Storm Water Drainage System (Subject area: Environmental Environmental Engineering)
Prepared by:
Guided by:
Name: Ankit Balyan
Mrs. Anjali Khabete
B. Tech IV !i"il# !i"il #
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CERTIFICATE
This is to certify that “Mr. Ankit Balyan” of B Tech IV semester 7th has satisfactory completed his seminar report on “Storm Water Drainae System in S!rat” d!rin academic year "##$ % "#&#.
Sinat!re of !ide'
Sinat!re of' (ead of Department
DATE: 11/11/09
CIVIL ENGINEERING DEPARTMENT S.V.NATIONAL INSTITUTE OF TECHNOLOGY, SURAT-395007
ACKNOWLEDGEMENT
I take opport!nity to e)press my deep sense of ratit!de and inde*tedness to “+rof. An,ali -ham*ete” in i/il 0nineerin department1 S.V.2.I.T1 S!rat for her /al!a*le !idance1 !sef!l comments and co3operation 4ith kind and enco!rain attit!de at all staes of the e)perimental 4ork for the s!ccessf!l completion of this 4ork. I am also thankf!l to S.V.2.I.T1 S!rat and its staff for pro/idin this opport!nity 4hich helped in ainin kno4lede and to make this 5rad!ate report s!ccessf!l.
Thank 6o! A!"# $%&'% U0(CE0(5
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Abstract…………………………………………………………………………………………….1 Introducon W!at is Storm"ater…………………………………………………………………1 Storm"ater #olluon……………………………………………………………….$ Storm Drain………………………………………………………………………………$ Ancient %istory…………………………………………………………………………& Storm"ater 'anagement Site Analysis…………………………………………………………………………….. Adjoining roeres………………………………………………………………… #ublic sa*ety……………………………………………………………………………. Esmang Storm"ater +uno,………………………………………………………….Storm"ater Drainage System in Surat……………………………………………… /ase Study: Increasing t!e Storm Water Drainage /aacity o* 'it!i +iver in 'umbai……………………………………………………………………………….0 /onclusion………………………………………………………………………………………11 +e*erences…………..…………………………………………………………………………11
A$STRACT STORM ATER DRAINAGE REFERS TO THE NETOR OF THE DRAINS LAID FOR THE PURPOSE OF CARRYING AAY THE ECESS RAIN ATER, STREET ASHINGS AND ROOF ASHINGS, SO AS TO CLEAN THE ROADS OF THE STATIONARY STAGNANT ATER. IN THE $ACDROP OF THE RECENT UR$AN FLOODS EPERIENCED IN SURAT, MUM$AI AND OTHER INDIAN CITIES THE ROLE OF THE STORM ATER DRAINS HAS ASSUMED A VERY CRITICAL ROLE IN THE UR$AN LANDSCAPE. A LOT MORE ATTENTION IS $EING GIVEN TO THE DEVELOPMENT OF PROPER DRAINAGE NETORS CAPA$LE OF MEETING NATURES ORST POSSI$LE DEMANDS. IT IS A DEVELOPING AREA IN THE FIELD OF ENVIRONMENTAL ENGINEERING TODAY AND A LOT OF OR IS $EING DONE IN DEVELOPING SUSTAINA$LE UR$AN DRAINAGE.
INT*5(+!TI5N HAT IS STORM ATER2
Storm4ater is a term !sed to descri*e 4ater that oriinates d!rin precipitation e/ents. It may also *e !sed to apply to 4ater that oriinates 4ith sno4melt or r!noff 4ater from o/er4aterin that enters the storm4ater system. Storm4ater that does not soak into the ro!nd *ecomes s!rface r!noff1 4hich either flo4s directly into s!rface 4ater4ays or is channeled into storm se4ers1 4hich e/ent!ally dischare to s!rface 4aters. Storm4ater is of concern for t4o main iss!es'
one related to the /ol!me and timin of r!noff 4ater flood control and 4ater
s!pplies81 and The other related to potential contaminants that the 4ater is carryin1 i.e. 4ater poll!tion.
A storm drainae system is a net4ork of str!ct!res1 channels and !nderro!nd pipes that carry storm 4ater rain 4ater8 to ponds1 lakes1 streams and ri/ers. The net4ork consists of *oth p!*lic and pri/ate systems.
)T5*M AT'* P544+TI5N
Beca!se imper/io!s s!rfaces parkin lots1 roads1 *!ildins1 compacted soil8 do not allo4 rain to infiltrate into the ro!nd1 more r!noff is enerated than in the !nde/eloped condition. This additional r!noff can erode 4aterco!rses streams and ri/ers8 as 4ell as ca!se floodin 4hen the storm4ater collection system is o/er4helmed *y the additional flo4. Beca!se the 4ater is fl!shed o!t of the 4atershed d!rin the storm e/ent1 little infiltrates the soil1 replenishes ro!nd4ater1 or s!pplies stream *aseflo4 in dry 4eather. +oll!tants enterin s!rface 4aters d!rin precipitation e/ents are termed as poll!ted r!noff . Daily h!man acti/ities res!lt in deposition of poll!tants on roads1 la4ns1 roofs1 farm fields1 etc. When it rains or there is irriation1 4ater r!ns off and !ltimately makes its 4ay to a ri/er1 lake1 or the ocean. While there is some atten!ation of these poll!tants *efore enterin the recei/in 4aters1 the 9!antity of h!man acti/ity res!lts in lare eno!h 9!antities of poll!tants to impair these recei/in 4aters. +oll!ted r!noff from roads and hih4ays is the larest so!rce of 4ater poll!tion in coastal areas today.
Fig 1 Relationship between impervious surfaces and surface runo
STORM DRAIN
A storm drain1 storm se4er :.S.81 storm4ater drain1 drain A!stralia and 2e4 ;ealand8 or drainae 4ell system :-8 is desined to drain e)cess rain and ro!nd 4ater from pa/ed streets1 parkin lots1 side4alks1 and roofs. Storm drains /ary in desin from small residential dry 4ells to lare m!nicipal systems. They are fed *y street !tters on most motor4ays1 free4ays and other *!sy roads1 as 4ell as to4ns in areas 4hich e)perience hea/y rainfall1 floodin and coastal to4ns 4hich e)perience re!lar storms.
Fig 2. Dierent types of storm water drains
ANCIENT HISTORY
Since the era that h!mans *ean li/in in concentrated /illae or !r*an settins1 storm4ater r!noff has presented itself as an iss!e. S!ch d4ellin styles can *e enerally related to the Bron
### years *efore present cities s!ch as +haistos 4ere desined to ha/e storm drains and channels to collect precipitation r!noff. At retan -nossos storm drains incl!de stone lined str!ct!res lare eno!h for a person to cra4l thro!h. An early specific e)ample of storm4ater r!noff system desin is fo!nd in the archaeoloical reco/ery at Minoan +haistos on rete. ?ther e)amples of early ci/ili
STORM ATER MANAGEMENT Storm4ater manaement is a f!ndamental consideration in the plannin and desin of !r*an de/elopment. By considerin storm4ater manaement at the initial desin phase it is possi*le to ens!re /ia*le storm4ater manaement sol!tions that are compati*le 4ith other desin o*,ecti/es for the site. SITE ANALYSIS
The site@s toporaphy 4ill ha/e a sinificant impact on the layo!t desin. This is *eca!se storm4ater drainae systems almost al4ays rely on ra/ity. The layo!t of the de/elopment m!st *e confi!red so as to allo4 e)cess storm4ater to *e ra/ity3drained to a drainae system. Toporaphy 4ill also affect r!noff onto the site from s!rro!ndin properties. 0)istin o/erland flo4 paths sho!ld *e identified and retained. Where modifications to these are !na/oida*le1 they sho!ld *e desined so as to maintain e)istin hydroloical conditions. Drainae easements1 nat!ral 4aterco!rses and flood prone land sho!ld also *e identified and considered in the desin process. It needs to *e *orne in mind that drainae easements containin !nderro!nd pipes can operate as o/erland flo4 paths d!rin intense rainfall e/ents. B!ildins m!st *e kept clear of drainae easements to ens!re p!*lic safety and to allo4 maintenance access. onsideration also needs to *e i/en to local soil conditions. ele/ant factors incl!de a*sorption capacity1 erosion potential1 soil salinity and the possi*ility of soil contamination from past acti/ities ADOINING PROPERTIES
?ne of the *asic principles of storm4ater manaement is to a/oid ad/erse storm4ater impacts on other properties. aref!l consideration m!st *e i/en to controllin s!rface r!noff and s!*soil drainae to ad,oinin properties. The redirection and concentration of storm4ater flo4s onto neih*orin properties may constit!te a n!isance@ at common la41 i/in affected o4ners a leal riht of redress. PU$LIC SAFETY
Storm4ater r!noff from rare and intense storm e/ents can pose serio!s risks to life and property. It is essential that the desin of o/erland flo4 paths1 on3site detention storaes and other storm4ater manaement meas!res meet rele/ant safety criteria for pedestrians1 /ehicles and property damae. =encin and landscapin sho!ld *e desined so as to minimi
ESTIMATING STORM-ATER RUNOFF alc!lation of the rate of storm34ater r!noff is important in determinin the si
is a direct f!nction of the a/erae rainfall rate d!rin the time that it takes the r!noff to tra/el from the most remote point of the tri*!tary area to the inlet or drain1 b8 that the a/erae fre9!ency of occ!rrence of the peak r!noff e9!als the a/erae fre9!ency of occ!rrence of the rainfall rate1 and c8 that the 9!antity of storm 4ater lost d!e to e/aporation1 infiltration1 and s!rface depressions remains constant thro!ho!t the rainfall. The coefficient of runoff is a coefficient 4hich acco!nts for storm34ater losses attri*!ted to e/aporation1 infiltration1 and s!rface depressions. The peak /al!e of the flo4 rate Q of storm3 4ater r!noff is estimated !sin the follo4in e9!ations' Q = CIA ftCs EEEEEEEEEEEEEEEEEEEEEEE..e9n &8 Q=
mCh EEEEEEEEEEEEEEEEEEEEEEE....e9n "8
Where C F coefficient of r!noff I F rainfall rate for a specified rainfall d!ration and a/erae fre9!ency of occ!rrence1 inh cmh8 A F tri*!tary area to the inlet or drain1 acres m"8 CHARACTER OF SURFACE +a/ement' Asphaltic and concrete Brick oofs a4ns And Sandy Soil' =lat1 " percent A/erae1 " to 7 percent Steep1 7 percent a4ns1 hea/y soil' =lat1 " percent A/erae1 " to 7 percent Steep1 7 percent
COEFFICIENT OF RUNOFF
#.7# % #.$G #.7# % #.HG #.7G % #.$G #.#G % #.&# #.&# % #.&G #.&G % #."# #.&C % #.&7 #.&H % #."" #."G % #.CG
Table 1 Typical values for the coecient of runo
A i/en site may ha/e areas 4ith different coefficients of r!noff all drainin to a common point. It is desira*le to !se a sinle coefficient of r!noff for the entire area. S!ch a dimensionless coefficient termed a wei!te" coefficient of runoff# C w1 can *e calc!lated !sin
4 F
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
e9n C8
4here A& $ A" $ and An are the area in acres m"81 and C & $ C " $ and C n are the correspondin coefficients of r!noff of the indi/id!al tri*!tary areas to a common point. A 4eihted coefficient of r!noff m!st *e calc!lated for each sement of the storm4ater drainae system. In the desin of a storm34ater drainae system1 r!noff m!st *e transported as fast as it is recei/ed1 !nless specific pro/isions are made for pondin of the e)cess r!noff 4hich the storm34ater drainae system cannot handle. Determination of the rainfall rate to *e !sed for desin p!rposes in/ol/es an e/al!ation of the potential damae 4hich co!ld occ!r as a res!lt of floodin. If the potential damae from floodin is hih1 the selection of an a/erae fre9!ency of occ!rrence of G# or &## years may *e 4arranted. If the potential damae from floodin is rather sliht1 the selection of an a/erae fre9!ency of occ!rrence of G1 or "G years may *e appropriate. In many cases1 the local a!thority ha/in ,!risdiction 4ill determine the a/erae fre9!ency of occ!rrence to *e !sed in the desin of storm34ater drainae systems.
STORM ATER DRAINAGE SYSTEM IN SURAT After the floods of "##J1 a lot of attention has *een i/en to the impro/isation of the storm 4ater disposal system of S!rat 4ith a oal to ens!re s!ch h!e 9!antities of 4ater can *e easily handled in the f!t!re. Till "##G1 S!rat had total storm 4ater drainae lines of "7G kms. Since "##J1 !nder the “Ka4arharlal 2ehr! 2ational :r*an ene4al Mission” these ha/e *een proposed to increase !pto >$& kms to incl!de the ne4 areas that ha/e *een added to the city since. This pro,ect also incl!des impro/in the capacity of the e)istin storm 4ater drains to handle flood sit!ations *etter. The pro,ect aims to achie/e follo4in oals'
There 4ill *e protection of mankind and other li/in oranisms from floodin There 4ill *e protection of ma,or e9!ipments and infrastr!ct!re from *ein ettin
damaed d!e to floods. To protect loss of man ho!rs1 *!siness ho!rs of 4orkin people and increase
prod!cti/ity1 there*y enhancin economic ro4th in the area. To 9!ickly remo/e the stanant 4ater as soon as possi*le so that epidemic can *e
a/oided and make the pa/ement free to res!me traffic The ne4 areas 4here the 4ork of layin of ne4 storm 4ater lines is *ein carried o!t in Ves!1 +al +alanpore and the ne4 eastern areas. The total pro,ect cost of the entire 4ork in proress is s >G# crores 4hich ha/e *een appro/ed *y the o/ernment. The pro,ected completion date is Dec "#&#. The entire !pradation is e)pected to *e o/er *y "#&". S!rat M!nicipal orporation has taken a ma,or initiati/e to replace secondary drain pipes 4ith &>##mm diameter pipes. Another area of concern that 4o!ld *e addressed in the ne4 !pradation process is to ha/e storm 4ater drains alon all smaller side roads 4hich pre/io!s did not ha/e these drains. This 4ill red!ce the *!rden on the main roads as pre/io!sly this 4ater 4as di/erted to the drains on the main roads leadin to o/erflo4in drains on the main roads.
Case Study: Increasing Storm Water Drainage Capacity of Mithi River and Mumbai City drains The Mithi i/er flo4s thro!h the city of M!m*ai and forms a principal channel to dischare storm 4ater and se4ae. This So!nd +ractice pertains to the 4idenin and deepenin of the Mithi ri/er and other city drains in a scientific and 4ell planned manner. This is intended not only to increase their dischare capacity *!t also to pre/ent floodin in lo43lyin areas ad,oinin the ri/er *y red!cin radients of the Mithi ri/er in its@ !pper reaches. The storm 4ater drainae for the Mithi ri/er catchment areas has *een disr!pted d!e to the encroachment of h!tments in lare n!m*ers1 storae facilities1 processin ind!stries1 4orkshops and scrap yards sit!ated alon the *anks of the Mithi i/er that make it diffic!lt e/en to delineate its path. Direct dischares of !ntreated se4ae1 4aste4ater from the !na!thori># km lenth in the island city area81 ma,or and minor channels "## km and H7 km lenth1 respecti/ely8 and &HJ o!tfalls1 4hich dischare all the s!rface r!noff into ri/ers and the Ara*ian Sea. ?f the &HJ o!tfalls1 there are ma,or o!tfalls in city1 4hich
drain to Ara*ian Sea directly1 > at Mahim creek and > at Mah!l creek. There are "$ o!t3falls in 4estern s!*!r*s drainin directly into sea 4hile &> drain into Mithi ri/er 4hich !ltimately ,oins Mahim creek. The location of the Mithi ri/er is an important administrati/e *o!ndary that di/ides the ity and the S!*!r*s. =loodin in the ri/er has direct or indirect implications for disr!ptin traffic on fi/e transport corridorsL entral ail4ay Main ine1 entral ail4ay (ar*or ine1 Western ail4ay ine1 Western 0)press (ih4ay1 and 0astern 0)press (ih4ay. The intensity of floodin follo4in the !nprecedented rainfall of $>> mm recorded at Santa r!< airport on "Jth K!ly "##G led to the s!*merence of lare areas ad,oinin the Mithi ri/er to an alarmin e)tent 4hich ca!sed disr!ption of the a*o/ementioned corridors of rail4ays and s!rface transport. The red!ced flood dischare capacity of the ri/er may ha/e 4orsened the sit!ation. =ollo4in the floodin in "##G1 the MMDA asked the W+S1 +!ne 4as to !ndertake hydroloical st!dy1 4hose report 4as s!*mitted in Kan!ary "##J. R*4&# % R*6+*%#"+ + #8* T*68"6%& R*+# 4)"##* )' CPRS, P4*
The first t4o sements1 4hich ha/e an oriin to Koesh4ari and Vikhroli ink oad to Sir MV oad ha/e Steep Slopes1 they pro/ide a s4ift dischare of 4ater eliminatin the chances of floodin. The do4nstream sements1 ho4e/er1 ha/e flat slopes and hence may ca!se floodin. +resently1 a ma)im!m of G# mCs dischare can *e accommodated in the do4nstream co!rses of the ri/er 4itho!t ca!sin any spill o/er. B!t the dischare correspondin to G# yr rainfall CH".G mm per ho!r8 or &## yr rainfall >&H.C mm per ho!r8 a/eraed thro!ho!t the stream lenth 4ill ca!se a se/ere flood in the s!rro!ndin areas. In order to mitiate floods1 follo4in remedial meas!res are recommended *y W+S1 +!ne' a8 Bandra -!rla omple) B-8 area &. +ro/idin a dreded channel of J# m 4idth from 3" m 4ith respect to Mean Sea e/el or MS8 conto!r in the sea to Mahim a!se4ay *ed le/el dreded to 3& m8 and remo/in e)istin rock o/er3crops. ". Widenin of the 4ater4ay from Mahim a!se4ay to Dhara/i Bride to &## m. C. Widenin of the *ed 4idth from the e)istin &7G m to "## m *et4een Dhara/i Bride and ST Bride. >. Widenin of Vakola 2alla from the earlier desined 4idth of ># m to J# m. G. Deepenin of *ed le/el at Mahim a!se4ay to 3& m and at ST Bride to #.J7
m. *8 :pstream of B- area &. Widenin of e)istin *ed from ST Bride to MV oad to &## m. ". Widenin of e)istin *ed from MV oad to Koesh4ari % Vikhroli ink oad to J# m C. Widenin of e)istin *ed from Koesh4ari % Vikhroli ink oad to Morar,i 2aar to ># m. >. Deepenin of e)istin *ed le/els' N N N N N N
ST Bride h. G.HH km8 from " m to #.J7 m Air India olony h. 7.#G km8 from C.&& m to &.# m Airport h. $.CH km8 from J.&G m to > m MV oad h. &#.>7 km8 from H.&" m to J.CG m Aarey Dairy =oot ?/er Bride h. &".&H km8 from &".7G m to &# m Koesh4ari3Vikhroli h. &> km8 from "#."G m to &H m
All the s!ested cross sections of Mithi i/er !pto h. &#.G km need to *e pro/ided 4ith slopes of & ' &.G. =!rther !pstream !pto Morar,i 2aar1 the re9!ired slope is & ' ". All the s!ested meas!res taken toether 4o!ld ro!hly do!*le the dischare capacity the i/er. A"#"+%& R*6+*%#"+
Moderatin the ri/er co!rse *y replacin e)istin sharp *ends 4ith loner entler
*ends.
+ro/idin 2on3ret!rn /al/es for cross drains. +ro/idin e!lar maintenance and dredin. +ro/idin smooth transition for 4ater4ays near *rides.
A6#"+ #%!* )' #8* C"#' A""#%#"+ + #8** *6+*%#"+
The ity Administration actin s4iftly on recommendations accepted most of them and directed M!m*ai Metropolitan eion De/elopment A!thority MMDA8 and M!nicipal orporation of 5reater M!m*ai M5M8 to take the necessary action. The 4ork 4as di/ided in t4o parts. The &&.H> km !pstream stretch from Vihar ake to ST Bride 4as i/en to M5M and the critical do4nstream part of the remainin J km 4as !ndertaken *y MMDA. The do4nstream stretch 4as more critical d!e to flat slopes and nearness to sea and 4as f!rther di/ided into t4o phases *y MMDA'
P8%* 1: It in/ol/es de3siltin and 4idenin of the stretch. The time frame decided for
this 4as & March "##J to C# K!ne "##J and is no4 finished. The amo!nt sanctioned
for the 4ork 4as s. C# crores. P8%* ;: It is planned for the post3monsoon period from & ?ct "##J to C# K!ne "##7 4ith a *!det of s. &## crores s!*,ect to /ariation after post monsoon st!dy8. It 4ill
in/ol/e dredin1 4idenin1 constr!ction of retainin 4all1 *ea!tification and *!ildin of ser/ice roads.
CONCLUSION S!rat is one of the fastest ro4in cities in the co!ntry today. With its rapidly chanin !r*an infrastr!ct!re1 it is a city on the rise. (o4e/er1 S!rat has al4ays faced the pro*lem of floodin o/er the period of time in recent history 4ith the 4orst flood e/er comin in "##J. essons need to *e learned from the past e)periences and they ha/e to *e learned fast. A ood storm disposal system has to *e p!t in place to match the rapid strides in !r*an de/elopment that S!rat has made o/er the years. The attention has shifted to this /ery critical area and the 4ork of re*!ildin it has already *e!n. A ood and efficient storm 4ater drainae system is *eneficial is more 4ays than one. It not only sa/es a lot of life and property on the day of the floods *!t also pre/ents epidemics ca!sed d!e to the lon standin stanant 4ater 4hich *ecomes a *reedin ro!nd for mos9!itoes and insects. S!rat lost a lot of money in the "##J floods1 a *etter and more efficient storm 4ater drainae system can sa/e another s!ch sit!ation from arisin in the f!t!re.
REFRENCES &. Stanley W. Trim*le "##78 Enc%c&o'e"ia of Water (cience1 +ress1 &GHJ paes ISB2 #H>$C$J"7& ". (oan . Michael1 O+haistos =ieldnotes.O T!e Mo"ern Anti)uarian "##78 C. Sch!eler1 Thomas . OThe Importance of Imper/io!sness.O eprinted in T!e *ractice of Water+!e" *rotection. "###. enter for Watershed +rotection. 0llicott ity1 MD. >. +eter oom*es1 Water Sensiti/e !r*an desin in the Sydney eion1 o4er (!nter and entral oast eional 0n/ironmental Manaement Stratey1 "##" G. (iedeman . Da/id1+01I+01 Storm3Water Drainae Systems in +ractical +l!m*in 0nineerin1 American Society of +l!m*in 0nineers1 &$$H J. S!rat M!nicipal orporation1 Drainae Department1 S!rat 7. http'en.4ikipedia.or4ikiStorm4ater
