SW3181002_Design Calculations_20240112

Cottages West
2316 Waxhaw-Indian Trail Road
Indian Trail, NC
CALCULATIONS WITHIN THIS PACKAGE INCLUDE:
Erosion Control, Temporary Diversion Ditches, Slope Matting, Storm Water Narrative,
Storm Drainage, Gutter Spread, Energy Dissipator,
SCM - Sand Filter, Water Quality, Volume Control, Peak Control,
Anti-Floatation, Soils Map
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ENGINEER OF RECORD: C �� '' .`��,�THEAST�/L.
Nicholas T. Vesely, PE 4." ��c'j•5`'\OA c�ROO'
North Carolina #047011 =
SEAL = :•a C-4911 o'
Bloc Design, PLLC = • 047011 _
(A V3 Southeast Company) �'Z•: ;',�., = •
C-672
2923 South Tryon Street, Suite 320 �•• Cyy�` •'�,;�
Charlotte, North Carolina 28203 %,$'p•fN•G,NEt �C?-.`� %,O,-•. •'-1;-••
7-,,,rillimo ''•,,,,,,IIII‘o• `
Original Calculation Certification Date: 04.13.22 LbIO
Revised Calculation Certification Date: 01.11.24
Bloc Design Project Number: 00915.00 c
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF BLOC DESIGN,PLLC.REPRODUCTION OR USE IS PROHIBITED WITHOUT THE WRITTEN CONSEN
OF BLOC DESIGN,PLLC.COPYRIGHT,BLOC DESIGN,PLLC 2024.

Sand Filter
•bloc

SCM Sizing Data - SCM #1
Pre-Development Drainage Basin Post-Development Drainage Basin
Drainage Area (Ad) 14.08 ac Drainage Area (Ad) 6.69 ac
Impervious Area (A) 1.25 ac Impervious Area (A) 4.51 ac
Impervious% (I) 8.9 % Impervious% (I) 67.5 %
Curve Number (CN) 63 Curve Number (CN) 86
Time of Concentration (Id 22.1 min Time of Concentration (Id 5.0 min
Watershed Requirements
Regulatory Jurisdiction: MS4 Phase II *Storm water regulations per local authority
Density (High/Low): HIGH storm water program
Water Quality Volume Calculations
Volumetric Runoff Coefficient (R„) Water Quality Volume (WQ„)
Rv= 0.05 +0.009 (I) WQ„= 1.0 Rv Ad
Rv= 0.66 in/in 12
1 inch/24 hour water quality control
WQ„= 0.37 ac. ft. WQ„= R„(I)
15,957 cf WQ„= 0.66 inches of runoff
Dam Safety Evaluation
Spillway Elevation = 673.50
Lowest Elevation at Toe of Slope = 665.00 Submittal to Dam
Embankment Height= 8.5 Safety NOT required
*Project calculations derived from the NCDEQ Stormwater Design Manual, Minimum Design Criteria (MDC) -
Effective:January 1, 2017
Cottages West
2316 Waxhaw Indrian Trail Rd
Indian Trail, NC
Completed By: NTV
Reviewed By: DSK
Original Date: 04.13.22
Revised Date: 01.11.24
Bloc Design Project Number: 00915.00
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED [-Mb
I O C
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #1
From SCM Sizing Data Sheet
Drainage Area (Ad) 6.69 ac Water Quality Volume (WQv)
Impervious Area (Al) 4.51 ac WQv= 0.37 ac. ft.
Impervious% (I) 67.5 % WQv= 15,957 ft3
Water Quality Release Rate
Regulatory Program: MS4 Phase II
Location: Non-Coastal
Design volume shall be held for minimum of 2 days
Sand Filter designed to treat 75%of the WQv WQv,red= 11,967 ft3
Sand filter ponding depth is limited to 6 ft
Initial assumption of sand filter ponding depth for WQv = 3.0 ft
Initial estimate of pond area = 3,989 sf
Sediment Chamber Sizing
Sediment chamber must hold 20%of the WQv
Sediment Chamber Volume (Vpre)
FVrequired = (0•20)WQv
FVrequired =6. 3,191 cf
Top of Sand Elevation = 668.00
Forebay Calculator
Elevation Area Incremental Accumulated Forebay
[ft] [ft2] Volume Volume Percentage
[ft3] [ft3] [%]
668.00 1,860
669.00 2,251 2056 2056 64
670.00 2,670 2461 4516 142
FVprovided = cf Sufficient Volume Provided
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED blOC
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #1
Filtration Bed Sizing
SCM Storage Volume
Storage Storage Storage Storage Height Inc. Acc. Acc.
Elevation Elevation Areaavg Volume Volume Volume
[ft.] Area [sf] Area [ac.] [ac.] [ft.] [ac.-ft.] [ft.3] [ac.-ft.]
668.00 3,720 0.085 r +
669.00 4,503 0.103 0.094 1.00 0.094 4,112 0.094
670.00 5,342 0.123 0.113 1.00 0.113 9,034 0.207
671.00 6,237 0.143 0.133 1.00 0.133 14,824 0.340
672.00 7,189 0.165 0.154 1.00 0.154 21,537 0.494
673.00 8,198 0.188 0.177 1.00 0.177 29,230 0.671
674.00 9,263 0.213 0.200 1.00 0.200 37,961 0.871
674.50 9,817 0.225 0.219 0.50 0.110 42,731 0.981
Water Quality Volume (WQv) = 11,967 ft3
Elevation of peak WQv= 670.51 -.ft Sufficient Volume Provided
Filter Bed Depth (df) Coefficient of Permeability of Filter Media (k)
df= 1.0 ft k= 4.0 ft/day
Average Height of Water Above Filter Bed (hf)
hf= 1.25 ft tf= 36 hours
Surface Area of Sand Filter Media (Af)
Af= (WQv)(df) / [(k)(hf+df)(ff)]
Af= 1,180 ft2
Af(provided) = 1,200 ft2 Sufficient Surface Area Provided
Stage-Storage and Stage-Discharge Relationship for Sand Filter
Sand Media Discharge (Qs)
Qs- WQv/tf=Af(provided) (k)(hf+df)/(df)
Sand Media Discharge Calculator
Depth Above Sand Sand Media
Elevation [ft] Media (hf) Discharge (Qs)
[ft] [cfs]
668.00 1
669.00 1.00 0.1 11
670.00 2.00 0.167
671.00 3.00 0.222
672.00 4.00 0.278
673.00 5.00 0.333
674.00 6.00 0.389
675.00 7.00 0.444
L.
INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED bloc
L
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #1
Underdrain System Sizing
Number of 6" Underdrain Pipes (N) = 3
Pipe Material = PVC
Pipe Slope (S) = 0.005 ft/ft
Flow Capacity with Provided Pipes (QU
Qc = (((D/16)8i3 x S1/2 ) / n)*N
Qc = 1.410 cfs
Designed Flow Through Underdrain Pipes with 50%Capacity Lost
Q = Q,/0.50
Q,= 0.195 cfs at Elevation of peak WQ„
Q = 0.390 cfs Sufficient Capacity Provided
Stormwater Volume Control
See HydroCAD Report for peak volume control stage-storge information
Freeboard Requirement
Embankment Height= 8.5 ft
Top of Berm Elevation = 674.50
50-yr Storage Elevation = 673.19
Freeboard = 15.7 in Sufficient Freeboard Provided
Cottages West
2316 Waxhaw Indrian Trail Rd
Indian Trail, NC
Completed By: NTV
Reviewed By: DSK
Original Date: 04.13.22
Revised Date: 01.11.24
Bloc Design Project Number: 00915.00
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED bloc
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

SCM Sizing Data - SCM #2
Pre-Development Drainage Basin Post-Development Drainage Basin
Drainage Area (Ad) 3.81 ac Drainage Area (Ad) 8.27 ac
Impervious Area (A) 0.00 ac Impervious Area (A) 5.44 ac
Impervious% (I) 0.0 % Impervious% (I) 65.8 %
Curve Number (CN) 59 Curve Number (CN) 85
Time of Concentration (Td 10.6 min Time of Concentration (Td 5.0 min
Watershed Requirements
Regulatory Jurisdiction: MS4 Phase II *Storm water regulations per local authority
Density (High/Low): HIGH storm water program
Water Quality Volume Calculations
Volumetric Runoff Coefficient (R„) Water Quality Volume (WQ„)
Rv= 0.05 +0.009 (I) WQ„= 1.0 Rv Ad
Rv= 0.64 in/in 12
1 inch/24 hour water quality control
WQ„= 0.44 ac. ft. R„(I)
19,279 cf WQ„= 0.64 inches of runoff
Dam Safety Evaluation
Spillway Elevation = 664.00
Lowest Elevation at Toe of Slope = 659.50 Submittal to Dam
Embankment Height= 4.5 Safety NOT required
*Project calculations derived from the NCDEQ Stormwater Design Manual, Minimum Design Criteria (MDC) -
Effective:January 1, 2017
Cottages West
2316 Waxhaw Indrian Trail Rd
Indian Trail, NC
Completed By: NTV
Reviewed By: DSK
Original Date: 04.13.22
Revised Date: 01.11.24
Bloc Design Project Number: 00915.00
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED [-Mb
I O C
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #2
From SCM Sizing Data Sheet
Drainage Area (Ad) 8.27 ac Water Quality Volume (WQv)
Impervious Area (Al) 5.44 ac WQv= 0.44 ac. ft.
Impervious% (I) 65.8 % WQv= 19,279 ft3
Water Quality Release Rate
Regulatory Program: MS4 Phase II
Location: Non-Coastal
Design volume shall be held for minimum of 2 days
Sand Filter designed to treat 75%of the WQv WQv,red= 14,459 ft3
Sand filter ponding depth is limited to 6 ft
Initial assumption of sand filter ponding depth for WQv = 3.0 ft
Initial estimate of pond area = 4,820 sf
Sediment Chamber Sizing
Sediment chamber must hold 20%of the WQv
Sediment Chamber Volume (Vpre)
FVrequired = (0•20)WQv
FVrequired = 3,856 cf
Top of Sand Elevation = 657.00
Forebay Calculator
Elevation Area Incremental Accumulated Forebay
[ft] [ft2] Volume Volume Percentage
[ft3] [ft3] [%]
658.00 4,475
659.00 5,261 4868 4868 126
660.00 5,911 5586 10454 271
FVprovided = 10,454 cf Excessive Volume Provided
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THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED blOC
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #2
Filtration Bed Sizing
SCM Storage Volume
Storage Storage Storage Storage Height Inc. Acc. Acc.
Elevation Elevation Areaavg Volume Volume Volume
[ft.] Area [sf] Area [ac.] [ac.] [ft.] [ac.-ft.] [ft.3] [ac.-ft.]
657.00 7,643 0.175 F
658.00 8,472 0.194 0.185 1.00 0.185 8,058 0.185
659.00 9,330 0.214 0.204 1.00 0.204 16,959 0.389
660.00 10,215 0.235 0.224 1.00 0.224 26,731 0.614
661.00 11,129 0.255 0.245 1.00 0.245 37,403 0.859
662.00 12,072 0.277 0.266 1.00 0.266 49,004 1.125
663.00 13,042 0.299 0.288 1.00 0.288 61,561 1.413
664.00 14,041 0.322 0.311 1.00 0.311 75,102 1.724
Water Quality Volume (WQv) = 14,459 ft3
Elevation of peak WQv= 658.72 'ft Sufficient Volume Provided
Filter Bed Depth (df) Coefficient of Permeability of Filter Media (k)
df= 1.0 ft k= 4.0 ft/day
Average Height of Water Above Filter Bed (hf)
hf= 0.86 ft tf= 36 hours
Surface Area of Sand Filter Media (Af)
Af= (WQv)(df) / [(k)(hf+df)(ff)]
Af= 1,728 ft2
Af(provided) = 1,950 ft2 Sufficient Surface Area Provided
Stage-Storage and Stage-Discharge Relationship for Sand Filter
Sand Media Discharge (Qs)
Qs- WQv/tf-Af(provided) (k)(hf+df)/(df)
Sand Media Discharge Calculator
Depth Above Sand Sand Media
Elevation [ft] Media (hf) Discharge (Qs)
[ft] [cfs]
657.00
658.00 1.00 0.181
659.00 2.00 0.271
660.00 3.00 0.361
661.00 4.00 0.451
662.00 5.00 0.542
663.00 6.00 0.632
664.00 7.00 0.722
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED bloc
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

Sand Filter Calculations - SCM #2
Underdrain System Sizing
Number of 6" Underdrain Pipes (N) = 3
Pipe Material = PVC
Pipe Slope (S) = 0.005 ft/ft
Flow Capacity with Provided Pipes (QU
Qc = (((D/16)8i3 x S1/2 ) / n)*N
Qc = 1.410 cfs
Designed Flow Through Underdrain Pipes with 50%Capacity Lost
Q = Q,/0.50
Q,= 0.245 cfs at Elevation of peak WQ„
Q = 0.491 cfs Sufficient Capacity Provided
Stormwater Volume Control
See HydroCAD Report for peak volume control stage-storge information
Freeboard Requirement
Embankment Height= 4.5 ft
Top of Berm Elevation = 664.00
50-yr Storage Elevation = 662.91
Freeboard = 13.1 in Sufficient Freeboard Provided
Cottages West
2316 Waxhaw Indrian Trail Rd
Indian Trail, NC
Completed By: NTV
Reviewed By: DSK
Original Date: 04.13.22
Revised Date: 01.11.24
Bloc Design Project Number: 00915.00
THE INFORMATION CONTAINED HEREIN IS THE PROPERTY OF V3 SOUTHEAST.REPRODUCTION OR USE IS PROHIBITED bloc
WITHOUT THE WRITTEN CONSENT OF V3 SOUTHEAST.COPYRIGHT,V3 SOUTHEAST 2022.

HydroCAD
Peak Volume
■
bloc

<12S>
3S
POST-1 (1 0% Offsite BYP SS-1
B A)
U U
1S 2S 4P -- 5L
PRE-1 POST-1 SCM #1 AP-1
<8S>
BYP/iSS-2
6S 7S 9P D 10L
PRE-2 POST-2 S #2 AP-2
(13s>
POST-2 (100% Offsite
BUA)
---N___
Subcat Reach on. Link Routing Diagram for 00915_SCM
�____ Prepared by HP Inc., Printed 1/11/2024
HydroCAD®10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 2
Time span=0.00-120.00 hrs, dt=0.01 hrs, 12001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: PRE-1 Runoff Area=14.080 ac 8.86% Impervious Runoff Depth=3.36"
Flow Length=738' Tc=22.1 min CN=62 Runoff=49.03 cfs 3.938 af
Subcatchment2S: POST-1 Runoff Area=8.100 ac 26.79% Impervious Runoff Depth=4.35"
Tc=5.0 min CN=71 Runoff=64.76 cfs 2.939 af
Subcatchment3S: BYPASS-1 Runoff Area=0.950 ac 0.00% Impervious Runoff Depth=3.25"
Tc=5.0 min CN=61 Runoff=5.75 cfs 0.257 af
Su bcatchment 6S: PRE-2 Runoff Area=3.810 ac 0.00% Impervious Runoff Depth=3.03"
Flow Length=561' Tc=10.6 min CN=59 Runoff=17.32 cfs 0.963 af
Subcatchment7S: POST-2 Runoff Area=8.270 ac 47.94% Impervious Runoff Depth=5.27"
Tc=5.0 min CN=79 Runoff=77.66 cfs 3.629 af
Subcatchment8S: BYPASS-2 Runoff Area=0.580 ac 0.00% Impervious Runoff Depth=3.25"
Tc=5.0 min CN=61 Runoff=3.51 cfs 0.157 af
Su bcatchment 12S: POST-1 (100%Offsite Runoff Area=6.690 ac 67.49% Impervious Runoff Depth=6.08"
Tc=5.0 min CN=86 Runoff=69.66 cfs 3.389 af
Subcatchment 13S: POST-2(100%Offsite Runoff Area=8.269 ac 65.85% Impervious Runoff Depth=5.96"
Tc=5.0 min CN=85 Runoff=85.02 cfs 4.109 af
Pond 4P: SCM#1 Peak Elev=673.64' Storage=34,700 cf Inflow=69.66 cfs 3.389 af
Outflow=65.19 cfs 3.389 af
Pond 9P: SCM#2 Peak Elev=663.44' Storage=67,395 cf Inflow=85.02 cfs 4.109 af
Outflow=69.33 cfs 4.109 af
Link 5L: AP-1 Inflow=70.75 cfs 3.646 af
Primary=70.75 cfs 3.646 af
Link 10L: AP-2 Inflow=72.35 cfs 4.266 af
Primary=72.35 cfs 4.266 af
Total Runoff Area = 50.749 ac Runoff Volume = 19.381 af Average Runoff Depth = 4.58"
65.83% Pervious = 33.406 ac 34.17% Impervious = 17.343 ac

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 1S: PRE-1
Runoff = 49.03 cfs @ 12.16 hrs, Volume= 3.938 af, Depth= 3.36"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
* 4.990 70 Offsite R-20, 25% imp, HSG
5.610 55 Woods, Good, HSG B
3.480 61 Pasture/grassland/range, Good, HSG B
14.080 62 Weighted Average
12.832 91.14% Pervious Area
1.247 8.86% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 100 0.0433 0.11 Sheet Flow, Sheet
Woods: Light underbrush n= 0.400 P2= 3.53"
7.1 638 0.0893 1.49 Shallow Concentrated Flow, Sc
Woodland Kv= 5.0 fps
22.1 738 Total
Subcatchment 1 S: PRE-1
Hydrograph
1 ■Runoff
501/ 49.03 cfs
45� Typ I I� 11r -
- I 1 1 1 1 iob-r _
40 ✓ 1 1 1 I 24-hi RaifffIl:7.747
35_in —[ L Fpumoff Area-14.080 ap -
30� R n ff V I me3. f
0 25� j � � I � � Runoff� �p h � ,
ii / ep -3 36
20 . fila—w Lntli3 '
151/ / 1 r —r 1— —I -r 1 T{i 1 2.' i'i i l l l
10a/ , 1 1 1 1 1 1 1 1 1 4`N -612
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 2S: POST-1
Runoff = 64.76 cfs @ 11.96 hrs, Volume= 2.939 af, Depth= 4.35"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
* 3.120 70 Offsite R-20 Zoning, 25% imp, HSG B
* 0.510 98 Public R/W Impervious
* 0.880 98 3,500 sf/Lot Impervious
3.590 61 >75% Grass cover, Good, HSG B
8.100 71 Weighted Average
5.930 73.21% Pervious Area
2.170 26.79% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 2S: POST-1
Hydrograph
1 ]— I —
70-" ■Runoff
64.76 cfs
657 T
sow / -
f - +Ob-r -
55
501/ / T F 24-ht-Rlaifhff1I#7.1741"
45 / 4 1yrico Ares . -I -
40 I nQ#1 V�Ii_nae-2.�39 f -
0 35_ / " - Runoff De .35" -
301
20 / IN�7h
15�
15
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 3S: BYPASS-1
Runoff = 5.75 cfs @ 11.96 hrs, Volume= 0.257 af, Depth= 3.25"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
0.950 61 >75% Grass cover, Good, HSG B
0.950 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 3S: BYPASS-1
Hydrograph
/ ❑Runoff
6Y 5.75 cfs 1 1
/
I T�pe� 1124-h r
5Y ' / H H .1-064r
I 244he RaiihfII#7.74"
4� I / 1 IRtincff Area=0.950 arc
R noff VoIume=0.257�af _
3LI - I / ± Runoff Depth=3.25 '
/ 1 c-5.0-mi-n -
2 / 1 I 1 ctN6h
�_ H H 1
I 1
I
0,�/ ,... . . . . // . . . // . //1����
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 6S: PRE-2
Runoff = 17.32 cfs @ 12.03 hrs, Volume= 0.963 af, Depth= 3.03"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
1.330 55 Woods, Good, HSG B
2.480 61 Pasture/grassland/range, Good, HSG B
3.810 59 Weighted Average
3.810 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.1 100 0.0440 0.27 Sheet Flow, Sheet
Range n= 0.130 P2= 3.53"
4.5 461 0.0592 1.70 Shallow Concentrated Flow, Sc
Short Grass Pasture Kv= 7.0 fps
10.6 561 Total
Subcatchment 6S: PRE-2
Hydrograph
—
19 H H — ■Runoff
18 17.32 cfs — ± 1 I H H I H H -
17 �T�p 112 �lr
16 — H- H fi H
15Oor
14 fi H H- hit`Rlatffd1I7.174"
13
12 j7 H -H H- - tRY 1-A - #
-
Ty
10 ffVImew. f
LL Rlanaff Be =3.0
H H H H H 4Iakw ILe�n ti 6i' -
56
I H H- H H 1— H H fib=�0 inin
3
2
% - 1— H H -
0 , ����IO�i�i�
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 7S: POST-2
Runoff = 77.66 cfs @ 11.96 hrs, Volume= 3.629 af, Depth= 5.27"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
* 1.860 70 Offsite R-20 Zoning, 25% imp, HSG B
* 0.850 98 Public R/W Impervious
* 2.650 98 3,500 sf/Lot Impervious
2.910 61 >75% Grass cover, Good, HSG B
8.270 79 Weighted Average
4.305 52.06% Pervious Area
3.965 47.94% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 7S: POST-2
Hydrograph
85�� H H •Runoff
80/ 77.66 cfs
� 14 I— —I 11�2 -lir
75
70 1 L I L L L 14-0b- r -
65:1
60/ / T 11 1 a 24.ht-RIaiflfdlI#7.1741"
3 45/ + H I nQ� I�me-3. 29 f
,g 40/ Rnaff De =a.2-7' -
35/30 j I4 � � � I c5 �ni�
254 / L I L LILL L I L (asJ 6t9
207
15
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 8S: BYPASS-2
Runoff = 3.51 cfs @ 11.96 hrs, Volume= 0.157 af, Depth= 3.25"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
0.580 61 >75% Grass cover, Good, HSG B
0.580 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 8S: BYPASS-2
Hydrograph
D Runoff
3.51 cfs
T1;p 11124-h r
+061
244he Rainfall=7.74"
IRuincff Area=0. 89 ap
2-/ / R1 n ff-Vh.f ne=0.r5T 1 f
Runoff Depth=3.25"
Tc=5.10
1 saN=
/ I I
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 12S: POST-1 (100% Offsite BUA)
Runoff = 69.66 cfs @ 11.96 hrs, Volume= 3.389 af, Depth= 6.08"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
* 3.120 98 (100% BUA) Paved roads w/curbs & sewers, HSG B
* 0.512 98 Public R/W Impervious
* 0.883 98 3,494.7 sf/Lot Impervious
2.175 61 >75% Grass cover, Good, HSG B
6.690 86 Weighted Average
2.175 32.51% Pervious Area
4.515 67.49% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 12S: POST-1 (100% Offsite BUA)
Hydrograph
75� 69.66 cfs ■Runoff
707 66 I I T I i I '
65/ 1 4 1— H 1 4 fOb r
60= /
55- I / L I t I J L ht_R1aifhfEII#1.174" -
50
_45
/ � n # V-Imes. f
u. u o ep -6 08
30/ / T 1 T T 1 T T T T I +c5
25 -/ - 1 4 H 4 d ik3-6
20/
15/ L I _ T - L I -
10
5/
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 13S: POST-2 (100% Offsite BUA)
Runoff = 85.02 cfs @ 11.96 hrs, Volume= 4.109 af, Depth= 5.96"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Area (ac) CN Description
* 1.860 98 (100% BUA) Paved roads w/curbs & sewers, HSG B
* 0.857 98 Public R/W Impervious
* 2.728 98 3,494.7 sf/Lot Impervious
2.824 61 >75% Grass cover, Good, HSG B
8.269 85 Weighted Average
2.824 34.15% Pervious Area
5.445 65.85% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, User
Subcatchment 13S: POST-2 (100% Offsite BUA)
Hydrograph
95_/ 17 T , I , J ■Runoff
90 85.02 cfs —�
85 /_ p 11-2 hr
80
75_� 'thor -
70
65/_ / t T 1- hTRlaifhfa1I#7.1741"
60
55j/
▪ 50 // - H t — Q1"19[Me 'l_0f PI
o 45 Runoff Be =5.96'
40 �
35�_ / — fi fi5�0
25= _
20
10 I J
5
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 11
Summary for Pond 4P: SCM #1
Inflow Area = 6.690 ac, 67.49% Impervious, Inflow Depth = 6.08" for 100-yr, 24-hr event
Inflow = 69.66 cfs @ 11.96 hrs, Volume= 3.389 af
Outflow = 65.19 cfs @ 11.98 hrs, Volume= 3.389 af, Atten= 6%, Lag= 1.5 min
Primary = 65.19 cfs @ 11.98 hrs, Volume= 3.389 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Peak Elev= 673.64' @ 11.98 hrs Surf.Area= 8,880 sf Storage= 34,700 cf
Plug-Flow detention time= 185.9 min calculated for 3.389 af(100°/0 of inflow)
Center-of-Mass det. time= 185.9 min ( 970.6 - 784.7 )
Volume Invert Avail.Storage Storage Description
#1 668.00' 42,731 cf Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
668.00 3,720 0 0
669.00 4,503 4,112 4,112
670.00 5,342 4,923 9,034
671.00 6,237 5,790 14,824
672.00 7,189 6,713 21,537
673.00 8,198 7,694 29,230
674.00 9,263 8,731 37,961
674.50 9,817 4,770 42,731
Device Routing Invert Outlet Devices
#1 Primary 665.50' 30.0" Round Culvert
L= 50.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/Outlet Invert= 665.50' / 665.00' S= 0.0100 '/' Cc= 0.900
n= 0.012, Flow Area= 4.91 sf
#2 Device 1 668.00' Sand Media
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.111 0.167 0.222 0.278 0.333 0.389 0.444
#3 Device 1 671.00' 3.00' long x 2.00' rise Peak Control Weir 2 End Contraction(s)
#4 Device 1 673.00' 5.00' long x 1.50' rise Top of OCS X 4.00 2 End Contraction(s)
Primary OutFlow Max=65.04 cfs @ 11.98 hrs HW=673.64' (Free Discharge)
4-1=Culvert (Passes 65.04 cfs of 77.30 cfs potential flow)
2=Sand Media (Custom Controls 0.37 cfs)
3=Peak Control Weir (Orifice Controls 32.11 cfs @ 6.17 fps)
4=Top of OCS (Weir Controls 32.56 cfs @ 2.61 fps)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 12
Pond 4P: SCM #1
Hydrograph
t I Io
75_ 69.66 cfs — El Inflowmary
70 , 65.19 cfs Irrile -Ai-�a�'6�0-a
65/ / r —I t —I - — 1 Ptak ale 6j13 4'
60/ , I I I _
55� O - 4�76 OC
50� I0
745 /
340- I
u_ 30� 1
25/ I
20/ %
i
15 -/
10 /
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 13
Summary for Pond 9P: SCM #2
Inflow Area = 8.269 ac, 65.85% Impervious, Inflow Depth = 5.96" for 100-yr, 24-hr event
Inflow = 85.02 cfs @ 11.96 hrs, Volume= 4.109 af
Outflow = 69.33 cfs © 12.00 hrs, Volume= 4.109 af, Atten= 18%, Lag= 2.7 min
Primary = 69.33 cfs @ 12.00 hrs, Volume= 4.109 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Peak Elev= 663.44' @ 12.00 hrs Surf.Area= 13,482 sf Storage= 67,395 cf
Plug-Flow detention time= 249.2 min calculated for 4.108 af(100% of inflow)
Center-of-Mass det. time= 249.6 min ( 1,037.0 - 787.5 )
Volume Invert Avail.Storage Storage Description
#1 657.00' 75,101 cf Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
657.00 7,643 0 0
658.00 8,472 8,058 8,058
659.00 9,330 8,901 16,959
660.00 10,215 9,773 26,731
661.00 11,129 10,672 37,403
662.00 12,071 11,600 49,003
663.00 13,042 12,557 61,560
664.00 14,041 13,542 75,101
Device Routing Invert Outlet Devices
#1 Primary 653.50' 30.0" Round Culvert
L= 65.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/Outlet Invert= 653.50' / 653.00' S= 0.0077 '/' Cc= 0.900
n= 0.012, Flow Area= 4.91 sf
#2 Device 1 657.00' Sand Media
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.181 0.271 0.631 0.451 0.542 0.632 0.722
#3 Device 1 659.50' 1.00' long x 3.00' rise Peak Control Weir 2 End Contraction(s)
#4 Device 1 662.50' 5.00' long x 1.50' rise Top of OCS X 4.00 2 End Contraction(s)
Primary OutFlow Max=69.17 cfs @ 12.00 hrs HW=663.44' (Free Discharge)
4-1=Culvert (Passes 69.17 cfs of 84.81 cfs potential flow)
2=Sand Media (Custom Controls 0.67 cfs)
3=Peak Control Weir (Orifice Controls 11.29 cfs @ 7.53 fps)
4=Top of OCS (Weir Controls 57.20 cfs @ 3.17 fps)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 14
Pond 9P: SCM #2
Hydrograph
_ ❑ Inflow
95'zz
85.02 cfs — ❑Primary l
85� T L II p'1� = . Ci
80- L t — 1 — 1 P-�a 3.441�
75Y 69.33 cfs
70
65h // SiC =V713§
60_ ,_ 1 — 1 -1 —H 1
w 554/
50-�" i
' —1 T 1
c 45
u_ 40V — 1
35=
30V 1 1 1 1 1 1 - — 1
25V Al-
20 / A
]— —1 —1 1 1 -1 1
154/
10V A
5=
0-
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 15
Summary for Link 5L: AP-1
Inflow Area = 7.640 ac, 59.10% Impervious, Inflow Depth = 5.73" for 100-yr, 24-hr event
Inflow = 70.75 cfs @ 11.98 hrs, Volume= 3.646 of
Primary = 70.75 cfs @ 11.98 hrs, Volume= 3.646 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Link 5L: AP-1
Hydrograph
L I I I A I A I I ❑ Inflow
7(1 r•f 0 Primary
75 70.75 cfs �r-
704
65:
HI +
60V /
554/ ' /
504 / /
a 45V / /
'U' /
40�
Li
30V /r-
254/
20V
154/
104
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

00915_SCM Type II 24-hr 100-yr, 24-hr Rainfall=7.74"
Prepared by HP Inc. Printed 1/11/2024
HydroCAD® 10.00-26 s/n 07600 ©2020 HydroCAD Software Solutions LLC Page 16
Summary for Link 10L: AP-2
Inflow Area = 8.849 ac, 61.53% Impervious, Inflow Depth = 5.78" for 100-yr, 24-hr event
Inflow = 72.35 cfs @ 12.00 hrs, Volume= 4.266 af
Primary = 72.35 cfs @ 12.00 hrs, Volume= 4.266 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.01 hrs
Link 10L: AP-2
Hydrograph
T 1 rt 1 1 i- 11 fi I T ❑ Inflow
80 f + — 0 Primary
75./ 72.35 cfs - — I—licT -ea=88 9 a�
70 -/ 7 1 L IT IT IJ 1 _L 1 1I
65/
60/ T T T T T I 7 IT 1 1 1
554/50V / I I t
+ 1
o 45/ T I
40
LL35_i/ I I I
30/ /
2/ F T T T 1 T IT TIT 71 T
0:/ / � ZZ Z
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)