SW6240903_Design Calculations_20241002

Docusign Envelope ID:61251431-CBD4-45FA-BF03-D915EDCBA56C
5245 Red Hill Church Rd
ri FLEET TEMPLE Coats, NC 27521
J ENGINEERING 910.658.2446
[e-mail]
PLLC Firm License P-2357
STORMWATER CALCULATIONS
FOR
42 MINI STORAGE
BUCKHORN TOWNSHIP
HARNETT COUNTY
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7/31/2024
Fleet Temple, PE
Fleet Temple Engineering, PLLC

42 MINI STORAGE
POND#2 - CALCULATIONS
PRE-CONSTRUCTION RUNOFF
TOTAL DRAINAGE AREA: 367258SF (8.4 AC.)
ROW CROPS: 6.4 AC. (C=0.35)
WOODS: 2.0 AC. (C=0.20)
WEIGHTED C=0.31
QI(PRE)=(0.31)(4.5IN/HR)(8.4AC.)= 11.7 CFS
Q10(PRE)=(0.31)(7.2IN/HR)(8.4AC.)= 18.8 CFS
Q100(PRE)=(0.31)(9.6IN/HR)(8.4AC.)= 25.0 CFS
POST-CONSTRUCTION RUNOFF:
DRAINAGE AREA TO POND: 261360SF (6.0AC) (C=0.90 DESIGN)
POND AREA: 1.6 AC. (EXCLUDED FROM DRAINAGE
CALCULATIONS)
AREA BY-PASSING POND: 0.8 AC. (WOODS) (C=0.20)
AREA BY-PASSING POND
QI(POST)=(0.20)(4.5IN/HR)(0.8AC.)=0.7 CFS
Q 10(POST)=(0.20)(7.2IN/HR)(0.8AC.)=1.2 CFS
Q 100(POST)=(0.20)(9.6IN/HR)(0.8AC.)=1.5 CFS
OUTFLOW FROM POND
Q1=4.85 CFS
Q10=10.97 CFS
Q100=35.20 CFS
TOTAL QI(POST) FROM SITE=5.6 CFS
TOTAL Q10(POST)FROM SITE=12.2 CFS
TOTAL Q100(POST)FROM SITE=36.7 CFS

POND#2 - MINIMUM REQUIRED TREATMENT VOLUME
TOTAL DRAINAGE AREA TO POND: 6.0 ACRES = 261360 SF
IMPERVIOUS AREA: 90%
Ia= 0.90
Rv=0.05 + (0.9)(0.90)= 0.86
DV REQUIRED=3,630(Rd)(Rv)(A) =3,630(1")(0.86)(6.0ac) = 18731 CF
Vmp REQUIRED=0.87(14/5)(18731CF)=45629CF
AVERAGE DEPTH OF POND
D(AVG)=VPP/APP
VPP(main pond)=51855 CF V(Forbay)=10427CF 10427cf/51855cf=20%
V(total)=51855CF + 10427CF= 62285CF
APP (total) =4679SF+ 15039SF= 19718SF
D(AVG)=62285CF/19718SF=3.2'

POND#2 - MINOR ORIFICE CALCULATIONS
TOP OF RISER: 430.00
PPE: 429.00
TOTAL VOL: 22915 cu.ft.
MIN. DEWATERING TIME: 2 days or 172800 sec.
MAX. DEWATERING TIME: 5 days or 432000 sec.
Cd: 0.60
g: 32.2 ft/s3
USING A 2.0" (r= 1.0") OUTLET PIPE, "Q" IS AS FOLLOWS:
Ho/3 = [430.00 - (429.00 + (1/12))] / 3
Ho/3: 0.31
A=3.14(1.0/12)^2
A=0.022 sf
Q=Cd * A * (2 * g * Ho/3)^0.5
22915 cf= (0.6)(0.022)[(2*32.2*0.31)^0.5]
time
22915 cf= 0.059
time
drawdown time=388528 seconds=4.5 days

POND#2 - RISER BUOYANCY CALCULATIONS
INSIDE DIAMETER: 36" =3.0 ft
WALL THICKNESS: 4" = 0.33 ft
BASE DIAMETER: 48"=4.0 ft
TOP ELEVATION: 430.00
FLOOR ELEVATION: 422.00
Yconcrete: 150 lb/cu.ft.
Ywater: 62.4 lb/cu.ft.
DISPLACEMENT (d) VOLUME AND WEIGHT
Vd=(3.14159) (2)^2 (h) + (3.14159) (1.83)^2 (8)
Vd=(12.57h+ 84.1) cu.ft.
Wd= 62.4(12.57h+ 84.1)
Wd=(784.4h+ 5247.8) lb
CONCRETE (c)VOLUME AND WEIGHT
Vc=(3.14159) (1.83)^2 (8) - (3.14159) (1.5)^2 (8) +(3.14159) (2)^2 (h)
Vc=(12.57h+ 27.6) cu.ft.
We = 150(12.57h+ 27.6)
We =(1,885.5h+4140.0) lb
REQUIRED BUOYANCY PREVENTION FACTOR= 1.1
We = 1.1Wd
(1885.5h+4140.0) = 1.1(784.4h+ 5247.8)
h =1.6 ft.
USE MINIMUM 20"BASE THICKNESS

Inflow Hydrograph Formulation
For Small Watersheds
Project 0052
Description NC 42 Mini Storage Pond#2
Location Harnett County
Client F&S Land Development
Drainage Area One
Frequency Duration
Design Storm Event 100 Year 24 Hours
Total Site Area 6.0 ac.
Total Drainage Area(A) 6.0 ac.
Hydraulic Length (L) 1200 ft.
Watershed Relief (H) 26 ft.
Time of Concentration (Tc) 8.0 min.
Post Development Pre Development
Rational C (for Q=CIA) 0.9 Rational C (for Q=CIA) 0.35
,Intensity(I) 9.60 in./hr. Intensity (I) 9.60 in./hr.
Peak Flow(Qp) 51.84 cfs Peak Flow (Qp) 20.16 cfs
SCS Curve Number(CN) 85 SCS Curve Number(CN) 64
'Ultimate Soil Storage (S) 1.765 in. 'Ultimate Soil Storage (S) 5.625 in.
Precipitation (P) 8.40 in. Precipitation (P) 8.40 in.
Runoff Depth (Q*) 6.60 in. Runoff Depth (Q*) 4.10 in.
Runoff Volume 143742 ft.3 Runoff Volume 89358 ft.3
Time to Peak(Tp) 0.55 hr. Time to Peak(Tp) 0.89 hr.
Post Development Pre Development Estimated Post Estimated
Time (hr.) _Inflow(cfs) Inflow(cfs) Development Outflow Storage (cf)
0.000 _ 0.00 0.00 0.00 0
0.025 0.26 0.04 0.02 0
0.050 1.03 0.16 0.06 220
0.075 2.31 0.35 0.14 1096
0.100 4.06 0.63 0.24 3050
0.125 6.24 0.97 0.38 6480
0.150 8.82 1.39 0.55 11755
0.175 11.74 1.88 0.74 19202
0.200 14.95 2.43 0.96 29106
0.225 18.38 3.04 1.22 41696
0.250 21.96 3.71 1 1.49 57144
0.275 25.62 4.43 1.80 75564
0.300 29.28 5.19 2.13 97002
0.325 32.88 5.99 2.48 121443
0.350 36.34 6.82 2.86 148802
0.375 39.58 7.68 3.25 178935
0.400 42.56 8.55 3.67 211633
0.425 45.20 9.44 4.11 246631
0.450 47.45 10.33 4.57 283610
0.475 49.28 11.23 5.04 322208
0.500 50.63 12.11 5.53 362019
0.525 51.49 12.97 6.03 402609
0.550 51.83 13.82 6.55 443519
0.575 51.66 14.63 7.07 484277

0.600 50.97 15.41 7.61 524405
0.625 49.78 16.15 8.15 563430
0.650 48.10 16.84 8.70 600894
0.675 45.99 17.47 9.25 636360
0.700 43.54 18.05 9.80 669425
0.725 41.06 18.57 10.36 699792
0.750 38.73 19.01 10.91 727426
0.775 36.52 19.39 11.47 752457
0.800 34.44 19.70 12.01 775004
0.825 32.48 19.93 12.56 795187
0.850 30.63 20.08 13.09 813115
0.875 28.88 20.15 13.62 828898
0.900 27.24 20.15 14.13 842638
0.925 25.69 20.06 14.63 854433
0.950 24.22 19.90 15.12 864381
0.975 22.84 19.66 15.59 872571
1.000 21.54 19.34 16.05 879094
2.000 2.06 4.65 14.11 530538
3.000 0.20 1.07 5.67 223023
4.000 0.02 0.25 2.28 90522
5.000 0.00 0.06 0.91 36449
6.000 0.00 0.01 0.37 14653
12.000 0.00 0.00 0.00 73
18.000 0.00 0.00 0.00 12
24.000 0.00 0.00 0.00 11
30.000 0.00 0.00 0.00 11
36.000 0.00 0.00 0.00 11
42.000 0.00 0.00 0.00 11
48.000 0.00 0.00 0.00 11
54.000 0.00 0.00 0.00 11
60.000 0.00 0.00 0.00 11
66.000 0.00 0.00 0.00 11
72.000 0.00 0.00 0.00 11
78.000 0.00 0.00 0.00 11
84.000 0.00 0.00 0.00 11
90.000 0.00 0.00 0.00 11
96.000 0.00 0.00 0.00 11
102.000 0.00 0.00 0.00 11
108.000 0.00 0.00 0.00 11
114.000 0.00 0.00 0.00 11
120.000 0.00 0.00 0.00 11

Stage-Storage Computation
100 yr Storm - Pond#2 Permanent Pool
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Zest
(ft2) (ft3) (ft3) (ft)
1 424 7124 0.0 0.0 0
1 425 8350 7737.0 7737.0 1 8.9538 0.0000 1.02
2 426 9613 8981.5 16718.5 2 9.7243 0.6931 1.96
3 427 10914 10263.5 26982.0 3 10.2029 1.0986 2.94
4 428 12252 11583.0 38565.0 4 10.5601 1.3863 3.98
4.5 428.5 12935 6296.8 44861.8 4.5 10.7113 1.5041 4.52
5 429 15039 6993.5 51855.3 5 10.8562 1.6094 5.11
Stage Storage Function
log-log plot y=1.2304x+8.8627
R2=0.9994
12.0000 -
iv
10.0000 .---- _♦ . . •
8.0000
61000
4.0000
2.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000 1.4000 1.6000 1.8000
LN(Z)
6 Stage Storage Function
5
4
N 3
m
m
co
2
1
0
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0
Storage(cf)
Constant 8.931587 Ks= 7568.83
Standard Error of Predicted Y 0.024885 b= 1.1792
R2 0.999045

Stage-Storage Computation
100 yr Storm - Pond#2 Forbay
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft) _
1 426 2363 0.0 0.0 0
2 427 3067 2715.0 2715.0 1 7.9065 0.0000 1.01
3 428 3839 3453.0 6168.0 2 8.7271 0.6931 1.97
4 429 4679 4259.0 10427.0 3 9.2522 1.0986 3.03
Stage Storage Function
log-log plot y= 1.2204x+7.8997
R2=0.9994
10.0000 -
9.0000 • •
8.0000 •
7.0000
6000
5 000
4. 000
3.0000
2.0000
1.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
a)
1.5
cn
0.5
0
0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0
Storage (cf)
Constant 7.899716 Ks= 2696.75
Standard Error of Predicted Y 0.022928 b= 1.2204
R2 0.999429

Stage-Storage Computation
100 yr Storm - Pond#2 Treatment Volume
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft)
1 429 20418 0.0 0.0 0
2 429.5 23169 10896.8 10896.8 0.5 9.2962 -0.6931 0.51
3 430 24904 12018.3 22915.0 1 10.0395 0.0000 0.98
4 431 29270 27087.0 50002.0 2 10.8198 0.6931 1.98
5 432 32657 30963.5 80965.5 3 11.3018 1.0986 3.04
Stage Storage Function y= 1.1178x+ 10.057
log-log plot R2=0.9996
2.0000 -
♦- -9A99--•-
8.0000
z 6.0000
J
4.0000
2.0000
0.0000
-0.8000 -0.6000 -0.4000 -0.2000 0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
1.5
cn
0.5
0 II 1
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0 70000.0 80000.0 90000.0
Storage (cf)
Constant 10.057332 Ks= 23328.88
Standard Error of Predicted Y 0.021504 b= 1.1178
R2 0.999604

100 r Storm - Pond#2
Results
Norm surf area= 0.5998 acres 26126 sq. ft.
Max surf area= 0.6694 acres 29160 sq. ft.
Peak Elevation= 431.54
Peak stage= 2.54
Peak outflow= 35.20
Initial Water level: Barrel: Minor Orifice: .
Z;= 429 ft. N= 1 N=' 1
Dc= 12 in. Dc= 2 in.
Stage-Storage: Cd= 0.6 Cd= 0.6
Ks= 23328.9 Z (invert)= 422 ft. Z (invert)= 430 ft.
b= 1.118
Zo= 429 ft (invert) Riser: (Circular) (Rectangular)
N=7 1 Dia. (in.) Length (ft.) Width (ft.)
Spillway: Cw= 3.33 36 1 0 1 0
L= 20 Cd=_ 0.65 Area Perimeter
Zcr= 431 ft. Z (top)=_ 430 ft. 7.1 9.4
Cw= 3
Riser Riser Minor RB
Time Time Inflow Storage Stage Outflow Orifice Weir Orifice Barrel Assembly Spillway
(hr) (min) (cfs) (ft3) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs)
0.00 0.0 0.0 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.03 1.5 0.3 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.05 3.0 1.0 23 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.08 4.5 2.3 116 429.01 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.10 6.0 4.1 324 429.02 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.13 7.5 6.2 689 429.04 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.15 9.0 8.8 1251 429.07 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.18 10.5 11.7 2045 429.11 0.0 0.0 0.0 0.0 9.71 0.0 0.0
0.20 12.0 15.0 3102 429.16 0.0 0.0 0.0 0.0 9.7 0.0 0.0

0.23 13.5 18.4 4448 429.23 0.0 0.0 0.0 0.0 9.8 0.0 0.0
0.25 15.0 22.0 6102 429.30 0.0 0.0 0.0 0.0 9.8 0.0 0.0
0.28 16.5 25.6 8078 429.39 0.0 0.0 0.0 0.0 9.9 0.0 0.0
0.30 18.0 29.3 10384 429.48 0.0 0.0 0.0 0.0 10.0 0.0 0.0
0.33 19.5 32.9 13019 429.59 0.0 0.0 0.0 0.0 10.1 0.0 0.0
0.35 21.0 36.3 15978 429.71 0.0 0.0 0.0 0.0 10.1 0.0 0.0
0.38 22.5 39.6 19248 429.84 0.0 0.0 0.0 0.0 10.2 0.0 0.0
0.40 24.0 42.6 22811 429.98 0.0 0.0 0.0 0.0 10.3 0.0 0.0
0.43 25.5 45.2 26641 430.13 1.4 13.1 1.4 0.0 10.4 1.4 0.0
0.45 27.0 47.5 30579 430.27 4.6 19.3 4.5 0.1 10.5 4.6 0.0
0.48 28.5 49.3 34440 430.42 8.5 23.8 8.4 0.1 10.6 8.5 0.0
0.50 30.0 50.6 38109 430.55 10.7 27.4 12.8 0.1 10.7 10.7 0.0
0.53 31.5 51.5 41701 430.68 10.8 30.4 17.7 0.1 10.8 10.8 0.0
0.55 33.0 51.8 45363 430.81 10.9 33.2 23.0 0.1 10.9 10.9 0.0
0.58 34.5 51.7 49048 430.94 11.0 35.8 28.8 0.1 11.0 11.0 0.0
0.60 36.0 51.0 52710 431.07 12.2 38.2 34.9 0.1 11.1 11.1 1.2
0.63 37.5 49.8 56195 431.20 16.3 40.3 41.0 0.1 11.1 11.1 5.2
0.65 39.0 48.1 59205 431.30 21.1 42.0 46.6 0.1 11.2 11.2 9.9
0.68 40.5 46.0 61636 431.38 25.6 43.4 51.2 0.1 11.3 11.3 14.3
0.70 42.0 43.5 63473 431.45 29.3 44.4 54.7 0.1 11.3 11.3 18.0
0.73 43.5 41.1 64754 431.49 32.1 45.0 57.2 0.1 11.3 11.3 20.7
0.75 45.0 38.7 65564 431.52 33.9 45.5 58.8 0.1 11.3 11.3 22.5
0.78 46.5 36.5 66001 431.54 34.9 45.7 59.7 0.1 11.3 11.3 23.5
0.80 48.0 34.4 66151 431.54 35.2 45.8 60.0 0.1 11.4 11.4 23.8
0.83 49.5 32.5 66082 431.54 35.0 45.7 59.9 0.1 11.4 11.4 23.7
0.85 51.0 30.6 65851 431.53 34.5 45.6 59.4 0.1 11.3 11.3 23.2
0.88 52.5 28.9 65501 431.52 33.7 45.4 58.7 0.1 11.3 11.3 22.4
0.90 54.0 27.2 65065 431.50 32.8 45.2 57.8 0.1 11.3 11.3 21.4
0.93 55.5 25.7 64569 431.49 31.7 44.9 56.9 0.1 11.3 11.3 20.3
0.95 57.0 24.2 64031 431.47 30.5 44.7 55.8 0.1 11.3 11.3 19.2
0.98 58.5 22.8 63467 431.45 29.3 44.4 54.7 0.1 11.3 11.3 18.0
1.00 60.0 21.5 62886 431.43 28.1 44.1 53.6 0.1 11.3 11.3 16.8
2.00 120.0 2.1 39750 430.61 10.8 28.8 15.0 0.1 10.8 10.8 0.0
3.00 180.0 0.2 26153 430.11 1.1 12.1 1.1 0.0 10.4 1.1 0.0
4.00 240.0 0.0 24342 430.04 0.3 7.3 0.2 0.0 10.4 0.3 0.0
5.00 300.0 0.0 23799 430.02 0.1 4.9 0.1 0.0 10.4 0.1 0.0
6.00 360.0 0.0 23581 430.01 0.0 3.6 0.0 0.0 10.3 0.0 0.0

12.00 720.0 0.0 23336 430.00 0.0 0.6 0.0 0.0 10.3 0.0 0.0
18.00 1080.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
24.00 1440.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
30.00 1800.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
36.00 2160.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
42.00 2520.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
48.00 2880.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
54.00 3240.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
60.00 3600.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
66.00 3960.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
72.00 4320.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
78.00 4680.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
84.00 5040.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
90.00 5400.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
96.00 5760.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
102.00 6120.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
108.00 6480.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
114.00 6840.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
120.00 7200.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0

Pre and Post Development Inflow Hydrographs
For 100 year, 24 hour Rainfall Event
60.00 - —
50.00 -
40.00icl
-
30.00 -
0
LI
20.00
10.00
0.00
0.000 0.500 1.000
Time(hr.)
—Post Development —Pre Development
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routing100yr.xlsx I hydgrph

100 yr 24 hr Post Development Inflow
& Estimated Outflow Hydrographs
60.00 -
50.00 -
40.00
icl
30.00
0
LI
20.00
10.00
1
0.00I
0.000 0.500 1.000
Time(hr.)
—Post Development Inflow (cfs) Estimated Post Development Outflow(cfs)
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routing100yr.xlsx 1-0 hydgrph

Inflow Hydrograph Formulation
For Small Watersheds
Project 0052
Description NC 42 Mini Storage Pond#2
Location Harnett County
Client F&S Land Development
Drainage Area One
Frequency Duration
Design Storm Event 10 Year 24 Hours
Total Site Area 6.0 ac.
Total Drainage Area(A) 6.0 ac.
Hydraulic Length (L) 1200 ft.
Watershed Relief (H) 26 ft.
Time of Concentration (Tc) 8.0 min.
Post Development Pre Development
Rational C (for Q=CIA) 0.9 Rational C (for Q=CIA) 0.35
,Intensity(I) 7.20 in./hr. Intensity (I) 7.20 in./hr.
Peak Flow(Qp) 38.88 cfs Peak Flow (Qp) 15.12 cfs
SCS Curve Number(CN) 85 SCS Curve Number(CN) 64
'Ultimate Soil Storage (S) 1.765 in. 'Ultimate Soil Storage (S) 5.625 in.
Precipitation (P) 5.12 in. Precipitation (P) 5.12 in.
Runoff Depth (Q*) 3.48 in. Runoff Depth (Q*) 1.66 in.
Runoff Volume 75775 ft.3 Runoff Volume 36134 ft.3
Time to Peak(Tp) 0.39 hr. Time to Peak(Tp) 0.48 hr.
Post Development Pre Development Estimated Post Estimated
Time (hr.) _Inflow(cfs) Inflow(cfs) Development Outflow Storage (cf)
0.000 _ 0.00 0.00 0.00 0
0.025 0.39 0.10 0.02 0
0.050 1.56 0.41 0.09 334
0.075 3.45 0.90 0.21 1654
0.100 5.99 1.58 0.37 4572
0.125 9.07 2.41 0.57 9629
0.150 12.58 3.39 0.82 17278
0.175 16.36 4.48 1.11 27857
0.200 20.26 5.65 1.44 41579
0.225 24.14 6.88 1.81 58521
0.250 27.82 8.12 2.21 78620
0.275 31.16 9.34 2.64 101672
0.300 34.03 10.52 3.11 127341
0.325 36.31 11.62 3.60 155174
0.350 37.90 12.61 4.12 184612
0.375 38.75 13.46 4.65 215020
0.400 38.81 14.16 5.21 245704
0.425 38.09 14.67 5.78 275944
0.450 36.61 15.00 6.36 305020
0.475 34.44 15.12 6.95 332243
0.500 31.80 15.04 7.54 356980
0.525 29.25 14.76 8.13 378812
0.550 26.91 14.28 8.72 397820
0.575 24.76 13.62 9.30 414190

0.600 22.78 12.82 9.88 428098
0.625 20.95 11.97 10.43 439707
0.650 19.27 11.18 10.97 449175
0.675 17.73 10.45 11.49 456648
0.700 16.31 9.76 11.98 462266
0.725 15.01 9.12 12.45 466162
0.750 13.80 8.52 12.89 468463
0.775 12.70 7.96 13.29 469289
0.800 11.68 7.44 13.66 468757
0.825 10.75 6.95 13.99 466979
0.850 9.89 6.49 14.28 464060
0.875 9.10 6.06 14.53 460105
0.900 8.37 5.66 14.74 455212
0.925 7.70 5.29 14.90 449476
0.950 7.08 4.94 15.02 442991
0.975 6.51 4.62 15.09 435845
1.000 5.99 4.31 15.12 428124
2.000 0.21 0.28 4.89 135535
3.000 0.01 0.02 1.34 37583
4.000 0.00 0.00 0.36 10287
5.000 0.00 0.00 0.10 2814
6.000 0.00 0.00 0.03 773
12.000 0.00 0.00 0.00 6
18.000 0.00 0.00 0.00 6
24.000 0.00 0.00 0.00 6
30.000 0.00 0.00 0.00 6
36.000 0.00 0.00 0.00 6
42.000 0.00 0.00 0.00 6
48.000 0.00 0.00 0.00 6
54.000 0.00 0.00 0.00 6
60.000 0.00 0.00 0.00 6
66.000 0.00 0.00 0.00 6
72.000 0.00 0.00 0.00 6
78.000 0.00 0.00 0.00 6
84.000 0.00 0.00 0.00 6
90.000 0.00 0.00 0.00 6
96.000 0.00 0.00 0.00 6
102.000 0.00 0.00 0.00 6
108.000 0.00 0.00 0.00 6
114.000 0.00 0.00 0.00 6
120.000 0.00 0.00 0.00 6

Stage-Storage Computation
10 yr Storm - Pond#2 Permanent Pool
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Zest
(ft2) (ft3) (ft3) (ft)
1 424 7124 0.0 0.0 0
1 425 8350 7737.0 7737.0 1 8.9538 0.0000 1.02
2 426 9613 8981.5 16718.5 2 9.7243 0.6931 1.96
3 427 10914 10263.5 26982.0 3 10.2029 1.0986 2.94
4 428 12252 11583.0 38565.0 4 10.5601 1.3863 3.98
4.5 428.5 12935 6296.8 44861.8 4.5 10.7113 1.5041 4.52
5 429 15039 6993.5 51855.3 5 10.8562 1.6094 5.11
Stage Storage Function
log-log plot y=1.2304x+8.8627
R2=0.9994
12.0000 -
iv
10.0000 .---- _♦ . . •
8.0000
63000
4.0000
2.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000 1.4000 1.6000 1.8000
LN(Z)
6 Stage Storage Function
5
4
N 3
m
m
co
2
1
0
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0
Storage(cf)
Constant 8.931587 Ks= 7568.83
Standard Error of Predicted Y 0.024885 b= 1.1792
R2 0.999045

Stage-Storage Computation
10 yr Storm - Pond#2 Forbay
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft) _
1 426 2363 0.0 0.0 0
2 427 3067 2715.0 2715.0 1 7.9065 0.0000 1.01
3 428 3839 3453.0 6168.0 2 8.7271 0.6931 1.97
4 429 4679 4259.0 10427.0 3 9.2522 1.0986 3.03
Stage Storage Function
log-log plot y= 1.2204x+7.8997
R2=0.9994
10.0000 -
9.0000 • •
8.0000 •
7.0000
6000
5 000
4. 000
3.0000
2.0000
1.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
a)
1.5
cn
0.5
0
0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0
Storage (cf)
Constant 7.899716 Ks= 2696.75
Standard Error of Predicted Y 0.022928 b= 1.2204
R2 0.999429

Stage-Storage Computation
10 yr Storm - Pond#2 Treatment Volume
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft) _
1 429 20418 0.0 0.0 0
2 429.5 23169 10896.8 10896.8 0.5 9.2962 -0.6931 0.51
3 430 24904 12018.3 22915.0 1 10.0395 0.0000 0.98
4 431 29270 27087.0 50002.0 2 10.8198 0.6931 1.98
5 432 32657 30963.5 80965.5 3 11.3018 1.0986 3.04
Stage Storage Function y= 1.1178x+ 10.057
log-log plot R2=0.9996
2.0000 -
♦- -9A99--•-
8.0000
z 6.0000
J
4.0000
2.0000
0.0000
-0.8000 -0.6000 -0.4000 -0.2000 0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
1.5
cn
0.5
0 II 1
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0 70000.0 80000.0 90000.0
Storage (cf)
Constant 10.057332 Ks= 23328.88
Standard Error of Predicted Y 0.021504 b= 1.1178
R2 0.999604

10 r Storm - Pond#2
Results
Norm surf area= 0.5998 acres 26126 sq. ft.
Max surf area= 0.6487 acres 28258 sq. ft.
Peak Elevation= 430.95
Peak stage= 1.95
Peak outflow= 10.97
Initial Water level: Barrel: Minor Orifice: .
Z;= 429 ft. N= 1 N=' 1
Dc= 12 in. Dc= 2 in.
Stage-Storage: Cd= 0.6 Cd= 0.6
Ks= 23328.9 Z (invert)= 422 ft. Z (invert)= 430 ft.
b= 1.118
Zo= 429 ft (invert) Riser: (Circular) (Rectangular)
N=7 1 Dia. (in.) Length (ft.) Width (ft.)
Spillway: Cw= 3.33 36 1 0 1 0
L= 20 Cd=_ 0.65 Area Perimeter
Zcr= 431 ft. Z (top)=_ 430 ft. 7.1 9.4
Cw= 3
Riser Riser Minor RB
Time Time Inflow Storage Stage Outflow Orifice Weir Orifice Barrel Assembly Spillway
(hr) (min) (cfs) (ft3) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs)
0.00 0.0 0.0 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.03 1.5 0.4 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.05 3.0 1.6 35 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.08 4.5 3.5 176 429.01 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.10 6.0 6.0 486 429.03 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.13 7.5 9.1 1025 429.06 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.15 9.0 12.6 1842 429.10 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.18 10.5 16.4 2974 429.16 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.20 12.0 20.3 4446 429.23 0.0 0.0 0.0 0.0 9.8 0.0 0.0

0.23 13.5 24.1 6270 429.31 0.0 0.0 0.0 0.0 9.9 0.0 0.0
0.25 15.0 27.8 8442 429.40 0.0 0.0 0.0 0.0 9.9 0.0 0.0
0.28 16.5 31.2 10946 429.51 0.0 0.0 0.0 0.0 10.0 0.0 0.0
0.30 18.0 34.0 13751 429.62 0.0 0.0 0.0 0.0 10.1 0.0 0.0
0.33 19.5 36.3 16814 429.75 0.0 0.0 0.0 0.0 10.2 0.0 0.0
0.35 21.0 37.9 20082 429.87 0.0 0.0 0.0 0.0 10.3 0.0 0.0
0.38 22.5 38.7 23493 430.01 0.0 2.9 0.0 0.0 10.3 0.0 0.0
0.40 24.0 38.8 26978 430.14 1.7 13.7 1.6 0.0 10.4 1.7 0.0
0.43 25.5 38.1 30321 430.26 4.3 19.0 4.3 0.1 10.5 4.3 0.0
0.45 27.0 36.6 33360 430.38 7.3 22.6 7.3 0.1 10.6 7.3 0.0
0.48 28.5 34.4 35995 430.47 10.3 25.4 10.2 0.1 10.7 10.3 0.0
0.50 30.0 31.8 38166 430.55 10.7 27.4 12.9 0.1 10.7 10.7 0.0
0.53 31.5 29.3 40064 430.62 10.8 29.1 15.4 0.1 10.8 10.8 0.0
0.55 33.0 26.9 41728 430.68 10.8 30.5 17.7 0.1 10.8 10.8 0.0
0.58 34.5 24.8 43178 430.73 10.8 31.6 19.8 0.1 10.8 10.8 0.0
0.60 36.0 22.8 44431 430.78 10.9 32.6 21.6 0.1 10.9 10.9 0.0
0.63 37.5 21.0 45503 430.82 10.9 33.3 23.2 0.1 10.9 10.9 0.0
0.65 39.0 19.3 46409 430.85 10.9 34.0 24.6 0.1 10.9 10.9 0.0
0.68 40.5 17.7 47162 430.88 10.9 34.5 25.8 0.1 10.9 10.9 0.0
0.70 42.0 16.3 47774 430.90 10.9 35.0 26.7 0.1 10.9 10.9 0.0
0.73 43.5 15.0 48257 430.92 11.0 35.3 27.5 0.1 11.0 11.0 0.0
0.75 45.0 13.8 48622 430.93 11.0 35.5 28.1 0.1 11.0 11.0 0.0
0.78 46.5 12.7 48878 430.94 11.0 35.7 28.5 0.1 11.0 11.0 0.0
0.80 48.0 11.7 49034 430.94 11.0 35.8 28.8 0.1 11.0 11.0 0.0
0.83 49.5 10.7 49098 430.95 11.0 35.9 28.9 0.1 11.0 11.0 0.0
0.85 51.0 9.9 49078 430.95 11.0 35.8 28.8 0.1 11.0 11.0 0.0
0.88 52.5 9.1 48980 430.94 11.0 35.8 28.7 0.1 11.0 11.0 0.0
0.90 54.0 8.4 48811 430.94 11.0 35.7 28.4 0.1 11.0 11.0 0.0
0.93 55.5 7.7 48577 430.93 11.0 35.5 28.0 0.1 11.0 11.0 0.0
0.95 57.0 7.1 48284 430.92 11.0 35.3 27.6 0.1 11.0 11.0 0.0
0.98 58.5 6.5 47935 430.90 10.9 35.1 27.0 0.1 10.9 10.9 0.0
1.00 60.0 6.0 47536 430.89 10.9 34.8 26.4 0.1 10.9 10.9 0.0
2.00 120.0 0.2 27373 430.15 1.9 14.5 1.9 0.0 10.4 1.9 0.0
3.00 180.0 0.0 24511 430.05 0.3 7.8 0.3 0.0 10.4 0.3 0.0
4.00 240.0 0.0 23843 430.02 0.1 5.2 0.1 0.0 10.4 0.1 0.0
5.00 300.0 0.0 23599 430.01 0.0 3.7 0.0 0.0 10.3 0.0 0.0
6.00 360.0 0.0 23484 430.01 0.0 2.8 0.0 0.0 10.3 0.0 0.0

12.00 720.0 0.0 23331 430.00 0.0 0.4 0.0 0.0 10.3 0.0 0.0
18.00 1080.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
24.00 1440.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
30.00 1800.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
36.00 2160.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
42.00 2520.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
48.00 2880.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
54.00 3240.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
60.00 3600.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
66.00 3960.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
72.00 4320.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
78.00 4680.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
84.00 5040.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
90.00 5400.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
96.00 5760.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
102.00 6120.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
108.00 6480.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
114.00 6840.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
120.00 7200.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0

Pre and Post Development Inflow Hydrographs
For 10 year, 24 hour Rainfall Event
45.00 - —
40.00
35.00
30.00
225.00
41
L° 20.00
15.00
10.00
5.00 \
0.00
0.000 0.500 1.000
Time(hr.)
—Post Development —Pre Development
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routingl0yr.xlsx I hydgrph

10 yr 24 hr Post Development Inflow
& Estimated Outflow Hydrographs
45.00 -
40.00
35.00
30.00
N 25.00
o
Li 20.00
15.00
10.00
5.00
0.00
0.000 0.500 1.000
Time(hr.)
—Post Development Inflow (cfs) Estimated Post Development Outflow(cfs)
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routing10yr.xlsx 1-0 hydgrph

Inflow Hydrograph Formulation
For Small Watersheds
Project 0052
Description NC 42 Mini Storage Pond#2
Location Harnett County
Client F&S Land Development
Drainage Area One
Frequency Duration
Design Storm Event 1 Year 24 Hours
Total Site Area 6.0 ac.
Total Drainage Area(A) 6.0 ac.
Hydraulic Length (L) 1200 ft.
Watershed Relief (H) 26 ft.
Time of Concentration (Tc) 8.0 min.
Post Development Pre Development
Rational C (for Q=CIA) 0.9 Rational C (for Q=CIA) 0.35
,Intensity(I) 4.50 in./hr. Intensity (I) 4.50 in./hr.
Peak Flow(Qp) 24.30 cfs Peak Flow (Qp) 9.45 cfs
SCS Curve Number(CN) 85 SCS Curve Number(CN) 64
'Ultimate Soil Storage (S) 1.765 in. 'Ultimate Soil Storage (S) 5.625 in.
Precipitation (P) 3.20 in. Precipitation (P) 3.20 in.
Runoff Depth (Q*) 1.76 in. Runoff Depth (Q*) 0.56 in.
Runoff Volume 38281 ft.3 Runoff Volume 12179 ft.3
Time to Peak(Tp) 0.31 hr. Time to Peak(Tp) 0.26 hr.
Post Development Pre Development Estimated Post Estimated
Time (hr.) _Inflow(cfs) Inflow(cfs) Development Outflow Storage (cf)
0.000 _ 0.00 0.00 0.00 0
0.025 0.38 0.22 0.02 0
0.050 1.48 0.85 0.09 319
0.075 3.25 1.84 0.20 1572
0.100 5.56 3.10 0.35 4315
0.125 8.29 4.51 0.55 9007
0.150 11.25 5.93 0.78 15976
0.175 14.27 7.25 1.05 25403
0.200 17.16 8.33 1.35 37304
0.225 19.74 9.08 1.69 51530
0.250 21.85 9.43 2.05 67773
0.275 23.35 9.34 2.44 85585
0.300 24.17 8.83 2.86 104403
0.325 24.24 7.95 3.29 123583
0.350 23.56 7.01 3.73 142439
0.375 22.17 6.18 4.18 160287
0.400 20.22 5.45 4.64 176481
0.425 18.24 4.80 5.10 190504
0.450 16.45 4.23 5.55 202330
0.475 14.83 3.73 6.00 212137
0.500 13.38 3.29 6.43 220090
0.525 12.07 2.90 6.85 226342
0.550 10.88 2.55 7.25 231037
0.575 9.82 2.25 7.62 234307

0.600 8.85 1.98 7.97 236279
0.625 7.98 1.75 8.29 237071
0.650 7.20 1.54 8.57 236797
0.675 6.49 1.36 8.82 235563
0.700 5.86 1.20 9.03 233470
0.725 5.28 1.06 9.20 230615
0.750 4.77 0.93 9.32 227092
0.775 4.30 0.82 9.41 222989
0.800 3.88 0.72 9.45 218390
0.825 3.50 0.64 9.44 213376
0.850 3.15 0.56 9.39 208025
0.875 2.84 0.50 9.30 202410
0.900 2.56 0.44 9.16 196601
0.925 2.31 0.38 8.98 190664
0.950 2.09 0.34 8.77 184661
0.975 1.88 0.30 8.51 178650
1.000 1.70 0.26 8.22 172686
2.000 0.03 0.00 1.65 37539
3.000 0.00 0.00 0.33 7581
4.000 0.00 0.00 0.07 1523
5.000 0.00 0.00 0.01 306
6.000 0.00 0.00 0.00 62
12.000 0.00 0.00 0.00 0
18.000 0.00 0.00 0.00 0
24.000 0.00 0.00 0.00 0
30.000 0.00 0.00 0.00 0
36.000 0.00 0.00 0.00 0
42.000 0.00 0.00 0.00 0
48.000 0.00 0.00 0.00 0
54.000 0.00 0.00 0.00 0
60.000 0.00 0.00 0.00 0
66.000 0.00 0.00 0.00 0
72.000 0.00 0.00 0.00 0
78.000 0.00 0.00 0.00 0
84.000 0.00 0.00 0.00 0
90.000 0.00 0.00 0.00 0
96.000 0.00 0.00 0.00 0
102.000 0.00 0.00 0.00 0
108.000 0.00 0.00 0.00 0
114.000 0.00 0.00 0.00 0
120.000 0.00 0.00 0.00 0

Stage-Storage Computation
1 yr Storm - Pond#2 Permanent Pool
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Zest
(ft2) (ft3) (ft3) (ft)
1 424 7124 0.0 0.0 0
1 425 8350 7737.0 7737.0 1 8.9538 0.0000 1.02
2 426 9613 8981.5 16718.5 2 9.7243 0.6931 1.96
3 427 10914 10263.5 26982.0 3 10.2029 1.0986 2.94
4 428 12252 11583.0 38565.0 4 10.5601 1.3863 3.98
4.5 428.5 12935 6296.8 44861.8 4.5 10.7113 1.5041 4.52
5 429 15039 6993.5 51855.3 5 10.8562 1.6094 5.11
Stage Storage Function
log-log plot y=1.2304x+8.8627
R2=0.9994
12.0000 -
iv
10.0000 .---- _♦ . . •
8.0000
63000
4.0000
2.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000 1.4000 1.6000 1.8000
LN(Z)
6 Stage Storage Function
5
4
N 3
m
m
co
2
1
0
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0
Storage(cf)
Constant 8.931587 Ks= 7568.83
Standard Error of Predicted Y 0.024885 b= 1.1792
R2 0.999045

Stage-Storage Computation
1 yr Storm - Pond#2 Forbay
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft)
1 426 2363 0.0 0.0 0
2 427 3067 2715.0 2715.0 1 7.9065 0.0000 1.01
3 428 3839 3453.0 6168.0 2 8.7271 0.6931 1.97
4 429 4679 4259.0 10427.0 3 9.2522 1.0986 3.03
Stage Storage Function
log-log plot y= 1.2204x+7.8997
R2=0.9994
10.0000 -
9.0000 • •
8.0000 •
7.0000
6000
5 000
4. 000
3.0000
2.0000
1.0000
0.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
a)
1.5
cn
0.5
0
0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0
Storage (cf)
Constant 7.899716 Ks= 2696.75
Standard Error of Predicted Y 0.022928 b= 1.2204
R2 0.999429

Stage-Storage Computation
1 yr Storm - Pond#2 Treatment Volume
Incremental Accumulated
Row Contour Contour Area Volume Volume(S) Stage(Z) In S In Z Z est
(ft2) (ft3) (ft3) (ft) _
1 429 20418 0.0 0.0 0
2 429.5 23169 10896.8 10896.8 0.5 9.2962 -0.6931 0.51
3 430 24904 12018.3 22915.0 1 10.0395 0.0000 0.98
4 431 29270 27087.0 50002.0 2 10.8198 0.6931 1.98
5 432 32657 30963.5 80965.5 3 11.3018 1.0986 3.04
Stage Storage Function y= 1.1178x+ 10.057
log-log plot R2=0.9996
2.0000 -
♦- -9A99--•-
8.0000
z 6.0000
J
4.0000
2.0000
0.0000
-0.8000 -0.6000 -0.4000 -0.2000 0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000
LN(Z)
Stage Storage Function
3.5 -
3
2.5
2
1.5
cn
0.5
0 II 1
0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0 70000.0 80000.0 90000.0
Storage (cf)
Constant 10.057332 Ks= 23328.88
Standard Error of Predicted Y 0.021504 b= 1.1178
R2 0.999604

1 r Storm - Pond#2
Results
Norm surf area= 0.5998 acres 26126 sq. ft.
Max surf area= 0.6178 acres 26912 sq. ft.
Peak Elevation= 430.29
Peak stage= 1.29
Peak outflow= 4.85
Initial Water level: Barrel: Minor Orifice: .
Z;= 429 ft. N= 1 N=' 1
Dc= 12 in. Dc= 2 in.
Stage-Storage: Cd= 0.6 Cd= 0.6
Ks= 23328.9 Z (invert)= 422 ft. Z (invert)= 430 ft.
b= 1.118
Zo= 429 ft (invert) Riser: (Circular) (Rectangular)
N=7 1 Dia. (in.) Length (ft.) Width (ft.)
Spillway: Cw= 3.33 36 1 0 1 0
L= 20 Cd=_ 0.65 Area Perimeter
Zcr= 431 ft. Z (top)=_ 430 ft. 7.1 9.4
Cw= 3
Riser Riser Minor RB
Time Time Inflow Storage Stage Outflow Orifice Weir Orifice Barrel Assembly Spillway
(hr) (min) (cfs) (ft3) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs)
0.00 0.0 0.0 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.03 1.5 0.4 0 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.05 3.0 1.5 34 429.00 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.08 4.5 3.2 167 429.01 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.10 6.0 5.6 459 429.03 0.0 0.0 0.0 0.0 9.6 0.0 0.0
0.13 7.5 8.3 960 429.06 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.15 9.0 11.3 1706 429.10 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.18 10.5 14.3 2719 429.15 0.0 0.0 0.0 0.0 9.7 0.0 0.0
0.20 12.0 17.2 4003 429.21_ 0.0 0.0 0.0 0.0 9.8 0.0 0.0

0.23 13.5 19.7 5548 429.28 0.0 0.0 0.0 0.0 9.8 0.0 0.0
0.25 15.0 21.8 7324 429.35 0.0 0.0 0.0 0.0 9.9 0.0 0.0
0.28 16.5 23.4 9290 429.44 0.0 0.0 0.0 0.0 9.9 0.0 0.0
0.30 18.0 24.2 11392 429.53 0.0 0.0 0.0 0.0 10.0 0.0 0.0
0.33 19.5 24.2 13567 429.62 0.0 0.0 0.0 0.0 10.1 0.0 0.0
0.35 21.0 23.6 15748 429.70 0.0 0.0 0.0 0.0 10.1 0.0 0.0
0.38 22.5 22.2 17869 429.79 0.0 0.0 0.0 0.0 10.2 0.0 0.0
0.40 24.0 20.2 19864 429.87 0.0 0.0 0.0 0.0 10.2 0.0 0.0
0.43 25.5 18.2 21684 429.94 0.0 0.0 0.0 0.0 10.3 0.0 0.0
0.45 27.0 16.4 23325 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
0.48 28.5 14.8 24806 430.06 0.4 8.8 0.4 0.0 10.4 0.4 0.0
0.50 30.0 13.4 26100 430.11 1.1 12.0 1.1 0.0 10.4 1.1 0.0
0.53 31.5 12.1 27204 430.15 1.8 14.2 1.8 0.0 10.4 1.8 0.0
0.55 33.0 10.9 28127 430.18 2.5 15.7 2.4 0.0 10.5 2.5 0.0
0.58 34.5 9.8 28883 430.21 3.1 16.9 3.0 0.0 10.5 3.1 0.0
0.60 36.0 8.9 29489 430.23 3.6 17.8 3.5 0.1 10.5 3.6 0.0
0.63 37.5 8.0 29963 430.25 4.0 18.5 3.9 0.1 10.5 4.0 0.0
0.65 39.0 7.2 30322 430.26 4.3 19.0 4.3 0.1 10.5 4.3 0.0
0.68 40.5 6.5 30581 430.27 4.6 19.3 4.5 0.1 10.5 4.6 0.0
0.70 42.0 5.9 30756 430.28 4.7 19.5 4.7 0.1 10.5 4.7 0.0
0.73 43.5 5.3 30858 430.28 4.8 19.7 4.8 0.1 10.5 4.8 0.0
0.75 45.0 4.8 30901 430.29 4.9 19.7 4.8 0.1 10.5 4.9 0.0
0.78 46.5 4.3 30893 430.29 4.8 19.7 4.8 0.1 10.5 4.8 0.0
0.80 48.0 3.9 30843 430.28 4.8 19.6 4.7 0.1 10.5 4.8 0.0
0.83 49.5 3.5 30760 430.28 4.7 19.5 4.7 0.1 10.5 4.7 0.0
0.85 51.0 3.2 30650 430.28 4.6 19.4 4.6 0.1 10.5 4.6 0.0
0.88 52.5 2.8 30518 430.27 4.5 19.2 4.4 0.1 10.5 4.5 0.0
0.90 54.0 2.6 30369 430.27 4.4 19.0 4.3 0.1 10.5 4.4 0.0
0.93 55.5 2.3 30207 430.26 4.2 18.8 4.2 0.1 10.5 4.2 0.0
0.95 57.0 2.1 30036 430.25 4.1 18.6 4.0 0.1 10.5 4.1 0.0
0.98 58.5 1.9 29858 430.25 3.9 18.3 3.9 0.1 10.5 3.9 0.0
1.00 60.0 1.7 29676 430.24 3.7 18.1 3.7 0.1 10.5 3.7 0.0
2.00 120.0 0.0 25077 430.07 0.6 9.5 0.5 0.0 10.4 0.6 0.0
3.00 180.0 0.0 24006 430.03 0.1 5.9 0.1 0.0 10.4 0.1 0.0
4.00 240.0 0.0 23665 430.01 0.1 4.2 0.0 0.0 10.3 0.1 0.0
5.00 300.0 0.0 23517 430.01 0.0 3.1 0.0 0.0 10.3 0.0 0.0
6.00 360.0 0.0 23441 430.00 0.0 2.4 0.0 0.0 10.3 0.0 0.0

12.00 720.0 0.0 23330 430.00 0.0 0.2 0.0 0.0 10.3 0.0 0.0
18.00 1080.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
24.00 1440.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
30.00 1800.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
36.00 2160.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
42.00 2520.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
48.00 2880.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
54.00 3240.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
60.00 3600.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
66.00 3960.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
72.00 4320.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
78.00 4680.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
84.00 5040.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
90.00 5400.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
96.00 5760.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
102.00 6120.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
108.00 6480.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
114.00 6840.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0
120.00 7200.0 0.0 23329 430.00 0.0 0.0 0.0 0.0 10.3 0.0 0.0

Pre and Post Development Inflow Hydrographs
For 1 year, 24 hour Rainfall Event
30.00 - —
25.00
20.00 -
15.00
0
LI
10.00
5.00
0.00
0.000 0.500 1.000
Time(hr.)
—Post Development —Pre Development
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routing1yr.xlsx I hydgrph

1 yr 24 hr Post Development Inflow
& Estimated Outflow Hydrographs
30.00 -
25.00
20.00
3 15.00
0
LI
10.00
5.00
0.00
0.000 0.500 1.000
Time(hr.)
Post Development Inflow (cfs) Estimated Post Development Outflow(cfs)
7/31/2024
C:\FTE PROJECTS\0052-STEPHENSON MINI-STORAGE\STORMWATER\Pond2 Routing1yr.xlsx 1-0 hydgrph