St Andrews Est-SY030722 STUDY OF MINOR TRIBUTARY TO
OLD DENTON CREEK
St. Andrew's ex ,
City of Coppell
By
John D. Evans, P.E.
For
Hennessey Engineering, Inc.
1417 W. Main Street
Carrollton, Texas 75006
July 22, 2003
ATTACHMENTS:
1. Map of site and cross-sections
2. HEC-RAS Exhibits: Plots of reaches and cross-sections 99/1/Pi vs/10
3. HEC-RAS Report—Project Data
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Project No. 13004
STUDY OF MINOR TRIBUTARY TO
OLD DENTON CREEK
St. Andrew'sner--An Addition to the City of Coppell
INTRODUCTION ESTATES
The purpose of this report is to demonstrate the effect on the flood plain of Old Denton Creek by
the proposed filling of the minor tributary flowing through St. Andrew's The tributary is
within a proposed subdivision and the development includes filling the channel conjunction with
installing a suitably sized storm pipe or culvert. Cs-MT
HYDROLOGIC & HYDRAULIC CHARACTERISTICS
The minor tributary has a calculated flow rate of 30 cfs for the 100-year storm event. Old Denton
Creek is shown to have a peak flow rate of 4,000 cfs according to the Letter of Map Revision
(LOMR) dated July 23, 1997 (Ref: 97-06-503P, Community/Panel No. 480170 0010 E).
Old Denton Creek is the remnant channel after the realignment and straightening of Denton
Creek to the north. The referenced LOMR states that the two channels have their own floodplain.
A separate flood profile (Sheet 11P)was added to the Flood Insurance Study (FIS) to
demonstrate the independent reach and stream cross-sections established by the LOMR.
The minor tributary joins Old Denton Creek some 750 feet from its confluence with Denton Creek.
This distance is sufficient to ensure Old Denton Creek is flowing independently of Denton Creek
and so only its hydraulic characteristics need to be considered when analyzing the effect of this
project.
HYDRAULIC ANALYSIS
Old Denton Creek was analyzed by extracting cross-section data from a 1"=200' scale plan of the
site supplemented by survey information provided by Hennessey Engineering.
The flow rate was given by the previous LOMR, as mentioned. An ineffective region was
assigned to the area of confluence of the minor tributary and Old Denton Creek. This takes into
consideration the stormwater in the minor tributary that does not allow the water in Old Denton
Creek to flow normal to the centerline of the channel. That is, the minor tributary is acting as a
pool of water that does not have a flow rate in the direction of Old Denton Creek.
HEC-RAS (version 3.1.1) was used to calculate the channel's hydraulic characteristics.
The final step was to assume an equal conveyance encroachment at the point of confluence and
which represented filling the volume of the flood plain that would otherwise exist before the
proposed development. Profile#1 is for the 100-year storm event without encroachment and
Profile#2 is for the 100-year storm flow with an encroachment yielding an increased flood
elevation of 0.9 ft.
RESULTS OF ANALYSIS
The results of the HEC-RAS computations (report at Attachment 3) show virtually no change in
surface water elevation as a result of the encroachment.
CONCLUSION
It is not unexpected that there is little or no effect on the flood elevation of Old Denton Creek
when the minor tributary channel is filled. The ineffective flow area of the channel where the
minor tributary joins with Old Denton Creek already removed that portion of the channel from the
model and so the encroachment did not change the hydraulic characteristics of the flow to an
appreciable degree. The only changes can be attributed to a change in Manning's n at the
wetted perimeter and, again, this did not have a significant effect. Filling the 100-year flood plain
along the minor tributary should be approved.
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Plan: Fill bib Old Denton Creek Mi~or Tributan/ RS: 100 Profile: PF 1
E.G. Elev (fi) 452.80 Element Left OB Channel Right OB
Vel Head (fi) 0,00 Wt. n-Val. 0.035 - 0.055
W.S. Elev (fi) 452.80 Reach Len. (fi)
CritWiS. (ft) 435.51 Flow Area (SCl ft) 515.78 161.78
E,G. Slope (fi/ft) 0.000000 ~ Area (sq fi) 515.78 161.78
Q Total (cfs) 30.00 Flow (cfs) 26.42 3,58
Top Width (fi) 57.41 Top Width (fi) 38.70 18.70
Vel Total (fi/s) 0.04 Avg. Vel. (fi/s) 0,05 0.02
Max Cid Dpth (ft) 18.10 Hydr. Del)bi (ft) 13.33 8.65
Conv. Total (cfs) 125420,3 ' Cony. (cfs) 110432.6 14987.7
Length Wtd. (fi) Wetted Per. (fi) 45.54 25.48
Min Ch El (fi) 434,70 Shear (Ib/sq fi) 0.00 0.00
Alpha 1.21 Stream Power (Fo/ft s) 0.00 0.00
Frcbi Loss (ft) Cum Volume (acre-fi)
C & E Loss (fi) Cum SA (acres)
Plan: Fill bib Old Denton Creek Minor Tributary RS: 100 Profile: PF 2
E.G. Elev (ft) 435.72 Element Left OB Channel Right OB
Vel Head (ft) 0.21 VVt. n-Val. 0.035
W,S. Elev (fi) 435.51 Reach Len. (fi)
C~t W.S. (fi) 435,51 Flow Area (sq fi) 8.13
[:G. Slope (fi/ft) 0.025218 Area (sq fi) 8.13 0.00
Q Total (cfs) 30.00 Flow (cfs) 30.00
Top Width (fi) 20.01 Top Width (fi) 20.01
Vel Total (fi/s) 3.69 Avg. Vel. (fi/s) 3.69
Max Chi Dpbi (fi) 0.81 Hydr. Depth (fi) 0.41
Cony. Total (cfs) 188.9 Cony. (cfs) 188.9
Length Wtd. (fi) Wetted Per. (fi) 20.07
Min Ch El (fl) 434.70: Shear (Ib/sq fi) 0.64
Alpha 1.00 Stream Power (lb/It s) 2.35
Frctn Loss (fi) Cum Volume (acre-fi)
C & E Loes (fi) Cum SA (acres)
Plan: Fill tfib Old Denton Creek Minor Tributary RS: 300 Profile: PF 2
E.G. Elev (ft) 436.25 Element Left OB Channel Right OB
Vel Head (fi) 0.03 Wt. n-Val. 0,035
W.S, Elev (it) 436.21 Reach Len. (it) 100,00 100.00 100.00
Cdt W,S. (ft) Flow Area (scIft) 20.66
E.G. Slope (fi/It) 0.001263 Area (sq fi) 20.66
Q Total (cfs) 30.00 Flow (cfs) 30.00
Top Width (ft) 21.33 Top Width (it) 21.33
Vel Total (fi/s) 1,45 Avg. Vel. (fi/s) 1.45
Max Chi Dpth (ft) 1.41 Hydr. Depth (it) 0.97
Cony. Total (cfs) 844.1 Cony. (cfs) 844.1
Length Wtd. (It) 100.00 Wetted Per. (it) 21.87
Min Ch El (it) 434.80 Shear (lb/scl It) 0.07
Alpha 1.00 Stream Power (lb/it s) 0.11
Frctn Loss (ft) 0.13 Cum Volt,ne (acre-fi) 0.08 0.00
C & E Loss (fi) 0.00 Cum SA (acres) 0.10
Plan: Fill bib Old Denton Creek Minor Tributary RS.' 200 Profile: PF 1
E.G. Elev (it) 452.80 Element Left OB Channel Right OB
Vel Heed (ft) 0.00 Wt. n-Vel. 0,035
W.S. Elev (it) 452.80 Reach Len. (it) 100.00 100.00 100.00
Cdt W.S. (it) Flow Area (sq ft) 677.56
E.G. Slope (it/it) 0.000000 Area (sq fi) 677.56
Q Total (cf, s) 30.00 Flow (cfs) 30.00
Top W'elth (ft) 57.41 Top W'Klth (it) 57.41
Vel Total (fi/s) 0,04 Avg. Vel. (fi/s) 0.04
Max Chi Dpth (it) 18.10 Hydr. Depth (fi) 11.80
Conv. Total (cfs) 129397.0 Cony. (cfs) 129397.0
LengthWtd. (fi) 100.00 Wetted Per, (fi) 71.02
Min Ch El (it) 434.70 Shear (Iblsq It) 0.00
Alpha 1.00 Stream Power (Ib/ft s) 0.00
Frctn Loss (ft) 0.00 Cum Volume (acre-it) 1.37 0.19
C & E Loss (fi) 0.00 Cum SA (acres) 0.11 0.02
Plan: Fill l~b Old Denton Creek Minor Tributary RS: 200 Profile: PF 2
I E.G. Elev (it) 436.11 Element Left OB Channel Right OB
Vel Head (it) 0.04 Wt. n-Vel. 0,035
W.S. Elev (fi) 436.07 Reach Len. (fi) 100.00 100.00 100.00
Cdt W.S. (fl) 435.51 Flow Area (sq fi) 19.86
E.G. Slope (fi/ft) 0.001431 Area (SCl It) 19.86
Q Total (cfs) 30.00 Flow (cfs) 30.00
Top Width (It) 21.24 Top Width (fi) 21.24
Vel Total (fi/s) 1.51 Avg. Vel. (fi/s) 1.51
Max Chi Dpth (fi) 1,37 Hydr. Depth (it) 0,93
Conv. Total (cfs) 793.1 Conv. (cfs) 793.1
LengthWtd. (fi) 100.00 Wetted Per. (It) 21,76
Min Ch El (fi) 434.70 Shear (Ib/sq It) 0.08
Alpha 1.00 Stream Power (lb/frs) 0.12
Frctn Loss (It) 0.37 Cum Volume (acre-it) 0.03 0.00
C & E Loss (it) 0.02 Cum SA (acres) 0.05
Plan: Fill thb Old Denton Creek St Andrews Manor RS: 0 Profile: PF 1
E.G. Elev (fi) I 452.61 Element Left OB Channel Right OB
v;~ H,,~d ,qt) I 0,21 Wt, n-Val, 0.055 0.035 ' _ 0.055
W.S. Elev (fi) 452.40 Reach Len. (fi)
Cnt W.S. (ft) 439.24 Flow Area (sq ft) 1.00 1083.00 1.00
E.G. Slope (fl~t) 0.000268 Area (sq fi) 1.00 1083.00; 1.00
Q Total (cfs) 4000.00 Flow (cfs) 0.15 3999.70 0.15
Top Width (fi) 80.00 Top Width (fi) 5,00 70.00 5.00
Vel Total (P/s) 3.69 Avg. Vel. (P/s) 0.15 3.69 0.15
Max Chi Dpth (fi) 19.90 Hydr. Depth (fi) 0.20 15.47 0.20
Conv. Total (cfs) 244314.5 Conv. (cfs) 9.2 244296.0 9.2
Length Wtd. (It) Wetted Per. (It) 5.02 88.43 5.02
Min Ch El (fi) 432.50 Shear (lb/sq fi) 0.00 0.20 0.00
Alpha 1.00 ! Stream Power (lb/ff s) 0.00 0.76 0.00
Frcth Loss (It) Cum Volume (acre-It)
C & E Loss (It) Cum SA (acres)
Plan: Fill trib Old Denton Creek St Andrews Manor RS: 0 Profile: PF 2
E.G. Elev (It) 452.61 Element Left OB Channel Right OB
Vel Head (fi) 0.21 VVt. n-Val. 0.055 0,035 0.055
W.S. Elev (fi) 452.40 Reach Len. (It)
C~ W.S. (It) 439.24 ! Flow Area (sq fi) 1.00 1083.00 1.00
E.G. Slope (p/fi) 0.000268: Area (scl It) 1 .IX) 1083.00 1.00
Q Total (cfs) 4000.00 Flow (cf's) 0.15 3999.70 0.15
Top Width (fi) 80.00 Top Width (It) 5.00 70.00 5.00
Vel Total (fi/s) 3.69 Avg. Vel. (it/s) 0.15 3.69 0.15
Max Chi Dpth (tt) 19.90 Hydr. Depth (ft) 0.20 15.47 0.20
Cony. Total (cfs) 244314.5 Conv. (cfs) 9.2 244296.0 9.2
Length Wtd. (It) Wetted Per. (fi) 5.02 88.43 5.02
Min Ch El (It) 432.50 Shear (Ib/sq fi) 0.00 0.20 0.00
Alpha 1.00 Sl~eem Power (lb/It s) 0.00 0.76 0.00
Frc~ Loss (fi) Cum Volume (acm-fi)
C & E Loss (fi) Cum SA (acres)
Plan: Fill trib Old Denton Creek Minor Tributan/ RS: 300 Profile: PF 1
E,G. Elev (It) 452.80 Element Left OB Chan~el Right OB
Vel Head (It) 0.00 Wt. n-Val. 0.035
W,S. Elev(ff) 452.80 Reach Len. (fi) 100.00 100.00 100.00
Crit W.S. (fi) Flow Area (sq fi) 673.56
E.G. Slope (ft/ff) 0.000000 Area (sq It) 673.56
Q Total (cfs) 30,00 Flow (cfs) 30.00
Top W~lth (ft) 57.39 Top Width (fi) 57.39
Vel Total (p/s) 0.04 Avg. Vel, (P/s) 0.04
Max Chi Dpth (fi) 18.00 Hydr. Depth (It) 11.74
Conv. Total (cf, s) 128304.7 Conv. (cfs) 128304.7
Length Wtd. (fi) 100.00 Wetted Per. (fi) 70.87
Min Ch El (tt) 434.80 Shear (Ib/sq fi) 0.00
Alpha 1.00 Stream Power (lb/It s) 0.00
Frcth Loss (fi) 0.00 Cum Volume (acre-It) 2.92 0.19
C & E Loss (It) 0.00 Cum SA (acres) 0.24 0.02
Plan: Fill trib Old Denton Creek St Andrews Manor RS: 330 Profile: PF 2
-~-.G, Elev (fi) 452.88 Element Left OB Channel Right OB
Vel Head (It) 0.45 Wt. n-Val, 0.035
W.S. Elev (tt) 452.43 Reach Len. (It) 230.00 230.00 230.00
Cdt W.S. (fi) Flow Area (sq fi) 741.24
E.G. Slope (lEft) 0.000738 Area (sq ft) 741.24
Q Total (cfs) 4000.00 Flow (cfs) 4000.00
Top Width (ft) 56,97 Top Width (tt) 56,97
Vel Total (ft/s) 5.40 Avg. Vel. (lEs) 5.40
Max Chi Dpth (fi) 19.63 Hydr. Depth (tt) 13.01
Conv. Total (cfs) 147255.7 Conv. (cfs) 147255.7
Length Wtd. (fi) 230.00 Wetted Per. (It) 73.23
Min Ch El (It) 432.80 Shear (Ib/sq fi) 0.47
AJpha 1.00 Stream Power (Ib/ff s) 2.52
Frctn Loss (fi) 0.16 Cum Volume (acre-fi) 0.00 6.15 0.00
C & E Loss (fi) 0.01 Cum SA (acres) 0.01 0.46 0.01
Plan: Fill trib Old Denton Creek St Andrews Manor RS: 100 Profile: PF 1
E.G. Elev (ft) 452.71 Element Left OB Channel Right OB
Vel Head (It) 0,41 Wt. n-Vel. 0.055 0,035 0.055
W.S. Elev (fi) 452.30 ! Reach Len. (ft) 100.00 100.00 100.00
Cdt W.S. (It) Flow Area (sq It) 0.68 779.09 0.68
E.G. Slope (lEft) 0.000646 ' Area (sq fi) 0.68 779.09 0.68
Q Total (cfs) 4000.00 Flow (cfs) 0.13 3999.74 0.13
Top Width (It) 69.04 Top Width (fi) 4.52 60.00 4.52
Vel Total (lEs) 5.13 Avg. Vel. (lEs) 0.19 5.13 0.19
MaxChlDpth(lt) 19.70 Hydr. Depth(It) 0.15 12.98 0.15
Conv. Total (cfs) 157395.4 Conv. (cfs) 5.2 157385.0 5,2
Length Wtd. (fi) 100.00 Wetted Per. (It) 4.53 75.06 4.53
Min Ch El (ft) 432.60 Shear (Ib/sq It) 0.01 0.42 0.01
Alpha 1.00 Sl~eam Power(lb/frs) 0.00 2.15 0.00
Frcth Loss (It) 0.04 Cum Volume (acre-It) 0.00 2.14 0.00
C & E Loss (ft) 0.06 Cum SA (acres) 0.01 0.15 0.01
Plan: Fill Nb Old Denton Creek St Andrews Manor RS: 100 =rofile: PF 2
E.G. Elev (fi) 452.71 Element Left OB Channel Right OB
Vel Head (fi) 0.41 Wt, reVal. 0,035
W.S. Bev (It) 452.30 Reach Len. (ft) 100.00 100.00 100.00
Cdt W.S. (tt) Flow Area (sq fi) 779.09
E.G, Slope (lEit) 0_._0__0~__53 Area (sq fi)_ 779.09
Q Total (cfs) 4000.00 Flew (cfs) 4000.00
Top Wid~ (fi) 60.00 Top W~lth (It) 60.00
Vel Total (lEs) 5.13 Avg. Vel. (it/s) 5.13
Max Chi Dpth (It) 19.70 Hydr. Depth (it) 12.98
Cony. Total (cfs) 156550,0 Conv. (cfs) 156550.0
Length Wtd. (ft) 100.00 Wetted Per. (it) 75.66
Min Ch El (ft) 432.60 Shear (Ib/sq tt) 0.42
Alpha 1,00 St~esm Power (lb/it s) 2.15
Frcth Loss (fi) 0.04 Cum Volume (acre-fi) 0.00 2.14 0.00
C & E Loss (fi) 0.06 Cum SA (acres) 0.01 0.15 0.01
Plan: Fill bib Old Denton Creek St Andrews Manor RS: 630 Profile: PF 1
E.G. Elev (it) 452~96 Element Leit OB Channel Right OB
Vel Head (fi) 0.05 Wt. n-Val. 0.035
W.S, Elev (it) 452.91 Reach Len. (it) 250.00 300.00 350.00
Crit W.S. (fi) Flow Area (sq ft) 2205.83
E.G. Slope (fi/It) 0.000051 Area (sq It) 2205.83
Q Total (cfs) 4000.00 Flow (cfa) 4000.00
Top Widlh (it) 137.31 Top Wid~ (it) 137.31
Vel Total (fi/s) 1.81 Avg. Vel. (fi/s) 1.81
Max Chi Dpth (it) 19.71 Hydr. Depth (fi) 16.06
Conv. Total (cfs) 559006.9 Conv. (cfs) 559006,9
Length Wtd. (fi) 300.00 Wetted Per. (it) 151.25
Min Ch El (fi) 433.20 Shear (Ib/sq ft) 0,05
Alpha 1,00 St]'eam Power (lb/It s) 0.08
Frcth Loss (it) 0.04 Cum Volume (acre-it) 0.00 16.30 0.00
C & E Loss (fi) 0.04 Cum~S~A(acres~)). 0.02 1.13 0.02
Plan: Fill bib Old Denton Creek St Andrews Manor RS: 630 Profile: PF 2
E.G. Elev (it) 452.96 Element Left OB Channel Right OB
Vel Head (it) 0.05 Wt. n-Val, 0.035
W.S. Elev (it) 452,91 Reach Len. (it) 250.00 300.00 350.00
Crit W.S. (ft) Flow Area (sq It) 2205.97
E.G. Slope (fi/ft) 0.000051 Area (sq It) 2205.97 1
Q Total (cfs) 4000.00 Flow (cfs) 4000.00
Top Width (fi) 137.32 Top Width (ft) 137.32
Vel Total (fi/s) 1,81 Avg. Vel, (fi/s) 1.81
Max Chi Dpth (it) 19.71 Hydr. Depth (it) 16.06
Cony. Total (cfa) 559057.4 Corw. (cfa) 559057.4
Lengthwtd, (fi) 300.00 Wetted Per. (fi) 151.25
Min Ch El (it) 433.20 Shear (Ib/sq It) 0.05
Alpha 1.00 Stream Power (lb/it s) 0.08
Frctn Loss (it) 0.04 Cum Volume (acre-fi) 0.00 16.30 0.00
C & E Loss (fi) 0.04 Cum SA (acres) 0.01 1.13 0.01
Plan: Fill bib Old Denton Creek St Andrews Manor RS: 330 Profile: PF 1
E.G. Elev (ft) 452.88 Element Left OB Channel Right OB
Vel Head (It) 0.45 Wt. n-Vel, 0.035
W.S. Elev (fi) 452.43 Reach Len. (fi) 230.00 230.00 230.00
Cnt W.S. (fi) Flow Area (sq It) 741.18
E,G. Slope (fi/it) 0.000738 Area (sq fi) 741,18
Q Total (cfls) 4000.00 Flow (cfa) 4000.00
Top W'a:lth (fi) 56.97 Top Width (fi) 56,97
Vel Total (it/s) 5.40 Avg. Vel. (it/s) 5.40
_Max Chi Dpth (fi) 19.63 Hydr. Depth (fi) 13.01
Conv. Total (cfs) 147239.0 Conv. (cfs) 147239.0
Leng~ Wtd. (ft) 230.00 Wetted Per. (it) 73.23
Min Ch El (it) 432.80 Shear (Ib/sq It) 0.47
Alpha 1,00 Stream Power (b/It s) 2,52
Frctn Loss (It) 0.16 Cum Volume (acre-it) 0.00 6.15 0.00
C & E Loss (fi) 0.01 Cum SA (acres) 0.02 0,46 0.02
Plan: Fill bib Old Denton Creek St Andrews Manor RS: 900 Profile: PF 2
E.~G_. Elev (It) 453.01 Element Left OB Channel Right OB
Vel Head (It) 0,15 Wt, n-Val. 0.035
W.S, Elev(ft) 452,87 Reach Len. (fi) 100.00 150,00 ~180.00
Crit W.S. (it) Flow Area (sq fi) 1298.47
E.G. Slope (fi/ft) 0.000191 Area (sq fi) 1298.47
Q Total (cfs) 4000.00 Flow (cfs) 4000.00
Top Width (it) 96.60 Top Width (it) 96.60
Vel Total (fi/s) 3.08 Avg. Vel. (fi/s) 3.08
Max Chi Dpth (fi) 19.37 Hydr. Depth (it) 13.44
Cony. Total (cfs) 289252.4 Conv. (cfs) 289252.4
Length Wtd. (It) 150.00 Wetted Per. (it) 108.03
Min Ch El (it) 433,50 Shear (Ib/sq It) 0.14
Alpha 1.00 Sb'eam Power (Iblit s) 0.44
Frctn Loss (ft) 0.01 Cum Volume (acre-fi) 0.00 32.24 0.00
C & E Loss (it) 0.04 Cum SA (acres) 0.01 2.07 0.01
Plan: Fill bib Old Denton Creek St Andrews Manor RS: 750 Profile: PF 1
E.G. Elev (It) 452.97 Element Left OB Channel Right OB
Vel Head (fi) 0.02 Wt. n-Val. 0,035
W.S. Elev (ft) 452.95 Reech Len. (fi) 90.00 120.00 150,00
Crit W.S. (fi) 436,35 Flow Area (sq fi) 3439.81
E,G. Slope (fi/fi) 0,000017 Area (sq fi) 3439.81 3584.57
Q Total (cfs) 4000.00 Flow (cfs) 4000.00
Top Wk:l~ (fi) 478.02 Top Width (fi) 188.95 289.08
Vel Total (fds) 1,t6 Avg. Vel. (fi/s) 1.16
Max Chi Dpth (it) 19.45 Hydr. Depth (it) 18,21
Conv. Total (cfs) 983566.9 Cony. (cfs) 983566.9
Length Wtd. (fi) 120.00 Wetted Per. (it) 196.80
Min Ch B (fi) 433.50 Shear 0b/sq It) 0.02
Alpha 1.00 Stream Power (Ib~t s) 0.02
Frdm Loss (fi) 0,00 Cum Volume (acre-fi) 0.00 24.08 6.18
C & E Loss (fi) 0,00 Cum SA (acres) 0.02 1.58 0.52
Plan:Filltrib Otd Denton Creek StAndrewsManorRS:750 Pmfile:PF2
E.G. Elev (fi) 452.97 Element Left OB Channel Right OB
Vel Head (fi) 0,02 Wt. n-Val, 0,035
W,S. Elev (fi) 452.95 Reach Len. (fi) .__ 90.00 120.00 150,00
Cfit W.S. (fi) 436.35 Flow Area (sq fi) 3440.05
E.G. Slope (fi/fi) 0.000019 Area (sq fi) 3440.05
Q Total (cfs) 4000.00 Flow (cfs) 4000,00
Top Width (fi) 188.95 Top Width (fi) 188.95
Vel Total (fi/s) 1.16 Avg, Vel. (fi/s) 1.16
Max Chi Dpth (It) 19.45 Hydr. Depth (It) 18.21
Cony. Total (cfs) 925206.5 Cony. (cfs) 925206.5
Length Wtd. (fi) 120.00 Wetted Per. (It) 215.75
Min Ch El (It) 433.50 Shear (Ib/sq fi) 0.02
Alpha 1,00 Stream Power (lb/it s) 0.02
Frcbi Loss (It) 0.00 Cum Volume (acre-It) 0.00 24.08 0.00
C & E Loss (fi) 0.00 Cum SA (acres) 0.01 1.58 0.01
Plan: Fill tfib Old Denton Creek St Andrews Manor RS: 1100 Profile: PF 1
E.G. Elev (fi) 453.04 Element Left OB Channel Right OB
Vel Head (fi) 0.09 Wt. n-Val. 0.035
W.S. Elev (fl) 452.95 Reach Len. (fi) 120.00 200.00 350.00
Cnt W.S. (ft) Flow Area (sq ft) 1620.12
E.G. Slope (fi/ft) 0.000110 ,Area (sq fi) 1620.12
Q Total (cfa) 4000.00 Flow (cf, s) 4000.00
Top Width (fi) 111.90 Top Width (fi) 111.90
Vel Total (fi/s) 2.47 Avg. Vel. (fi/s) 2.47
Max Chi Dpth (fi) 19.75 Hydr. Deplh (fi) 14.48
Cony. Total (cfa) 381730.7 Cnnv. (cfa) 381730.7
Length Wtd. (fi) 200.00 Wetted Per. (fi) 123.92
Min Ch El (it) 433.20 Shear (Ib/sq It) 0.09
Alpha 1.00 St]'eam Power (ll)/ff s) 0.22
Frcth Loss (ft) 0.03 Cum Volume (acre-fi) 0.00 38.93 13.58
C & E Loss (fi) 0.01 Cum SA (acres) 0.02 2.55 1.12
Plan: Fill htb Old Denton Creek St Andrews Manor RS: 1100 Profile: PF 2
E.G. Elev (fi) 453.05 Element Left OB Channel Right OB
Vel Head (fi) 0.09 Wt. n-Val, 0,035
W.S. Elev (it) 452.95 Reach Len. (it) 120.00 200.00 350.00
Crit W.S. (fi) Flow Area (sq fi) 1620.33
E.G. Slope (fi/ft) 0.000110 Area (sq It) 1620.33
Q Total (cfa) 4000,00 Flow (cfa) 4000.00
Top Wtolh (fi) 111.90 Top W'~lth (fi) 111.90
Vel Total (fi/s) 2.47 Avg. Vel. (fi/s) 2.47
Max Chi Dpth (fi) 19.75 Hydr. Depth (fi) 14.48
Conv. Total (cfa) 381799.1 Conv. (cfa) 381799.1
Length Wtd. (fi) 200.00 Wetted Per. (fi) 123.92
Min Ch El (fi) 433.20 Shear (Iblsq It) 0.09
Alpha 1.00 Stream Power (Ib/ff s) 0.22
Frctn Loss (fi) 0.03 Cum Volume (acm-fi) 0.00 38.94 0.00
C & E Loss (it) 0.01 Cum SA (acres) 0.01 2.55 0.01
Plan:Flllbib Okl Denton Creek St Andmws Manor RS:900 Profifa:PF 1
E.G. Elev (fi) 453.01 Element Left OB Channel Right OB
Vel Head (fi) 0.15 Wt. n-Val. 0.035
W.S. Elev (fi) 452.86 Reach Len. (fi) 100.00 150.00 180.00
C_ ~W.S. (ft) FlowArea (sq fi) 1298.29
E.G. Slope (ft/ft) 0.000191 Area (SCl tt) 1298.29
Q Total (cfa) 4000.00 Flow (cfa) 4000.00
Top Width (ft) 96.59 Top Width (fi) 96.59
Vel Total (fi/s) 3.08 i Avg. Vel. (fi/s) 3.08
Max Chi Dpth (fi) 19.36: kb/dr. Depth (fi) 13.44
Cony. Total (cfa) 289196.6 Ceav. (efa) 289196.6
Length Wtd. (fi) 150.00 Wetted Per. (it) 108.03
Min Ch El (it) 433.50 I Shear (Ib/sq It) 0.14
Alpha 1,00 ' Stream Power (lb/it s) 0.44
Frc'aq Loss (tt) 0.01 Cum Volume (acre-it) 0.00 32.23 13.58
C & E Loss (fi) 0.04 Cum SA (acres) 0.92 2.07 1.12