8. Stream Hydrology

7/23/2019 8. Stream Hydrology

http://slidepdf.com/reader/full/8-stream-hydrology 1/76

An Introductory Guide to Hydrology Using

WinTR-55

Prepared By:

Stormater Solutions !ngineering" ##$

%&& !ast Sumner Street ' Hart(ord" Wisconsin 5)&*+,stormater-solutions-engineering,com '**-+)-..+

http://www.stormwater-solutions-engineering.com/

http://www.stormwater-solutions-engineering.com/



Ho Hydrology relates to Bridges toProsperity

• Gat/er in(ormation (rom t/ecommunity on t/e /ig/est ri0er/eig/t e0er o1ser0ed

• Se0eral assumptions are needed tocalculate t/e runo2 and /ig/ aterele0ation

• $ompare t/e o1ser0ed /ig/ aterri0er ele0ation and t/at computed



30er0ie

• Ho are runo2 4os generated

• Ho WinTR-55 can 1e used tocalculate runo26storm ater 4os



30er0ie

• Section %: Hydrology

• Section *: WinTR-55



%676% TR-55 Tutorial 5

A

D

CC

B

EE

Su1-area6Reac/ $oncepts

R e a c h 1 c

R

e a c h 2 e

• Watershed -

system o( su1-areasand reac/es

• Sub-areas 8 areasit/in a aters/edt/at generatesruno2

• Reaches -

representaters/ed 4opat/s 9streamc/annels or

structures

/ttp:66,si,nrcs,usda,go06products6W*;6H<H6docs6WinTR556WinTR55=e>p=

users,ppt

Section %: Hydrology



Reading Topograp/ic ?aps(or Tc

$ontour @points

upstream

Possi1le s/eet4o location 8

long" s/alloslope

Possi1le s/alloconcentrated

4o:* or ) distinct4o regimes

9slope% calculation (or

$/annel CloMay 1e a1le to

disregard cul0ertsunder roadays,

T/ese contourlo1es identi(y

di0ides /ere4o splits le(t

and rig/t


Boundaryindicates limit o(

aters/ed 8 ridgeo( /ig/ points t/at

deDne 4o1oundary

$losed area

indicate alocaliEeddepression or a

/ig/ point9peaF



%676% TR-55 Tutorial +

Su1-area6Reac/ $oncepts

• Watershed - system o( su1-areas and reac/es

• Sub-areas 8 areas o( a aters/ed t/at generateruno2

- Clos6disc/arges into t/e upstream end o(

reac/es • Reaches or Routing !lements- represent

aters/ed stream 4o pat/s or structures

– Channel Routing elements - Stream

Reac/es – Structure Routing elements -

Reser0oir6Structure Reac/es

• Waters/ed Outlet - donstream end o( t/e

aters/ed 9reuired (or all aters/eds» Typically disc/arges to a reac/


users,ppt




Su1-area6Hydrology$oncepts

• Hydrology is 1ased on se0eral (actors: – T/e size o( t/e drainage area,

– T/e a1ility o( t/e nati0e soil to inDltrate ater at

t/e start o( a rain(all e0ent" or capture ot/erise9inDltration 0egetation capture e0apotranspiration initial a1straction, T/is isappro>imated in t/e TR-55 met/od 1y utiliEingCN 9aFa R$J" or Runo2 $ur0e Jum1ers,

– T/e time it taFes (or t/e entire area 9or su1areato contri1ute 4o to t/e donstream point o(interest 9Time of Concentration,




%676% TR-55 Tutorial .

Su1 Area $oncepts -Sc/ematics

R

e a c h

2 c

( R e a c h R o

u t i n g )

Outlet

R e a c h 1a ( s t o r a g e r o u t i n g )

S u b - a r e

a B

S u b - a r e a A

S u b - a r e a C

Legend:

Storage Area

Sub-Area Inflow Points


users,ppt




Ketermining $J - Soil Types

• Based on @Hydrologic Soil GroupclassiDcation – In t/e U,S," can 1e (ound at:

e1soilsur0ey,nrcs,usda,go0• A sand6gra0el su1 soils

To

• K c/aracteristics o( a etland – Silt or clay soil" poorly drained

• 3utside t/e US" need soil engineer or localin(o on soil types




Hydrologic Soil Groups




Hydrologic Soil Groups

Crom USKA:

• Hydrologic soil groups are 1ased on estimates o(runo2 potential, Soils are assigned to one o( (ourgroups according to the rate of water inltrationwhen the soils are not protected by vegetation,are thoroughly wet, and receive precipitationfrom long-duration storms.

• T/e soils in t/e United States are assigned to(our groups 9A" B" $" and K and t/ree dualclasses 9A6K" B6K" and $6K,


S i % H d l



Hydrologic Soil Group - A

• Group A, Soils /a0ing a highinltration rate 9lo runo2potential /en t/oroug/ly et,

T/ese consist mainly o( deep" elldrained to e>cessi0ely drained sandsor gra0elly sands, T/ese soils /a0e a

/ig/ rate o( ater transmission,


S ti % H d l



Hydrologic Soil Group - B

• Group B, Soils /a0ing a moderateinltration rate /en t/oroug/lyet, T/ese consist c/ie4y o(

moderately deep or deep"moderately ell drained or elldrained soils t/at /a0e moderately

Dne te>ture to moderately coarsete>ture, T/ese soils /a0e a moderaterate o( ater transmission,

• $onsists o( sandy silts" silty sandL


S ti % H d l



Hydrologic Soil Group - $

• Group $, Soils /a0ing a slowinltration rate /en t/oroug/lyet, T/ese consist c/ie4y o( soils

/a0ing a layer t/at impedes t/edonard mo0ement o( ater orsoils o( moderately Dne te>ture or

Dne te>ture, T/ese soils /a0e a slorate o( ater transmission,

• $onsist o( silty clays" sandy claysL


Section % Hydrology



Hydrologic Soil Group - K

• Group K, Soils /a0ing a 0ery slo inDltrationrate 9/ig/ runo2 potential /en t/oroug/lyet, T/ese consist c/ie4y o( clays t/at /a0e

a /ig/ s/rinF-sell potential" soils t/at /a0ea /ig/ ater ta1le" soils t/at /a0e a claypanor clay layer at or near t/e sur(ace" andsoils t/at are s/allo o0er nearly

imper0ious material, T/ese soils /a0e a0ery slo rate o( ater transmission,

• $onsists o( predominantly clayey soils,





Hydrologic Soil Group 8 Kual Groups

• I( a soil is assigned to a dual/ydrologic group 9A6K" B6K" or $6K"t/e Drst letter is (or drained areas

and t/e second is (or undrained areas, 3nly t/e soils t/at in theirnatural condition are in group D

are assigned to dual classes,• $an consist o( peat" etland soils"

clayey soils" or e0en undrained

sands6gra0els,





Hydrologic Soil Group 8We1 Soil Sur0ey

In t/e U,S:

%, Cind #ocation*, KeDne @Area o( Interest

Crom tool 1ar" dra polygon around proMect aters/ed

), @Soil Kata !>plorer ta1

N, @Soil Properties and Ceatures

5, @Hydrologic Soil Group

, @ie Rating

N)

5

%"*





GroupGroup

Hydrologic Soil Group 8We1 Soil Sur0ey 3utput

Soil Jame Group Area" O





$J 8 Soil Type

• *%&-I-TR-55" Second !d," une%.7,,, – Actual Tec/nical Release 9TR in TR-55

– Jot a manual (or t/e program" 1ut t/e1acF ground literature (or t/e program

– /ttp:66,/ydrocad,net6pd(6TR-55O*&?

anual,pd( • KeDnes $Js (or general areas

9imper0ious" per0ious" etc, as ell asselect land uses,



http://www.hydrocad.net/pdf/TR-55%20Manual.pdf






$JCrom *%&-I-TR-55

Imper0ious Area:

$J.7

General #and

Use91ased on imp,area





$JCrom *%&-I-TR-55

Jot all cropland

is createdeualL





$JCrom *%&-I-TR-55





$JCrom *%&-I-TR-55

• Some regulatory agencies reuirecomparison to pre-de0eloped conditions, – Pre-de0elopment

– 3r pre-!uropean settlement

• Some restrict t/e $Js in pre-de0elopedmodels to pasture or meado – T/is can artiDcially loer t/e $J 9less runo2

compared to agricultural $Js





Area

• !it/er 1y $AK" or (rom We1 SoilSur0ey" or estimated,

• Area o( indi0idual su1-aters/eds"composite areas" or 1y similar $J

• $ommonly" areas are di0ided 1y su1aters/ed" or areas it/ same Time

o( $oncentration





$omposite $JWinTR-55 does t/is (or youQ

• Cor use /en adding areas 9A it/di2erent $Js,

• $omposite $J9Ai

$Ji

69Ai

• !>ample: Area 9A

$J A$JAcres

residential 5% 7) N"*N*

industrial 5% .% N")%

nati0e scru1 %+* 5 %%"*&.

%5O imp . .7 75775O nati0e 5& 5 )"**)

(arm 9SR %"%7& 75 %&&"*7

sum %"5%) sum %*N"NN7

$omposit

e 7*

y gy




Storm Kata Crom *%&-I-TR-55

• @T/e /ig/est peaF disc/arges(rom small aters/eds in t/eUnited States are usually caused

1y intense" 1rie( rain(alls t/atmay occur as distinct e0ents oras part o( a longer storm, T/eseintense rainstorms do not usuallye>tended o0er a large area andintensities 0ary greatly, 3necommon practice in rain(all-runo2analysis is to de0elop a synt/eticrain(all distri1ution to use in lieuo( actual storm e0ents 9B-%,

y gy

• Generally" t/ere are N standard rain(alldistri1utions it/in t/e US,




y gy

Storm Kata Crom *%&-I-TR-55




Time o( $oncentration 9Tc

• Based on longest /ydraulic pat/ o(aters/ed or su1-aters/ed,

• ) 9actually N di2erent types o( ater

4o:%, S/eet Clo

*, S/allo $oncentrated

), Kitc/N, Pipe 9not modeled in some programs" suc/ as WinTR-55

• Add all indi0idual 4o segments (or Tc

y gy




#ongest Pat/

• 3nce t/e rain t/at (alls on t/e (urt/est 9timepoint (rom t/e disc/arge" t/e entire aters/edis assumed to 1e reac/ing t/e out(all, T/iscan /elp deDne t/e peaF o( t/e /ydrograp/,

• T/e longest /ydraulic pat/ used /enanalyEing times o( concentration typicallystart at eit/er t/e /ig/ point in t/e su1-

aters/ed or a long" 4at area,• S/eet 4o ill typically control 8 ma>imiEe

lengt/ at s/allo slope,




#ongest Pat/ 8 ?inimum Time Crom *%&-I-TR-55

• Regardless o( #ongest Pat/ Tc calculations" T/e minimum Tc used in TR-55 is &,% /our9page )-N,

•In large aters/eds t/is constraint will probably not 1e an issue,

• T/is constraint may 1e an issue /enmodeling smaller or /ig/ly imper0ious areas,

• T/is minimum Tc is also typically applied toRational ?et/od calculations (or storm seersiEing




S/eet CloCrom *%&-I-TR-55

• S/eet 4o is 4o o0er plane sur(aces

• Typically s/ort 9%&& (eet" ma>imum" and

can 1e restricted to loer lengt/s 1y regulatory

agencies 9or 1y WinTR-55

• Pro(essional Mudgment needed (orend conditions




S/eet CloCrom WinTR-55 CA;s

• Is there any way to increase the sheet ow lengthbeyond 100 feet in !in"#-$$%&

• @Jo, A(ter muc/ discussion and researc/" t/ede0elopment team (elt t/at s/eet 4o greater t/an

%&& as 0ery unusual in natural aters/eds, Cormore in(ormation on t/e su1Mect read W,H, ?erFels@Re(erences on Time o( $oncentration it/ Respectto S/eet Clo as posted in Tec/nical Re(erences

and H<H Papers on arious Topics"/ttp:66,si,nrcs,usda,go06products6W*;6H<H6Tools=?odels6WinTR55,/tml in t/e USKA-JR$S WestJational Tec/nology Support $enter e1site,




S/eet CloCrom *%&-I-TR-55

• @T/e range o( mean dept/ is &,&&*V (orpa0ed areas to &,&*V (or 0egetatedareas,

• S/eet 4o ?anningVs @n 0alues are (or0ery s/allo 4o dept/s,

• @It is important to note t/at" particularly

(or unpa0ed sur(aces" t/ese (riction(actors are dierent t/an t/osetraditionally used (or c/annel 4o,

USKA" @T!$HJI$A# J3T! J&,




S/eet Clo ?anningsCrom *%&-I-TR-55




S/allo concentrated 4oCrom *%&-I-TR-55

• A(ter a ma>imum o( )&&(eet" s/eet 4o usually1ecomes s/alloconcentrated 4o,

• Ketermine elocity

• Ketermine segment Tra0el Time 9Tt

• By euation: – *&,)*5*9s&,5 pa0edX

– %,%)N59s&,5 unpa0edX

• Tt#engt/6




$/annel and Pipe CloCrom *%&-I-TR-55

• Typically non-pressure4o is assumed (orpipes and cul0erts9WinTR-55 does not

calculate pressure 4o• Use standard euations

(or open c/annel 4o

• Ketermine elocity

• Ketermine segment Tra0el Time 9Tt

• Tt#engt/6

Reading Topograp/ic ?apsSection %: Hydrology



Reading Topograp/ic ?aps(or Tc

$ontour @points

upstream

Possi1le s/eet4o location 8long" s/allo

slope

Possi1le s/alloconcentrated

4o:* or ) distinct4o regimes

9slope% calculation (or

$/annel Clo

May 1e a1le todisregard cul0ertsunder roadays,

T/ese contourlo1es identi(y

di0ides /ere4o splits le(t

and rig/t

Boundary indicates

limit o( aters/ed8 ridge o( /ig/

points t/at deDne4o 1oundary

$losed areaindicate alocaliEed

depression or a/ig/ point

9peaF

/ i / 4Section %: Hydrology



W/at is a Reac/6In4uenceon Tc

• Reaches - representaters/ed 4o pat/s9stream c/annels or

structures• Generally utiliEed to

route one su1 1asint/roug/ anot/er

• @Reac/ $% as s/oncan also 1e a part o(t/e Tc (or Su1 Area $,

/ i / 4Section %: Hydrology



W/at is a Reac/6In4uenceon Tc

• In t/is scenario" t/e Tc o(su1 area B is sum o( itstimes (or s/eet 4o"s/allo concentrated" and

any c/annel or pipe 4o,• T/e Tc o( su1 area B at t/e

donstream end o( Reac/$% is Tc9B Tt9Reac/ $%,

• Reac/ routing is a crucialstep in runo2 /ydrograp/de0elopment




Summary o( $J" and Tra0el KataInput Kata

SUB AR!A Residential Industrial $rop Brus/6Woods Total 9Ac= $J

7) .% 75 5

A %N%,N. *7,N% *N+,7) %&),% 5*&,.& 7%

B &,&& &,&& 5N+,N *,*N 5N.,7+ 75

$ &,&& &,&& %.N,+% %5),.. )N7,+& +

K &,&& &,&& +5,*+ %&&,*& %+5,N+ +N

S/eet Clo S/allo $oncentrated

#engt/ Slope n #engt/ Assumed Hig/ Pt Krop #o Pt Slope

A %&& *,&&O &,*N *%)5 .77 %5 .+) &,+&O

B %&& *,&&O &,*N 5.% .77 5& .)7 &,77O

$ %&& *,&&O &,*N *N)5 .77 N5 .N) %,75O

K %&& *,&&O &,*N %N*% .77 *& .7 %,N%O

$/annel Clo

#engt/ Slope n YS WP

A &+) &,%&O &,&+ *77 %&&

B &,%&O &,&+ *77 %&&

$ %.&+ &,%&O &,&+ *77 %&&

K %5.7 &,%&O &,&+ *77 %&&

R!A$H

#engt/ Slope Bottom Widt/ Side Slope n

$% ).7%,&.NN &,%&O %& )H:% &,&+

K% *+&7,%NN &,%&O %& )H:% &,&+




Runo2 ;uantiDcationCrom *%&-I-TR-55

• T/e Tec/nical Report o2ers ) ays o(determining runo2 uantities:











A li 1ilit t P ( i lSection %: Hydrology



Applica1ility to Pro(essionalUse

• Wit/ limited input" computer programs can automatically calculate tra0el times" composite$Js" and times o( concentration,

• Some programs allo (or (eer roug/ness0aria1les t/an pro0ided in re(erence documents,

• It is use(ul to manually calculate tra0el times"composite $Js" and times o( concentration (oreasier re0ie60eriDcation purposes,

• ?ost computer programs also allo a @directinput o( t/ese manually calculated 0alues,




Hydrograp/ Ke0elopment Crom *%&-I-TR-55

• Hydrograp/s can 1e de0eloped usingse0eral met/ods,

• $ommonly used is t/e procedurelisted in $/apter 5 o( *%&-I-TR-55

• W/ile eac/ runo2 /ydrograp/ isdi2erent" typically t/e distri1ution is

similar" only di2er in time scale anduantity o( runo2 – Kependant on Tc and $J

/ttp:66isddc,dot,go063#PCiles6CHWA6&%&5.

? d l 3 t t T / i lSection %: Hydrology



?odel 3utputs 8 Tec/nicalBasis

• H!$-**" 'hapter () #etention and*etention +acilities" pro0idesdiscussion on /ydrograp/ routing

t/roug/ detention (acilities,

/ttp:66isddc,dot,go063#PCiles6CHWA6&%&5.

? d l 3 t t T / i lSection %: Hydrology




• Stage-Kisc/arge Ratings (or an 3utlet is s/on

• Stage-Kisc/arge-torage Relations/ips t/at someprograms can present" Must depicts anot/er Fnon0aria1le

H!$-**" 7-N&

?odel 3utputs Tec/nicalSection %: Hydrology




• Storage-Indicator ta1les"and grap/icalrepresentation

H!$-**" p 7-N& <7-N

A li 1ilit t P ( i lSection %: Hydrology



Applica1ility to Pro(essionalUse

• $omputer programs are commonly used to1ypass time consuming de0elopment o(/ydrograp/s and routing calculations,

• A common 1eneDt (or computer models isinteraction o( Zinterconnected ponds andde0elopment o( /ydrograp/s it/ datapoints e0ery minute,

• Some pro(essionals still pre(er manualcalculation t/oug/ 8 it is ise to 1e (amiliarit/ 1ot/,

Section *: WinTR-55



A1out WinTR-55 9general

• WinTR855 is a single-e0ent rain(all-runo2"small aters/ed /ydrologic model,

• T/e model generates /ydrograp/s (rom

1ot/ ur1an and agricultural areas and atselected points along t/e stream system,

• Hydrograp/s are routed donstreamt/roug/ c/annels and6or reser0oirs,

• ?ultiple su1-areas can 1e modeled it/int/e aters/ed,

Crom Win TR-55User Guide"

Section *: WinTR-55



Ho to Konload

• WinTR-55 9$omputer Program – /ttp:66,si,nrcs,usda,go06products6W*;6H<H6tools=models6

intr55,/tml

3ptional Additional Re(erence ?aterials

•

TR-55 9Tec/nical Release 55 – /ttp:66,/ydrocad,net6pd(6TR-55O*&?anual,pd(

• H!$-** 9ydraulic ngineering 'ircular /o. , econd

dition, 'hapter () *etention nd #etention +acilities – /ttp:66,(/a,dot,go06engineering6/ydraulics6li1rary=listing,c

(marc/i0edtrue – /ttp:66isddc,dot,go063#PCiles6CHWA6&%&5.),pd(

CR!!Q

Section *: WinTR-55



WinTR-55 IJPUTS

General

• User Jame

• ProMect Jame

• State" $ounty 9i(applica1le

• Su1 title

• Area $/aracteristics

• Reac/

• Structure

Area $/aracteristics

• Su1-Area James

• Su1-AreaKescription

• Su1-area Clos toReac/ 3utlet

– Weig/ted $J – Tc 9/ours

– Area 9units

Section *: WinTR-55



$omposite $J 8 WinTR-55

$licF t/isL

LTo get t/is indo

T/en enter acreage ne>t

to appropriate $J

Section *: WinTR-55



Storm Kata 8 WinTR-55

• Program reuires storm data entryprior to Tc

• $ustom unit /ydrograp/s and rain(all

distri1utions are also accepted inputs

• USKA rain(all in(ormation pro0ided(or all counties in U,S,

– Will auto populate rainfall depths

– Will auto populate rainfall distributiont!pe

Section *: WinTR-55



Storm Kata 8 WinTR-55

$licF t/isL

LTo get t/is indo

Section *: WinTR-55



Storm Kata 8 WinTR-55Select t/is 1utton toauto populate storm

data 1ased on State and$ounty indicated on

/ome screen,

3r enter speciDc data9as reuired 1y

regulatory agency

accept

Select rain(all type

Section *: WinTR-55



Tc Inputs 8 WinTR-55

$licF t/isL

LTo get t/is indo

• Ho to enter Time o($oncentration Kata

Section *: WinTR-55



Reac/ Kata - WinTR-55

• $an model stream" c/annels" etc,donstream o( a su1area oraters/ed $licF t/isL

LTo get t/is

indo

P tti It All T t/Section *: WinTR-55



Putting It All Toget/erWinTR-55 Kata Screen




Putting It All Toget/erClo Pat/




Putting It All Toget/erResults




Putting It All Toget/erResults

Section *: WinTR-55



Additional Tools

Reser0oir

Routing

Section *: WinTR-55



3utlet Structure- WinTR-55

• A @Structure in WinTR-55 re(ers tostructure routing elements – A reser0oir6pond

– A reac/ it/ signiDcant storage and6or aconstricted outlet

Section *: WinTR-55




• UnliFe H!$-RAS" WinTR-55does not /a0e dynamicrouting capa1ilitiesL – As a reac/ disc/arges" t/e

structure Dlls and 1eginsto disc/arge,

– !0entually t/e reac/ may stop 4oing (olloing arain e0ent 8 a dry ditc/"(or e>ample 8 /ile t/e

structure may /a0e only aportion o( t/e total in4o,

– T/is may 1e pro1lematic,

?odeledReac/

?odeledStructure

KonstreamReac/

Ground

HG#

T/is condition J3T modeled

?odeled

Reac/

?odeledStructure

KonstreamReac/

Section *: WinTR-55




• Jote cul0ertsand riser6pipecom1inationsare modeled t/esame

• Also" pipe invertto spillway is

measured att/e pipe e>it"not entrance

Section *: WinTR-55




Lor Kou1le clicFt/isL

LTo get t/isindo

$licF t/isL

Pipe oreir

Section *: WinTR-55




Kou1le clicFt/isL

LTo get t/isindo

Section *: WinTR-55



Reac/ Routing - WinTR-55

Assign t/ereac/ to t/e su1

area

Section *: WinTR-55



Reac/ Clo - WinTR-55

$licF t/isL

LTo get t/isindo

Lor clicF t/isL

Section *: WinTR-55



Run ?odel - WinTR-55

• T/e model can 1e run (or numericalor grap/ical output

• T/e model can 1e run (or multiple

storm e0ents 9numerical output• !rrors may 1e t/e result o(

@structure o0ertopping 8 i,e," t/e

structure outlet is undersiEed" or notenoug/ storage is a0aila1le

Section *: WinTR-55



Run ?odel - WinTR-55

$licF t/isL

LTo get t/isindo

Select rain(alle0ents" t/en Run



Run ?odel 9output 8 WinTR-

Section *: WinTR-55



Run ?odel 9output WinTR55

Su1area peaFReac/ 9upstream

peaF

Reac/ 9upstreampeaF

Reac/ 9upstreampeaF

PeaF Clo #ag 9in tooutStructure

out4o issame as

donstreamreac/ out4o

Structure

out4o issame as


Structure

out4o issame as


Run ?odel 9Grap/ical 8

Section *: WinTR-55



Run ?odel 9Grap/ical WinTR-55

$licF t/isL

LSelect Areas"storms" and

structure trials

LT/en PlotL


structure trials


structure trials


structuretrialsL

Lto getgrap/ical

representation

Section *: WinTR-55



?odel 3utputs

• Use t/e numerical outputs to analyEepeaF 4o" time to peaF" structurepeaF lag times" etc,

• T/e grap/ical outputs can 1e used toestimate time to drain a structure – 9some communities reuire drain times

o( *N to N7 /ours

Documents

8. Stream Hydrology