18
Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 1 Indirect Measurement Summary Little Missouri River above Long Creek near Albert Pike, Arkansas Ouachita River Basin Miscellaneous Site Q= 28,800 ft 3 /s Flood of June 11, 2010 Type of measurement: Slope Area Location of site: A miscellaneous site above the inflow of Long Creek on the Little Missouri River. Lat N 34˚23’21”, Long W 93˚52’43” This site was selected because it was a straight converging reach upstream of Long Creek. This reach runs almost due south. A low water bridge crosses the river approximately 4300 feet downstream of the indirect measurement location. Long Creek comes into Little Missouri River on the right bank approximately 4860 ft downstream. A constriction occurs 800 ft downstream of the indirect measurement site as the valley walls narrow from a highly resistant layer of novaculite. Surveys were also conducted in the area of the constriction to check if critical depth computations for flow can be made in this constricted area. The site is Approximately 5.72 miles northwest of Langley, Arkansas, 12.08 miles southwest of Norman, Arkansas, 14.9 miles west of Caddo Gap, Arkansas, and 31.1 miles east of Cove, Arkansas. Survey of site: Site was selected on Tuesday June 15, 2010 by Robert Holmes during reconnaissance of the flood area. High water marks were flagged on the evening of June 15, 2010 by Robert Holmes. A survey commenced on the morning of June 16, 2010 by Ferrell Killian, Aaron Pugh, and Jonathon Gillip. The initial occupation point (OC-1)was a pin driven into the gravel bar at the upstream cross section. An arbitrary Northing/Easting of 5000/5000 was assumed with an elevation of 100. The azimuth was established with a compass bearing of magnetic north. After the point was vacated by the total station survey, a Trimble GPS unit was setup to occupy the point for several hours to establish the horizontal (NAD83) and vertical position (NAVD88) of each survey point. The survey was continued downstream of the indirect measurement site in order to capture additional high water marks along the river as well as the channel geometry of the constricted area. The Survey of the indirect measurement site was made using a Sokkia Set 3c 3-second total station, serial number 23110. The survey plots off from the DRG as the result of the original survey azimuth not starting at true north. XS-4 is the channel (and floodplain) cross section at the constriction.

Indirect Measurement Summary - USGS The left o the grave wall that judgment The main edge and based on---Little Miss verbank wa l road with is the left ed. At XS1 channel co willows/bru

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Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 1

Indirect Measurement Summary

Little Missouri River above Long Creek near Albert Pike, Arkansas Ouachita River Basin

Miscellaneous Site Q= 28,800 ft3/s

Flood of June 11, 2010

Type of measurement: Slope Area Location of site: A miscellaneous site above the inflow of Long Creek on the Little Missouri River. Lat N 34˚23’21”, Long W 93˚52’43” This site was selected because it was a straight converging reach upstream of Long Creek. This reach runs almost due south. A low water bridge crosses the river approximately 4300 feet downstream of the indirect measurement location. Long Creek comes into Little Missouri River on the right bank approximately 4860 ft downstream. A constriction occurs 800 ft downstream of the indirect measurement site as the valley walls narrow from a highly resistant layer of novaculite. Surveys were also conducted in the area of the constriction to check if critical depth computations for flow can be made in this constricted area. The site is Approximately 5.72 miles northwest of Langley, Arkansas, 12.08 miles southwest of Norman, Arkansas, 14.9 miles west of Caddo Gap, Arkansas, and 31.1 miles east of Cove, Arkansas. Survey of site: Site was selected on Tuesday June 15, 2010 by Robert Holmes during reconnaissance of the flood area. High water marks were flagged on the evening of June 15, 2010 by Robert Holmes. A survey commenced on the morning of June 16, 2010 by Ferrell Killian, Aaron Pugh, and Jonathon Gillip. The initial occupation point (OC-1)was a pin driven into the gravel bar at the upstream cross section. An arbitrary Northing/Easting of 5000/5000 was assumed with an elevation of 100. The azimuth was established with a compass bearing of magnetic north. After the point was vacated by the total station survey, a Trimble GPS unit was setup to occupy the point for several hours to establish the horizontal (NAD83) and vertical position (NAVD88) of each survey point. The survey was continued downstream of the indirect measurement site in order to capture additional high water marks along the river as well as the channel geometry of the constricted area. The Survey of the indirect measurement site was made using a Sokkia Set 3c 3-second total station, serial number 23110. The survey plots off from the DRG as the result of the original survey azimuth not starting at true north. XS-4 is the channel (and floodplain) cross section at the constriction.

Summary

Dischargmiscellan Drainag Unit Dis(Region

y---Little Miss

ge and Gageneous site.

e area: 18.2

charge: 18) is below,

souri River ab

e Height: 2

2 mi2 as det

,580 cfs/mi2

with this flo

bove Long Cr

Cross Se

8,800 cfs. N

termined by

. Crippen anood approxim

reek near Alb

ection Locat

No Gage Hei

Albert Rea o

nd Bue (197mately plotte

bert Pike, Ark

tions

ight was det

of the USGS

77) envelopeed.

kansas

termined as t

S using NHD

e curve for th

P

this is a

D Plus.

his region

Page 2

Summary

Nature ofell in a vthe USGthe rates few minu Field conthrough toverbankincluded subsectiocross sec See the freach. M4H01773M4H01776

M4H01799M4H01800M4H0180

y---Little Miss

of flood: Thvery short peS streamgagof rise from

utes. The Ou

nditions: Ththe reach. Ek which consthe two ban

on of the totaction, and XS

following vid

3.MP4---Little6.MP4---Little

XS9.MP4—Little0.MP4—Little1.MP4---Little

souri River ab

his flood waseriod of timege 10 miles d

m survivors inuachita mou

he indirect reEach of the thsists of the g

nk areas withal cross sectiS3 is the mo

deo clips to v

Missouri Rive Missouri Rive1 (most upstrea Missouri Rive Missouri Rive Missouri Rive

bove Long Cr

s a flash flooe starting jusdownstream n the Albert untains are a

each is fairlyhree cross segravel road bh the trees, anion. XS1 is st downstrea

view the cha

er above Long er above Long am XSECT) er above Long er above Long er above Long

reek near Alb

od of extremst before or awere as muPike Campgknown “floo

y straight witections was sbed and left vnd 3) the rigthe most ups

am cross sec

annel and flo

Creek at the InCreek at the in

Creek at the inCreek at indireCreek at Indire

bert Pike, Ark

me nature. Aat midnight ouch as 8 ft/hoground indicod hotspot”

th nearly unisubdivided invalley wall, tght overbankstream cross

ction.

oodplain con

ndirect reach. ndirect reach.

ndirect reach. ect reach. Maiect reach. Left

kansas

s much as 7 on June 10. our. Anecdoate as much in the United

iform boundnto 3 subsecthe 2) main

k, which is a s section, XS

nditions for t

This is right ovThis is right ov

Left overbank in channel at Xft overbank at X

P

inches of raRates of rise

otal accountsas 3 feet in

d States.

dary roughnections: 1) thchannel, whpanhandle

S2 is the mid

the indirect

verbank of XSverbank upstre

along road at XXS1 XS 3.

Page 3

ain e at s of a

ess e left

hich

ddle

3 eam of

XS1

Summary

The left othe gravewall that judgment

The mainedge andbased on

y---Little Miss

overbank wael road with is the left edt.

At XS1

n channel cod willows/bru engineering

Approxima

HWM flow

souri River ab

as estimated a small amodge of the le

1 looking do

onsists of graush on right g judgment a

ate  

w line 

bove Long Cr

to have an nunt of trees/

eft overbank.

ownstream th

avel/cobble bedge. N val

and weighted

A

is

reek near Alb

n value of 0./brush on the. The estima

hrough left o

bed in the malue assignedd composite

Rig

sub

tre

Approximate l

s just beyond

bert Pike, Ark

039. The lee right edge ate of n=0.03

overbank alo

ain channel d to main cha

n.

ght edge of le

bsection.  Som

ees/brush. 

location of XS

 car 

kansas

eft overbank and grass on39 is based o

ong gravel ro

with trees/bannel subsec

ft overbank 

me influence 

S 3 

P

is made up on the left valon engineeri

oad.

rush on the lction was 0.0

of 

Page 4

of lley ing

left 058

Summary

y---Little Misssouri River abbove Long Cr

XS1 look

XS1 loo

reek near Alb

king downst

oking upstre

bert Pike, Ark

tream

eam

kansas

PPage 5

Summary

At XS

Right oveengineeri

In right

y---Little Miss

S3 looking o

erbank is maing judgmen

overbank ar

souri River ab

on right bank

ade up of trent.

rea at XS3. H

bove Long Cr

k looking towresultin

ees. An n va

Hydrograph

reek near Alb

ward left banng from floo

alue of 0.08 w

er is holdingHWMs

bert Pike, Ark

nk. Hydrolood.

was assigned

g pole horizo

kansas

ogist pointing

d to this sub

ontal at appr

P

g out tree sc

section base

roximate leve

Page 6

ar

ed on

el of

Summary

Right

ComputSAM 2.1 wComputatidischarge csmall compbaseline leSAC: Reach X1 - X2 X2 - X3 X1 - X3 Definitions:

Spread: th(k=1.0

HF: frictioL: reach lK2: downCX: the cRC: velocRX: velo

XSECT

y---Little Miss

t overbank su

ations: was used to proon). The reachcomputed for tputational biasngth, the final

dH,fall length (ft) (ft) 0.60 104. 0.90 143. 1.50 247.

he percent differen0), divided by the don head which is thlength; K1, upstrea

nstream section concomputed dischargcity head change icity head change i

Subarea W

souri River ab

ubsection at

ocess the Total h was contractithis measuremes in SAM2.1 indischarge was

h Discharge S (cfs) 29806. 28204. 28813.

nce between dischadischarge computehe sum of Q*Q*Lam section conveynveyance ge divided by the dn contracting sectiin expanding sectio

CRWS n

bove Long Cr

XS1. Note

Station Surveying from X1 toent was 28,200

n the determina computed to b

Spread HF (%) (ft 1 0.61 0 0.82 0 1.43

arge computed wited with full expans

L/(K1*K2) over subyance;

discharge computeion divided by fricon divided by frict

ROSS SECTArea (ft2)

T

reek near Alb

hydrographeHWMs

y data and reado X2 and slight0 cfs. After revation of baselinbe 28,800 cfs.

CX RC t) __________11 0.991 0.00028 1.000 0.08735 0.997 0.052

th no expansion losion loss breaches

d with no expansioction head tion head

TION PROT P

bert Pike, Ark

er holding ro

dy it for input itly expanding fview by Mark Sne length. Usin

Following are

RX ER____________0 -0.037 # 7 0.000 # 2 -0.015 #

ss (k=0) and disch

on loss (k=0)

OPERTIESR K (x 0

kansas

od at approx

into the SAC pfrom X2 to X3Smith, it was fng the newly de the output dia

R

harge computed wi

0.001) %

P

ximate level

program (Slope. The original

found there wadetermined corragnostics from

ith full expansion

V F

Page 7

of

e Area

s a rect

m

loss

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 8

X1 LOB 113.1 0.039 80.5 21.6 23.3 3.45 7.025 2 6.9 0.63

X1 Main 113.1 0.058 1996.1 157.8 162.7 12.27 272.77 77 10.9 0.54

X1 ROB 113.1 0.08 1237.1 205.4 206.7 5.99 75.964 21 4.9 0.35

X1 Total 113.1 3314 385 393 8.44 355.759 100 8.5 0.51

X2 LOB 114 0.039 161.9 24.4 27.7 5.84 20.061 5 9.1 0.62

X2 Main 114 0.058 2008.1 146.2 151 13.3 289.558 75 10.5 0.5

X2 ROB 114 0.08 1254.5 210.4 211.5 5.93 76.556 20 4.5 0.32

X2 Total 114 3424 381 390 8.78 386.174 100 8.2 0.48

X3 LOB 114.6 0.039 182.4 24.7 28.3 6.44 24.124 6 9.5 0.62

X3 Main 114.6 0.058 2157.6 159.4 163.5 13.2 309.518 79 10.4 0.5

X3 ROB 114.6 0.08 995.2 180.1 180.6 5.51 57.832 15 4.2 0.31

X3 Total 114.6 3335 364 372 8.96 391.473 100 8.5 0.49

Sensitivity analysis was conducted on the n values for the main channel and both overbank subsections. The value of n was allowed to range from 0.042 to 0.070 in the main channel, from 0.032 to 0.060 in the left overbank (LOB) and from 0.060 to 0.100 in the right overbank (ROB).

Original Sensitivity Analysis Results of Holmes FALL N

LOB N Main

N ROB Q Q(1-2) Q(2-3) Q st. dev.

XS2 V LOB XS2 Vmain XS2 ROB

XS2 Froude

1.50 0.039 0.051 0.080 30,800 32,600 29,800 1,419 9.00 11.90 4.40 0.53

1.50 0.039 0.051 0.100 29,200 30,400 28,500 961 8.80 11.70 3.50 0.50

1.50 0.039 0.051 0.060 33,000 35,200 31,800 1,724 9.10 12.00 6.00 0.57

1.50 0.039 0.056 0.080 28,900 30,600 28,000 1,320 9.00 10.90 4.50 0.50

1.50 0.039 0.042 0.080 34,800 36,300 33,900 1,212 8.70 14.00 4.30 0.60

1.50 0.045 0.051 0.080 30,700 32,400 29,700 1,365 7.80 11.90 4.40 0.53

1.50 0.051 0.051 0.080 30,700 32,300 29,700 1,311 6.90 11.90 4.40 0.53

1.50 0.039 0.060 0.080 27,600 29,100 26,700 1,212 9.10 10.20 4.50 0.47

1.50 0.051 0.046 0.080 32,900 34,300 32,000 1,159 6.80 13.10 4.40 0.56

1.50 0.039 0.058 0.080 28,200 29,800 27,300 1,266 9.10 10.50 4.50 0.48

1.50 0.032 0.058 0.080 28,700 30,300 27,700 1,311 11.10 10.60 4.50 0.49

1.50 0.060 0.058 0.080 27,900 29,200 27,148 1,038 5.90 10.60 4.50 0.48

1.50 0.039 0.070 0.080 24,900 26,080 24,188 956 9.20 8.80 4.50 0.43

1.50 0.039 0.058 0.100 26,900 28,100 26,100 1,007 9.00 10.40 3.30 0.46

1.50 0.039 0.058 0.060 30,300 32,100 29,300 1,419 9.10 10.60 6.00 0.52

The sensitivity analysis reveals the following 1. A change in the LOB n value from the minimum (0.032) to the maximum (0.060)

resulted in a decrease of the discharge of 3% 2. A change in the main channel n value from the minimum (0.042) to the maximum

(0.070) resulted in a decrease of the discharge of 40% 3. A change in the ROB n value from the minimum (0.060) to the maximum (0.10) resulted

in a decrease in discharge of 13% Evaluation:

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 9

Use 28,800 cfs and consider it good to fair reliability. The indirect is graded at good to fair (10 to 15%) based on the following:

1. The high water marks were flagged and surveyed within 4 days of the flood. A good wash line was evident on the left valley wall and a several good high water marks were found in the right overbank. However, there was some variability in the high water marks.

2.The reach was nearly uniform in cross sectional area (neither expanding or contracting), with total Area being 3314, 3424, and 3335 square feet in XS1, XS2, and XS3.

3.The diagnostics (Spread near 0, CX approaching 1, and small values of RX) all look very good.

4. The velocity head change from XS1 to XS3 is less than 5% of the friction head in this reach. The lower this ratio the more accurate the measurement per Kirby (1987).

5.There is little evidence that the reach cross section main channel has changed much during the flood. The channel is remarkably stable.

6.There is no evidence that this flood was a debris flow based on evidence left behind such as scouring and deposition.

7.During the field recon, it was thought that the constriction 427 ft downstream of XS3 might induce critical flow depth. As such a surveyed cross section and high water marks were collected at the constriction. Using HWMs at the constriction, the mean hydraulic depth (D=A/T) computes as 9.63 ft with a cross sectional area of 2,196 ft2. From critical flow

equation ( gDV ), the flow (assuming the computed depth was critical depth) was

38,600 cfs, which way overestimated the flow given from SAC. In addition, a new four section SAC run that included XS4 estimated the Froude number at the constriction to be 0.67, much less than the critical flow state. The critical flow computation was not helpful in determining the actual flow, but puts an definitive upper bound on the possible peak flow at this location.

Previous computations: None Remarks: After review by Mark Smith, peak streamflow was changed from 28,200 cfs to 28,800 cfs. Also measurement quality was slightly downgraded from good to good-fair based on recommendation from Smith. Computed By: Robert R. Holmes, Jr. PhD, P.E., D.WRE National Flood Specialist Date: July 29, 2010

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 10

Checked By: Daniel M. Wagner Arkansas Water Science Center Date:October 6, 2010 Reviewed By: Mark Smith Regional Surface Water Specialist Date: December 10, 2010 Approval: Mark E. Smith Surface Water Specialist, Central Water Science Field Team Date: January 21, 2011

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 11

Appendix Little Missouri River above Long Creek near Albert Pike, Arkansas

Flood of June 11, 2010 Graphs from SAM

Note: Smith, in his review, recomputed the baseline distances due to the fact that SAM used the left edge of each cross section to determine the baseline distances rather than the baseline itself.

Plan View (Little Missouri River above Long Creek/99999999)

RH-9-FRH-8-FRH-7-F

RH-6-FRH-5-G

RH-4-F

RH-3-G

RH-2-PRH-1-F

RH-17-P

RH-16-GRH-15-FRH-14-F

RH-13-G

RH-12-GRH-11-G

RH-10-G

LH-7-P

LH-6-P

LH-5-P

LH-4-F

LH-3-P

LH-2-F

LH-1-F

4120

4220

4320

4420

4520

4620

4720

4820

4920

5020

4560 4660 4760 4860 4960 5060 5160 5260 5360 5460

Easting

No

rth

ing

RB HWMs

LB HWMs

Ref Line

X4

X3

X2

X1

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 12

High Water Marks Profile (Little Missouri River above Long Creek/99999999)

RH-16-GRH-15-FRH-14-FRH-13-GRH-11-GRH-12-GRH-10-G

RH-9-F

RH-7-FRH-8-F

RH-2-P

RH-1-F

RH-3-G

RH-6-F

RH-4-FRH-5-G

RH-17-P

LH-1-FLH-4-FLH-2-FLH-5-P

LH-3-PLH-6-P

LH-7-P

105.0

107.0

109.0

111.0

113.0

115.0

117.0

-100 100 300 500 700 900 1100

Distance

Ele

vati

on

RB HWMs

LB HWMs

X4

X3

X2

X1

Best Fit "Eye Ball" Line for HWM

114.6113.1

114.0

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 13

Cross Section X3

X3-40

X3-39

X3-38X3-37X3-36X3-35X3-33

X3-32X3-31

X3-29X3-30

X3-28X3-27X3-26

X3-25X3-24X3-23

X3-22

X3-21X3-20

X3-19

X3-18X3-17X3-16

X3-15X3-14X3-13

X3-12X3-11X3-10

X3-9

X3-8

X3-7

X3-6

X3-5X3-4

X3-1

90.0

95.0

100.0

105.0

110.0

115.0

120.0

0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 450.0

Station

Ele

vati

on

n=0.058n=0.080

n=0.039

Cross Section X2

X2-35

X2-34X2-22X2-30

X2-29

X2-28X2-27

X2-26

X2-25X2-24

X2-23

X2-22

X2-21X2-20

X2-19

X2-18

X2-17-REW

X2-16X2-15X2-14X2-13

X2-12X2-11

X2-10-LEW

X2-9

X2-8X2-7

X2-6

X2-5X2-4X2-3

X2-1

90.0

95.0

100.0

105.0

110.0

115.0

120.0

0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 450.0

Station

Ele

vati

on

n=0.058

n=0.039

n=0.080

Summary

RoughnMain CMain chacompositrock and width). The left sThe rightThe low Chow (19The Bed be represequations

DDDS RT

Followin

Meyer-P

90.0

95.0

100.0

105.0

110.0

115.0

120.0

0

Ele

vati

on

y---Little Miss

ness Estimhannel annel was este n value. Tgravel bed l

shore was est shore was ewater chann959), enginematerial siz

sentative of ts are as follo

D90= 0.15 meteD84=0.38 ft D50 = 0.15 ft; 0

(friction slopeR = 16 ft; 4.9 m

=148 ft, ng are compu

eter Muller(

X

X1-4X1-3

X1-2

X1-1

.0 50.0

n=0.039

souri River ab

mates

stimated by dThe main chalow water ch

stimated to bestimated to nel was estimeering judgete data came the size of grows: ers

0.048 m e)=0.0043

meters

utations:

1948) equat

XXX

X1-

X1-7X1-6

X1-5

0 100.0

n=0.058

bove Long Cr

doing a weigannel had brhannel (47 ft

be n= 0.090.be n = 0.080

mated to be 0tment, and sfrom the gra

ravel presen

ion for grave

Cro

X

X1-17

X1-16-

X1-15X1-14X1-13X1-12X1-11X1-10-LEWX1-9

-8

150.0

8

reek near Alb

ghted (by wirush and treet in width) an

0. 0.031. This weveral theoravel bar 170

nt at the indir

el bed stream

oss Section X1

X1X1-22

X1-21X1-20

X1-19

X1-18

-REW

200.0

Station

bert Pike, Ark

dth) estimates on the leftnd a treed/br

was based oretical equati00 feet belowrect location

ms

X1-

X1-24X1-251-232

250.0

n=0.080

kansas

te of the maint shore (70 ftrush right sh

n published ions based ow the reach bn. The data f

(metric uni

X1-28X1-27

-26

300.0

0

Pa

n channel ft in width), ahore (42 ft in

n values in on bed materbut was judgfor the theore

its) ---n = 0.0

X1-

X1-31

X1-30X1-29

350.0 4

age 14

a n

ial. ged to etical

028,

32

400.0

Summary

Jarretts (

Limerino

Froelich’units)----

Griffiths A weighte

Wi70474215

cn

For this in

judgmentBarnes (1sensitivit

y---Little Miss

1984) equati

os (1970) for

’s (1978) equ-- n = 0.024;

(1981) equa

ed value of n idth(W) n’ 0.4 0’ 09.9

15913.11c

ndirect, a n va

t, weighting 1967, http://pty analysis d

souri River ab

ion for moun

r gravel strea

uation for gr

ation for grav

for the main n W*n0.090 6.3 0.031 1.460.080 3.36

11.1

0698.09.

alue of 0.058

of n values pubs.usgs.go

data.

bove Long Cr

ntain stream

ams in Califo

ravel and cob

vel rivers

channel is 0.0n

69 6 13

was used for

from channeov/wsp/wsp_

reek near Alb

ms

fornia

bble streams

(

056.

the main cha

el width (abo_1849/pdf/w

bert Pike, Ark

(Engl

(E

s

(all SI units)

annel. This w

ove), examiwsp_1849.pd

kansas

ish units) ---

English units

) ---- n = 0.0

was based on eination of ph

df), and revie

Pa

- n = 0.038;

s) ---n =0.03

(English

31.

engineering hotos from ew of the

age 15

33;

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 16

SAC INPUT DATA T1 SAC/WSPRO Input for Little Missouri River above Long Creek (99999999) T2 Shortened reach 3-2 by 10 feet (to 143 ft) - MES Q WS 112.9 XS X3 378 GR 0,115.1 7.7,108.6 24,109.2 35.2,107.4 42.4,103.1 50.5,98.4 51.4,97.2 GR 54.1,96.2 63.8,97.2 73.6,97.2 76.3,96.3 85.4,96 99.5,96.5 104.9,97.2 GR 112.3,97.4 116.3,98.2 122.7,99.9 140.1,100.8 155.7,101.6 165.5,103.6 GR 176.8,107.7 181.8,107.9 187.9,107.7 196.3,108.4 217.8,108.3 GR 235.3,107.4 251.1,105.9 257.3,105.8 276.5,105 303.3,105.6 GR 331.5,107.7 339.3,107.5 346.7,106.6 355.8,106.9 369.4,107.2 GR 380.8,110.7 394.4,115.8 N .039 .058 0.08 SA 24.0 181.8 HP 4 X3 113.1 XS X2 235 GR 0,117.9 12.1,105.9 28.3,106.2 39.9,105.3 49.9,101 62.6,99.7 70.4,100 GR 75.2,98.8 76.5,97.3 77.7,95.6 84.4,94.6 88.5,95.3 99.4,95.4 GR 114.3,95.2 116.5,95.9 124,97.4 126.2,98.9 133.2,100.5 146.7,101.9 GR 154.4,102.9 165.7,107.3 174.5,108.6 183.9,107.9 193.5,108.6 GR 218.6,107.2 236.1,105.5 254.6,105.7 289.4,107.6 319.1,109.5 GR 342.4,109.1 369.9,108.9 388.1,115.1 N .039 .058 .08 SA 28.3 174.5 HP 4 X2 114.0 XS X1 131 GR 0,117.4 7.4,111.4 14.9,104.9 28.2,105.1 49.2,103.1 71.4,100.5 GR 81.3,101.2 98.3,99.8 102.9,98.4 103.7,97.4 104.3,96.3 112.5,95.9 GR 120.8,96.2 132.1,96.3 140.9,96.1 143.6,97.3 145.6,100 159.2,102.9 GR 176.3,106.9 187.6,107.8 194.6,106.9 202.1,107.4 214.2,106.5 GR 240,106.1 247,106.4 266.2,107.8 291,109.6 307.9,110.6 336,111.5 GR 350,112.5 362.3,113.7 377.4,116.2 N 0.039 0.058 0.08 SA 28.2 187.6 HP 4 X1 114.6

Summary---Little Missouri River above Long Creek near Albert Pike, Arkansas Page 17

SAC OUTPUT DISCHARGE COMPUTATIONS Reach dH,fall length Discharge Spread HF CX RC RX ER (ft) (ft) (cfs) (%) (ft) X1 - X2 0.60 104. 29806. 1 0.611 0.991 0.000 -0.037 # X2 - X3 0.90 143. 28204. 0 0.828 1.000 0.087 0.000 # X1 - X3 1.50 247. 28813. 0 1.435 0.997 0.052 -0.015 # Definitions: Spread, the percent difference between discharge computed with no expansion loss (k=0) and discharge computed with full expansion loss (k=1.0), divided by the discharge computed with full expansion loss HF, friction head- HF = sum of Q*Q*L/(K1*K2) over subreaches; Q, discharge; L, reach length; K1, upstream section conveyance; K2, downstream section conveyance CX, the computed discharge divided by the discharge computed with no expansion loss (k=0) RC, velocity head change in contracting section divided by friction head RX, velocity head change in expanding section divided by friction head ER, warnings, *-fall <' 0.5ft, @-conveyance ratio exceeded, #-reach too short error, 1-negative or 0 fall ******, terms that can not be computed because' of strong expansion in reach

Summary

Append

y---Little Miss

dix1—Anc

souri River ab

cillary Com

bove Long Cr

mputation

reek near Alb

n of Q at C

bert Pike, Ark

Constrictio

kansas

on Downs

Pa

tream

age 18