2024.04.03-Sennebogen Expansion SWM Report-Signed

Stormwater Management Report

For

Sennebogen Expansion
1957 Sennebogen Trail, Stanley, NC
Property ID: 3691941330/54664

Date: April 4, 2024
CES Project #8189

Prepared By: CES Group Engineers, LLP
3525 Whitehall Park Drive, Suite 150
Charlotte, NC 28273
704.489.1500
List of Exhibits:
· Exhibit 1: Drawing Number C1.1 - Pre-development Drainage Area Map
· Exhibit 2: Drawing Number C1.2 - Post-development Drainage Area Map
· Exhibit 3: Sediment Basin Calculations
· Exhibit 4: Stormwater Conveyance Calculations
· Exhibit 5: Stormwater Drainage calculations (Hydro CAD, 2, 10, 25, 50 and 100
Yr storm)
· Exhibit 6: Soil Maps

Project Description

The proposed project includes the construction of a detached commercial building addition to the two
existing buildings totaling 48,000 sf with the associated parking lot, drives, proposed gravel demonstration
pad, and sand filter. The proposed use of the building will be vehicle services. There is one existing
connection to Sennebogen Trail. There is an existing intermittent stream onsite as determined in the field
by Atlas Environmental Inc. on September 29, 2023 that will be partially impacted by the proposed work.

Pre-Development Conditions

The pre-development site is divided into two drainage areas, DA-1 and DA-2. The DA-1 is 7.60 acres and
has HSG B & D soils, resulting in a CN value 71. DA-1 includes the existing original building truck docks and
a portion of Sennebogen Trail as well as several acres of undeveloped area west of Sennebogen Trail. DA-
1 includes the upstream extents of the existing intermittent stream. The pre-development time of
concentration for DA-1 was calculated to be 19.4 minutes. DA-2 is 1.34 acres and has HSG B soils which
results in a CN value of 72. DA-2 consists of the northernmost portion of the truck drive in bays,
Sennebogen trail, concrete pad and wooded area. The pre-development time of concentration for DA-2
was calculated to be 7.3 minutes (see attached Tc calculations in HydroCAD report).

Pre-development drainage areas summary:

Area Name Total Drainage
Area (Sf)
Total Drainage
Area (Ac)
Total
Impervious
Area (Sf)
Total
Impervious
Area (Ac)
Tc (Min)
DA-1 330,991 7.60 77,146 1.77 19.4
DA-2 58,307 1.34 23,324 0.54 7.3

Post-Development Conditions

The post-development site is divided into three drainage areas, DA-1A, DA-1B and DA-2.

The proposed contributing drainage area to the proposed sand filter consists of grass, open space,
proposed buildings, sidewalks, parking lots, drives, and a gravel demonstration pad. For purposes of this
analysis, the drainage area was divided into impervious and open space areas. The post-development
drainage area DA-1 is 9.27 acres. The drainage area has HSG B & D soils which results in a weighted CN
value of 84. The post-development time of concentration was calculated to be 6.6 minutes.

The proposed sand filter was modeled in HydroCAD. The sand filter will be an above ground facility to
provide water quality treatment of the first 1.0” of rainfall over the entire contributing drainage area
based on the maximum buildout of the site. The sand filter will also control the peak flows from the 1-yr,
2-yr, and 10-yr, 24-hour storm events. The control structure will be a concrete riser with 4’x4’ inside
dimensions. The water quality design volume will completely drain through the sand filter. The 1-yr, 2-yr
and 10-yr storms will be controlled with a series or orifices/weirs in the primary riser structure. A 24”W x
8”H rectangular weir will be set at elevation 739.50. A 24”W x 6”H rectangular weir will be set at elevation
740.75. The top of the riser will be set at 741.25 with a top trash rack extending above this elevation.
There will also be a 20’ wide emergency spillway on the west side of the embankment which will be lined
with class B riprap with spillway elevation of 741.50. The top of the embankment will be set at 743.00.

The second post-development drainage area that discharges offsite, DA-1B is 0.27 acres and has HSG D
soils which results in a weighted CN value of 80. The post-development time of concentration was
assumed to be 5 minutes. This area includes the pervious areas downstream of the sand filter and
stormwater conveyance system, primarily consisting of the slope down to the outfall.

The third post-development drainage area that discharges offsite, DA-2 is 0.44 acres and has HSG B soils
which results in a weighted CN value of 84. The post-development time of concentration was assumed to
be 5 minutes. This area includes areas of existing parking lot and sidewalks as well as some open space
areas towards the north end of the existing/proposed development.

Post-development drainage areas summary:

Area Name Total Drainage
Area (Sf)
Total Drainage
Area (Ac)
Total
Impervious
Area (Sf)
Total
Impervious
Area (Ac)
Tc (Min)
DA-1A 403,915 9.27 230,292 5.29 6.6
DA-1B 11,678 0.27 0 0 5
DA-2 19,316 0.44 11,932 0.27 5

STORMWATER MANAGEMENT ANALYSIS-PRE AND POST ANALYSIS

A summary of the pre and post-developed flows for the 2-yr, 10-yr, and 25-yr storm events is included
below. We are able to provide pre-vs post flow reduction for the 2-yr and 10-yr storm events. We've tried
to route as much of the proposed impervious area and overall area through the sand filter as possible.

Summary of pre and post-discharges for DA-1 (DA-1A + DA-1B):

2-yr (cfs) 10-yr (cfs) 25-yr (cfs)
PRE 7.80 17.38 23.67
POST 5.20 14.81 30.28

Summary of pre and post-discharges for DA-2:

2-yr (cfs) 10-yr (cfs) 25-yr (cfs)
PRE 2.31 4.87 6.52
POST 1.47 2.52 3.16

Analysis Methodology & Design Parameters

The existing and proposed drainage areas have been analyzed utilizing a modified version of the NRCS
SCS TR-20 method. The analysis program “HydroCAD” Version 10.20 by HydroCAD Software Solutions
LLC was used to calculate and plot the runoff hydrographs. The program incorporates the time of
concentration, CN values, 24-hour rainfall events, and project drainage areas to calculate the runoff
characteristics. IDF information from NOAA has been utilized for storm events.

Additional information used in the analysis includes the SCS Unit Hydrograph, a minimum time of
concentration of 5 minutes, separate runoff calculations for impervious and pervious areas, and dynamic
storage and conveyance routing to account for any variable tailwater conditions.

Water Quality Measures

Per the NCDEQ Stormwater Standards, water quality for a high density development is to provide
treatment volume for the 1" storm event. The development proposes one (1) water quality measure to
capture and treat a large portion of the site. The forebay is designed for 85% minimum TSS removal and
is anticipated to treat greater than the 1" storm event for the site. The proposed sand filter system shall
be designed to clean all water entering the system to the satisfaction of NCDEQ. Refer to Exhibit 5 for 1"
stormwater calculations.

Stormwater Conveyance

The proposed stormwater conveyance system consists of both swales and a closed pipe system. The
proposed pipe materials include Type S HDPE, Class III RCP and Class IV RCP. The pipe system was sized
utilizing Hydraflow Storm Sewers for the 10-yr storm event. Refer to Exhibit 4 for the stormwater
conveyance calculations.

Soil Erosion Control

The proposed project includes three soil erosion control phases. Phase 1 is to install two rock dams in the
existing stream area and a bypass drainage pipe system to convey the offsite runoff around the majority
of the proposed construction area. Also included are silt fence, silt fence outlets and a riprap apron.

Phase 2 is to add a construction entrance, concrete washout, silt fence, silt fence outlets, temporary
diversion ditches, slope drains and sediment basin. The sediment basin is sized to handle the 10-yr runoff
from approximately 7.50 acres of contributing drainage area.

Phase 3 is to install a second sediment basin in the location of the permanent sand filter. This will allow
the remaining portion of the demonstration pad to be filled and raised to final grade. The upstream
drainage area must be completely stabilized before installing the sand filter system, gravel, and sand to
prevent clogging the system. Riprap aprons at outfalls were sized utilizing the NCDEQ Erosion Control
Design Manual section 6.41 on Outfall Stabilization Structures. The sediment basin is sized to handle the
10-yr runoff from approximately 9.33 acres of contributing drainage area.

Refer to Exhibit 3 for the Sediment Basin calculations.

Exhibit 1
Drawing Number C1.1: Pre-development Drainage Area Map

SLT Enterprises, LLC
SLT Enterprises, LLC
Curtis Phillips
Pamela W. Phillips
Mishelle S. Dean
Catherleen H. Sherrill
SE
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Old
HEAVY DUTY PAVEMENT OVERLAY
HEAVY DUTY PAVEMENT OVERLAY
ADDITION
45,840-sf
WAREHOUSE
8''F
SS
SS
SS
2''W
PRE-DEVELOPMENT
DRAINAGE AREA 1
DA-1
7.60 AC
CN=71
TC=19.4 MIN
PRE-DEVELOPMENT
DRAINAGE AREA 2
PRE DA-2
1.34 AC
CN=72
TC=7.3 MIN
TC
PATH
(TYP)
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C1.1
PRE-DEV
DRAINAGE AREA
MAP
JM
MK -
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R
Know what's below.
Call before you dig.
NORTH CAROLINA
ONE-CALL CENTER INC.
DIAL 811 or 1-800-632-4949
2 BUSINESS DAYS BEFORE DIGGING
www.ncocc.org
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DRAWN BY:
CHECKED BY:
PROJECT NO:
DRAWING TITLE:
DRAWING NUMBER:
SEAL:
DATE:NO:REVISION DESC.
DRAWING REVISIONS
Copyright 2024 CES Group Engineers, LLP
PR
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REVISED BY:
ISSUED BY:
CES Group Engineers, LLP
3525 Whitehall Park Drive, Suite 150
Charlotte, NC 28273
PH: 704.489.1500
www.ces-group.net
ENGINEERS
PLANNERS
SURVEYORS
SCIENTISTS
CO. SEAL:
ISSUE DATE:
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02/22/2024
8189.0823
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LEGEND
DRAINAGE AREA

Exhibit 2
Drawing Number C1.2: Post-development Drainage Area Map

1111
11
1111
SLT Enterprises, LLC
SLT Enterprises, LLC
Curtis Phillips
Pamela W. Phillips
Mishelle S. Dean
Catherleen H. Sherrill
SE
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HEAVY DUTY PAVEMENT OVERLAY
HEAVY DUTY PAVEMENT OVERLAY
ADDITION
45,840-sf
WAREHOUSE
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
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PROPOSED POST
CONSTRUCTION BMP
MH-508
DI-400
DI-112
DI-111
DI-106
DI-105
DI-401
MH-506
CB-103
MH-102MH-504
FES-500
DI-402
DI-113
DI-107
CB-300
CB-301
76
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6
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7
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770775
8''F
SS
SS
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2''W
DI-403
POST-DEVELOPMENT
DRAINAGE AREA 1A
9.27 AC
CN=84
TC=6.6 MIN
POST-DEVELOPMENT
DRAINAGE AREA 2
0.44 AC
CN=84
TC=5 MIN
POST-DEVELOPMENT
DRAINAGE AREA 1B
0.27 AC
CN=80
TC=5 MIN
MH-104
YI-101
MH-505
FES-100
YI-200
OS-600
YI-201
MH-503
MH-502
MH-501
YI-202
YI-203
MH-507
DI-108
DI-109
DI-110
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POST-DEV
DRAINAGE AREA
MAP
JM
MK -
SC
R
Know what's below.
Call before you dig.
NORTH CAROLINA
ONE-CALL CENTER INC.
DIAL 811 or 1-800-632-4949
2 BUSINESS DAYS BEFORE DIGGING
www.ncocc.org
LEGEND
DRAINAGE AREA
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DRAWN BY:
CHECKED BY:
PROJECT NO:
DRAWING TITLE:
DRAWING NUMBER:
SEAL:
DATE:NO:REVISION DESC.
DRAWING REVISIONS
Copyright 2024 CES Group Engineers, LLP
PR
O
J
E
C
T

D
E
S
C
R
I
P
T
I
O
N
:
REVISED BY:
ISSUED BY:
CES Group Engineers, LLP
3525 Whitehall Park Drive, Suite 150
Charlotte, NC 28273
PH: 704.489.1500
www.ces-group.net
ENGINEERS
PLANNERS
SURVEYORS
SCIENTISTS
CO. SEAL:
ISSUE DATE:
-
-
-
-
-
-
-
--
-
-
-
-
-
-
-
-
-
-
-
-
02/22/2024
8189.0823
SE
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Exhibit 3
Sediment Basin Calculations

Areas (sf) 10-yr 5 min
7.84 Total Drainage Area (Acres)341682 C I (in/hr)
41.95 Peak Flow from 10-year Storm (cfs) Q is calculated based on Drainage Area 0.75 7.13
Do Not Use Temporary Sediment Trap
Okay Skimmer Sediment Basin User entry
Okay Temporary Sediment Basin
Calculated Value
4.90 Disturbed Area (Acres)213238
Updated to comply with NPDES Permit Conditions
TGH and BRB 07/03/2012
Updated to provide instructions and additional checks
JEC 07/17/2023
Phase 2
Simplified design
Okay
4.90 Disturbed Area (Acres)
Imported from the "Measure Selection" tab.
41.9 Peak Flow from 10-year Storm (cfs)
8811.488 Required Volume ft3 Minimum sediment storage volume. Based upon the disturbed area.
18271 Required Surface Area ft 2 Required surface area of basin. Based upon peak flow for the entire drainage area.
95.6 Suggested Width ft
191.2 Suggested Length ft
100 Trial Top Width at Emergency Spillway Invert ft
200 Trial Top Length at Emergency Spillway Invert ft
2 Trial Side Slope Ratio Z:1 (2.5:1 or flatter)
3 Trial Depth ft (2 to 13.5 feet above grade)
Depth as measured from bottom of basin to crest of emergency spillway.
88 Bottom Width ft
188 Bottom Length ft
16544 Bottom Area ft2
54744 Actual Volume ft 3 Okay
20000 Actual Surface Area ft 2 Okay
Use Spillway Capacity Sheet to Size Primary and Emergency Spillways
2 Skimmer Size (inches) Skimmer Size Formula based on the use of a Faircloth skimmer type
0.167 Head on Skimmer (feet) (Inches)
1.75 Orifice Size (1/4 inch increments) 1.5
3.05 Dewatering Time (days)2 Dewatering time is computed for the REQUIRED volume and takes into consideration the head on skimmer and orifice size.
Suggest about 3 days 2.5 The skimmer must take at least 2 days and no more than 5 days to dewater the REQUIRED volume.
3
4
5
6
8
Check L:W ratio Check dam height (max. 15 ft)
Okay 2:1 to 6:1 Okay Water surface for 10-year storm can be no greater than 13.5 feet in depth (13 ft + 0.5 ft of head on spillway assumed).
Cleanout elevation (ft)
739.00 Elevation of bottom of basin near riser structure
740.5 Depth at one-half of sediment storage volume. Elevation to be staked in the field.
ft3
Stage (ft) Area (ft2) Area (ac) Avg Area (ac) Increm. Cumulative
738 15,802 0.363 0.000 0.000 0.000 0
739 16,800 0.386 0.374 0.374 0.374 16,301
740 17,824 0.409 0.397 0.397 0.772 33,613
741 18,273 0.419 0.414 0.414 1.186 51,662
741.5 19,111 0.439 0.429 0.215 1.401 61,007
742 19,948 0.458 0.448 0.224 1.625 70,772
743 21,047 0.483 0.471 0.471 2.095 91,270
Temporary Sediment Basin
Volume (ac-ft)
Areas (sf) 10-yr 5 min
9.33 Total Drainage Area (Acres)406550 C I (in/hr)
49.91 Peak Flow from 10-year Storm (cfs) Q is calculated based on Drainage Area 0.75 7.13
Do Not Use Temporary Sediment Trap
Okay Skimmer Sediment Basin User entry
Okay Temporary Sediment Basin
Calculated Value
6.66 Disturbed Area (Acres)290000
Updated to comply with NPDES Permit Conditions
TGH and BRB 07/03/2012
Updated to provide instructions and additional checks
JEC 07/17/2023
Phase 3
Simplified design
Okay
6.66 Disturbed Area (Acres)
Imported from the "Measure Selection" tab.
49.9 Peak Flow from 10-year Storm (cfs)
11983.47 Required Volume ft3 Minimum sediment storage volume. Based upon the disturbed area.
21740 Required Surface Area ft 2 Required surface area of basin. Based upon peak flow for the entire drainage area.
104.3 Suggested Width ft
208.5 Suggested Length ft
105 Trial Top Width at Emergency Spillway Invert ft
210 Trial Top Length at Emergency Spillway Invert ft
2 Trial Side Slope Ratio Z:1 (2.5:1 or flatter)
5.5 Trial Depth ft (2 to 13.5 feet above grade)
Depth as measured from bottom of basin to crest of emergency spillway.
83 Bottom Width ft
188 Bottom Length ft
15604 Bottom Area ft2
103105 Actual Volume ft 3 Okay
22050 Actual Surface Area ft 2 Okay
Use Spillway Capacity Sheet to Size Primary and Emergency Spillways
2.5 Skimmer Size (inches) Skimmer Size Formula based on the use of a Faircloth skimmer type
0.208 Head on Skimmer (feet) (Inches)
1.75 Orifice Size (1/4 inch increments) 1.5
3.71 Dewatering Time (days)2 Dewatering time is computed for the REQUIRED volume and takes into consideration the head on skimmer and orifice size.
Suggest about 3 days 2.5 The skimmer must take at least 2 days and no more than 5 days to dewater the REQUIRED volume.
3
4
5
6
8
Check L:W ratio Check dam height (max. 15 ft)
Okay 2:1 to 6:1 Okay Water surface for 10-year storm can be no greater than 13.5 feet in depth (13 ft + 0.5 ft of head on spillway assumed).
Cleanout elevation (ft)
738.00 Elevation of bottom of basin near riser structure
740.8 Depth at one-half of sediment storage volume. Elevation to be staked in the field.
ft3
Stage (ft) Area (ft2) Area (ac) Avg Area (ac) Increm. Cumulative
739 18,028 0.414 0.000 0.000 0.000 0
740 19,595 0.450 0.432 0.432 0.432
741 21,218 0.487 0.487 0.487 0.919
741.5 22,052 0.506 0.497 0.248 1.167 50,847
742 22,899 0.526 0.526 0.263 1.430 62,297
743 24,636 0.566 0.546 0.546 1.976 86,064
Temporary Sediment Basin
Volume (ac-ft)

Exhibit 4
Stormwater Conveyance Calculations

d50 (ft) La (ft)
W1=Do + La
W1 (ft)
W2=3*Do W2
(ft)*T(ft)H=(2/3)*Do
H (ft)
FES-1 (EC Ph 2) 23.6 24 0.5 15 17.00 6.00 1.125 1.33
FES-100 38.0 30 0.5 17 19.50 7.50 1.125 1.67
FES-500 26.5 30 0.5 20 22.50 7.50 1.125 1.67
dmax=1.5*d50
*T=1.5*dmax (Min. *T=10") Apron Thickness = *T
Min. La=10 ft
H=Depth of apron
Rip-Rap Apron Summary Table
Outlet Discharge
(cfs)Do (in)
Minimum TW Condition
Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Return to Main Worksheet
FES-1 (EC Phase 2)
Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Return to Main Worksheet
FES-100
Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Return to Main Worksheet
FES-500

Exhibit 5
Stormwater Drainage calculations (Hydro CAD, 2, 10, 25, 50
and 100 Yr storm)

Sand Filter Design
DATE:4/3/2024
PROJECT:Sennebogen
PROJECT #:8189.0823CD
DESIGNER:SMC
Post Development DA 1A
1
Pre-Dev Post-Dev
330,991 403,915
7.60 9.27
77,146 230,292
1.77 5.29
5.83 3.99
23% 57% *measured from the midpoint of the design storm
2
0.56
0.435
0.56
18,955
14,216
6.00
havg (ft)3.00
2,369 75% WQv / hmax filter
3
Pre-Dev Post-Dev
330,991 403,915 Area HSG CN CN*Area
7.60 9.27 Impervious 1.77 B 98 173.56
71 84 Open Space 0.47 B 61 28.67
95 95 Woods 3.56 B 55 195.80
Woods 1.8 D 77 138.60
19.4 6.6 536.63 Sum
71 CN Weighted
Area HSG CN CN*Area
Impervious 5.29 B and D 98 518.10
Open Space 3.23 B 61 196.78
Open Space 0.76 D 80 60.80
775.68 Sum
84 CN Weighted
4
9.55 *From HydroCAD Node 7S (Post Dev (Modified CN))
5
Post-Dev
1.95
2.58
1.16
0.89
6
Drawdown Time (hr)
40
Post-Dev
0.132
RELEASE RATES
Water Quality
WQv Release (cfs)
WATER QUALITY PEAK FLOW
WQp (cfs)
Area (sf)
Area (ac)
CN
CNm (modified, P=1 in)
Travel Time Tt (min)
Post-Development
CPv (ac-ft)
Qd (in)
P (in, 1-yr, 24-hr))
S (in)
CHANNEL PROTECTION VOLUME
75% WQv (cf)
hmax filter(ft)
Min. Surface Area (ft)
HYDROLOGIC PARAMETERS
CURVE NUMBER CALCULATION
Pre-Development
% Impervious
WATER QUALITY CALCULATIONS
Runoff Coefficient, Rv
WQv (ac-ft)
WQv (in)
WQv (cf)
NCDEQ Stormwater Design Manual
Chapter 11 - Sand Filter (Rev September 20, 2009)
SITE DATA
Target Sand Filter Effectiveness
Area to Sand Filter (sf)
Impervious (ac)Removal Rate 85% TSS
Pervious (ac)
Area to Sand Filter (ac)Detention Time (days)*2
Impervious (sf)Media Depth 1.5 ft
=0.05 +0.009 ∗
=1.0 ∗ ∗
12
=
1000
[10 +5 +10 − 10
+1.25 . ]
=1000
−10
=2.58− 0.2

+0.8
! " =
(43,560 ∗ )
()* +,-+. /01 ∗3,600)
= ∗
12
Sand Filter Design
7
1253.2
1.5
3.5
1.000
1.667
1,462
2
54.1
27.0
8
Stage (ft)Area (ft2)Area (ac) Increm. Cumulative
739.00 18,028 0.4139 0.0000 0.0000
740.00 19,595 0.4498 0.4319 0.4319
741.00 21,218 0.4871 0.4685 0.9003
742.00 22,899 0.5257 0.5064 1.4067
743.00 24,636 0.5656 0.5456 1.9523
9
738
Stage Height
739.00 1
740.00 2
741.00 3
742.00 4
743.00 5
0.00 -738
0.00 -738
0.00 -738
10
Stage Storage (ac-ft)
738 #N/A
#N/A 0.3264
739 0.0000
11
14,216
0.132
5 0.005
44 6
3 0.196
4 1.571
4 0.40
3280 0.20
50%
1640
2
0.0052
8.5653
Storage Depth (ft)
Perforation Capacity (cfs)
Total Capacity (cfs)
Holes per Row Underdrain Capacity (cfs)
Number of perforations Unclogged Capacity (cfs)
*Needs to be greater than 1' depth
discharge and min. drawdown capacity
Percent clogged
Unclogged Perforations
Length of each pipe (ft)Underdrain Size (in)
Number of cleanouts per pipe Underdrain A (ft2)
Rows per foot Underdrain P (ft)
WQv (ft3)
Drawdown (cfs)
Compute Perforation Capacity Compute Underdrain Capacity
No. of pipes Underdrain Slope (ft/ft)
DRAWDOWN AND UNDERDRAIN DESIGN
Minimum Drawdown Discharge
WATER QUALITY ELEVATION
0.000
0.138
0.178
0.217
-29.084
WATER QUALITY AND CHANNEL PROTECTION ELEVATIONS (ESTIMATED)
0.4685
0.5064
STAGE-DISCHARGE
Top of Filter Media
Discharge (cfs)
0.5456
0.257
-29.084
-29.084
STAGE-STORAGE
Volume (ac-ft)
Avg Area (ac)
0.0000
0.4319
Permeability, k (ft/day)
Avg height of water, hf (ft)
Filter Drain Time, tf (days)
Filter Surface Area, Af (ft2)
Length-to-Width Ratio
Length (ft)
SEDIMENTATION
As (ft2)
FILTRATION
Filter Bed Depth, df (ft)
Width (ft)
SEDIMENTATION AND FILTRATION CHAMBERS
240 ∗ 2 ∗) ∗ ,
3 =
∗,3
4 ∗ℎ6 + ,3 ∗ "3
Sand Filter Design
DATE:4/3/2024
PROJECT:Sennebogen
PROJECT #:8189.0823CD
DESIGNER:SMC
Post Development DA 1B
1
Pre-Dev Post-Dev
11,678
0.00 0.27
0
0.00 0.00
0.00 0.27
#DIV/0! 0% *measured from the midpoint of the design storm
2
Pre-Dev Post-Dev
0 11,678 Area HSG CN CN*Area
0.00 0.27 0.00
#DIV/0! 80 0.00
#REF! #REF!0.00
0.00
5 0.00 Sum
#DIV/0!CN Weighted
Area HSG CN CN*Area
Open Space 0.27 D 80 21.45
0.00
0.00
21.45 Sum
80 CN Weighted
NCDEQ Stormwater Design Manual
Chapter 11 - Sand Filter (Rev September 20, 2009)
SITE DATA
Target Sand Filter Effectiveness
Area to Sand Filter (sf)
Area to Sand Filter (ac)Detention Time (days)*2
Impervious (sf)Media Depth 1.5 ft
Impervious (ac)Removal Rate 85% TSS
Pervious (ac)
CN
CNm (modified, P=1 in)
Travel Time Tt (min)
Post-Development
% Impervious
HYDROLOGIC PARAMETERS
CURVE NUMBER CALCULATION
Pre-Development
Area (sf)
Area (ac)
=
1000
[10 +5 +10 − 10
+1.25 . ]
Sand Filter Design
DATE:4/3/2024
PROJECT:Sennebogen
PROJECT #:8189.0823CD
DESIGNER:SMC
Post Development DA 2
1
Pre-Dev Post-Dev
58,307 19,316
1.34 0.44
23,324 11,932
0.54 0.27
0.80 0.17
40% 62% *measured from the midpoint of the design storm
2
Pre-Dev Post-Dev
58,307 19,316 Area HSG CN CN*Area
1.34 0.44 Impervious 0.54 B 98 52.47
72 84 Open Space B 61 0.00
#REF! #REF! Woods 0.80 B 55 44.17
0.00
7.3 5 96.64 Sum
72 CN Weighted
Area HSG CN CN*Area
Impervious 0.27 B 98 26.84
Open Space 0.17 B 61 10.34
0.00
37.18 Sum
84 CN Weighted
NCDEQ Stormwater Design Manual
Chapter 11 - Sand Filter (Rev September 20, 2009)
SITE DATA
Target Sand Filter Effectiveness
Area to Sand Filter (sf)
Area to Sand Filter (ac)Detention Time (days)*2
Impervious (sf)Media Depth 1.5 ft
Impervious (ac)Removal Rate 85% TSS
Pervious (ac)
Post-Development
HYDROLOGIC PARAMETERS
CURVE NUMBER CALCULATION
Pre-Development
% Impervious
Area (sf)
Area (ac)
CN
CNm (modified, P=1 in)
Travel Time Tt (min)
=
1000
[10 +5 +10 − 10
+1.25 . ]
CES Group Engineers, LLP 274 N. Highway 16
Denver, NC 28037
Buoyant Weight of Concrete 87.6 lbs/ft^3
Weight of Water 62.4 lbs/ft^3
Safety Factor (S.F.) 1.50 Footing depth to be a minimum of 8 inches in depth.
Height of structure, h = 4.25 ft. Outlet Structure Weight, W(s) =3351 lbs
Structure wall thickness, t =6 in. Displaced Water Weight, W(w) =5304 lbs
Outlet box inside dimension, w =4 ft. Req'd Base Weight, W(b) =4605 lbs
Required Footing Volume, V(f) =53 cf Standard Footing Length, L =7.00 ft.
Provided Footing Volume, V(f) =61 cf Standard Footing Width, W =7.00 ft.
Footing Check okay Minimum Footing Depth, D =1.00 ft.
Footing Size to be used: Length =7.00 ft.
Width =7.00 ft. Outlet Structure - Dry Pond
Depth =1.25 ft.
Outlet Structure Weight, W(s) = 4(w + t) x t x h x W(bc)
where, w = outlet box inside dimension, ft.
Displaced Water Weight, W(w) = 4 x (w + 2t) x W(w) x h t = structure wall thickness, ft.
h = height of structure, ft.
Required Base Weight, W(b) = (W(w) x S.F.) - W(s) W(bc)= buoyant weight of concrete, lbs/ft^3
W(w)= weight of water, lbs/ft^3
Required Footing Volume, V(f) = W(b) / W(bc) S.F.= safety factor
Sennebogen
Project Number:8189
Original Date:4/2/24 DB:SC
Revision Date:PM:JM
Standard Data Standard Footing Assumptions
Outlet Structure - Dry Pond
Structure Dimensions Object Weights
Footing Size
Equations used:
Drainage Area 2Drainage Area 1
1S
Pre-Dev 1
5S
Post Dev 1A
7S
Post Dev (Modified CN)
8S
Pre-Dev 2
11S
Post Dev 1B
13S
Post-Dev 2
6P
Sand Filter
12L
Analysis Point 1
Routing Diagram for 8189-Sand Filter-Detailed Design
Prepared by CES Group Engineers, LLP, Printed 4/3/2024
HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Subcat Reach Pond Link
Sennebogen - Sand Filter Design
8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 2HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Rainfall Events Listing
Event# Event
Name
Storm Type Curve Mode Duration
(hours)
B/B Depth
(inches)
AMC
1 1-inch Type II 24-hr Default 24.00 1 1.00 2
2 1-yr Type II 24-hr Default 24.00 1 2.78 2
3 2-yr Type II 24-hr Default 24.00 1 3.36 2
4 10-yr Type II 24-hr Default 24.00 1 4.91 2
5 25-yr Type II 24-hr Default 24.00 1 5.83 2
6 50-yr Type II 24-hr Default 24.00 1 6.57 2
7 100-yr Type II 24-hr Default 24.00 1 7.32 2
Sennebogen - Sand Filter Design
8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 3HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Area Listing (all nodes)
Area
(acres)
CN Description
(subcatchment-numbers)
7.600 71 (1S)
9.710 84 (5S, 13S)
8.860 96 (7S)
1.340 72 (8S)
0.270 80 (11S)
27.780 84 TOTAL AREA
Sennebogen - Sand Filter Design
8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 4HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Soil Listing (all nodes)
Area
(acres)
Soil
Group
Subcatchment
Numbers
0.000 HSG A
0.000 HSG B
0.000 HSG C
0.000 HSG D
27.780 Other 1S, 5S, 7S, 8S, 11S, 13S
27.780 TOTAL AREA
Sennebogen - Sand Filter Design
8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 5HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Ground Covers (all nodes)
HSG-A
(acres)
HSG-B
(acres)
HSG-C
(acres)
HSG-D
(acres)
Other
(acres)
Total
(acres)
Ground
Cover
Subcatchment
Numbers
0.000 0.000 0.000 0.000 27.780 27.780 1S, 5S, 7S, 8S,
11S, 13S
0.000 0.000 0.000 0.000 27.780 27.780 TOTAL AREA
Sennebogen - Sand Filter Design
8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 6HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pipe Listing (all nodes)
Line# Node
Number
In-Invert
(feet)
Out-Invert
(feet)
Length
(feet)
Slope
(ft/ft)
n Width
(inches)
Diam/Height
(inches)
Inside-Fill
(inches)
Node
Name
1 5S 0.00 0.00 441.0 0.0110 0.013 0.0 15.0 0.0
2 7S 0.00 0.00 441.0 0.0110 0.013 0.0 15.0 0.0
3 6P 737.00 736.30 70.4 0.0099 0.013 0.0 30.0 0.0
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 7HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=0.01"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=0.01 cfs 0.005 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=0.15"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=2.02 cfs 0.117 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=0.63"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=9.55 cfs 0.465 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=0.01"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=0.00 cfs 0.001 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=0.08"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=0.02 cfs 0.002 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=0.15"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=0.10 cfs 0.006 af
Peak Elev=739.23' Storage=0.098 af Inflow=2.02 cfs 0.117 afPond 6P: Sand Filter
Primary=0.02 cfs 0.111 af Secondary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.111 af
Inflow=0.03 cfs 0.113 afLink 12L: Analysis Point 1
Primary=0.03 cfs 0.113 af
Total Runoff Area = 27.780 ac Runoff Volume = 0.596 af Average Runoff Depth = 0.26"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 8HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
Runoff = 0.01 cfs @ 23.99 hrs, Volume= 0.005 af, Depth= 0.01"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.007
0.007
0.006
0.006
0.005
0.005
0.004
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.000
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=7.600 ac
Runoff Volume=0.005 af
Runoff Depth=0.01"
Flow Length=742'
Tc=19.4 min
CN=71
0.01 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 9HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
Runoff = 2.02 cfs @ 12.00 hrs, Volume= 0.117 af, Depth= 0.15"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=9.270 ac
Runoff Volume=0.117 af
Runoff Depth=0.15"
Flow Length=688'
Tc=6.6 min
CN=84
2.02 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 10HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 141% of capacity of segment #3
Runoff = 9.55 cfs @ 11.98 hrs, Volume= 0.465 af, Depth= 0.63"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
10
9
8
7
6
5
4
3
2
1
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=8.860 ac
Runoff Volume=0.465 af
Runoff Depth=0.63"
Flow Length=688'
Tc=6.6 min
CN=96
9.55 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 11HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 0.00 cfs @ 17.74 hrs, Volume= 0.001 af, Depth= 0.01"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.002
0.002
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=1.340 ac
Runoff Volume=0.001 af
Runoff Depth=0.01"
Flow Length=326'
Tc=7.3 min
CN=72
0.00 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 12HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 0.02 cfs @ 12.00 hrs, Volume= 0.002 af, Depth= 0.08"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.025
0.024
0.023
0.022
0.021
0.02
0.019
0.018
0.017
0.016
0.015
0.014
0.013
0.012
0.011
0.01
0.009
0.008
0.007
0.006
0.005
0.004
0.003
0.002
0.001
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=0.270 ac
Runoff Volume=0.002 af
Runoff Depth=0.08"
Tc=5.0 min
CN=80
0.02 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 13HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 0.10 cfs @ 11.98 hrs, Volume= 0.006 af, Depth= 0.15"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.115
0.11
0.105
0.1
0.095
0.09
0.085
0.08
0.075
0.07
0.065
0.06
0.055
0.05
0.045
0.04
0.035
0.03
0.025
0.02
0.015
0.01
0.005
0
Type II 24-hr
1-inch Rainfall=1.00"
Runoff Area=0.440 ac
Runoff Volume=0.006 af
Runoff Depth=0.15"
Tc=5.0 min
CN=84
0.10 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 14HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 0.15" for 1-inch event
Inflow = 2.02 cfs @ 12.00 hrs, Volume= 0.117 af
Outflow = 0.02 cfs @ 24.09 hrs, Volume= 0.111 af, Atten= 99%, Lag= 725.3 min
Primary = 0.02 cfs @ 24.09 hrs, Volume= 0.111 af
Routed to Link 12L : Analysis Point 1
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 739.23' @ 24.09 hrs Surf.Area= 0.422 ac Storage= 0.098 af
Plug-Flow detention time= 2,504.5 min calculated for 0.111 af (95% of inflow)
Center-of-Mass det. time= 2,477.1 min ( 3,384.8 - 907.6 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 15HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.02 cfs @ 24.09 hrs HW=739.23' (Free Discharge)
1=Culvert (Passes 0.02 cfs of 23.94 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.02 cfs)
3=Orifice/Grate ( Controls 0.00 cfs)
4=Orifice/Grate ( Controls 0.00 cfs)
5=Orifice/Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=739.00' (Free Discharge)
6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Inflow Area=9.270 ac
Peak Elev=739.23'
Storage=0.098 af
2.02 cfs
0.02 cfs
0.02 cfs
0.00 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 16HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 1-inch Rainfall=1.00"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 17HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth > 0.14" for 1-inch event
Inflow = 0.03 cfs @ 12.01 hrs, Volume= 0.113 af
Primary = 0.03 cfs @ 12.01 hrs, Volume= 0.113 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.028
0.026
0.024
0.022
0.02
0.018
0.016
0.014
0.012
0.01
0.008
0.006
0.004
0.002
0
Inflow Area=9.540 ac
0.03 cfs
0.03 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 18HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=0.64"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=4.74 cfs 0.404 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=1.34"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=21.69 cfs 1.033 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=2.34"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=32.72 cfs 1.725 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=0.68"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=1.47 cfs 0.076 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=1.09"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=0.55 cfs 0.024 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=1.34"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=1.09 cfs 0.049 af
Peak Elev=740.09' Storage=0.472 af Inflow=21.69 cfs 1.033 afPond 6P: Sand Filter
Primary=3.00 cfs 1.018 af Secondary=0.00 cfs 0.000 af Outflow=3.00 cfs 1.018 af
Inflow=3.07 cfs 1.043 afLink 12L: Analysis Point 1
Primary=3.07 cfs 1.043 af
Total Runoff Area = 27.780 ac Runoff Volume = 3.311 af Average Runoff Depth = 1.43"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 19HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
Runoff = 4.74 cfs @ 12.14 hrs, Volume= 0.404 af, Depth= 0.64"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
5
4
3
2
1
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=7.600 ac
Runoff Volume=0.404 af
Runoff Depth=0.64"
Flow Length=742'
Tc=19.4 min
CN=71
4.74 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 20HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 320% of capacity of segment #3
Runoff = 21.69 cfs @ 11.98 hrs, Volume= 1.033 af, Depth= 1.34"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=9.270 ac
Runoff Volume=1.033 af
Runoff Depth=1.34"
Flow Length=688'
Tc=6.6 min
CN=84
21.69 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 21HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 483% of capacity of segment #3
Runoff = 32.72 cfs @ 11.97 hrs, Volume= 1.725 af, Depth= 2.34"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=8.860 ac
Runoff Volume=1.725 af
Runoff Depth=2.34"
Flow Length=688'
Tc=6.6 min
CN=96
32.72 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 22HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 1.47 cfs @ 12.00 hrs, Volume= 0.076 af, Depth= 0.68"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
1
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=1.340 ac
Runoff Volume=0.076 af
Runoff Depth=0.68"
Flow Length=326'
Tc=7.3 min
CN=72
1.47 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 23HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 0.55 cfs @ 11.97 hrs, Volume= 0.024 af, Depth= 1.09"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.6
0.55
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=0.270 ac
Runoff Volume=0.024 af
Runoff Depth=1.09"
Tc=5.0 min
CN=80
0.55 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 24HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 1.09 cfs @ 11.96 hrs, Volume= 0.049 af, Depth= 1.34"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-yr Rainfall=2.78"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
1
0
Type II 24-hr
1-yr Rainfall=2.78"
Runoff Area=0.440 ac
Runoff Volume=0.049 af
Runoff Depth=1.34"
Tc=5.0 min
CN=84
1.09 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 25HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 1.34" for 1-yr event
Inflow = 21.69 cfs @ 11.98 hrs, Volume= 1.033 af
Outflow = 3.00 cfs @ 12.27 hrs, Volume= 1.018 af, Atten= 86%, Lag= 17.4 min
Primary = 3.00 cfs @ 12.27 hrs, Volume= 1.018 af
Routed to Link 12L : Analysis Point 1
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 740.09' @ 12.27 hrs Surf.Area= 0.453 ac Storage= 0.472 af
Plug-Flow detention time= 735.7 min calculated for 1.018 af (99% of inflow)
Center-of-Mass det. time= 727.2 min ( 1,560.7 - 833.5 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 26HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=3.00 cfs @ 12.27 hrs HW=740.09' (Free Discharge)
1=Culvert (Passes 3.00 cfs of 35.16 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.11 cfs)
3=Orifice/Grate (Orifice Controls 2.89 cfs @ 2.46 fps)
4=Orifice/Grate ( Controls 0.00 cfs)
5=Orifice/Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=739.00' (Free Discharge)
6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
24
22
20
18
16
14
12
10
8
6
4
2
0
Inflow Area=9.270 ac
Peak Elev=740.09'
Storage=0.472 af
21.69 cfs
3.00 cfs
3.00 cfs
0.00 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 27HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 1-yr Rainfall=2.78"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 28HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth > 1.31" for 1-yr event
Inflow = 3.07 cfs @ 12.26 hrs, Volume= 1.043 af
Primary = 3.07 cfs @ 12.26 hrs, Volume= 1.043 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
3
2
1
0
Inflow Area=9.540 ac
3.07 cfs
3.07 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 29HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=0.98"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=7.80 cfs 0.618 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=1.82"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=29.30 cfs 1.404 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=2.91"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=40.15 cfs 2.146 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=1.03"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=2.31 cfs 0.115 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=1.53"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=0.77 cfs 0.034 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=1.82"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=1.47 cfs 0.067 af
Peak Elev=740.45' Storage=0.638 af Inflow=29.30 cfs 1.404 afPond 6P: Sand Filter
Primary=5.09 cfs 1.389 af Secondary=0.00 cfs 0.000 af Outflow=5.09 cfs 1.389 af
Inflow=5.20 cfs 1.423 afLink 12L: Analysis Point 1
Primary=5.20 cfs 1.423 af
Total Runoff Area = 27.780 ac Runoff Volume = 4.384 af Average Runoff Depth = 1.89"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 30HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
Runoff = 7.80 cfs @ 12.14 hrs, Volume= 0.618 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
8
7
6
5
4
3
2
1
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=7.600 ac
Runoff Volume=0.618 af
Runoff Depth=0.98"
Flow Length=742'
Tc=19.4 min
CN=71
7.80 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 31HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 432% of capacity of segment #3
Runoff = 29.30 cfs @ 11.98 hrs, Volume= 1.404 af, Depth= 1.82"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=9.270 ac
Runoff Volume=1.404 af
Runoff Depth=1.82"
Flow Length=688'
Tc=6.6 min
CN=84
29.30 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 32HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 593% of capacity of segment #3
Runoff = 40.15 cfs @ 11.97 hrs, Volume= 2.146 af, Depth= 2.91"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=8.860 ac
Runoff Volume=2.146 af
Runoff Depth=2.91"
Flow Length=688'
Tc=6.6 min
CN=96
40.15 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 33HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 2.31 cfs @ 12.00 hrs, Volume= 0.115 af, Depth= 1.03"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=1.340 ac
Runoff Volume=0.115 af
Runoff Depth=1.03"
Flow Length=326'
Tc=7.3 min
CN=72
2.31 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 34HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 0.77 cfs @ 11.96 hrs, Volume= 0.034 af, Depth= 1.53"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
0.85
0.8
0.75
0.7
0.65
0.6
0.55
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=0.270 ac
Runoff Volume=0.034 af
Runoff Depth=1.53"
Tc=5.0 min
CN=80
0.77 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 35HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 1.47 cfs @ 11.96 hrs, Volume= 0.067 af, Depth= 1.82"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-yr Rainfall=3.36"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
1
0
Type II 24-hr
2-yr Rainfall=3.36"
Runoff Area=0.440 ac
Runoff Volume=0.067 af
Runoff Depth=1.82"
Tc=5.0 min
CN=84
1.47 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 36HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 1.82" for 2-yr event
Inflow = 29.30 cfs @ 11.98 hrs, Volume= 1.404 af
Outflow = 5.09 cfs @ 12.19 hrs, Volume= 1.389 af, Atten= 83%, Lag= 12.3 min
Primary = 5.09 cfs @ 12.19 hrs, Volume= 1.389 af
Routed to Link 12L : Analysis Point 1
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 740.45' @ 12.19 hrs Surf.Area= 0.467 ac Storage= 0.638 af
Plug-Flow detention time= 560.7 min calculated for 1.389 af (99% of inflow)
Center-of-Mass det. time= 554.7 min ( 1,379.4 - 824.8 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 37HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=5.09 cfs @ 12.19 hrs HW=740.45' (Free Discharge)
1=Culvert (Passes 5.09 cfs of 37.17 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.12 cfs)
3=Orifice/Grate (Orifice Controls 4.97 cfs @ 3.73 fps)
4=Orifice/Grate ( Controls 0.00 cfs)
5=Orifice/Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=739.00' (Free Discharge)
6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Inflow Area=9.270 ac
Peak Elev=740.45'
Storage=0.638 af
29.30 cfs
5.09 cfs
5.09 cfs
0.00 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 38HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 2-yr Rainfall=3.36"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 39HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth > 1.79" for 2-yr event
Inflow = 5.20 cfs @ 12.17 hrs, Volume= 1.423 af
Primary = 5.20 cfs @ 12.17 hrs, Volume= 1.423 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
5
4
3
2
1
0
Inflow Area=9.540 ac
5.20 cfs
5.20 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 40HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=2.05"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=17.38 cfs 1.298 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=3.19"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=50.31 cfs 2.463 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=4.44"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=59.81 cfs 3.280 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=2.13"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=4.87 cfs 0.238 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=2.81"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=1.39 cfs 0.063 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=3.19"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=2.52 cfs 0.117 af
Peak Elev=741.41' Storage=1.102 af Inflow=50.31 cfs 2.463 afPond 6P: Sand Filter
Primary=14.54 cfs 2.448 af Secondary=0.00 cfs 0.000 af Outflow=14.54 cfs 2.448 af
Inflow=14.81 cfs 2.511 afLink 12L: Analysis Point 1
Primary=14.81 cfs 2.511 af
Total Runoff Area = 27.780 ac Runoff Volume = 7.459 af Average Runoff Depth = 3.22"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 41HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
[47] Hint: Peak is 163% of capacity of segment #3
Runoff = 17.38 cfs @ 12.13 hrs, Volume= 1.298 af, Depth= 2.05"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=7.600 ac
Runoff Volume=1.298 af
Runoff Depth=2.05"
Flow Length=742'
Tc=19.4 min
CN=71
17.38 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 42HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 743% of capacity of segment #3
Runoff = 50.31 cfs @ 11.98 hrs, Volume= 2.463 af, Depth= 3.19"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=9.270 ac
Runoff Volume=2.463 af
Runoff Depth=3.19"
Flow Length=688'
Tc=6.6 min
CN=84
50.31 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 43HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 883% of capacity of segment #3
Runoff = 59.81 cfs @ 11.97 hrs, Volume= 3.280 af, Depth= 4.44"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=8.860 ac
Runoff Volume=3.280 af
Runoff Depth=4.44"
Flow Length=688'
Tc=6.6 min
CN=96
59.81 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 44HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 4.87 cfs @ 11.99 hrs, Volume= 0.238 af, Depth= 2.13"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
5
4
3
2
1
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=1.340 ac
Runoff Volume=0.238 af
Runoff Depth=2.13"
Flow Length=326'
Tc=7.3 min
CN=72
4.87 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 45HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 1.39 cfs @ 11.96 hrs, Volume= 0.063 af, Depth= 2.81"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
1
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=0.270 ac
Runoff Volume=0.063 af
Runoff Depth=2.81"
Tc=5.0 min
CN=80
1.39 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 46HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 2.52 cfs @ 11.96 hrs, Volume= 0.117 af, Depth= 3.19"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-yr Rainfall=4.91"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Type II 24-hr
10-yr Rainfall=4.91"
Runoff Area=0.440 ac
Runoff Volume=0.117 af
Runoff Depth=3.19"
Tc=5.0 min
CN=84
2.52 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 47HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 3.19" for 10-yr event
Inflow = 50.31 cfs @ 11.98 hrs, Volume= 2.463 af
Outflow = 14.54 cfs @ 12.11 hrs, Volume= 2.448 af, Atten= 71%, Lag= 8.1 min
Primary = 14.54 cfs @ 12.11 hrs, Volume= 2.448 af
Routed to Link 12L : Analysis Point 1
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 741.41' @ 12.11 hrs Surf.Area= 0.503 ac Storage= 1.102 af
Plug-Flow detention time= 352.4 min calculated for 2.448 af (99% of inflow)
Center-of-Mass det. time= 349.0 min ( 1,157.7 - 808.7 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 48HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=14.48 cfs @ 12.11 hrs HW=741.41' (Free Discharge)
1=Culvert (Passes 14.48 cfs of 46.74 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.16 cfs)
3=Orifice/Grate (Orifice Controls 8.04 cfs @ 6.03 fps)
4=Orifice/Grate (Orifice Controls 3.02 cfs @ 3.02 fps)
5=Orifice/Grate (Weir Controls 3.26 cfs @ 1.30 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=739.00' (Free Discharge)
6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
55
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=9.270 ac
Peak Elev=741.41'
Storage=1.102 af
50.31 cfs
14.54 cfs
14.54 cfs
0.00 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 49HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 10-yr Rainfall=4.91"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 50HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth > 3.16" for 10-yr event
Inflow = 14.81 cfs @ 12.11 hrs, Volume= 2.511 af
Primary = 14.81 cfs @ 12.11 hrs, Volume= 2.511 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Inflow Area=9.540 ac
14.81 cfs
14.81 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 51HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=2.76"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=23.67 cfs 1.750 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=4.04"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=62.94 cfs 3.119 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=5.36"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=71.41 cfs 3.956 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=2.85"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=6.52 cfs 0.319 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=3.63"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=1.78 cfs 0.082 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=4.04"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=3.16 cfs 0.148 af
Peak Elev=741.71' Storage=1.259 af Inflow=62.94 cfs 3.119 afPond 6P: Sand Filter
Primary=29.62 cfs 3.060 af Secondary=5.01 cfs 0.043 af Outflow=34.64 cfs 3.104 af
Inflow=30.28 cfs 3.142 afLink 12L: Analysis Point 1
Primary=30.28 cfs 3.142 af
Total Runoff Area = 27.780 ac Runoff Volume = 9.373 af Average Runoff Depth = 4.05"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 52HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
[47] Hint: Peak is 222% of capacity of segment #3
Runoff = 23.67 cfs @ 12.13 hrs, Volume= 1.750 af, Depth= 2.76"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=7.600 ac
Runoff Volume=1.750 af
Runoff Depth=2.76"
Flow Length=742'
Tc=19.4 min
CN=71
23.67 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 53HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 929% of capacity of segment #3
Runoff = 62.94 cfs @ 11.98 hrs, Volume= 3.119 af, Depth= 4.04"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=9.270 ac
Runoff Volume=3.119 af
Runoff Depth=4.04"
Flow Length=688'
Tc=6.6 min
CN=84
62.94 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 54HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 1054% of capacity of segment #3
Runoff = 71.41 cfs @ 11.97 hrs, Volume= 3.956 af, Depth= 5.36"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=8.860 ac
Runoff Volume=3.956 af
Runoff Depth=5.36"
Flow Length=688'
Tc=6.6 min
CN=96
71.41 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 55HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 6.52 cfs @ 11.99 hrs, Volume= 0.319 af, Depth= 2.85"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
7
6
5
4
3
2
1
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=1.340 ac
Runoff Volume=0.319 af
Runoff Depth=2.85"
Flow Length=326'
Tc=7.3 min
CN=72
6.52 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 56HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 1.78 cfs @ 11.96 hrs, Volume= 0.082 af, Depth= 3.63"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
1
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=0.270 ac
Runoff Volume=0.082 af
Runoff Depth=3.63"
Tc=5.0 min
CN=80
1.78 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 57HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 3.16 cfs @ 11.96 hrs, Volume= 0.148 af, Depth= 4.04"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-yr Rainfall=5.83"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
3
2
1
0
Type II 24-hr
25-yr Rainfall=5.83"
Runoff Area=0.440 ac
Runoff Volume=0.148 af
Runoff Depth=4.04"
Tc=5.0 min
CN=84
3.16 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 58HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 4.04" for 25-yr event
Inflow = 62.94 cfs @ 11.98 hrs, Volume= 3.119 af
Outflow = 34.64 cfs @ 12.06 hrs, Volume= 3.104 af, Atten= 45%, Lag= 5.1 min
Primary = 29.62 cfs @ 12.06 hrs, Volume= 3.060 af
Routed to Link 12L : Analysis Point 1
Secondary = 5.01 cfs @ 12.06 hrs, Volume= 0.043 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 741.71' @ 12.06 hrs Surf.Area= 0.515 ac Storage= 1.259 af
Plug-Flow detention time= 289.9 min calculated for 3.104 af (100% of inflow)
Center-of-Mass det. time= 286.8 min ( 1,088.8 - 802.0 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 59HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=29.56 cfs @ 12.06 hrs HW=741.71' (Free Discharge)
1=Culvert (Passes 29.56 cfs of 49.42 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.17 cfs)
3=Orifice/Grate (Orifice Controls 8.79 cfs @ 6.59 fps)
4=Orifice/Grate (Orifice Controls 4.05 cfs @ 4.05 fps)
5=Orifice/Grate (Weir Controls 16.54 cfs @ 2.23 fps)
Secondary OutFlow Max=4.95 cfs @ 12.06 hrs HW=741.71' (Free Discharge)
6=Broad-Crested Rectangular Weir (Weir Controls 4.95 cfs @ 1.15 fps)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=9.270 ac
Peak Elev=741.71'
Storage=1.259 af
62.94 cfs
34.64 cfs
29.62 cfs
5.01 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 60HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 25-yr Rainfall=5.83"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 61HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth > 3.95" for 25-yr event
Inflow = 30.28 cfs @ 12.06 hrs, Volume= 3.142 af
Primary = 30.28 cfs @ 12.06 hrs, Volume= 3.142 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Inflow Area=9.540 ac
30.28 cfs
30.28 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 62HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=3.36"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=28.91 cfs 2.131 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=4.73"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=73.11 cfs 3.656 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=6.10"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=80.72 cfs 4.500 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=3.47"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=7.89 cfs 0.387 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=4.30"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=2.09 cfs 0.097 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=4.73"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=3.66 cfs 0.174 af
Peak Elev=741.87' Storage=1.340 af Inflow=73.11 cfs 3.656 afPond 6P: Sand Filter
Primary=39.49 cfs 3.518 af Secondary=11.58 cfs 0.122 af Outflow=51.07 cfs 3.641 af
Inflow=40.56 cfs 3.615 afLink 12L: Analysis Point 1
Primary=40.56 cfs 3.615 af
Total Runoff Area = 27.780 ac Runoff Volume = 10.944 af Average Runoff Depth = 4.73"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 63HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
[47] Hint: Peak is 271% of capacity of segment #3
Runoff = 28.91 cfs @ 12.12 hrs, Volume= 2.131 af, Depth= 3.36"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=7.600 ac
Runoff Volume=2.131 af
Runoff Depth=3.36"
Flow Length=742'
Tc=19.4 min
CN=71
28.91 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 64HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 1079% of capacity of segment #3
Runoff = 73.11 cfs @ 11.98 hrs, Volume= 3.656 af, Depth= 4.73"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=9.270 ac
Runoff Volume=3.656 af
Runoff Depth=4.73"
Flow Length=688'
Tc=6.6 min
CN=84
73.11 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 65HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 1191% of capacity of segment #3
Runoff = 80.72 cfs @ 11.97 hrs, Volume= 4.500 af, Depth= 6.10"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=8.860 ac
Runoff Volume=4.500 af
Runoff Depth=6.10"
Flow Length=688'
Tc=6.6 min
CN=96
80.72 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 66HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 7.89 cfs @ 11.99 hrs, Volume= 0.387 af, Depth= 3.47"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
8
7
6
5
4
3
2
1
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=1.340 ac
Runoff Volume=0.387 af
Runoff Depth=3.47"
Flow Length=326'
Tc=7.3 min
CN=72
7.89 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 67HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 2.09 cfs @ 11.96 hrs, Volume= 0.097 af, Depth= 4.30"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=0.270 ac
Runoff Volume=0.097 af
Runoff Depth=4.30"
Tc=5.0 min
CN=80
2.09 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 68HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 3.66 cfs @ 11.96 hrs, Volume= 0.174 af, Depth= 4.73"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-yr Rainfall=6.57"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
4
3
2
1
0
Type II 24-hr
50-yr Rainfall=6.57"
Runoff Area=0.440 ac
Runoff Volume=0.174 af
Runoff Depth=4.73"
Tc=5.0 min
CN=84
3.66 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 69HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 4.73" for 50-yr event
Inflow = 73.11 cfs @ 11.98 hrs, Volume= 3.656 af
Outflow = 51.07 cfs @ 12.04 hrs, Volume= 3.641 af, Atten= 30%, Lag= 3.9 min
Primary = 39.49 cfs @ 12.04 hrs, Volume= 3.518 af
Routed to Link 12L : Analysis Point 1
Secondary = 11.58 cfs @ 12.04 hrs, Volume= 0.122 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 741.87' @ 12.04 hrs Surf.Area= 0.521 ac Storage= 1.340 af
Plug-Flow detention time= 254.0 min calculated for 3.640 af (100% of inflow)
Center-of-Mass det. time= 251.8 min ( 1,049.3 - 797.5 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 70HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=39.43 cfs @ 12.04 hrs HW=741.87' (Free Discharge)
1=Culvert (Passes 39.43 cfs of 50.73 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.18 cfs)
3=Orifice/Grate (Orifice Controls 9.15 cfs @ 6.87 fps)
4=Orifice/Grate (Orifice Controls 4.48 cfs @ 4.48 fps)
5=Orifice/Grate (Weir Controls 25.62 cfs @ 2.58 fps)
Secondary OutFlow Max=11.54 cfs @ 12.04 hrs HW=741.87' (Free Discharge)
6=Broad-Crested Rectangular Weir (Weir Controls 11.54 cfs @ 1.55 fps)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=9.270 ac
Peak Elev=741.87'
Storage=1.340 af
73.11 cfs
51.07 cfs
39.49 cfs
11.58 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 71HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 50-yr Rainfall=6.57"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 72HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth = 4.55" for 50-yr event
Inflow = 40.56 cfs @ 12.04 hrs, Volume= 3.615 af
Primary = 40.56 cfs @ 12.04 hrs, Volume= 3.615 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Inflow Area=9.540 ac
40.56 cfs
40.56 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 73HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Time span=0.00-160.00 hrs, dt=0.01 hrs, 16001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7.600 ac 0.00% Impervious Runoff Depth=3.99"Subcatchment 1S: Pre-Dev 1
Flow Length=742' Tc=19.4 min CN=71 Runoff=34.36 cfs 2.530 af
Runoff Area=9.270 ac 0.00% Impervious Runoff Depth=5.44"Subcatchment 5S: Post Dev 1A
Flow Length=688' Tc=6.6 min CN=84 Runoff=83.39 cfs 4.206 af
Runoff Area=8.860 ac 0.00% Impervious Runoff Depth=6.84"Subcatchment 7S: Post Dev (Modified CN)
Flow Length=688' Tc=6.6 min CN=96 Runoff=90.13 cfs 5.052 af
Runoff Area=1.340 ac 0.00% Impervious Runoff Depth=4.10"Subcatchment 8S: Pre-Dev 2
Flow Length=326' Tc=7.3 min CN=72 Runoff=9.30 cfs 0.458 af
Runoff Area=0.270 ac 0.00% Impervious Runoff Depth=4.99"Subcatchment 11S: Post Dev 1B
Tc=5.0 min CN=80 Runoff=2.40 cfs 0.112 af
Runoff Area=0.440 ac 0.00% Impervious Runoff Depth=5.44"Subcatchment 13S: Post-Dev 2
Tc=5.0 min CN=84 Runoff=4.18 cfs 0.200 af
Peak Elev=741.99' Storage=1.404 af Inflow=83.39 cfs 4.206 afPond 6P: Sand Filter
Primary=47.39 cfs 3.976 af Secondary=18.22 cfs 0.215 af Outflow=65.62 cfs 4.191 af
Inflow=48.88 cfs 4.088 afLink 12L: Analysis Point 1
Primary=48.88 cfs 4.088 af
Total Runoff Area = 27.780 ac Runoff Volume = 12.558 af Average Runoff Depth = 5.42"
100.00% Pervious = 27.780 ac 0.00% Impervious = 0.000 ac
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 74HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre-Dev 1
[47] Hint: Peak is 323% of capacity of segment #3
Runoff = 34.36 cfs @ 12.12 hrs, Volume= 2.530 af, Depth= 3.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 7.600 71
7.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
17.4 100 0.0320 0.10 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.2 382 0.1060 5.24 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.8 260 0.0460 5.33 10.65 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
19.4 742 Total
Subcatchment 1S: Pre-Dev 1
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=7.600 ac
Runoff Volume=2.530 af
Runoff Depth=3.99"
Flow Length=742'
Tc=19.4 min
CN=71
34.36 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 75HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 5S: Post Dev 1A
[47] Hint: Peak is 1231% of capacity of segment #3
Runoff = 83.39 cfs @ 11.98 hrs, Volume= 4.206 af, Depth= 5.44"
Routed to Pond 6P : Sand Filter
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 9.270 84
9.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 5S: Post Dev 1A
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=9.270 ac
Runoff Volume=4.206 af
Runoff Depth=5.44"
Flow Length=688'
Tc=6.6 min
CN=84
83.39 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 76HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post Dev (Modified CN)
[47] Hint: Peak is 1330% of capacity of segment #3
Runoff = 90.13 cfs @ 11.97 hrs, Volume= 5.052 af, Depth= 6.84"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 8.860 96
8.860 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 45 0.2840 0.20 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.5 202 0.0130 2.31 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.3 441 0.0110 5.52 6.78 Pipe Channel,
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
6.6 688 Total
Subcatchment 7S: Post Dev (Modified CN)
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=8.860 ac
Runoff Volume=5.052 af
Runoff Depth=6.84"
Flow Length=688'
Tc=6.6 min
CN=96
90.13 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 77HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Pre-Dev 2
Runoff = 9.30 cfs @ 11.99 hrs, Volume= 0.458 af, Depth= 4.10"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 1.340 72
1.340 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.9 31 0.0450 0.09 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.36"
1.1 179 0.0170 2.65 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
0.2 78 0.2590 8.19 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
0.1 38 0.1130 8.35 16.69 Trap/Vee/Rect Channel Flow,
Bot.W=0.00' D=1.00' Z= 2.0 '/' Top.W=4.00'
n= 0.035
7.3 326 Total
Subcatchment 8S: Pre-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
10
9
8
7
6
5
4
3
2
1
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=1.340 ac
Runoff Volume=0.458 af
Runoff Depth=4.10"
Flow Length=326'
Tc=7.3 min
CN=72
9.30 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 78HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 11S: Post Dev 1B
Runoff = 2.40 cfs @ 11.96 hrs, Volume= 0.112 af, Depth= 4.99"
Routed to Link 12L : Analysis Point 1
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 0.270 80
0.270 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 11S: Post Dev 1B
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
2
1
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=0.270 ac
Runoff Volume=0.112 af
Runoff Depth=4.99"
Tc=5.0 min
CN=80
2.40 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 79HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Subcatchment 13S: Post-Dev 2
Runoff = 4.18 cfs @ 11.96 hrs, Volume= 0.200 af, Depth= 5.44"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-yr Rainfall=7.32"
Area (ac) CN Description
* 0.440 84
0.440 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 13S: Post-Dev 2
Runoff
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
4
3
2
1
0
Type II 24-hr
100-yr Rainfall=7.32"
Runoff Area=0.440 ac
Runoff Volume=0.200 af
Runoff Depth=5.44"
Tc=5.0 min
CN=84
4.18 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 80HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Pond 6P: Sand Filter
Inflow Area = 9.270 ac, 0.00% Impervious, Inflow Depth = 5.44" for 100-yr event
Inflow = 83.39 cfs @ 11.98 hrs, Volume= 4.206 af
Outflow = 65.62 cfs @ 12.03 hrs, Volume= 4.191 af, Atten= 21%, Lag= 3.2 min
Primary = 47.39 cfs @ 12.03 hrs, Volume= 3.976 af
Routed to Link 12L : Analysis Point 1
Secondary = 18.22 cfs @ 12.03 hrs, Volume= 0.215 af
Routed to nonexistent node 7L
Routing by Stor-Ind method, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Peak Elev= 741.99' @ 12.03 hrs Surf.Area= 0.526 ac Storage= 1.404 af
Plug-Flow detention time= 226.8 min calculated for 4.190 af (100% of inflow)
Center-of-Mass det. time= 224.9 min ( 1,018.5 - 793.6 )
Volume Invert Avail.Storage Storage Description
#1 739.00' 1.953 af Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
739.00 0.414 0.000 0.000
740.00 0.450 0.432 0.432
741.00 0.487 0.468 0.900
742.00 0.526 0.506 1.407
743.00 0.566 0.546 1.953
Device Routing Invert Outlet Devices
#1 Primary 737.00'30.0" Round Culvert
L= 70.4' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 737.00' / 736.30' S= 0.0099 '/' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 739.00'Special & User-Defined
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
Disch. (cfs) 0.000 0.102 0.142 0.183 0.224 0.264 0.305 0.346
#3 Device 1 739.50'24.0" W x 8.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Device 1 740.75'24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#5 Device 1 741.25'4.0" x 4.0" Horiz. Orifice/Grate X 9.00 columns
X 8 rows C= 0.600 in 48.0" x 48.0" Grate (50% open area)
Limited to weir flow at low heads
#6 Secondary 741.50'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 81HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Primary OutFlow Max=47.61 cfs @ 12.03 hrs HW=741.99' (Free Discharge)
1=Culvert (Passes 47.61 cfs of 51.73 cfs potential flow)
2=Special & User-Defined (Custom Controls 0.18 cfs)
3=Orifice/Grate (Orifice Controls 9.43 cfs @ 7.07 fps)
4=Orifice/Grate (Orifice Controls 4.79 cfs @ 4.79 fps)
5=Orifice/Grate (Orifice Controls 33.22 cfs @ 4.15 fps)
Secondary OutFlow Max=18.21 cfs @ 12.03 hrs HW=741.99' (Free Discharge)
6=Broad-Crested Rectangular Weir (Weir Controls 18.21 cfs @ 1.84 fps)
Pond 6P: Sand Filter
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=9.270 ac
Peak Elev=741.99'
Storage=1.404 af
83.39 cfs
65.62 cfs
47.39 cfs
18.22 cfs
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 82HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Pond 6P: Sand Filter
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
550500450400350300250200150100500
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Special & User-Defined
Orifice/Grate
Orifice/Grate
Orifice/Grate Broad-Crested Rectangular Weir
Pond 6P: Sand Filter
Surface
Storage
Stage-Area-Storage
Storage (acre-feet)
10
Surface/Horizontal/Wetted Area (acres)
0.550.50.450.40.350.30.250.20.150.10.050
El
e
v
a
t
i
o
n

(
f
e
e
t
)
746
745
744
743
742
741
740
739
Custom Stage Data
Sennebogen - Sand Filter Design
Type II 24-hr 100-yr Rainfall=7.32"8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 83HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Summary for Link 12L: Analysis Point 1
Inflow Area = 9.540 ac, 0.00% Impervious, Inflow Depth = 5.14" for 100-yr event
Inflow = 48.88 cfs @ 12.03 hrs, Volume= 4.088 af
Primary = 48.88 cfs @ 12.03 hrs, Volume= 4.088 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-160.00 hrs, dt= 0.01 hrs
Link 12L: Analysis Point 1
Inflow
Primary
Hydrograph
Time (hours)
1601501401301201101009080706050403020100
Fl
o
w

(
c
f
s
)
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=9.540 ac
48.88 cfs
48.88 cfs
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 84HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 1S: Pre-Dev 1
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 0.01 0.005 0.01
1-yr 2.78 4.74 0.404 0.64
2-yr 3.36 7.80 0.618 0.98
10-yr 4.91 17.38 1.298 2.05
25-yr 5.83 23.67 1.750 2.76
50-yr 6.57 28.91 2.131 3.36
100-yr 7.32 34.36 2.530 3.99
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 85HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 5S: Post Dev 1A
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 2.02 0.117 0.15
1-yr 2.78 21.69 1.033 1.34
2-yr 3.36 29.30 1.404 1.82
10-yr 4.91 50.31 2.463 3.19
25-yr 5.83 62.94 3.119 4.04
50-yr 6.57 73.11 3.656 4.73
100-yr 7.32 83.39 4.206 5.44
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 86HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 7S: Post Dev (Modified CN)
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 9.55 0.465 0.63
1-yr 2.78 32.72 1.725 2.34
2-yr 3.36 40.15 2.146 2.91
10-yr 4.91 59.81 3.280 4.44
25-yr 5.83 71.41 3.956 5.36
50-yr 6.57 80.72 4.500 6.10
100-yr 7.32 90.13 5.052 6.84
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 87HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 8S: Pre-Dev 2
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 0.00 0.001 0.01
1-yr 2.78 1.47 0.076 0.68
2-yr 3.36 2.31 0.115 1.03
10-yr 4.91 4.87 0.238 2.13
25-yr 5.83 6.52 0.319 2.85
50-yr 6.57 7.89 0.387 3.47
100-yr 7.32 9.30 0.458 4.10
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 88HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 11S: Post Dev 1B
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 0.02 0.002 0.08
1-yr 2.78 0.55 0.024 1.09
2-yr 3.36 0.77 0.034 1.53
10-yr 4.91 1.39 0.063 2.81
25-yr 5.83 1.78 0.082 3.63
50-yr 6.57 2.09 0.097 4.30
100-yr 7.32 2.40 0.112 4.99
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 89HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Subcatchment 13S: Post-Dev 2
Event Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-inch 1.00 0.10 0.006 0.15
1-yr 2.78 1.09 0.049 1.34
2-yr 3.36 1.47 0.067 1.82
10-yr 4.91 2.52 0.117 3.19
25-yr 5.83 3.16 0.148 4.04
50-yr 6.57 3.66 0.174 4.73
100-yr 7.32 4.18 0.200 5.44
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 90HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Pond 6P: Sand Filter
Event Inflow
(cfs)
Outflow
(cfs)
Primary
(cfs)
Secondary
(cfs)
Elevation
(feet)
Storage
(acre-feet)
1-inch 2.02 0.02 0.02 0.00 739.23 0.098
1-yr 21.69 3.00 3.00 0.00 740.09 0.472
2-yr 29.30 5.09 5.09 0.00 740.45 0.638
10-yr 50.31 14.54 14.54 0.00 741.41 1.102
25-yr 62.94 34.64 29.62 5.01 741.71 1.259
50-yr 73.11 51.07 39.49 11.58 741.87 1.340
100-yr 83.39 65.62 47.39 18.22 741.99 1.404
Sennebogen - Sand Filter Design
Multi-Event Tables8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
Page 91HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
Events for Link 12L: Analysis Point 1
Event Inflow
(cfs)
Primary
(cfs)
Elevation
(feet)
1-inch 0.03 0.03 0.00
1-yr 3.07 3.07 0.00
2-yr 5.20 5.20 0.00
10-yr 14.81 14.81 0.00
25-yr 30.28 30.28 0.00
50-yr 40.56 40.56 0.00
100-yr 48.88 48.88 0.00
Sennebogen - Sand Filter Design
Table of Contents8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
TABLE OF CONTENTS
Project Reports
1 Routing Diagram
2 Rainfall Events Listing
3 Area Listing (all nodes)
4 Soil Listing (all nodes)
5 Ground Covers (all nodes)
6 Pipe Listing (all nodes)
1-inch Event
7 Node Listing
8 Subcat 1S: Pre-Dev 1
9 Subcat 5S: Post Dev 1A
10 Subcat 7S: Post Dev (Modified CN)
11 Subcat 8S: Pre-Dev 2
12 Subcat 11S: Post Dev 1B
13 Subcat 13S: Post-Dev 2
14 Pond 6P: Sand Filter
17 Link 12L: Analysis Point 1
1-yr Event
18 Node Listing
19 Subcat 1S: Pre-Dev 1
20 Subcat 5S: Post Dev 1A
21 Subcat 7S: Post Dev (Modified CN)
22 Subcat 8S: Pre-Dev 2
23 Subcat 11S: Post Dev 1B
24 Subcat 13S: Post-Dev 2
25 Pond 6P: Sand Filter
28 Link 12L: Analysis Point 1
2-yr Event
29 Node Listing
30 Subcat 1S: Pre-Dev 1
31 Subcat 5S: Post Dev 1A
32 Subcat 7S: Post Dev (Modified CN)
33 Subcat 8S: Pre-Dev 2
34 Subcat 11S: Post Dev 1B
35 Subcat 13S: Post-Dev 2
36 Pond 6P: Sand Filter
39 Link 12L: Analysis Point 1
10-yr Event
40 Node Listing
41 Subcat 1S: Pre-Dev 1
42 Subcat 5S: Post Dev 1A
43 Subcat 7S: Post Dev (Modified CN)
44 Subcat 8S: Pre-Dev 2
45 Subcat 11S: Post Dev 1B
46 Subcat 13S: Post-Dev 2
Sennebogen - Sand Filter Design
Table of Contents8189-Sand Filter-Detailed Design
Printed 4/3/2024Prepared by CES Group Engineers, LLP
HydroCAD® 10.20-4b s/n 10182 © 2023 HydroCAD Software Solutions LLC
47 Pond 6P: Sand Filter
50 Link 12L: Analysis Point 1
25-yr Event
51 Node Listing
52 Subcat 1S: Pre-Dev 1
53 Subcat 5S: Post Dev 1A
54 Subcat 7S: Post Dev (Modified CN)
55 Subcat 8S: Pre-Dev 2
56 Subcat 11S: Post Dev 1B
57 Subcat 13S: Post-Dev 2
58 Pond 6P: Sand Filter
61 Link 12L: Analysis Point 1
50-yr Event
62 Node Listing
63 Subcat 1S: Pre-Dev 1
64 Subcat 5S: Post Dev 1A
65 Subcat 7S: Post Dev (Modified CN)
66 Subcat 8S: Pre-Dev 2
67 Subcat 11S: Post Dev 1B
68 Subcat 13S: Post-Dev 2
69 Pond 6P: Sand Filter
72 Link 12L: Analysis Point 1
100-yr Event
73 Node Listing
74 Subcat 1S: Pre-Dev 1
75 Subcat 5S: Post Dev 1A
76 Subcat 7S: Post Dev (Modified CN)
77 Subcat 8S: Pre-Dev 2
78 Subcat 11S: Post Dev 1B
79 Subcat 13S: Post-Dev 2
80 Pond 6P: Sand Filter
83 Link 12L: Analysis Point 1
Multi-Event Tables
84 Subcat 1S: Pre-Dev 1
85 Subcat 5S: Post Dev 1A
86 Subcat 7S: Post Dev (Modified CN)
87 Subcat 8S: Pre-Dev 2
88 Subcat 11S: Post Dev 1B
89 Subcat 13S: Post-Dev 2
90 Pond 6P: Sand Filter
91 Link 12L: Analysis Point 1

Exhibit 6
Soil Maps

Soil Map—Lincoln County, North Carolina
(Post Dev DA)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 1 of 3
39
1
9
5
5
0
39
1
9
5
9
0
39
1
9
6
3
0
39
1
9
6
7
0
39
1
9
7
1
0
39
1
9
7
5
0
39
1
9
7
9
0
39
1
9
5
5
0
39
1
9
5
9
0
39
1
9
6
3
0
39
1
9
6
7
0
39
1
9
7
1
0
39
1
9
7
5
0
39
1
9
7
9
0
498240 498280 498320 498360 498400 498440 498480 498520 498560 498600 498640
498240 498280 498320 498360 498400 498440 498480 498520 498560 498600 498640
35° 25' 17'' N
81
°

1
'

9
'
'

W
35° 25' 17'' N
81
°

0
'

5
3
'
'

W
35° 25' 9'' N
81
°

1
'

9
'
'

W
35° 25' 9'' N
81
°

0
'

5
3
'
'

W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,870 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 28, Sep 13, 2023
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2022—May
10, 2022
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Soil Map—Lincoln County, North Carolina
(Post Dev DA)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 2 of 3
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
CeB2 Cecil sandy clay loam, 2 to 8
percent slopes, moderately
eroded
7.1 79.9%
PeC2 Pacolet sandy clay loam, 8 to
15 percent slopes,
moderately eroded
0.0 0.0%
WyC Wynott-Winnsboro-Rowan
complex, 8 to 15 percent
slopes
1.8 20.1%
Totals for Area of Interest 8.9 100.0%
Soil Map—Lincoln County, North Carolina Post Dev DA
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 3 of 3
Hydrologic Soil Group—Lincoln County, North Carolina
(HSG Map)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 1 of 4
39
1
9
5
5
0
39
1
9
5
9
0
39
1
9
6
3
0
39
1
9
6
7
0
39
1
9
7
1
0
39
1
9
7
5
0
39
1
9
7
9
0
39
1
9
5
5
0
39
1
9
5
9
0
39
1
9
6
3
0
39
1
9
6
7
0
39
1
9
7
1
0
39
1
9
7
5
0
39
1
9
7
9
0
498240 498280 498320 498360 498400 498440 498480 498520 498560 498600 498640
498240 498280 498320 498360 498400 498440 498480 498520 498560 498600 498640
35° 25' 17'' N
81
°

1
'

9
'
'

W
35° 25' 17'' N
81
°

0
'

5
3
'
'

W
35° 25' 9'' N
81
°

1
'

9
'
'

W
35° 25' 9'' N
81
°

0
'

5
3
'
'

W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 50 100 200 300
Feet
0 25 50 100 150
Meters
Map Scale: 1:1,870 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 28, Sep 13, 2023
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2022—May
10, 2022
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Lincoln County, North Carolina
(HSG Map)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
CeB2 Cecil sandy clay loam, 2
to 8 percent slopes,
moderately eroded
B 7.1 79.9%
PeC2 Pacolet sandy clay
loam, 8 to 15 percent
slopes, moderately
eroded
B 0.0 0.0%
WyC Wynott-Winnsboro-
Rowan complex, 8 to
15 percent slopes
D 1.8 20.1%
Totals for Area of Interest 8.9 100.0%
Hydrologic Soil Group—Lincoln County, North Carolina HSG Map
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 3 of 4
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Lincoln County, North Carolina HSG Map
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
11/2/2023
Page 4 of 4