Stormwater system, Integrated storm water management separate system water management, separate system, combined system, Urban flooding
M odu le 8 – ( L3 1 – L3 4 ) : “St or m W a t e r & Flood M a n a ge m e n t l d
”: ”
St or m w a t e r m a n a ge m e n t , de sign of dr a in a ge syst e m , flood
r ou t in g t h r ou gh ch a n n e ls a n d r e se r voir , flood con t r ol a n d r ou t in g t h r ou gh ch a n n e ls a n d r e se r voir flood con t r ol a n d r e se r voir ope r a t ion , ca se st u die s. St or m W a t e r M a n a ge m e n t g 3 1 3 1St or m W a t e r M a n a ge m e n t St or m W a t e r M a n a ge m e n t
L31 L31 L31– L31
Topics Cove r e d Topics Cove r e d
St orm wat er runoff; Harvest ing, St orm wat er runoff; Harvest ing, St orm wat er syst em , I nt egrat ed st orm St orm wat er syst em , I nt egrat ed st orm wat er m anagem ent , separat e syst em , wat er m anagem ent , separat e syst em , wat er m anagem ent separat e syst em wat er m anagem ent separat e syst em
com bined syst em , Urban flooding com bined syst em , Urban flooding
St orm wat er runoff, syst em , St orm wat er runoff, syst em ,
Keywords: Keywords:
harvest ing, m anagem ent , Urban flooding. harvest ing, m anagem ent , Urban flooding. a a est est
g, a age a age e t , U ba e t , U ba ood ood g g
g, St orm w at er Runoff St orm w at er Runoff
St orm w at er is rainwat er & m elt ed snow t hat runs off
st reet s, lawns, & ot her sit es.
Wh When st orm w at er t t is absorbed int o t he ground, it is i b b d i t t h d it i filt ered & replenishes aquifers or flows int o st ream s/ rivers.
I n urbanized areas , im pervious areas like pavem ent & roofs prevent wat er from nat urally soaking int o ground.
Wat er runs Wat er runs rapidly int o st orm drains, sewer syst em s, & rapidly int o st orm drains sewer syst em s &
drainage dit ches and can cause : D/ s flooding ; St ream bank erosion; I ncreased t urbidit y, Habit at dest ruct ion; Changes in t he st ream flow hydrograph; Changes in t he st ream flow hydrograph; Com bined Com bined
sewer overflows ; I nfrast ruct ure dam age &
Cont am inat ed st ream s, rivers, & coast al wat er
St or m w a t e r H a r ve st in g St or m w a t e r H a r ve st in g
St orm w at er - concern for t he volum e and t im ing of runoff
w at er ( w at er ( flood flood cont rol & wat er supplies) & ot her relat ed cont rol & wat er supplies) & ot her relat ed wat er pollut ion .
St orm wat er is also a resource of readily available wat er.
Techniques of h f st orm wat er harvest ing h w it h point source h wat er m anagem ent & purificat ion, can pot ent ially m ake urban environm ent s self sust aining in t erm s of wat er.
St or m w a t e r h a r ve st in g
is t he collect ion, accum ulat ion, t reat m ent or purificat ion, & st oring for it s event ual reuse.
I t can also include ot her cat chm ent areas from m an m ade I t can also include ot her cat chm ent areas from m an m ade surfaces, such as roads, or ot her urban environm ent s such as parks, gardens & playing fields .
St or m w a t e r M a n a ge m e n t
Managing t he quant it y & qualit y - " St orm w at er
Managem ent ”
" The t erm Best Managem ent Pract ice ( BMP) is oft en used t o refer t o bot h st ruct ural or engineered cont rol devices & syst em s ( e.g. y ( g ret ent ion ponds p ) ) t o t reat pollut ed st orm wat er, as well as operat ional or procedural pract ices.
There are m any form s of st orm wat er m anagem ent & There are m any form s of st orm wat er m anagem ent & BMPs , including:
- m anage st orm wat er t o cont rol flooding and erosion;
- m anage & cont rol hazardous m at erials t o prevent & t l h d t i l t t release of pollut ant s t o environm ent ( source cont ro
- plan and const ruct st orm wat er syst em s so t hat p
y
St or m w a t e r M a n a ge m e n t …
- Acquire and prot ect nat ural wat erways where t hey st ill exist or can be rehabilit at ed; st ill exist or can be rehabilit at ed;
- Build " soft " st ruct ures such as ponds, swales or
wet lands t o work wit h exist ing or " hard" drainage
st ruct ures, such as pipes and concret e channels; st ruct ures such as pipes and concret e channels;
- Revise current st orm wat er regulat ions t o address com prehensive st orm wat er needs;
- Enhance and enforce exist ing ordinances t o m ake sure • Enhance and enforce exist ing ordinances t o m ake sure propert y owners consider t he effect s of st orm wat er before, during & aft er developm ent of t heir land;
- Educat e a com m unit y about how it s act ions affect Ed i b h i i ff
wat er qualit y , & what it can do t o im prove it ; and
- Plan carefully t o creat e solut ions before problem s becom e t oo great .
Urbanized areas: More im pervious areas - Effect s of
st orm wat er Road flooding: accident s, washout s, driver delays. Building & propert y flooding: st ruct ural & propert y dam age, sewer backup, foundat ion set t lem ent , dam age sewer backup foundat ion set t lem ent devalued propert ies.
Environm ent al dam age. Ut ilit y service int errupt ions.
I ncreased clean- up cost s, healt h hazards, personal inconvenience, increased insurance cost s. inconvenience, increased insurance cost s.
Solu t ion s: Concret e, St eel & HDPE pipe, Concret e
st ruct ures, Swales and ponds Why Manage St orm wat er? Why Manage St orm wat er?
Manage large am ount of st orm wat er t o avoid flooding & ot her inconveniences.
Tradit ional st orm w at er m anagem ent design - focused on T dit i l t t t d i f d collect ing st orm wat er in piped net works & t ransport ing it off sit e as quickly as possible, eit her direct ly t o a st ream or river, t o a large st orm wat er m anagem ent facilit y
( basin) , or t o a com bined sewer syst em flowing t o a
wast ewat er t reat m ent plant . p
Low im pact developm ent ( LI D) & wet weat her green
infrast ruct ure address t hese concerns t hrough a variet y of
t echniques, including st rat egic sit e design, m easures t o t echniques including st rat egic sit e design m easures t o cont rol sources of runoff, & t hought ful landscape planning. I nt egrat ed St orm w at er Managem ent I nt egrat ed St orm w at er Managem ent
I nt egrat ed wat er m anagem ent ( I WM) of st orm wat er - address m any of t he issues affect ing t he healt h of wat erways & wat er supply challenges facing t he wat erways & wat er supply challenges facing t he m odern urban cit y.
I WM- S know n as low im pact developm ent in USA, or
Wat er Sensit ive Urban Design ( WSUD) in Aust ralia .
I WM has t he pot ent ial t o im prove runoff qualit y, reduce t he risk & im pact of flooding & deliver an addit ional t he risk & im pact of flooding & deliver an addit ional wat er resource t o augm ent pot able supply.
Developm ent of m odern cit y oft en result s in increased dem ands for wat er supply due t o populat ion growt h dem ands for wat er supply due t o populat ion growt h
Alt ered runoff predict ed by clim at e change has p pot ent ial t o increase t he volum e of st orm wat er t hat can cont ribut e t o drainage & flooding problem s. I nt egrat ed St orm w at er Managem ent I nt egrat ed St orm w at er Managem ent
I WM offers several t echniques including: st orm wat er harvest ( reduce am ount of wat er causing flooding) , harvest ( reduce am ount of wat er causing flooding) ,
infilt rat ion ( t o rest ore t he nat ural recharge of
groundwat er) ,
b f l biofilt rat ion or bioret ent ion b ( ( e.g., rain gardens d ) t o ) st ore & t reat runoff & release it at a cont rolled rat e t o reduce im pact on st ream s & wet land t reat m ent s ( t o st ore, cont rol runoff & provide habit at in urban areas) .
I WM - in it s infancy & brings t oget her elem ent s of drainage science, ecology & a realizat ion t hat drainage science ecology & a realizat ion t hat t radit ional drainage solut ions t ransfer problem s furt her d/ s t o t he det rim ent of our environm ent & precious wat er resources. precious wat er resources Low I m pact Developm ent ( LI D ) :
LI D: LI D aim s t o rest ore nat ural wat ershed funct ions t hrough i
l h d f i h h sm all- scale t reat m ent at t he source of runoff. The goal is t o design a hydrologically funct ional sit e t hat m im ics pre- developm ent condit ions.
LI D – Land developm ent – w orks wit h nat ure t o m anage st orm wat er as close t o it s source as possible. st orm wat er as close t o it s source as possible
LI D principles – preserve & recreat e nat ural landscape feat ures, m inim ize effect ive im perviousness t o creat e f funct ional & appealing sit e drainage t hat t reat st orm w at er t i l & li it d i t h t t t t t as source.
Pract ices – bioret ent ion facilit ies, rain gardens, veget at ed , g , g rooft ops, rain barrels & perm eable pavem ent s.
LI D – w at er m anaged in a way t hat reduces im pact of built area & prom ot es nat ural wat er m ovem ent area & prom ot es nat ural wat er m ovem ent LI D & Green I nfrast ruct ure LI D & Green I nfrast ruct ure
LI D rest ore a wat ershed’s hydrologic ecological funct ions
LI D – a sust ainable st orm wat er pract ice
Green I nfrast ruct ure Green I nfrast ruct ure - refer t o syst em s & pract ices t hat refer t o syst em s & pract ices t hat
use or m im ic nat ural processes t o infilt rat e, evapo- t ranspirat e ( ret urn of wat er t o t he at m osphere eit her t hrough evaporat ion or by plant s) , or reuse st orm wat er on h h b l ) t he sit e where it is generat ed.
Green infrast ruct ure Green infrast ruct ure- used at a wide range of landscape used at a wide range of landscape
scales in place of, or in addit ion t o, m ore t radit ional st orm wat er cont rol elem ent s t o support principles of LI D.
Wet Weat her Green I nfrast ruct ure Wet Weat her Green I nfrast ruct ure : encom passes : encom passes
approaches & t echnologies t o infilt rat e, evapot ranspire , capt ure, & reuse st orm wat er t o m aint ain or rest ore nat ural hydrology h d l
Benefit s of LI D & Green I nfrast ruct ure Benefit s of LI D & Green I nfrast ruct ure
Social, econom ic & environm ent al benefit s include:
Socia l: Socia l: Reduct ion in urban heat island effect , Provides Reduct ion in urban heat island effect Provides
“ green j obs’/ ” green business” opport unit ies; Educat ional inform at ion provided t hrough st reet kiosks; Crim e reduct ion ; Healt h benefit s t hrough walking, Crim e reduct ion ; Healt h benefit s t hrough walking biking, running t rails
Econ om ic: Energy cost reduct ion using wind powered
LED light ing; Wat er conservat ion ; Green Ent erprise Business Opport unit ies
En vir on m e n t a l: En vir on m e n t a l:
Carbon sequest rat ion; I m proved Carbon sequest rat ion; I m proved wat er qualit y t hrough 90% capt ure of st orm wat er; Carbon foot print reduct ion; Recycling & beneficial use. Wat ershed Based St orm wat er Managem ent . Wat ershed Based St orm wat er Managem ent .
Reduct ion of flood dam age t o life & propert y.
Goa ls:
Minim izat ion of st orm wat er runoff from new developm ent .
Reduct ion of soil erosion from const ruct ion act ivit ies.
I nsurance of adequat e st orm w at er facilit ies, including I f d t t t f ilit i i l di culvert s, bridges, & ot her in- st ream st ruct ures.
Maint enance of groundwat er recharge. g g
Prevent ion/ reduce of non- point st orm wat er pollut ion.
Maint enance of surface wat ers t o ensure t heir bi l biological & st orm w at er m anagem ent funct ions, i l & t t t f t i
Prot ect ion of public healt h & welfare, t hrough operat ion & m aint enance of st orm wat er syst em s. p y Wat ershed Based St orm wat er Managem ent Wat ershed Based St orm wat er Managem ent
Pr in ciple s:
1. Views regulat ory com pliance as a m inim um requirem ent for accept ance.
2. Requires a st orm wat er m anagem ent plan considering wat ershed wide needs considering wat ershed- wide needs
3. Focuses on achieving good environm ent al result s for t he wat ershed in a cost - effect ive m anner
4. I nt egrat es st orm wat er plans int o proj ect developm ent and proj ect feat ures.
5. Uses collaborat ive part nerships t o leverage and deliver a com binat ion of wat ershed im provem ent s.
5. Uses collaborat ive part nerships t o leverage and
6. A coordinat ed m it igat ion/ enhancem ent st rat egy.
St orm w at er Cont rol Measures St orm w at er Cont rol Measures t orm wat er Managem ent – t orm wat er Managem ent – Separat e Syst em Separat e Syst em S S
P ll Pollut ed d st orm w at er runoff ff t ransport ed - d t hrough h h Municipal Separat e St orm Sewer Syst em s, from which it is oft en discharged unt reat ed int o local w at er bodies.
To prevent harm ful pollut ant s from being w ashed or dum ped int o w at er bodies, appropriat e pollut ion cont rol m easures should be developed cont rol m easures should be developed.
Separat e syst em s are com prised of t w o independent piping syst em s: one syst em for " sanit ary" sewage ( i.e., sewage from ( i f h hom es & businesses) and one & b i ) d syst em for st orm wat er
Wast e Wast e st orm wat er wat er t orm wat er Managem ent – t orm wat er Managem ent – Com bined Syst em Com bined Syst em S S
A com bined sewer syst em conveys bot h sanit ary A com bined sewer syst em conveys bot h sanit ary sewage & st orm wat er in one piping syst em
During norm al dry weat her condit ions, sanit ary wast es collect ed in t he com bined sewer syst em are divert ed t o t he Wast ewat er Treat m ent Plant .
During periods of significant rainfall, t he capacit y of a During periods of significant rainfall t he capacit y of a com bined sewer m ay be exceeded - let t he excess flow, ( m ixt ure of st orm wat er & sanit ary wast es) , discharged direct ly int o large discharged direct ly int o large wat er bodies - excess flow is called Com bined Sewer Overflow ( CSO) . O fl ( CSO)
Wast e wat er
Ur ba n iz a t ion Effe ct s & b i i ff Floodin g g
Nat ural surface is covered by art ificial st ruct ures
Urbanized wat ershed
I t increases im pervious areas
Rural Discharge wat ershed
Channel charact erist ics of shape, slope, & roughness- bet t er known slope & roughness- bet t er known
Changes flow pat t ern & qualit y of runoff
Tim e
is also influenced
Est im at ion of losses is sim plified
I t leads t o higher peak flow and short er t im e t o peak and causes t he inundat ion problem at t he low- lying areas and undesirable load t o t he downst ream areas downst ream areas
Ur ba n Floodin g - Ca u se s
Met eorological fact ors: Rainfall; Cyclonic st orm s;
Sm all scale st orm s; Tem perat ure; Snowfall and Sm all- scale st orm s; Tem perat ure; Snowfall and snowm elt
Hydrological fact ors: Soil m oist ure level; Groundwat er
condit ions; infilt rat ion; im pervious cover; Channel di i i fil i i i Ch l condit ions; Tidal effect s et c.
Hum an fact ors: Hum an fact ors: Land use/ land cover changes; in Land use/ land cover changes; in
appropriat e drainage syst em s; occupat ion of flood plain areas; sudden release of wat er from dam s; clim at e change; urban m icro clim at e; indiscrim inat e clim at e change; urban m icro clim at e; indiscrim inat e wast e disposal et c.
Ur ba n Flood Pr oble m s
The im pact s m ay include loss of m oney, t em porary disrupt ion t o t ransport at ion syst em s.
I nconvenience t o cit y life I i t it lif
I t can also cause erosion and inst abilit y of soils on st eep slopes t hreat ening houses. p g
The ext rem e event s result in inundat ion for a prolonged durat ion
Heavy rainfall, t idal influences and lack of adequat e drainage syst em is a serious problem affect ing on m any coast al cit ies. affect ing on m any coast al cit ies
Due t o t he com plexit y of t he problem , advanced m odeling t ools are required.
Ur ba n iz a t ion I m pa ct s
Modificat ion of flooding charact erist ics by int roducing st orm drains
- –
Rapid rem oval of wat er from t he drained area decreases t he t im e and infilt rat ion
To delay t he Peak rat e of runoff To delay t he Peak rat e of runoff – increasing an increasing an area’s st orage capacit y and delaying out flow
Runoff from st reet s t o drainage syst em Runoff from st reet s t o drainage syst em Flooding due t o : Lim it ed int ake capacit y of t he
drainage syst em ; I nsufficient capacit y of t he pipe
syst emAppr oa ch e s in Ur ba n H ydr ology Appr oa ch e s in Ur ba n H ydr ology
Em pirical Lum ped- Param et er Approach
Considerat ion of t he ent ire drainage area as a single unit
Est im at ion of flow at only t he m ost downst ream point d t i t
Assum pt ion of t he rainfall is uniform ly dist ribut ed in t im e and space over t he dist ribut ed in t im e and space over t he wat ershed
Apply t echniques such as unit hydrograph Apply t echniques such as unit hydrograph t echniques
Appr oa ch e s in Ur ba n H ydr ology Appr oa ch e s in Ur ba n H ydr ology
Physical – Process Approach: I nvolves follow ing
st eps Det erm ine a design st orm
Deduct losses from t he design st orm t o arrive at an excess rainfall rat e
Det erm ine t he flow t o a gut t er or som e defined channel by overland flow equat ions h l b l d fl
Rout e t hese gut t er flow t o m ain channel flow
Rout e t he flow t hrough t he principal conveyance syst em
Det erm ine t he out flow hydrograph D t i t h t fl h d h Measures for Reducing/ Delaying St orm Measures for Reducing/ Delaying St orm Runoff Runoff Runoff Runoff
Large flat roofs
P Porous parking lot s ki l t w w w.greenhighwayspart nership.org
I ncrease recharge
Plant ing a high delaying grass Plant ing a high delaying grass
I ncrease forest cover
Det ent ion basins Det ent ion basins
Grassed wat erways
Porous sidew alks Porous sidew alks w w w.greenhighwayspart nership.org
Roof t op gardens
Fount ain st orage Fount ain st orage
Ca se St u dy: St or m w a t e r D r a in a ge for a n
Ur ba n Ar e a : Ur ba n Ar e a : St udy area: A Housing Colony – Sant acruz Mum bai
To st udy t he act ual sit uat ion of t he flooding problem in a To st udy t he act ual sit uat ion of t he flooding problem in a low lying urban area subj ect ed t o t idal effect s and suggest m easures.
Present ly t he area is affect ed by frequent flooding in l h ff d b f fl d m ost of t he m onsoon season as t his area is low- lying com pared t o t he nearby areas.
Pr e se n t st a t u s of t h e dr a in a ge syst e m
Two subm ersible pum ps ( capacit y of 10 HP each) pum ping t he st orm wat er t o t he road drainage syst em pum ping t he st orm wat er t o t he road drainage syst em
A 900 m m diam et er pipe ( slope of 1 in 1000) draining direct ly t o t he Mit hi River.
7 a re A e
pipe
th f o2 2 7
900 mm
s re tu a e fPresent Drainage Syst em Capacit y
The Mit hi River is passing nearby and t he drainage • syst em drains int o t he river, which is subj ect ed t o syst em drains int o t he river, which is subj ect ed t o t idal effect . When t he wat er level rises in t he river and high t ide • occurs t he out fall of drain is subj ect ed t o t idal effect s occurs t he out fall of drain is subj ect ed t o t idal effect s and consequent flooding.
During t he year 2004 a new 900 m m diam et er • pipeline was laid t o solve t he flooding problem and pipeline was laid t o solve t he flooding problem and t hat year t he area was not subj ect ed t o flooding. But in 2005, highest ever recorded rainfall occurred • during t he m onsoon and t he area w as severely d i h d h l affect ed by floods. Present drainage system capacity
St orm wat er discharge t hrough t he pum ping syst em
St orm wat er discharge t hrough t he 900 m m diam et er
3 pipe drain Q = 0.492 m / s.
Tot al drainage capacit y of t he present syst em Tot al drainage capacit y of t he present syst em
3 0.543 m / s.
Rat ional form ula: Rat ional form ula: C C – runoff coefficient runoff coefficient
Q Q = CiA; CiA;
= 1.0; Q – 0.543 m 3/ s; A – area t o be drained = 18
2;
acres = 7.28 ha = 72875 m i - rainfall int ensit y = ?? m m / hr. ?? m m / hr
From t he above calculat ion it is found t hat t he syst em is capable of discharging only 25 m m / hr rainfall
Drainage Problem ..
The m axim um hourly rainfall int ensit y in m ost of t he year is m ore t han 25 m m / hr
During t he m onsoon, River overflows and in addit ion if During t he m onsoon River overflows and in addit ion if t he heavy rainfall happens sim ult aneously wit h t he rising t ide a reverse flow occurs leading t o heavy flooding sit uat ion in t he area. flooding sit uat ion in t he area
Problem in select ing t he Design Crit eria
- – Unavailabilit y of adequat e nat ural slope t o Unavailabilit y of adequat e nat ural slope t o facilit at e gravit y flow
- – Tidal effect s encount ered at t he exit point
- – Lack of space t o provide appropriat e drainage L k f id i d i arrangem ent s since t he ground levels of surrounding area had been raised m uch higher t han t hose of t his colony.
D isch a r ge t o be dr a in e d by t h e syst e m for va r iou s r a in fa ll in t e n sit ie s va r iou s r a in fa ll in t e n sit ie s 4.00
3.00 ar ge m 3 /s 2 .024
- H ydr a u lic a n a lysis
- H ydr a u lic a n a lysis 2.00 Storm Disch 2 1.417 1. 61 9 2
- Q= AR
u sin g M a n n in g’s for m u la 1.00 0. n h r 2 y r riod h r 10 yr eriod /hr 5 y r e riod 50 61 1. 01 2 h r 5 y rs eri o d
2/ 3 S
1/ 2 / n
40
80 120 160 d i f ll i i ( /h ) 0.00 25 mm/ h r ol d des ig n /h 50 mm re turn pe 80 mm/ h retur n p e / 10 0 m m return p e Measured rainfall intensity (mm/hr) 70 mm/ h return p e Recommendations
The present exist ing ground level has t o be increased at least 60 cm in t he lower levels of t he low lying area, so t hat an adequat e slope is available for t he area, so t hat an adequat e slope is available for t he proposed new drain.
A sm all gut t er all along t he int ernal road of t he area leading t o t he lowest point . Since t he exist ing 900 m m leading t o t he lowest point Since t he exist ing 900 m m pipe is alm ost at ground level, it is advisable not t o have cross connect ion inlet s ot her t han t he exist ing inlet s t o t his exist ing 900 m m diam et er pipe drain. l h 900 d d
Ent ry of st orm wat er from t he surrounding areas needs t o be prevent ed needs t o be prevent ed
The cross connect ions t o t he nearby Draining Nullah has t o be cut off as t he lat t er has a high invert level, which would give rise t o a reverse flow. which would give rise t o a reverse flow
Re fe r e n ce s Re fe r e n ce s
Am erican Societ y of Civil Engineers and Wat er Environm ent
Federat ion ( ASCE and WEF) . 1998. Urban Runoff Qualit y
Managem ent . WEF Manual of Pract ice No. 23, ASCE Manual and
Report on Engineering Pract ice No. 87. ht t p: / / ndm a.gov.in/ ndm a/ guidelines.ht m l
ht t p: / / w w w .epa.gov/ oaint rnt / st orm w at er/ index.ht m
ht t p: / / wrm in.nic.in ht t p: / / wrm in nic in
Nat ional Research Council of t he Nat ional Academ ies ( NRC) . 2008.
“ Urban St orm w at er Managem ent in t he Unit es St at es.” The Nat ional Academ ies Press. Washingt on, DC. Nat ional Academ ies Press Washingt on DC
Tu t or ia ls - Qu e st ion !.?
Crit ically st udy t he st orm w at er m anagem ent issues in I ndia. What are t he m aj or issues in I ndia What are t he m aj or problem s in im plem ent ing appropriat e st orm w at er m anagem ent syst em s in I ndian g y cit ies like Mum bai/ Kolkot t a?. h t t p:/ / n dm a .gov.in / n dm a / gu ide lin e s.h t m l
Com pare t he st orm wat er m anagem ent Com pare t he st orm wat er m anagem ent
pract ices in USA, UK and I ndia and propose pract ices in USA, UK and I ndia and propose pract ices in USA, UK and I ndia and propose pract ices in USA, UK and I ndia and propose
bet t er m anagem ent pract ices for I ndian bet t er m anagem ent pract ices for I ndian Cit ies. Cit ies.Prof. T I Eldho, Department of Civil Engineering, IIT Bombay
Se lf Eva lu a t ion - Qu e st ion s!
Discuss st orm wat er runoff & param et ers influencing on wat ershed basis. wat ershed basis
What is t he “ Best Managem ent Pract ices” relat ed t o “ St orm w at er Managem ent ” ?.
Discuss I nt egrat ed St orm wat er Managem ent pract ices.
What are t he goals & principles of wat ershed based S St orm w at er Managem ent ?. ?
Different iat e bet ween “ Separat e” & “ Com bined” st orm wat er m anagem ent syst em . st orm wat er m anagem ent syst em
What are im port ant m easures for delaying st orm runoff?
Assign m e n t - Qu e st ion s?. g Q
I llust rat e various st orm wat er harvest ing t echniques.
Why we have t o m anage st orm wat er?. y g
Discuss t he feat ures of “ Low I m pact Developm ent & Green I nfrast ruct ure” wit hin t he perspect ive of st orm w at er m anagem ent . t t t
I llust rat e im port ant st orm wat er cont rol m easures.
What are t he im port ant effect s of urbanizat ion on What are t he im port ant effect s of urbanizat ion on runoff?.
Discuss t he im port ant causes of urban flooding. p g
Different iat e bet ween “ em pirical lum ped param et er approach” and “ physical process approach” in urban hydrology. h d l
Un solve d Pr oble m !. Un solve d Pr oble m !
What are t he im port ant st orm w at er What are t he im port ant st orm w at er m anagem ent problem s in your wat ershed area?. m anagem ent problem s in your wat ershed area?.
Collect t he necessary dat a for t he st orm w at er Collect t he necessary dat a for t he st orm w at er design in your area. design in your area. design in your area design in your area
Wit h t he help of rainfall dat a, t opo Wit h t he help of rainfall dat a, t opo-- sheet and sheet and ot her m aps such as drainage net w ork m aps, ot her m aps such as drainage net w ork m aps, ot her m aps such as drainage net w ork m aps, ot her m aps such as drainage net w ork m aps, LU/ LC m ap, road net w ork, design an effect ive LU/ LC m ap, road net w ork, design an effect ive st orm w at er m anagem ent plan for your st udy st orm w at er m anagem ent plan for your st udy area. area area. area
Dr. T. I. Eldho Dr. T. I. Eldho Professor, Professor, Department of Civil Engineering, Department of Civil Engineering, p p g g g g Indian Institute of Technology Bombay, Indian Institute of Technology Bombay, Mumbai, India, 400 076. Mumbai, India, 400 076. Email: Email: Email: Email: eldho@iitb.ac.in eldho@iitb.ac.in eldho@iitb.ac.in eldho@iitb.ac.in