f stratgy implmntatin rviw tim frams 35

7 DEVELOPING STORMWATER MANAGEMENT PLANS 7.1 Prcss Strmwatr managmnt planning shuld aim t: idntify prpsd managmnt actins which will cst-ffctivly addrss th strmwatr issus f a catchmnt r sub-catchmnt; and dfin mchanisms and arrangmnts fr th implmntatin f ths actins, including managmnt, funding, prfrmanc rviw, mnitring, rprting and futur rvisin f th plan. Strmwatr managmnt planning shuld b basd n th gnral mdl f rsurc managmnt planning illustratd in Figur 5. Th prcss f dvlping plans shuld: idntify th valus and cnditins t b prtctd r rstrd; idntify thrats t ths valus and cnditins, and managmnt bjctivs addrssing ths thrats; idntify and assss managmnt ptins t addrss managmnt bjctivs r thrats; adpt prfrrd managmnt ptins, including managmnt bjctivs and targts; idntify mans f implmnting managmnt ptins; and idntify an implmntatin and prfrmanc rviw prgram. This squnc f th planning prcss is imprtant in nsuring managmnt ffrt is ffctivly fcussd n prtctin r rstratin f th significant and pririty catchmnt valus. Attmpting t addrss a lng list f pssibl strmwatr issus, withut rfrnc t hw ths issus affct achivmnt f bjctivs, is unlikly t b cst-ffctiv. It is imprtant that th Strmwatr Managmnt Plans: ncurag cmmunity invlvmnt in strmwatr managmnt; ncurag th prsrvatin f valud xisting lmnts f th watr nvirnmnt; maximis th cntrl f strmwatr runff at surc; idntify and priritis an apprpriat mix f cst-ffctiv strmwatr managmnt practics t suit th particular pprtunitis, cnstraints and rquirmnts f a catchmnt; and incrprat mnitring prcdurs fr fdback and imprvmnt f th plan. Idntifying th valus, managmnt bjcti vs, and ky clgical/hydrlgical prcsss shuld b undrtakn as part f th catchmnt planning prcss. Catchmnt Managmnt Plans shuld idntify th ky uss and valus acrss a catchmnt and stablish watr quality targts t sustain thm. Urban strm watr is just n f many issus which may impact n catchmnt valus and uss. Thrfr, it shuld prfrably b cnsidrd in cntxt with ths thr issus. In many aras, rginal valus, uss and watr quality targts hav nt bn stablishd as part f a Catchmnt Managmnt Plan r thr planning prcss. Whr ths ar nt in plac, th 36

stnnwatr managmnt planning prcss may nd t incrprat an additinal stag in rdr t idntify ths valus and targts. Whn stting spcific watr quality bjctivs fr th idntifid nvirnmntal valus, rfr t tb Australian and Nw Zaland Watr Quality Guidlins fr Frsh and Marin Watrs (2000). c:> Idntify nvirnmntal valus ~ Mnitr cnditin Establish gals and and prfrmanc targts ~ Managmnt actins ~ Figur 5 - Stps in rsurc managmnt (adaptd fmm Natinal Watr Quality Managmnt Stratgy -Implmntatin Guidlins (1998) 7.2 Essntial lmnts in dvlping plan 7.2.1 Establish framwrk Th first task in th prcss can invlv stablishing th vrall framwrk fr th plan and th plan prparatin prcss. This may includ stablishing: th purps f th plan; th scp f th plan; rspnsibilitis fr stnnwatr managmnt within th catchmnt; th bundaris fr th plan (g catchmnt/sub-catchmnt, municipality, individual twnship); public and thr stakhldr cnsultatin prcsss; and rlvanc f th findings r rcmmndatins f any thr rlvant plan. 7.2.2 Idntify stakhldrs and partnrship mchanisms Lack f tchnical knwldg is nly n bstacl t imprvd stnnwatr managmnt. Mr ftn, th main cnstraint is a lack f agrmnt that imprvd nvirnmntal prfnnanc is imprtant, r a lack f cnsnsus n stnnwatr managmnt priritis. Kys t achiving mr ffctiv actin includ: gnrating cmmitmnt t a bst practic apprach; stablishing agrd priritis and managmnt stratgis r actins; and stablishing a basis fr nging cpratin with and crdinatin btwn agncis and thr stakhldrs. 37

Cmmitmnt is achivd mstly thrugh invlvmnt f a wid crss sctin f authritis, ky agncy rprsntativs, and thr stakhldrs in th planning prcss and in th assignmnt f accuntabilitis. It is imprtantfr ths with a rl in imprving th nvirnmntal managmnt f strmwatr t shar in th prcss f dvlping th plan. TIlls mans invlving rprsntativs frm arss functinal aras f authritis, ky agncis, and thr stakhldrs. Many stakhldrs hav thir wn spcific intrsts in dcisins n urban drainag and drainag crridr managmnt. Sm xampls f th typs f stakhldrs ar listd in Tabl 2. Tabl 2 - Pssibl stakhldrs and thir intrsts Stakhldr typ Prprty wnrs adjacnt t drainag crridrs Envirnmntal grups Drainag authritis Swrag authritis Envirnmntal rgulatry authritis Natural rsurc managmnt agncis Rad authritis Businss Twn plannrs Infrastructur nginrs Opratins Intrst Prtctin f prprty frm flding, lcal ara amnity, and rcratin pprtunity, pprtunitis t incrprat strmwatr tratmnt masurs. Idntificatin f nvirnmntal valus, impacts f urban strmwatr. Efficint prvisin and pratin f drainag srvics, drainag infrastructur standards, strmwatr tratmnt, pratin f th drainag systm, rciving watr managmnt, risk and liability. Swr vrflws, tratmnt plant dischargs, strmwatr infiltratin. Dsignatin f nvirnmntal valus and uss, watr quality targts. Th licnsing f dischargs. Pllutin prvntin. Prtctin f bita, habitat, natural cmmunitis and th balanc and quitabl us f natural rsurcs. Minimising pllutin frm rads and cnstructin activitis, nsuring rad surfacs ar quickly draind f strmwatr. Adptin f bst practic t minimis pllutin. Land us planning, cntrls n land usrs, urban frm, infrastructur rquirmnts. Enginring standards, minimisatin f liability, risk and csts. Srvic/maintnanc standards, pllutin rspns, nfrcmnt, cst minimisatin. 7.2.3 Idntify activitis and cnditins A critical stag in th planning prcss invlvs th gathring f infrmatin t supprt th rst f th planning prcss and nsuring th activ invlvmnt f th ky participants. During this incptin stag, it is imprtant t gain an undrstanding f th xtnt t which Xisting and ptntial futur activitis may thratn rciving nvirnmnts, and hw wll xisting managmnt prcsss within lcal authritis and thr agncis dal with strmwatr issus. Exampls f typical strmwatr issus and thir rigins ar listd in Appndix 3. It is imprtant t us th incptin stag t stablish hw a rviw f managmnt prcsss will b undrtakn. Th rviw shuld cvr planning, rgulatin, ducatin, nfrcmnt and pratins as wll as any xisting structural apprachs t managing strmwatr impacts as utlind blw in Tabl 3. Th rlatinship btwn th lcal authrity and thr agncy activitis shuld als b 38

xamind. This infrmatin will cntribut t th frmulatin f managmnt stratgis latr in th planning prcss. Tabl 3 - Rviw f managmnt prcsss Planning Opratins Rgulatin Educatin Structural masurs Planning schm, planning plicis, prmit cnditins Spcificatins fr srvic dlivry (g wast cllctins), asst maintnanc activitis (g lcal rads), dpt pratins Intgratin btwn plicy, planning cntrls, lcal laws and nfrcmnt activitis Prgrams aimd at ths invlvd in activitis with ptntial t affct th strmwatr systm Incrpratin f structural masurs int buildings, rads and drainag systms t rduc nvirnmntal impacts Dcumnt th natur f urban land us It is imprtant t cmpil an vrall pictur f land us activitis. This is bst rprsntd by a plan f land us zns cvring th ara. Hwvr, lcal knwldg f diffrncs btwn land us typs must b applid. Fr xampl, t distinguish btwn ld and nw industrial aras which may diffr in th typs f industris and th quality r standard f assciatd infrastructur and thrfr th lvl f impact n strmwatr. In additin t sit spcific activitis thr ar a numbr f transint activitis, such as building cnstructin, which must b accuntd fr. Othr xampls includ building maintnanc activitis, hm car srvicing and s n. Transint activitis can b significant pllutrs and ar difficult t cntrl. Dcumnt th strm watr systm It is als imprtant t dcumnt th strmwatr systm. This is bst prsntd as a map with physical faturs shwing th catchmnts (main catchmnts and sub-catchmnts), th drainag systm (main drains) and th rciving nvirnmnts which might includ pn watr curss, wtlands, watr bdis and s n. 7.2.4 Idntify valus and bjctivs Envirnmntal valus ar particular valus, r uss f th nvirnmnt, that ar imprtant fr a halthy csystm r fr public bnfit, wlfar, safty r halth and which rquir prtctin frm th ffcts f pllutin wast dischargs and dpsits. Thr ar a numbr f tchniqus availabl fr assssing catchmnt and watr bdy valus that rlat t strmwatr managmnt. A prliminary assssmnt f ths valus shuld b undrtakn, which may b rfind fllwing rcipt f additinal infrmatin. It may b usful t stablish ths 39

valus by hlding a stakhldr wrkshp t btain cmmunity input int th idntificatin f th valus. Ths valus may als b mappd vr th catchmnt ara. Catchmnt valus may includ clgical valus (aquatic fauna and flra, trrstrial fauna, urban bushland), scial valus (public halth and safty, rcratinal us f watrs, visual amnity) and cnmic valus (watr us, aquacultur, strmwatr rus tc). Fllwing idntificatin f th valus f a strmwatr systm and its catchmnt, managmnt bjctivs can b dvlpd t prtct ths valus (rfr t Australian and Nw Zaland Watr Quality Guidlins fr Frsh and Marin Watrs (2000)). Strmwatr managmnt bjctivs aim t dfin th utcms w sk t achiv in ur managmnt f strmwatr t prtct r rstr th idntifid catchmnt r watrway valus. It is likly that thr sts f bjctivs will b apprpriat. Th first may b lng-trm bjctivs (ffctivly a 'visin' fr th catchmnt) and th scnd bing mr shrt trm, quantifiabl bjctivs. Ths shrt-trm bjctivs can dfin what th plan shuld sk t achiv, and may b th basis fr valuating th prfrmanc f th plan at th nd f a crtain prid (g 3 yars). Th third st f bjctivs rlat t nw dvlpmnt. Th strmwatr managmnt bjctivs fr nw dvlpmnt aim t dfin th strmwatr utcms which will b rquird f nw dvlpmnt within th catchmnt, including rdvlpmnt f urban sits. Ths bjctivs shuld idally dfin utcms sught, rathr than stratgis t b mplyd, in rdr t facilitat flxibility and ncurag innvatin in th managmnt f strmwatr at nw dvlpmnt sits. Ths bjctivs shuld b dfind in trms f (and linkd t) th catchmnt valu(s) t which thy rlat. Ths bjctivs shuld b cnsistnt with and incrprat th principls f clgically sustainabl dvlpmrit, as apprpriat. 7.2.5 Idntify thrats t valus, cnditins and bjctivs A list f majr sit spcific and transint activitis with ptntial t damag rciving nvirnmnts shuld b prpard which idntifis: th typ f strm watr thrat; and a significanc rating f th thrat. In arriving at a significanc rating, cnsidratin shuld b givn t th magnitud and frquncy f ccurrnc (g quantity f pllutant lad gnratd r svrity f pllutin spills and frquncy) and th lvl f public cncrn abut ths. Thr will sldm b data availabl n th impact f ths activitis n rciving nvirnmnts. Hwvr, an infrmd assssmnt can b basd n prfssinal judgmnt and xprinc as wll as lcal knwldg, histry f spills, cmplaints, ag f infrastructur and s n. 7.2.6 Idntify managmnt stratgis A rang f stratgis and actins t manag urban strmwatr thrats t rciving watr valus shuld b cnsidrd. Ths shuld tak int accunt lcal, rginal r catchmnt-wid impacts and bnfits, and will includ a mix f stratgis rlatd t: at-surc managmnt stratgis such as planning and dsign masurs; in-transit structural cntrls; and 40

rci ving watr managmnt. Chaptr 3 idntifis sm f th rspnss that may b implmntd as part f ths stratgis. Ths rspnss includ a varity f planning, rgulatry, infrastructur, surc cntrl, and ducatinal apprachs. Th slctin and dsign f any spcific managmnt apprach will b strngly influncd by lcal cnditins, such as sustainabl lad issus, runff rspnss t land us chang, rciving watr rspnss t pllutants, and pakflw cnsidratins. Hwvr, as ntd in Sctin 4.4 Uncrtainty managrs may nd t act n th basis f th prcautinary principl as a dgr f uncrtainty xists with many aspcts f strm watr managmnt. It may b ncssary t undrtak prliminary dsign f stratgis as a basis fr cmmunity assssmnt f ptins and t tst thir tchnical and administrativ fficincy. Prliminary dsign shuld cnsidr: prtcting dwnstram nvirnmntal valus via sustainabl ladings r cncntratins; 9 allcating sustainabl ladings acrss catchmnt surcs, g wastwatr, nrban strmwatr, rural/agricultural runff tc; G dtrmining bst managmnt practics; prliminary sizing and csting f cmpnnts ncssary t nsur cmplianc with sustainabl lading allcatd t strm watr runff; lcal nvirnmntal quality issus; and changing cmmunity xpctatins and incrasd stringncy f rquirmnts. 7.3 Lcal ara dvlpmnt plans Lcal ara dvlpmnt plans ar a cmmn rquirmnt f Stat and Lcal Gvrnmnt Planning apprval prcsss. Many jurisdictins rquir th cnsidratin f utility srvics (drainag, swrag, watr supply) as part f ths plans r as part f strmwatr mastr plans. Sm jurisdictins may rquir intgratd and cmprhnsiv tratmnt f bi-physicallandscap cmpnnts, alng with th prpsd land us chang and dsign principls. Drainag authritis typically rquir that ths plans ar cnsistnt with Strm watr Guidlins r drainag standards, which st ut systm dsign rquirmnts, including majr and minr flw pathways. Ths 'atsurc' tchniqus ar addrssd as Bst ManagmntPractics (BMP) r Watr Snsitiv Urban Dsign Principls. Intgratd land and watr planning at th lcal rsidntial, cmmrcial and industrial ara ffrs pprtunitis fr significant nhancmnt f blck, strtscap, and prcinct landscap and watr us valus, and a significant rductin in pak discharg and pllutin missins frm th sit. Prviusly, drainag authritis undrtk th dvlpmnt f a main drainag mastr plan, as th basis fr mting thir srvic prvisin bligatins. With th shift in rl f th drainag crridrs frm singl purps 'drainag' functin t multi-purps us, a nd fr gratr intgratin acrss rlatd jurisdictins has ccurrd. Lcal dvlpmnt plans shuld idntify pprtunitis t scur multipl watr supply, pn spac, rcratin and cnsrvatin bnfits. Ths plans ar mrging as a critical tl t assist jurisdictins with shard rspnsibilitis fr srvic prvisin r managmnt within drainag crridrs t crdinat thir planning. 41

Intgratd land and watr planning at th suburb r district lvl ffrs pprtunitis fr significant nhancmnt f urban watrways as: crridrs f significant pn spac and landscap valus; ppl and wildlif mvmnt crridrs; attnuatin f flws and intrcptin f strmwatr pllutants systms; cratin f valuabl rcratin and cnsrvatin wtlands, pnds, laks. 7.3.1 Dvlpmnt bjctivs Rquirmnts fr dvlpmnt may b xprssd as qualitativ r quantitativ prfrmanc bjctivs, srvic r infrastructur standards r guidlins. Ths may b cntaind in Catchmnt Managmnt Plans usually as rciving watr quality bjctivs r discharg rquirmnts. Or thy may b cntaind in a Strmwatr Managmnt Plan. Th Dvlpmnt Plan shuld idntify hw ths bjctivs r rquirmnts will b achivd. 7.3.2 Administrativ framwrk Thr is a divrs array f administrativ prcdurs baring n this cmpnnt. All Stats and Trritris hav planning structurs prscribing prcdurs and standards t b incrpratd int lcal gvrnmnt urban stratgy r plicy plans. Lcal gvrnmnt authritis usually maintain urban stratgy and plicy plans and lcal ara dvlpmnt plans as th basis fr dvlpmnt apprvals. Thr has bn a significant shift away frm prscribd managmnt masurs in rcnt yars t a mr stratgic and guidlins fcusd apprach. Th dvlpmnt f Australian Mdl Cd fr Rsidntial Dvlpmnt (AMCORD, 1995) is an xampl f this shift. Th Cd incrprats xtnsiv matrial n intgratd strmwatr managmnt practics. Strmwatr, landscap and rcratin managmnt grups within lcal gvrnmnt authritis maintain stratgy and mastr plans as th basis fr intgratin with land us planning, and th ffctiv prvisin f srvics. Stat nvirnmntal agncis may stablish nvirnmnt prtctin plicis and rquirmnts fr managmnt plans undr Stat nvirnmntal lgislatin. Statutry nvirnmnt plicis ar mr ftn rlatd t catchmnt plans than lcal dvlpmnt plans. S catchmnt plans and statutry nvirnmnt prtctin plicis may dsignat dvlpmnt rquirmnts in trms f qualitativ r quantitativ prfrmanc bjctivs. As ntd abv, thr ar many xampls whr a lcal gvrnmnt authrity, ithr indpndntly r in cllabratin with adjining authritis, has undrtakn th dvlpmnt f Strmwatr Managmnt Plans and Bst Managmnt Practic guidlins. Sm xampls includ: Strmwatr Cmmitt Victria (1999), Urban Strmwatr: Bst Practic Envirnmntal Managmnt Guidlins. Nw Suth Wals EPA (1997), Draft: Managing Urban Strmwatr: Cuncil Handbk. Watr and Rivrs Cmmissin (1998), A Manualfr Managing Urban Strmwatr Quality in Wstrn Australia. Dpartmnt f Natural Rsurcs and Dpartmnt f Envirnmnt (Qunsland) (1998), Strmwatr Quality Cntrl Guidlins fr Lcal Gvrnmnt. 42

7.4 Assssing altrnativs and slcting prfrrd ptins Th achivmnt f 'bst practic' will dpnd n th succssful intgratin f a numbr f stratgis and actins t prtct strmwatr quality acrss functinal aras within th authrity and crdinatin with thr agncis and stakhldrs. Managmnt ptins shuld b valuatd against critria f cst, ffctivnss in th lng-trm in prtcting r nhancing valus, pprtunitis fr implmntatin, and capability f th authrity r thr agncis t implmnt. Accptanc by th cmmunity shuld als b cnsidrd. 7.4.1 Dvlping actins Whr particular managmnt masurs r ptins rat highly against th abv critria, dtaild actins shuld b frmulatd. Whr rlvant, ths actins shuld includ: G G suggstd changs t th land us planning framwrk, urban dvlpmnt guidlins, infrastructur standards, tc; suggstd changs t spcificatins fr srvic dlivry; th typ, lcatin and indicativ cst f structural tratmnt masurs; targt audincs fr ducatin and training prgrams r nfrcmnt; spcific lcatins fr targtd prgrams (a particular industrial r cmmrcial ara r rciving nvirnmnt); th nd t furthr invstigat th xtnt r natur f strmwatr thrats; th nd fr crdinatin with thrs; rspnsibility fr lading implmntatin (i cuncil dpartmnt, agncy r thr); and suggstd prfrmanc masurs and rprting framwrk. Thr is als likly t b a nd fr a stratgy t addrss th inclusin f gnral plicis and bjctivs int an xisting authrity crprat plan and land us planning framwrk. This stratgy shuld als dal with th intgratin f actins acrss functinal aras within th authrity, and any arrangmnts fr crdinatin with thr agncis. Prpar and xhibit a draft plan A draft Strmwatr Managmnt Plan shuld b prpard and mad availabl fr rviw by stakhldrs including th cmmunity. An adquat xhibitin prid shuld b prvidd fr th public t accss and rviw th draft dcumnt. Prpar final plan Fllwing rcipt f cmmnts frm stakhldrs n th draft plan, a final strmwatr managmnt plan can b prpard. 7.5 Implmnting Strmwatr Managmnt Plans Prparatin f Strmwatr Managmnt Plans clarly cnstituts nly th first stp twards th ultimat aim f imprvd nvirnmntal utcms. It is ssntial fr strm watr managrs t als fcus n th implmntatin f th plans. 43

It is imprtant fr Strmwatr Managmnt Plans t b viwd as 'liv' dcumnts, which ar activly cnsultd, rviwd and rvisd. Strmwatr managrs shuld adpt a mdl f 'cntinuus imprvmnt' in th prgrssiv rfinmnt f Strmwatr Managmnt Plans. Strmwatr managrs shuld activly mnitr th ffctivnss f th plan, and rprt n th findings f tbat mnitring t th cmmunity. Such mnitring and rprting is cnsidrd t frm an intgral cmpnnt f th 'cntinuus imprvmnt' f Strmwatr Managmnt Plans. Th prparatin f a Strmwatr Managmnt Plan can b cnsidrd as part f a strmwatr managmnt prcss (r systm) fr a catchmnt. This is illustratd in Figur 6. This managmnt prcss can b basd n th Envirnmntal Managmnt Systm apprach utlind in th ISO 14000 sris f standards. Prpar strmwatr managmnt plan Imprv implmntatin ifrquird Implmnt plan's rcmmndatins Mnitr and rviw th ffctivnss f th plan Rvis plan if rquird It is imprtant t nt that: Figur 6 - Th Strm watr managmnt prcss th prparatin f th plan is nly n part f tb prcss; G th rviw f th implmntd practics can lad t rvisins t th plan; and th strmwatr managmnt planning prcss is nvr 'finishd' (i imprvmnts can b mad t th plan using th rsults f th mnitring and rviw prcss). Public rprting can includ bth a prgrss rprt n th plan's implmntatin and rprting n th nvirnmntal utcms achivd by th plan's actins. This rprting culd b includd in stat-f-th-nvirnmnt rprts, rgular nwslttrs, and/r n ntic bards in public aras nar watrcurss. This public rprting is imprtant if cmmunity supprt fr th plan is t b maintaind. Fdback frm th public can als b rqustd tbrugh this prcss, which can assist in th mnitring and rviw f th plan. 44

8 PERFORMANCE REVIEW Scintifically rigrus mnitring f strm watr discharg quality and pllutant lads is cmplx, rquiring carful dsign, stablishmnt f stram gauging and aut-samplrs, and multipl sampling vr a numbr f vnts. Th NWQMS Guidlins jr Watr Quality Mnitring and Rprting (2000) prvid infrmatin guiding th dsign f mnitring prgrams, slctin f indicatrs, and lcatin and frquncy f sampling. Th Guidlins includ sm lw cst mnitring tchniqus capabl f idntifying impairmnt f bita and pllutant catgris. In viw f th financial and tchnical rsurc dmands f vnt basd mnitring, and th brad unifrmity fr similar land uss and managmnt practics rginally, cnsidratin shuld b givn t cllabratin acrss lcal gvrnmnt aras and with Stat gvrnmnt agncis, in stablishing jint mnitring prgrams. As part f implmntatin f th Strmwatr Managmnt Plan, authritis shuld idntify spcific milstns and bjctivs which nabl mnitring and rviw f th implmntatin prcss. Ths milstns shuld rlat t: achiving imprvmnts in spcific rciving nvirnmnt valus which ar currntly thratnd; r rductins in spcific strmwatr thrats. Prfrmanc in implmnting th Strmwatr Managmnt Plan shuld b assssd annually and rprtd back t th cmmunity and stakhldrs. Whr rsurcs ar availabl fr lng trm scintific mnitring, prgrams shuld b carfully dsignd. Thr may b a nd t rviw xisting baslin data bfr dvlping a mnitring and rviw prgram. Th plan shuld idntify data dficincis and mnitring rquirmnts. This mnitring diffrs frm th mnitring/auditing f th plan's implmntatin. Mnitring nabls rviw f: th plan's prfrmanc in rducing urban strmwatr pllutin; th watr quality and clgy rspns f prtctd dwnstram watrs; and cmmunity prcptin and accptanc f th stratgy. Thr distinct mnitring catgris ar invlvd. Ths ar: a brad charactrisatin f physical, chmical and bilgical cmpnnts ncssary t charactris th gmrphlgy, hydr-chmistry and clgy f systms, and dtrmin thir significanc; analysis t idntify trnds in watr quality and clgy f watrs, and indicatrs f chang in clgical cmpsitin and structur; and prfrmanc basd mnitring t rviw spcific plicis r practics in mdifying flw pattrns and rspns prcsss t scur spcific watr quality r clgical bjctivs. Appndix 4 utlins th scp f watr quality and clgy data rquirmnts. 45

9 A VIEW TO THE FUTURE Many urban cmmunitis, lcal authritis and dvlprs in Australia ar nw adpting a mr intgratd land and drainag apprach t strmwatr managmnt, at th lcal sub-divisin, urban drain and watrway lvls. Th substantial scial, cnmic and nvirnmntal bnfits ar driving cmmunitis twards this chang. Mdifid apprachs and tchniqus bing adptd by cmmunitis cmpris: " intgratin f rainwatr managmnt int architctural dsign fr buildings and assciatd landscaping *: applis t watr supply, wastwatr managmnt and its rcycling " imprvd urban frm and sub-divisin dsign which intgrats strm watr managmnt, grywatr r-us and landscaping int th rsidntial blck and prcinct lvls (gry watr r-us ptins nd t b valuatd n a cas-by-cas basis) '" '" '" tchniqus usd includ infiltratin, rainwatr tanks, and grassd swals and wtlands in plac f pipd drains. *: ths ar particularly attractiv in situatins f grnfild dvlpmnt and urban rnwal rtntin f natural strams within th urban aras, r cnstructin f vgtatd watrways in plac f larg pip r cncrt channl main drains *: as part f this apprach, fld crridrs ar dvlpd as pn spacs and landscap faturs which can includ wtland and flw dtntin facilitis, pnds, riparian and fld way vgtatin, with parklands and pdstrian and cycl pathways *: watrways can als b usd as a watr supply distributin systm fr scnd class (strmwatr) watr supply purpss prtctin r rstratin f rginal watrways such as primary strams and thir fldplains, r laks r stuaris and thir frshr zns *: in this apprach, urban and rginal watrways and thir crridrs ar intgratd as cntiguus systms *: bnfits includ ffctiv drainag, prtctin f nvirnmntal and us valus, ppl and wildlif mvmnt crridrs This framwrk is illustratd in Figur 7 - Intgratd framwrk guiding th dvlpmnt f managmnt stratgis. Such an intgratd apprach rquirs strmwatr managrs t slct and apply masurs which mbrac a rang f valus (safty, watr supply, pn spac and mvmnt amnity, cnmy, sustainability, landscap, clgy and rcratin). Ths masurs nd t b apprpriat t th fllwing nds: buildings, trrain, lcal watrways and crridrs and scndary and primary watrbdis. Onc slctd, ths nds will thn nd t b intrlinkd s, fr xampl: th trrain assssmnt addrsss implicatins fr lcal watrways and th primary watr bdy; 46

" th lcal watrways assssmnt incrprats implicatins fr th primary watr bdy and fds back t th trrain assssmnt; and " th primary watr bdy assssmnt fds back t bth th trrain and watr bdy assssmnts. Fr ffctiv implmntatin f a truly intgratd and systmatic apprach t strmwatr managmnt, managrs must hav a strng cmmitmnt t dvlping thir knwldg and skills, s thy ar abl t apply th bst mix f tls r lcal prblms. Thy must als b cmmittd t undrstanding th rl f ducatin in strm watr managmnt. Ths Urban Strmwatr Guidlins ncurag managrs t apply bst drainag and pllutin managmnt practics t prtct basic nvirnmntal and us valus f dwnstram watrs. Thy ncurag a mr intgratd apprach t urban land and watr planning and managmnt and this intgratd framwrk dfins ur lng-trm bjctiv in Intgratd Catchmnt Managmnt - whr w want t gt t. 47

CATCHMENT V... ------... ---, I BUILDINGS & LANDSCAPE I Assss utcms Functin, frm Slct watr I & xtrnal f+ faturs & -+ in rlatin t I building & valus mgmt masurs I trnal valus I I 't I LOCAL RUNOFF AREAS (blck, strtscap, nighburhd) I I Idntify valus, Slctmgmt Hydr & bi- --J> I thrats & masurs. gchm prcsss I pprtunitis Assss utcms in rlatin t lcal & xtrnal valus 't URBAN W ATERW A Y & CORRIDOR (drains/strams, wtlands/puds, laks) Idntify valus, Slct mgmt Hydr & bithrats & ~ masurs --J> gchm prcsss pprtunitis i==:... Assss utcms in rlatin t watrway " & xtrnal valus 't REGIONAL W ATERW A YS (Strams & thir crridrs r laks & stuaris & thir frshr) Idntify valus, Slct mgmt thrats & --J> masurs ~ pprtunitis Hydr & bigchm prcsss Assss utcms in rlatin t rginal & xtrnal valus Figur 7 -Intgratd framwrk guiding th dvlpmnt f managmnt stratgis 48

APPENDIX 1: NWQMS GUIDELINE DOCUMENTS Papr N. Titl Plicis and Prcss fr Watr Quality Managmnt I Watr Quality Managmnt - An Outlin f th Plicis 2 Plicis and Principls - A Rfrnc Dcumnt 3 Implmntatin Guidlins Watr Quality Bnchmarks 4 Australian and Nw Zaland Watr Quality Guidlins fr Frsh and Marin Watrs 4a An Intrductin t th Australian and Nw Zaland Watr Quality Guidlins fr Frsh and Marin Watrs 5 Australian Drinking Watr Guidlins - Summary 6 Australian Drinking Watr Guidlins 7 Australian Guidlins fr Watr Quality Mnitring and Rprting 7a Australian Guidlins fr Watr Quality Mnitring and Rprting - Summary Grundwatr Managmnt 8 Guidlins fr Grundwatr Prtctin in Australia Guidlins fr Diffus and Pint Surcs 9 Rural Land Uss and Watr Quality - A Cmmunity Rsurc Dcumnt 10 Guidlins fr Urban Strmwatr Managmnt II Guidlins fr Swrag Systms - Efflunt Managmnt 12 Guidlins fr Swrag Systms - Accptanc f Trad Wast (Industrial Wast) 13 Guidlins fr Swrag Systms - Sludg (Bislids) Managmnt (draft) 14 Guidlins fr Swrag Systms - Us f Rc1aimd Watr (draft) 15 Guidlins fr Swrag Systms - Swrag Systm Ovrflws (draft) 16a. Efflunt Managmnt Guidlins fr Dairy Shds 16b Efflunt Managmnt Guidlins fr Dairy Prcssing Plants 17 Efflunt Managmnt Guidlins fr Intnsiv Piggris 18 Efflunt Managmnt Guidlins fr Aquus Wl Scuring and Carbnising 19 Efflunt Managmnt Guidlins fr Tanning and Rlatd Industris 20 Efflunt Managmnt Guidlins fr Winris and Distillris 49

APPENDIX 2: IMPACTS OF URBANISATION ON THE STORMWATER ENVIRONMENT It is imprtant fr managrs t hav an undrstanding f th many, ftn intracting impacts f urban strmwatr, as a cnsqunc f urbanisatin activitis, n human and csystm halth. This will hlp t: " bas managmnt dcisins n ESD; Q mak cst-ffctiv dcisins which targt th caus f a prblm, nt th symptm;.. dvlp actins that bnfit aquatic csystm halth; and " dvlp managmnt actins tailrd t a particular catchmnt t minimis impacts - thr ar n simpl gnric slutins. Urbanisatin will gnrat significant changs within a catchmnt including changs t its hydrlgy, watr quality, watrway channls, riparian vgtatin, and aquatic habitats. HYDROLOGY Runff frm nn-urban catchmnts is influncd by factrs such as: rainfall- rainfall intnsity, duratin and th prid btwn rainfall vnts all influnc runff rats and vlums; " vapratin - dirct vapratin frm watr bdis and vaptranspiratin frm sil and vgtatin rducs runff; sils, particularly sil prmability - runff vlums tnd t b highr frm catchmnts with lw prmability sils. Sil mistur lvls can vary acrss catchmnts, influncd by bth tpgraphy and rainfall. Sils with high mistur lvls gnrat highr runff; " vgtatin - this influncs vaptranspiratin rats and grundwatr charactristics. Runff vlums and rats ar gnrally highr frm a rural catchmnt than frm a frstd catchmnt; " tpgraphy - runff rats tnd t b highr frm stpr catchmnts; and " watrcurs charactristics - flw rats frm catchmnts with stp, narrw watrcurss ar highr than ths frm flat, wid watrcurss. Runff charactristics frm nn-urban catchmnts can thrfr b highly variabl. Fr xampl, tw adjacnt catchmnts culd hav diffrnt runff rspnss t th sam rainfall vnt, du t diffrnt tpgraphy, sils and vgtatin. Urbanisatin rsults in larg imprvius aras bing cnstructd within a catchmnt. Ths can rang frm 25-50% f a standard rsidntial catchmnt. Highr imprvius aras ccur in highdnsity, industrial r cmmrcial aras. Ths imprvius aras dcras rainfall infiltratin and vaptranspiratin acrss a catchmnt. This incrass runff vlums and acclrats vrland flw vlcitis. Th strmwatr "transprt systms" in urban aras (pips and lind channls) tnds t b mr hydraulically fficint than natural watrcurss. This furthr incrass flw rats. 50

Strmwatr runff in urban catchmnts is ftn frm imprvius surfacs such as rads and pavd aras. As such, sil charactristics, tpgraphy and vgtatin gnrally hav a minr ffct n urban runff rats. Urban runff is cmmnly lss variabl frm undr nn-urban catchmnts. Ths changs can hav a numbr f ffcts n th stramflw rgim, including: G G incrasd frquncy f runff vnts. Runff will ccur fr almst all rainfall vnts, rathr than nly larg vnts fr rural r frstd catchmnts; highr vlums, pak flws, flw vlcitis, bd shar strss. This can caus channl rsin and widning, rsulting in incrasd turbidity and sdimntatin; mr rapid rat f watr lvl ris and fall during flds; mr frqunt inundatin f fldplains; dcrasd grundwatr flw du t rducd rainfall infiltratin; and rducd bas flws in watrcurss, causd by lwr grundwatr dischargs. Excss gardn watring and lakag frm watr pips may cmpnsat fr this. Th gratst diffrnc btwn pak flws frm nn-urban and urban catchmnts cmmnly ccurs fr frqunt fld vnts. This ftn ccurs fr vnts with an avrag rcurrnc intrval f 2 t 5 yars. It is causd by th prvius aras nly cntributing runff frm ths largr vnts. Figur 8 illustrats this chang. \ 20 \ UrbanI, rural... pak... flw 10... rati......... 0 -... --- ~ 0.1 1 10 100 Avrag Rcurrnc Intrval (yars) Figur 8 -Indicativ rati f pak flws frm urban and rural catchmnts (aflr Cdnr l a11988) Changs t flw pattrns aftr urbanisatin can rsult in a rang f nvirnmntal impacts, including:.. public safty, dirct and indirct prprty and infrastructur damag. This is causd by th highr flw rats and vlcitis; altrd channl frm and incrasd sdimnt transprt. Scuring f channls by highr flws can widn and dpn watrcurss. Th scurd sdimnts can b dpsitd in dwnstram watrbdis; 51

uprting f riparian and aquatic vgtatin by th highr flws. Thr can als b a shrtr prid fr ths plants t r-stablish btwn flds; th mr frqunt runff vnts caus mr frqunt pllutant inputs t watrways. Gratr runff vlums als gnrat highr pllutant ladings; th wtting and drying cycls in frshwatr wtlands can b altrd by th incrasd runff. This can impact n th wtland's vgtatin and fauna; altrd tidal cnditins in stuaris. Th salinity pattrns in stuaris and stuarin wtlands can b altrd by th highr runff; and mr frqunt flds incras th frquncy f disturbanc t aquatic csystms. This is likly t rduc th divrsity f aquatic fauna. Th mvmnt f aquatic fauna may b hindrd by th altrd flw cnditins. WATER QUALITY Many substancs prsnt in watr that ar ftn calld "pllutants" ar ssntial t th functin f aquatic csystms. Ths includ: suspndd slids - ths slids can cntain rganic mattr fr prcssing by aquatic inscts and micr-rganisms. Thy als prvid a hm fr crtain inscts and "sil" fr aquatic plants; nutrints - ar usd by aquatic plants and alga; and lavs - prvid a fd surc fr aquatic inscts and bactria. Tabl 4 lists cmmns surcs f pllutants in strmwatr. Typical instantanus cncntratins f a numbr f pllutants ar prsntd in Tabl 5. In nn-urban catchmnts, factrs influncing watr quality includ th gchmistry f th undrlying bdrck and th catchmnt's sils. Riparian and catchmnt vgtatin ar als influncrs. Agricultural land us als affcts watr quality in rural aras. Pllutant cncntratins thrfr vary, bth within and btwn ths catchmnts. 52

Tabl 4 - Cmmn surcs f pllutants in strmwatr Pllutant Sdimnt Nutrints Oxygn dmanding substancs ph (acidity) Micr-rganisms (including pathgns) Txic rganics Havy mtals Grss pllutants (littr and dbris) Oils and surfactants Incrasd watr tmpratur Runff frm imprvius surfacs Salinity Cmmn surc Sil rsin during land dvlpmnt, building Stram bd/bank rsin Particulats frm pavmnt and vhicl war R-suspnsin f prviusly sdimntd matrial Atmsphric dpsitin f particulats Spillag/iUgal discharg f particulats Discharg f rganic mattr (g laf littr, grass) Particulats frm car washing Particulats frm th wathring f buildings/structurs Wathring f bdrck Ersin f sils having adsrbd nutrints Rlas frm sdimnts as a rsult f dcmpsitin f rganic matrial Washff f frtilisr Swr vrflws/sptic tank laks Animalfbird facs missins and washff Dtrgnts frm car washing Spillag/illgal discharg Atmsphric dpsitin Washff f rganic mattr frm urban landscap & agricultur Atmsphric dpsitin Swr vrflws/sptic tank laks, swag fflunt discharg AnimaUbird facs missins & washff Spillag/illgal dischargs Atmsphric dpsitin (acid rain) Industrial spillag/illgal discharg Washff f rganic matrial & dcmpsitin Ersin f rfing matrial Mbilisatin f acid sulfat sils as a rsult f urban drainag r sil stripping AnimaUbird facs missins & washff Swr vrflws/sptic tank laks, swag fflunt discharg Washff f rganic matrial & dcmpsitin Washff, drift f psticids, rsin f sil having adsrbd psticids Washff, lakag f hrbicids, rsin f sil having adsrbd hrbicids Spillag/illgal discharg Swr vrflws/sptic tank laks, swag fflunt dischargs Atmsphric dpsitin f particulats particulats frm vhicl war and missins Swr vrflws/sptic tank laks, swag fflunt discharg particulats frm wathring f buildings/structurs Rlas frm sdimnts as a rsult f dcmpsitin f rganic matrial Industrial spillag/illgal discharg Pdstrians and vhicl missins, war, littring Spills frm wast cllctin systms Laf-fall frm trs Dispsal f lawn clippings Spills and accidnts Wathring f asphalt pavmnts, rlas frm sdimnts, spillag/illgal dischargs, missins, laks frm vhicls, surfactants frm car washing Discharg f rganic mattr high in natural ils Organic mattr Rmval f riparian vgtatin Discharg f grundwatr high in salinily as a rsult f drainag, r lvatin f grundwatr lvl as a rsult f urbanisatin. Wastwatr fflunt dischargs. - 53

Tabl 5 - Rang f typical pllutant cncntratins in strmwatr Pllutant Dry wathr cncntratins Wt wathr vnt man cncntratins Frst Rural Urban Frst Rural Urban Suspndd slids 1-20 3-270 1-350 1-140 4-200 20-1000 (mg/l) Nutrints (mgil): Ttal phsphrus 0.006-0.24 0.008-0.81 0.001-2.2 0.01-0.42 0.03-1.3 0.12-1.6 Ttal nitrgn 0.04-1.2 0.12-4.2 0.1-11.6 0.27-0.66 0.23-5.1 0.6-8.6 Micr-rganisms: Facal clifrms 0-200 10-100 40-40,000 260-4,000 700-3,000 4,000- (cfu/100ml) 200,000 Incrasd watr nla 5 nla tmpratur ) (Surc: aftr Simn! t al (1994), Frgusn t al (1994), Sharpm (I995b, )) Urbanisatin f a catchmnt intrducs a rang f nw pllutant surcs. In additin, th highr runff vlums, cmbind with lvatd pllutant lvls, incrass pllutant ladings. Tabl 6 utlins a rang f th ptntial nvirnmntal impacts which rsult frm urban strmwatr pllutin. Pllutant Suspndd slids Turbidity Tabl 6 - Ptntial nvirnmntal impacts f urban strmwatr quality Ptntial impact Phsphrus and nitrgn --~--------~----------~ Ammnia, mtals and psticids Organic matrial (BOD) Grss pllutants / littr Incrasd tmpratur Micr-rganisms (g pathgns) dpsitd sdimnt affcts aquatic insct habitats rducs watr clarity, impacting n fish and aquatic plants stimulats ~;wth f alga and undsirabl aquatic plants txic t fish and aquatic inscts at high lvls rducs disslvd xygn lvls, impacting n fish and aquatic inscts, and may transfrm pllutants int mr bi-availabl and txic frms. visually unattractiv, dcmpsing lavs rduc disslvd xygn lvls affcts lif cycls f aquatic fauna, dprsss disslvd xygn lvls, ncurags grwth f undsirabl aquatic plants caus disas in humans in cntact with strmwatr (g swimming, bating) 54

CHANNEL FORM Natural watrcurss cmmnly hav thr zns: G upland rachs: ths tnd t b stp, narrw, fast flwing, rlativly straight and hav rsinrsistant bds; middl rachs: ths cmmnly hav mdrat slps, channl widths and flw vlcitis. Thy tnd t b mr sinuus with mdratly rsiv channl bds; and lwr rachs: cmmnly ths rachs hav lw bd slps and flw vlcitis. Thy tnd t b wid, sinuus and hav fldplains and sdimnt bds. Ths natural channl systms ar in a stat f dynamic quilibrium, ftn changing frm with larg flds. Th mst significant changs t stram gmtry ccur whn th flw xcds th bank-full flw rat. In Australia, th bank-full flw rat is ftn btwn th 1.5 yar and 5 yar avrag rcurrnc intrval fld vnt. Ths changs ccur largly in th lwr and t a lssr xtnt th middl rachs. Riparian vgtatin plays a majr rl in stabilising th banks f watrcurss and fldplains. During urban dvlpmnt, this vgtatin is cmmnly rmvd, pssibly rplacd by xtic vgtatin. Th channl gmtry may als b physically altrd. Incrasd flws aftr urbanisatin can hav a significant impact n channl frm. This is particularly th cas in th lwr rachs. Highr flw vlcitis ar mr rsiv than prdvlpmnt. Ths flws can disldg riparian vgtatin. Highr sdimnt lads frm upstram urban catchmnts ar dpsitd in ths rachs. Th frquncy f bank-full flw rats als incrass. This ftn causs widning f channls. Ovrall, th impacts n channl frm may nt b vidnt fr sm distanc dwnstram f an urban ara. Thy may als b suprimpsd n any prvius impacts causd by rural land uss. Sdimnt transprt pattrns vary with lcatin alng watrcurss. Uppr rachs tnd t b sdimnt surc zns, middl rachs sdimnt transprt zns and.1wr rachs sdimnt dpsitin zns. Estuaris and bachs ar als sdimnt dpsitin zns. In a "natural" systm, flw rats and sdimnt transprt ar in a stat f dynamic quilibrium. Fllwing urbanisatin, bth flw rats and sdimnt lads can incras, ptntially altring this stat. This can rsult in channl rsin and incrasd sdimnt dpsitin in lwr rachs and stuaris. Managmnt practics that ar dsignd t trap cars sdimnt (g grss pllutant traps) can caus dwnstram rsin prblms du t sdimnt starvatin. Sdimnt lads may b rducd t r blw pr-dvlpmnt lvls. Th sdimnt cnvying capacity f fldwatrs may nt b mt by th rducd sdimnt lads, rsulting in bank rsin. Starving f castal bachs f sand causd by rducd sdimnt lads may als ccur. 55

RIPARIAN VEGETATION Riparian vgtatin plays a numbr f imprtant rls in th watr nvirnmnt. Ths includ: shading, lwring watr tmpraturs and rducing light pntratin; lavs and branchs prviding a surc f rganic carbn and nutrints; stabilising channl banks; lgs and tr rts prviding an imprtant habitat fr aquatic fauna; prviding a habitat fr trrstrial fauna, including inscts that ar a fd surc fr fish; pllutin cntrl, trapping pllutants in vrland flw; and wd cntrl, as nativ vgtatin can inhibit th grwth f nxius wds. Th rmval f riparian vgtatin and its pssibl rplacmnt with xtic spcis is a cmmn pattrn in rural and urban land aras. Highr flw vlcitis aftr urbanisatin can als disldg riparian vgtatin. Th nvirnmntal impacts causd by rmving riparian vgtatin can includ: c highr watr tmpraturs; lss f rganic mattr inputs r rplacmnt with unsuitabl laf littr frm xtic plants; lss f aquatic and trrstrial habitats; dcrasd bank stability; incrasd pllutant lads; and xtic wd invasin. AQUATIC HABITATS In-stram bjcts in watrcurss prvid imprtant aquatic habitats. Thy prvid aquatic inscts and fish with shltr frm high flws, shad, rfug aras and spawning sits. Thy fall int thr main grups: bd matrial (g rcks and gravl) and variatins in bd shap (g pls and rapids); falln trs and branchs (snags); and aquatic plants. Wtlands and fldplains ar als imprtant aquatic habitats. Ths habitats ar ftn partially r ttally dstryd in urban aras. Physical changs, high flw rats and sdimntatin can caus this. Th lss f habitat rsults in highr and lss variabl flws, lss f rfug aras and spawning sits. This cmmnly rducs th divrsity and abundanc f aquatic fauna and flra. 56

WATERCOURSE BARRIERS AND CONSTRICTIONS Bridgs, culvrts, wirs, drp structurs and thr structurs ar cmmnly built n watrcurss in urban aras. Ths barrirs can: G altr flw pattrns in watrcurss, incrasing flw vlcitis; impact n th mvmnt f aquatic inscts and fish; chang sdimnt transprt pattrns, rsulting in sdimnt dpsitin r scuring in unxpctd aras; and 9 culvrts and bridgs acrss stuaris can rduc upstram tidal flushing and incras tidal vlcitis in th vicinity f th cnstructin. 57

APPENDIX 3: STORMWATER ISSUES Th fllwing list f majr physical and chmical strssrs ar basd n th ight majr issus idntifid in th Australian and Nw Zaland Guidlins fr Frsh and Marin Watr Quality (ANZECC & ARCANZ, 2000a). Tabl 7 rlats ths strssrs r cnditins t th rang f strm watr rlatd surcs, impacts and rlatd strssrs. Tabl 7 - Majr physical and chmical strssrs Envirnmntal Typical Surcs Impacts Rlatd strssrs & impairmnt issus mdifirs Impact f pathgns Sullag, swr Clsur f bachs, Facal clifrrns, n halth vrflws, sptic, human infctin, bactria, viruss, animals illnss and disas rtntin tim Impact f xygn Sullag, swr Lw disslvd Organic mattr, dpltin vrflws, sptic xygn, smlls, strss ammnia, mixing, animal wast, grass t aquatic lif tmpratur, nitrat and laf littr Impact f txicants Cars, car parks, Bi-accumulatin, Psticids, including mtals and rads, prcssing dath f aquatic lif hrbicids, lad, zinc, psticids industris, spills, suspndd slids, atmsphric sulphat, rganic dt:psitin. mat'l, ph Impact f particulat Rads, urban land Smthring f Silt, sand, gravl, mattr us, cnstructin aquatic plants & clays, rtntin tim sits, mdifid animals, impact n drainag fding, impact n light Impact f flating Cmmrcial aras, Mainly visual, Papr, plastic, lavs, dbris and surfac fast fd utlts, intrfrs with dad vgtatin, algal scums plant dbris aquatic lif scums, il Nuisanc plant Sullag, sptic, swr Prmts plant and Phsphrus, grwth vrflws, animals, algal grwth, blu nitrgn, rganic STP dischargs, grn algal blms mattr, mixing, lavs rtntin tim, tmp Impact f changs in Changs in Pattrn f particulat Vlum, frquncy, flw rgims, catchmnt land us & dpsitin & vlcity incrasd strrnwatr vgtatin, changs r-suspnslon, runff. in drainag washut f bita - mrphlgy succssin prcsss, DO rgims. Changs in physical Lss f riparian Mdificatin t habitat vgtatin, chang in channl mrphlgy, substrat chang in flw & frquncy 58

APPENDIX 4: DESIGN OF MONITORING PROGRAMS Tabl 8 builds n dfining th issus, and th infrmatin rquirmnts, f gd mnitring dsign practic utlind in th Australian Guidlins fr Watr Quality Mnitring and Rprting (ANZECC & ARCANZ, 2000b). It addrsss th mst cmmn issus and infrmatin nd catgris arising in strmwatr managmnt. Tabl 8 - Cmmn issus and infrmatin nd catgris arising in strmwatr managmnt Managmnt Issus Infrmatin rquirmnts Mnitring catl!ry Idntificatin f Currnt uss f watr bdis. Charactrisatin f nvirnmntal valus Eclgical significanc f prvailing watr quality and csystms clgy Outlin f prblms and Aras f xcdnc f watr Charactrisatin f prvailing issus quality critria and watr quality and clgy, cnstitunts having a charactrisatin f watr ptntial t impact n th quality and clgical halth r viability f th prcsss, trnd analysis f csystm r uss changs in watr quality and clgy, analysis f changs in prcsss. Dtrminatin f sustainabl Sustainabl lading f ky Charactrisatin f watr lading runff cnstitunts cnsistnt quality and clgical with maintaining ky watr prcsss quality critria and cmpsitin and structur f csystm Dtrminatin f xisting r Estimatin f cumulativ Charactrisatin f rainfall - futur lading lads n critical dwnstram runff and cnstitunt nds assciatd with land xprts as a functin f land uss and managmnt uss and managmnt practics acrss th practics catchmnt Evaluatin f xprt Estimatin flvl f Charactrisatin f watr rductin fr managmnt cnstitunt intrcptin r quality and clgical stratgis immbilisatin fr diffrnt prcsss. Prfrmanc managmnt practics mnitring fr a rang f managmnt practics Rviw f th prfrmanc Evaluat rductin in xprts Prfrmanc mnitring f f th stratgy and its and changs in watr quality vrall systm, prfrmanc cmpnnts and clgy in rlatin t mnitring f cmpnnts, bjctivs trnd analysis 59

APPENDIX 5: BIBLIOGRAPHY ACT Planning Authrity (1992), Dsign Guidlins fr Grss Pllutant Traps, ACT Planning Authrity (1992), Dsign Guidlins fr Watr Pllutin Cntrl Pnds. ACT Planning Authrity (1993), Enginrd Watrway Dsign Guidlins. ACT Planning Authrity (1993), Guidlinsfr Ersin and Sdimnt Cntrl. ACT Planning and Land Managmnt (1999), Land Capability Assssmnt Guidlins. Amrican Scity f Civil Enginrs and Watr Envirnmnt Fdratin (1993), Dsign and Cnstructin f Urban Strmwatr Managmnt Systms, ASCE Manuals and Rprts f Enginring Practic N 77, WEF Manual f Practic, FFD-20. Andrsn J, Cntr fr Castal Managmnt, Suthrn Crss Univrsity (1999), Basic Dcisin Supprt Systm fr Managmnt f Urban Strams, LWRRDC Occasinal Papr 8/99, Land and Watr Rsurcs Rsarch and Dvlpmnt Crpratin. ARMCANZ & ANZECC (1994a), Guidlins fr Swrag Systms - Accptanc f Trad Wasts (Industrial Wast). Natinal Watr Quality Managmnt Stratgy Papr N 12, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ARMCANZ & ANZECC (1994b), Plicis and Principls - A Rfrnc Dcumnt. Natinal Watr Quality Managmnt Stratgy Papr N 2, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ARMCANZ & ANZECC (1998), Implmntatin Guidlins. Natinal Watr Quality Managmnt Stratgy Papr N 3, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ARMCANZ & ANZECC (1999), Guidlins fr Swrag Systms - Efflunt Managmnt. Natinal Watr Quality Managmnt Stratgy Papr N 11, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ANZECC & ARMCANZ (2000a), Australian and Nw Zaland Guidlins fr Frsh and Marin Watr Quality. Natinal Watr Quality Managmnt Stratgy Papr N 4, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ARMCANZ & ANZECC (2000b), Australian Guidlins fr Watr Quality Mnitring and Rprting. Natinal Watr Quality Managmnt Stratgy Papr N 7, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. 60

ARMCANZ & ANZECC (2000c), Draft Guidlins fr Swrag Systms - Sludg (Bislids) Managmnt (In prss). Natinal Watr Quality Managmnt Stratgy Papr N 13, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. ARMCANZ & ANZECC (2000d), Guidlins fr Swrag Systms - Us f Rclaimd Watr. Natinal Watr Quality Managmnt Stratgy Papr N 14, Australian and Nw Zaland Envirnmnt and Cnsrvatin Cuncil & Agricultur and Rsurc Managmnt Cuncil f Australia and Nw Zaland, Canbrra. Brisban City Cuncil (2000), Watr Quality Managmnt Guidlins. Califrnia Strmwatr Quality Task Frc (1993), Califrnia Strm Watr Bst Managmnt Handbk - Municipal, prpard by Camp Drssr McK. Calw P and Ptts GE (1992), Th Rivrs Handbk: Hydrlgical and Eclgical Principls, Blackwll Scintific Publicatins, Lndn. Claridg G (1991), An vrviw f wtland valus: A ncssary prliminary t wis us, prsntd t th Wtland Wrkshp, Nwcastl, Fbruary. Cmmnwalth Dpartmnt f Halth, Husing and Cmmunity Srvics (1992), AMCORD Urban: Guidlins fr Urban Husing. Cmmnwalth f Australia (1992), Natinal Stratgy fr Eclgically Sustainabl Dvlpmnt. Cuncil f Australian Gvrnmnts (1994), Cmmuniqu, Rprt f th Wrking Grup n Watr Rsurc Plicy, (Mting f25 Fbruary 1994 in Hbart). Dpartmnt f Cnsrvatin and Envirnmnt, (Victria) (1990), Envirnmntal Guidlins fr Rivr Managmnt Wrks. Dpartmnt f Cnsrvatin and Land Managmnt (Nw Suth Wals) (1992), Urban Ersin and Sdimnt Cntrl Manual. Dpartmnt f Envirnmnt and Hritag (Qunsland) (1993), Pumicstn Passag, its catchmnt and BriN Island: Draft intgratd Managmnt Stratgy. Dpartmnt f Husing and Rginal Dvlpmnt (1995), Grn citis - Stratgy Papr #3, May. Dpartmnt f Husing (Nw Suth Wals) and Landcm (1998), Managing Urban Strmwatr Sils and Cnstructin, Sydny. Dpartmnt f Natural Rsurcs and Dpartmnt f Envirnmnt (Qunsland) (1998), Strmwatr Quality Cntrl Guidlins fr Lcal Gvrnmnt. Dpartmnt f Natural Rsurcs, Brisban City Cuncil and Institut Municipal Enginring (Qunsland) (1993), Qunsland Urban Drainag Manual, Vlums 1 and 2. Dpartmnt f Planning, (Nw Suth Wals) (1993), Bttr Drainag: Guidlins fr th Multipl Us f Drainag Systms, Sydny. Dpartmnt f Planning, (Nw Suth Wals) (1992), Outdr Rcratin and Opn Spac: Planning Guidlins fr Lcal Gvrnmnt 61

Dpartmnt f Planning and U Tban Dvlpmnt, th Watr Authrity f Wstrn Australian and th Envirnmnt Prtctin Authrity (1994), Planning and Managmnt Guidlinsfr Watr Snsitiv Urban (Rsidntial) Dsign, prpard by Whlans and Halprn Glick Maunsll, in assciatin with Thmpsn Palmr and Institut fr Scinc. Envirnmnt Prtctin Authrity and Dpartmnt f Land and Watr Cnsrvatin, (Nw Suth Wals) (1999), What W Nd Is... A Cmmunity Educatin Prjct, Sydny. Envirnmnt Prtctin Authrity (Nw Suth Wals) (1997), Managing Urban Strmwatr: Tratmnt Tchniqus. Envirnmnt Prtctin Authrity, (Nw Suth Wals) (1997), Managing Urban Strmwatr: Cuncil Handbk. Draft. Envirnmnt Prtctin Authrity (Nw Suth Wals) (1998), Managing Urban Strmwatr: Surc Cntrl. Draft. Envirnmnt Prtctin Authrity (Suth Australia) (1999), Strmwatr Pllutin Prvntin - Cd f Practic fr th Building and Cnstructin Indusfry. Envirnmnt Prtctin Authrity (Suth Australia) (1996), Strmwatr Pllutin Cntrl - Gnral Cd f Practic fr Lcal Gvrnmnt. Envirnmnt Prtctin Authrity (Suth Australia) (1996), Strmwatr Pllutin Cntrl - Gnral Cd f Practic fr th Cmmunity. Envirnmnt Prtctin Authrity (Victria) (1990), Sdimnt pllutin cntrl n cnstructin sits, TG 208/90. Envirnmnt Prtctin Authrity (Victria) (1991), Cnstructin tchniqus fr sdimnt pllutin cntrl, Publicatin 275. Envirnmnt Prtctin Authrity (Victria) (1994), Drain stabilisatin tchniqus, Publicatin N. 407. Envirnmnt Prtctin Authrity (Victria) (1996), Envirnmntal Guidlins fr Majr Cnstructin Sits. Envirnmntal Prtctin Authrity (Wstrn Australia), Watr Authrity f Wstrn Australia and Dpartmnt f Planning and Urban Dvlpmnt (1993), Watr Snsitiv Urban (Rsidntial) Dsign Guidlins. Institutin f Enginrs (1995), Sil Ersin and Sdimnt Cntrl: Enginring Guidlins fr Qunsland Cnstructin Sits, IEAust Qld Divisin. Khn 1D and O'Cnnr WG (1990), Bilgical Infrmatin fr Managmnt f Nativ Frshwatr Fish in Victria, Dpartmnt f Cnsrvatin and Envirnmnt, Victria, Victrian Gvrnmnt Printing Offic, Mlburn. Kuringai Municipal Cuncil (1993), Strmwatr Managmnt Manual. Marshall Macklin Mnaghan Ltd (1994), Strmwatr Managmnt Practics Planning and Dsign Manual, prpard fr Ontari Ministry f Envirnmnt and Enrgy, Canada. Mlburn Watr (1992), Opn Spac 2000 - Implmnting th Visin, A Stratgy fr th Dvlpmnt and Enhancmnt f Mlburn's Opn Spac Ntwrk. 62

Mlburn WatrlMlburn Watrways and Parks (1993), Catchmnt Impacts: th Urban Watrway Challng, Backyard t th Bay Prgram. Ministry f Envirnmnt and Enrgy Ontari (1993), Intgrating Watr Managmnt Objctivs int Municipal Planning Dcumnts. Natinal Capital Planning Authrity (Australian Capital Trritry) (1993), Dsigning Subdivisins t Sav and Manag Watr, Building Bttr Citis Prgram Occasinal Papr Sris 1, Papr 3. Nwbury R and Gabury M (1993), Stram Analysis and Fish Habitat Dsign, A Fild Manual, Nwbury Hydraulics Ltd, Gibsns, British Clumbia, Canada. O'Lughlin EM, Yung WJ and Mlly JD (1992), Urban Strmwatr: Impacts n th Envirnmnt. CSlRO Divisin f Watr Rsurcs Cnsultancy Rprt 92/29. Ontari Ministry f Envirnmnt and Enrgy and Ministry f Natural Rsurcs (1993), Intgrating Watr Managmnt Objctivs int Municipal Planning Dcumnts, Trnt, Canada. Ontari Ministry f Envirnmnt and Enrgy and Ontari Ministry f Natural Rsurcs (1993), Subwatrshd Planning, Trnt. Main Rads Dpartmnt (Qunsland) (1998), Sil Ersin and Sdimnt Cntrl Manual. Rain A Wand Gardinr IN (1995), Rivrcar: Guidlins fr th Eclgically Sustainabl Managmnt f Rivrs and Riparian Vgtatin, Land and Watr Rsurcs Rsarch and Dvlpmnt Crpratin Occasinal Papr N 03/95. Rsnr L.A. (1992), Currnt Watr Quality Issus in Strmwatr Managmnt in th Unitd Stats, Intrnatinal Sympsium n Urban Strmwatr Managmnt, Sydny. Schulr TR (1995), Sit Planning fr Urban Stram Prtctin, Mtrplitan Washingtn Cuncil f Gvrnmnts, Washingtn DC. Sharpin MG (1995), Strmwatr Quality Charactristics frm Urban and Nn-urban Catchmnts in Suth-astrn Australia, prcdings, AWW A 16th Fdral Cnvntin, Sydny. Standing Cmmitt n Rivrs and Catchmnts (Victria) (1991), Guidlins fr Stabilising Watrways, Rural Watr Cmmissin f Victria. Sustainabl Land and Watr Rsurcs Managmnt Cmmitt Subcmmitt n Watr Rsurcs (1996), Natinal Principls fr th Prvisin f Watr Fr Ecsystms, Agricultur and Rsurc Managmnt Cuncil f Australia & Nw Zaland and Australian and Nw Zaland Envirnmnt & Cnsrvatin Cuncil Occasinal Papr SWR N 3. Swan Rivr Trust, (Wstrn Australia) (1999), An Actin Plan t Clan Up th Swan-Canning Rivrs and Estuary. Trrn Institut (1993), Clan Watr in yur Watrshd: A Citizns Guid t Watrshd Prtctin, prpard in cpratin with th Unitd Stats Envirnmntal Prtctin Agncy. Trrn Institut (1996), A Watrshd Apprach t Urban Runff: Handbkfr Dcisin Makrs, Trrn Institut, Washingtn DC. Urban Watr Rsarch Assciatin f Australia (1995), Bnchmarking and Bst Practic fr Urban Watrway Managmnt, Rsarch Rprt N. 87, January 1995. 63

US Envirnmntal Prtctin Agncy (1990), Urban Targting and Bst Managmnt Practic Slctin. An Infrmatin and Guidanc Manualfr Stat NPS Prgram Staff Enginrs. US Envirnmntal Prtctin Agncy (1993), Guidanc Spcifying Managmnt Masursfr Surcs f Nn-Pint Pllutin in Castal Watrs, Offic f Watr, Washingtn DC, EPA 840-B- 92-002 (http://www.pa.gv/owowinpsimmgi). Victrian Strmwatr Cmmitt (1999), Urban Strmwatr: Bst Practic Envirnmntal Managmnt Guidlins, CSIRO Publishing, Mlburn. Wast Managmnt Cuncil (Victria) and Institut f Municipal Enginring Australia (1996), Bst Practics in Littr Managmnt - A Guid fr Lcal Gvrnmnt. Watr and Rivrs Cmmissin, (Wstrn Australia) (1998), Evaluatin f Cnstructd Wtlands in Prth, Wstrn Australia. Watr and Rivrs Cmmissin, (Wstrn Australia) (1998), A Manualfr Managing Urban Strmwatr Quality in Wstrn Australia. Watr and Rivrs Cmmissin (Wstrn Australia) (1998), Lgislativ Optins fr Urban Strmwatr. Watr Envirnmnt Fdratin and Amrican Scity f Civil Enginrs (1998), Urban Runff Quality Managmnt. 64

APPENDIX 6: GLOSSARY AND COMMON TERMS Fr th purpss f this dcumnt ths trms hav th fllwing maning: Abatmnt Actin t rduc th lvl r intnsity f pak discharg r pllutant cncntratin r lads dischargd in strm vnts. Abitic Th nn-living cmpnnts f a systm. Adsrptin Bnding f mtal and nutrints nt th surfacs f suspndd particls, by way f physical, chmical and bilgical prcsss, and thir rmval by a prcss f sdimntatin f th suspndd particls. Aratin Th injctin f air thrugh diffusrs int watr bdis, r rapid mchanical mixing f th surfac f watr bdis t prmt ntrainmnt f atmsphric air int th watr clumn. A tratmnt prcss adptd in situatins f high lading f xygn dmanding substancs. Arbic r xic zn An nvirnmnt in which thr is fr xygn. Anarbic r anxic zn An nvirnmnt dvid f xygn Armuring r stabilisatin Th us f rck, gtxtil and/r vgtatin t bind th sil frming th bank r bd f channls such as t rsist rsin by lvatd flw vlcitis. Atmsphric dpsitin Pllutants accumulating acrss urban surfacs as a rsult f dpsitin f fin air brn slids. Vhicl and industrial air missins may cnstitut a significant cntributin t lvls f lad and nitrats acrss urban aras Attnuatin Th rductin in th magnitud f flws, cncntratins r lads f pllutants. Avrag Rcurrnc Intrval (ARI) Avrag tim btwn vnts f a givn valu. Bankfull flw Th flw rat at which a stram r channl will run full. Th frquncy f bankfull cnditins is cmmnly adptd as th critria fr maintaining th channl crss sctin and frdm frm sdimntatin in th lngr trm. This frquncy will vary accrding t climatic rgins. 65

Bank stabilisatin (Rfr t Armuring r stabilisatin) Basflw Th undrlying flw rat that cannt b dirctly attributd t strm vnts. Baskt A simpl stl msh cllctin dvic placd in pits f grss pllutant traps t cllct dbris and rubbish. Bd trap A structur dsignd t intrcpt and rtain sdimnt carrid in flw by mans f bd lad prcsss. Bst Managmnt Practic (BMP) Structural masurs usd t str r trat urban strmwatr runff t rduc flding, rmv pllutin r t prvid thr amnitis. Bi-accumulatin Th prcss in which substancs ar accumulatd by rganisms, frm watr dirctly r by cnsumptin f fd cntaining th substancs. Bichmical Oxygn Dmand (BOD) Th xygn cnsumptin (rspiratin) rsulting frm bactrial brakdwn f rganic matrial, r as a rsult f sm inrganic xygn rducing spcis (ammnia). Bi-divrsity Th variability amng living rganisms frm all surcs (including trrstrial, marin and thr aquatic csystms and th clgical cmplxs f which thy ar part) and includs: (a) divrsity within spcis and btwn spcis; and (b) divrsity f csystms. Bifilm A glatinus shath f alga and micr-rganisms, including bnthic alga and bactria, frmd n gravl and sdimnt surfacs and surfacs f larg plants. Bi-mnitring Survys f th bidivrsity f slctd bilgical grups r familis, and cmparisn t a rfrnc sit fr a similar csystm, as a masur f csystm halth. Bita Living rganisms in strams. 66

Buffr zns A vgtatd strip btwn th dg f a stram r drainag channl and a land us activity, dsignd t trap th latral vrland flw brn pllutants. Catchmnt A tpgraphically dfind ara draind by a stram such that all utflw is dirctd t a singl pint. Channl Th bd and banks f a stram r cnstructd drain. Cllids Fin abitic and bitic particls f typically 0.1 11m t 1 nm in diamtr. Critical dwnstram nds Th mst snsitiv dwnstram watr bdis in rspct t sustainabl pllutant lads, which dictat land us and managmnt practic rquirmnts acrss thir catchmnt. Dnitrificatin Th rductin f nitrat r nitrit t nitrgn gas, in th absnc f xygn. Dtntin (dry) basins A basin dsignd t tmprarily dtain strm r fld watrs, t attnuat pak flws dwnstram t accptabl lvls. Discharg Th vlum f flw passing a prdtrmind sctin in a unit tim. Disslvd fractin Th part f a watr sampl passing thrugh a 0.45 11m pr siz filtr papr. It will includ bth a truly disslvd and cllidal matrial fractin. Disslvd Oxygn (DO) Th lvl f dissl vd xygn in strams is a critical prprty sustaining aquatic bita, and in dtrmining th risk f ccurrnc f anxic cnditins. Drainag ntwrk Th systm f channls and pips and vrland flw pathways which drain a catchmnt ara. Ntwrks typically cmpris a main drain, branch drains, and cllctr drains. Easmnt (right f way) A crridr f land vr which th drainag functin is th primary rl. Efflunt Sanitary, industrial r agricultural discharg frm wastwatr tratmnt plants r tratmnt lagns. 67

Evnt A singl prcipitatin and assciatd runff ccurrnc. Evnt Man Cncntratin Th avrag cncntratin f a pllutant vr th prid f an vnt discharg. It is nrmally dtrmind by th sum f th cncntratins (fr multipl sampls takn during th prid f th vnt discharg) multiplid by th flw wightd vlum f th sampl, dividd by th cumulativ vlum f th sampls. Filtr A layr f granular matrial dsignd t intrcpt fin particulat matrial. It may b usd as part f a subsil drain, r as a structur t trat surfac runff prir t rcharg f grundwatr r discharg t a drain. Fldway Crridr f land idntifid as a majr strmwatr flw path, ftn is assciatin with a minr (pip r channl) flw path. Flw rtardatin S Dtntin Basins Frquncy (Rfr t Avrag Rcurrnc Intrval) Gmrphlgy Prcsss f wathring, flw and sdimnt transprt which dtrmin th pattrn f drainag faturs acrss a catchmnt, and th quilibrium btwn sdimnt accumulatin in channls and sdimnt r-suspnsin. Gtxtil A thin, flxibl prmabl sht f synthtic matrial usd t allw th transmissin f watr thrugh th prs f th matrial whil prvnting th transmissin f sil particls. Grain siz distributin Th statistical distributin f grain (by wight) passing a rang f siv sizs. Gry watr Nn-ptabl watr drivd frm thr hushld uss, suitabl (with r withut tratmnt) fr thr uss such as tilt flushing, gardn watring. Grss Pllutant Trap (GPTs) A trap dsignd tu intrcpt cars particulat matrial (by sdimntatin) and trash and dbris (by scrns r bms). OPTs may b incrpratd int th inlt pits, cllctr drains r main drains. 68

Gully pt, inlt pit A radsid inlt pit, dsignd t cllct stnnwatr runff washd frm pavd surfacs and t intrcpt sdimnt and littr prir t ntry int th drainag ntwrk. Imprmabl r imprvius surfac Th part f th catchmnt surfacd with matrials which prvnt infiltratin f rainwatr int th undrlying sil and grundwatr. Indirct drainag Th braking f th dirct cnnctin f rf dwnpips t stnnwatr drains, and imprvius ara washff t inlts and drains, by thir discharg t prvius aras r infiltratin dvics, and ultimat vrland r subsil intrcptin at th prprty bundary by th stnnwatr ntwrk. Infiltratin pit, trnch, basin A stn filld pit, trnch r dtntin basin dsignd t nhanc runff infiltratin int th subsil and grundwatr zns. Intgratd catchmnt managmnt Managing natural rsurcs within a 'whl f systm' apprach. In a stnnwatr cntxt, it rquirs a whl f catchmnt and ttal urban watr cycl basd dsign and managmnt apprach, with intgral cnsidratin f land and watr prcsss and valus. Lading Th ttal mass f a pllutant dischargd during a stnn vnt. Th tnn may als b usd t dscrib th mass f pllutant intrcptd (g/sq mtr) by a dvic during a stnn vnt, r n an annual basis. Multipl us Facilitis mting a rang f functins g urban watrways accmmdating drainag, pllutin intrcptin, landscap, rcratin and watr supply functins. Off-lin and n-lin Off-lin facilitis ar lcatd adjacnt t but ff th drain r majr flw pathway, such as t trat lw flws r th discharg f a branch drain. On-lin r in-lin facilitis ar lcatd within th drain r majr flw pathway such as t trat vnt flws. On-sit and ff-sit On-sit facilitis ar lcatd n individual rsidntial r dvlpmnt blcks s as t nhanc lcal dtntin and intrcptin f runff and pllutants. Off-sit facilitis ar lcatd n drainag ntwrks t prvid ara wid dtntin and intrcptin f runff and pllutants. Oil trap r sparatrs A stilling tank cnfigurd t sparat lightr ily mattr, scums and hydrcarbns frm stnnwatr. 69

On-sit strm watr dtntin (OSD) A rquirmnt fr dvlprs f land t cmpnsat fr incrasd runff du t incrass in imprviusnss n blcks. Ovrland flw Th cmpnnt f rainfall (xcss) which is nt rmvd by infiltratin and dischargs dwn th slp as surfac flw. Prmabl (prus) pavmnt Pavmnts cmprising matrials which facilitat infiltratin f rainwatr and transfr t th undrlying sub-sil. Pint surc and nn-pint surc pllutin Pint surc is any discrnibl cnfind and discrt cnvyanc, including pips, channls, cnduits. Nn-pint surc is a diffus pllutin surc withut a singl pint f rigin r spcific discharg pint. Pllutant rtntin Th prprtin f pllutant lad intrcptd and rtaind by a dvic, ithr n an vnt r annual basis. Pllutin Cntrl Pnds A shallw pl f watr, charactrisd by aras f mrgnt aquatic plants and pn watr, dsignd t intrcpt vnt dischargs and nabl adsrptin and sdimntatin f pllutants, and t supprt a divrs rang f micr-rganisms and plants assciatd with th brakdwn f rganic matrial and uptak f nutrints. Th dtntin f vnt flws and sttling f suspndd particls and assciatd pllutants is a ky cmpnnt f pnd pllutant intrcptin prcsss. Rcycld watr Tratd strmwatr, grywatr r black watr suitabl fr a rang f uss g tilt flushing, irrigatin, industrial prcssing r thr suitabl applicatins. Rmbilisatin Th transfrmatin f sdimntd pllutants by micrbial r chmical prcsss int a disslvd frm and transfr by diffusin frm th sdimnt pr watr int th watr clumn. R-suspnsin Th physical ntrainmnt f sdimntd particls by lvatd flws, r as a rsult f sdimnt biturbatin. Rtarding r Rtntin Basin S Dtntin Basin Rughnss cfficint A factr dscribing th rughnss (irrgularitis) f surfacs rlatd t flw nrgy lss. 70

Runff Th prtin f prcipitatin n a drainag ara r surfac that is dischargd frm th drainag ara t drainag. Sdimnt trap A structur dsignd t intrcpt and rtain sdimnt transprtd by th flw. Sdimntatin Th physical prcss f sttling f suspndd particulats undr frcs f gravity. Th sdimntatin fficincy is a functin f ddy frcs in th sttling basin, and th prid f dtntin f flw in th basin. Swr vrflw Th discharg f swag t surfac watr r strmwatr drainag as a rsult f swag flw xcding th swr capacity (infiltratin f rainwatr), r swr blckag. Strm watr Watr flwing vr grund surfacs and in natural strams and drains as a dirct rsult f rainfall vr a catchmnt. Strm watr Quality Intrcptin Dvics (SQIDs) S Bst Managmnt Practics Strm watr Tratmnt Masurs (STMs) S Bst Managmnt Practics Strt swping Th rmval f particulats and littr frm strt surfacs by swping r vacuuming. Sub-catchmnt A tpgraphically dfind ara draind by a tributary r branch drain f a primary stram r main drain draining a catchmnt. Subsurfac drain A drain dsignd t intrcpt sub-sil watr and thrby lwr th sil watr tabl. Swals A grassd pn channl, dsignd t intrcpt and cnvy surfac runff t a drainag ntwrk inlt, prmt infiltratin, prmt intrcptin f particulat matrial by th vgtatin, and t prvid a landscap lmnt. Swirl sparatr A dvic which uss th flw nrgy t crat a vrtx, nhancing th sparatin by gravity f watr and particulat matrials. 71

Ttal Catchmnt Managmnt (TCM) S Intgratd Catchmnt Managmnt Ttal urban watr cycl basd managmnt Th intgratd managmnt f all cmpnnts f th hydrlgical cycl within urban aras (surfac watr, sil intrflw, grundwatr, watr supply and rcycld wastwatr) and th landscap t scur a rang f scial, cnmic and nvirnmntal bnfits. Watr Snsitiv Urban Dsign Dsign f subdivisins, buildings and landscap which nhancs th pprtunitis fr at-surc cnsrvatin f watr, rainfall dtntin and us, infiltratin, and intrcptin f pllutants in surfac runff frm th blck. Wtlands (artificial) A shallw pl f watr, charactrisd by xtnsiv aras f mrgnt aquatic plants, dsignd t supprt a divrs rang f micr-rganisms and plants assciatd with th brakdwn f rganic matrial and uptak f nutrints. Wtlands may b dsignd as prmannt wt basins (prnnial), r altrnating btwn dry and wt basins (phmral), r cmbining ths tw systms (xtndd dtntin). Wt basin S Pllutin Cntrl Pnds 72