SW3200901_2020-09-01 - Stormwater Management Plan_20200908

Engineers, Surveyors, Planners, Scientists
Del iveri ng Solutions.
301 McCullough Drive, Suite 109, Charlotte, North
Carolina, 28262
p. 704-548-0333
[e-mail]
Job Number: 2020-0122
Stormwater Management Plan (SWMP)
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No. F-1016
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PROJECT SUMMARY
Project Name: Pinnacle Cranes
Location: Town of Midland, Cabarrus County, North Carolina
Type: Stormwater Management Plan
Reviewing Agency: Town of Midland, North Carolina DEQ
HYDROLOGIC SUMMARY
Rainfall Data:
Rainfall Distribution:
Detention Policy:
Water Quality:
Hydrology Modeling Program:
DESIGN SUMMARY
NOAA Atlas 14, Volume 2, Version 3, 2004
1-yr
2.91 "
2-yr
3.51"
10-yr
5.12"
25-yr
6.09"
50-yr
6.86"
100-yr
7.65"
NRCS Type II 24 hour
Town of Midland, Cabarrus County
Town of Midland, North Carolina DEQ
HydroCAD 10.0
Detention: Sand Filter
Water Quality: Sand Filter
Receiving Water Body: Unnamed Tributaries of Muddy Creek
Minimum Design Criteria:
-Water quality = first flush (or first 1" of rainfall) per NCDEQ
-Detention = post to pre-release rates for the 1-year (NCDEQ), 2-year (Town of Midland), 10-
year (NCDEQ), 25-year (Town of Midland), and 100-year (Cabarrus County) storm events
-Freeboard = 0.5 feet above the 100-year elevation
REVISIONS

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TABLE OF CONTENTS
1.0 Introduction............................................................................................................................................ 1
2.0 Hydrologic Analysis............................................................................................................................. 1
3.0 Pre -Developed Analysis...................................................................................................................... 2
4.0 Post -Developed Analysis.................................................................................................................... 2
5.0 Outlet Design........................................................................................................................................ 3
6.0 Water Quality......................................................................................................................................4
7.0 Conclusion.............................................................................................................................................. 4
TABLES
Table 1 - Pre -developed Subarea Characteristics............................................................................. 2
Table 2 - Pre -developed Peak Flow Rates.......................................................................................... 2
Table 3 - Post -developed Subarea Characteristics............................................................................ 3
Table 4 - Allowable and Proposed Release Rates to NW............................................................... 3
Table 5 - Allowable and Proposed Release Rates with Sand Filter Performance Summary...... 3
Table 6 - Water Quality Calculations...................................................................................................4
APPENDICES
Appendix A: USDA Soils and NOAA Rainfall Reports
Appendix B: Water Quality Calculations
Appendix C: HydroCAD Output
Appendix D: Storm Sewer Calculations

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1.0 INTRODUCTION
The following report provides a detailed analysis and design of the Stormwater Management Plan
for Pinnacle Cranes. The proposed site is located northwest of US-601, northeast of Fieldstone
Trace, and southeast of Slatebrooks Drive. The proposed project area involves the development of
grassy open area and wooded area into an industrial development. The Stormwater Management
Plan was prepared in accordance with the requirements of both the Town of Midland and the North
Carolina DEQ. The runoff from this site will be routed through a sand filter for water quality and
quantity control before discharging to existing roadway swales which outlet to unnamed tributaries
of Muddy Creek.
Figure 1 — Site Location Map
2.0 HYDROLOGIC ANALYSIS
Hydrologic parameters such as Runoff Curve Number (RCN) and Time of Concentration were
determined using standard Natural Resources Conservation Service (NRCS) methodology. The 1-,
2-, 10-, 25-, 50-, and 100-year storm event discharge amounts were calculated using the NRCS
TR-55 method. This analysis reflects the NRCS Type II distribution, 24-hr storm duration. Rainfall
depths were obtained from NOAA Atlas 14, Volume 2, Version 3, 2004. The peak flow rates were
computed using the HydroCAD 10.0 computer program.
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3.0 PRE -DEVELOPED ANALYSIS
The pre -developed condition, as seen on Sheet 6.0 of the plan set, consists of grassy open space
and wooded area in good condition in Type "C" soils (Badin channery silt loam and Kirksey silt
loam). The subarea Pre NW naturally drains to the northwest to an existing roadway swale along
Slatebrooks Drive. The subarea Pre SE naturally drains to the southeast to an existing roadway
swale along US-601. Both subareas eventually discharge into Muddy Creek.
All pre -developed subarea characteristics are summarized in Table 1. Pre -developed peak flow
rates are provided in Table 2. All time of concentration calculations can be found in the HydroCAD
output in Appendix C.
Table 1 -Pre-developed Subarea Characteristics
Tributary
Runoff
%
Time of
Subarea
Area
Curve
Impervious
Concentration
Identifier
(acres)
Land Usage
Number
(%)
(min)
Open Space,
Pre NW
1.004
Woodland
74
0%
13.5
Open Space,
Pre SE
6.537
Woodland
74
0%
34.6
Total
7.541
1 -
1 74
1 0%
1 -
Table 2 -Pre-developed Peak Flow Rates
Storm Event
(year)
Pre NW Peak Flow
Rates
(cfs.)
Pre SE
Peak Flow Rates
(cfs.)
1
1.11
3.97
2
1.67
6.08
10
3.36
12.56
25
4.46
16.78
50
5.35
20.23
100
6.28
23.82
4.0 POST -DEVELOPED ANALYSIS
The post -developed condition, as seen on Sheet 6.1 of the plan set, shows the post -developed
condition. The Pinnacle Cranes project will utilize a sand filter within a dry basin to provide water
quality and quantity control for the proposed development. Post SE consists of a new building,
parking lot, and gravel area that will drain to the Sand Filter which discharges to the swale along
US-601. Post NW consists of the proposed driveway entrances which will drain offsite undetained,
but will not increase peak flow rates to the swale along Slatebrooks Drive.
The post -developed subarea characteristics are summarized in Table 3. The post -developed
allowable release rates and proposed release rates for the swale along Slatebrooks Drive (NW
outfall) can be found in Table 4. The post -developed allowable release rates, proposed release
rates, and the Sand Filter performance summary can be found in Table 5. HydroCAD output has
been provided in Appendix C.
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Table 3 -Post-developed Subarea Characteristics
Tributary
Runoff
%
Time of
Subarea
Area
Curve
Impervious
Concentration
Identifier
(acres)
Land Usage
Number
(%)
(min)
Open Space and
Post NW
0.263
Impervious Area
91
69%
5.0
Open Space, Woodland,
Post SE
7.278
Gravel, Impervious Area
91
77%
6.6
Total
7.541
1 -
1 91
1 77%
1 -
Table 4 -Allowable and Proposed Release Rates to NW
Storm
Event
(yr.)
Pre NW Peak
Flow Rates
(cfs.)
Allowable
Release Rates
(cfs.)
Proposed NW
Release Rates
(cfs.)
1
1.11
1.11
0.93
2
1.67
1.67
1.18
10
3.36
3.36
1.83
25
4.46
4.46
2.22
50
5.35
-
2.53
100
6.28
6.28
2.85
Table 5 -Allowable and Proposed Release Rates with Sand Filter Performance Summary
Storm
Event
(yr.)
Pre SE
Peak Flow
Rates
(cfs.)
Allowable
Release Rates
(cfs.)
Sand Filter
Proposed
Release Rates
(cfs.)
Maximum
W.S.E., T.O.B.
= 514.50
(feet)
Storage
Volume
Utilized
(ac-ft)
1
3.97
3.97
1.52
510.89
0.685
2
6.08
6.08
4.38
511.12
0.799
10
12.56
12.56
11.37
511.93
1.222
25
16.78
16.78
14.23
512.41
1.491
50
20.23
-
17.03
512.76
1.688
100
23.82
1 23.82
1 17.78
1 513.12
1 1.901
Storage Utilized (100-yr event): 1.901 ac-ft
Storage Provided (Top of Bank = 514.50 ft.): 2.779 ac-ft
5.0 OUTLET DESIGN
The outlet structure for the Sand Filter will be located on the north side of the basin. The location of
this structure can be seen on Sheet 6.1 of the plan set.
Sand Filter - Outlet Control Structure
• Area of sand required = 2469 sf.
• Area of sand provided = 2885 sf.
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• Top of sand — 509.00 ft.
• Bottom of sand/top of gravel — 507.00 ft.
• Bottom of gravel — 506.00 ft.
• Top of Bank — 514.50 ft.
• 100-year elevation — 513.12 ft.
• 1 sf stage outlet — Sand filter to underdrain, underdrain at 506.00 ft. with turn -up to 508.00 ft.
• 2nd stage outlet — (2) 28-inch wide by 6-inch high windows, invert at 510.70 ft.
• 3rd stage outlet — NCDOT grate 840.16, top of casting at 512.40 ft.
• Tailwater Control — 18-inch outlet pipe with 0.51 % slope, invert at 508.00 ft. (controls 1 sf
through 3rd stage outlets)
• Emergency Spillway — 35-foot long reinforced earthen weir, crest of weir at 514.00 ft.
6.0 WATER QUALITY
The North Carolina DEQ requires that the first flush (or first I" of rainfall) gets treated for water
quality. The water quality volume shall be drawn down for a period of two to five days. Water
quality drawdown for the basin will be provided by the basin's 1 sf stage outlet listed in Section 5.0.
Water quality calculations are summarized in Table 6 and provided in Appendix B.
Table 6 -Water Qualitv Calculations
Tributary
Percent
Water Quality
Water Quality
Required
Provided
area
Impervious
Volume
Elevation
Sand Area
Sand Area
Basin Identifier
(acres)
(%)
(ac-ft)
(feet)
(sf.)
(sf.)
Sand Filter
7.278
77%
0.448
510.42
2469
2885
7.0 CONCLUSION
The proposed stormwater management plan for Pinnacle Cranes meets all requirements for
detention and water quality as set forth by the Town of Midland and the North Carolina DEQ.
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APPENDIX A:
USDA Soils and NOAA Rainfall Reports

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APPENDIX A:
USDA Soils and NOAA Rainfall Reports

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Map Scale: 1:3,220 if printed on A portrait (8.5" x 11") sheet.
$ Meters N
0 45 90 180 270
Feet
0 150 300 600 900
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
USDA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
Hydrologic Soil Group—Cabarrus County, North Carolina
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Hydrologic Soil Group—Cabarrus County, North Carolina
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
BaB
Badin channery silt
loam, 2 to 8 percent
slopes
C
7.4
35.9%
KkB
Kirksey silt loam, 1 to 6
percent slopes
C
13.3
64.1 %
Totals for Area of Interest
20.7
100.0%
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.
USDA Natural Resources Web Soil Survey 6/22/2020
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group—Cabarrus County, North Carolina
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources Web Soil Survey 6/22/2020
Conservation Service National Cooperative Soil Survey Page 4 of 4

Precipitation Frequency Data Server
Page 1 of 4
NOAA Atlas 14, Volume 2, Version 3
Location name: Midland, North Carolina, USA*
Latitude: 35.2199*, Longitude:-80.5159°
Elevation: 517.55 ft**
* source: ESRI Maps
'"�w„
** source: USGS
..�:s�
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)'
Average
recurrence interval (years)
1
2
5
10
25
501
100 j200
500
1000
0.408
0.482
0.561
0.617
0.680
0.723
0.762
0.796
0.833
0.859
5-min
(0.376-0.443)
(0.444-0.525)
(0.515-0.610)
(0.565-0.669)
(0.620-0.736)
(0.657-0.783)
(0.689-0.825)
(0.716-0.862)
(0.743-0.904)
(0.760-0.933)
0.652
0.771
0.898
0.986
1.08
1.15
1.21
1.26
1.32
1.35
10-min
(0.601-0.708)
(0.710-0.840)
(0.825-0.977)
(0.904-1.07)
(0.989-1.17)
1 (1.05-1.25)
1 (1.10-1.31)
1 (1.14-1.37)
1 (1.18-1.43)
(1.20-1.47)
0.815
0.969
1.14
1.25
1.37
1.46
1.53
1.59
1.66
1.70
15-min
(0.751-0.885)
(0.892-1.06)
1 (1.04-1.24)
1 (1.14-1.35)
1 (1.32-1.58) 11
(1.38-1.66)
1 (1.43-1.72)
1 (1.48-1.80)
1 (1.50-1.84)
1.12
1.34
1.61
1.81
2.03
2.20
2.34
2.48
2.64
2.75
30-min
(1.03-1.21)
1 (1.23-1.46)
1 (1.48-1.76)
1 (1.66-1.96)
1 (1.86-2.20)
1 (2.00-2.38)
1 (2.12-2.54)
1 (2.23-2.68)
1 (2.35-2.86)
(2.43-2.99)
60-min
1.39
1.68
2.07
2.35
2.71
2.98
3.23
3.48
3.79
4.01
(1.28-1.51)
(1.55-1.83)
(1.90-2.25)
(2.16-2.55)
(2.47-2.93)
(2.70-3.22)
(2.92-3.49)
(3.13-3.76)
(3.38-4.11)
(3.55-4.36)
1.61
1.95
2.42
2.77
3.23
3.57
3.91
4.24
4.67
5.00
2-hr
(1.48-1.76)
(1.79-2.13)
(2.21-2.65)
(2.53-3.03)
(2.93-3.52)
(3.23-3.89)
(3.51-4.26)
(3.79-4.62)
(4.13-5.10)
(4.38-5.46)
1.72
2.08
2.59
2.99
3.52
3.93
4.35
4.77
5.34
5.79
3-hr
(1.57-1.89)
1 (1.90-2.28)
1 (2.37-2.84)
1 (2.72-3.27)
1 (3.19-3.84)
1 (3.55-4.29)
1 (3.89-4.73)
1 (4.24-5.19)
1 (4.69-5.83)
1 (5.03-6.32)
2.07
2.50
3.12
3.61
4.26
4.78
5.31
5.85
6.59
7.17
6-hr
(1.90-2.27)
1 (2.29-2.74)
1 (2.86-3.42)
1 (3.29-3.94)
1 (3.87-4.64)
1 (4.31-5.20)
1 (4.75-5.77)
1 (5.18-6.36)
1 (5.77-7.16)
2.46
2.97
3.72
4.33
5.15
5.82
6.50
7.22
8.21
9.01
12-hr
(2.26-2.69)
(2.73-3.26)
(3.41-4.08)
(3.95-4.73)
(4.67-5.61)
(5.23-6.32)
(5.79-7.06)
(6.36-7.83)
(7.12-8.89)
(7.71-9.77)
2.91
3.51
4.41
5.12
6.09
6.86
7.65
8.47
9.59
10.5
24-h r
(2.70-3.15)
(3.26-3.81)
(4.09-4.78)
(4.74-5.54)
(5.61-6.58)
(6.30-7.41)
(7.01-8.27)
(7.73-9.15)
(8.72-10.4)
(9.49-11.4)
3.42
4.12
5.13
5.93
7.02
7.89
8.78
9.70
11.0
12.0
2tlay
(3.17-3.68)
(3.82-4.45)
(4.76-5.54)
(5.49-6.40)
(6.48-7.56)
(7.26-8.50)
(8.06-9.46)
(8.87-10.5)
(9.97-11.8)
(10.8-12.9)
3.62
4.35
5.40
6.22
7.35
8.25
9.17
10.1
11.4
12.5
3tlay
(3.36-3.90)
1 (4.05-4.69)
1 (5.01-5.81)
1 (5.77-6.70)
1 (6.79-7.91)
1 (7.60-8.88)
1 (8.43-9.87)
1 (9.27-10.9)
(10.4-12.3)
1 (11.3-13.5)
3.83
4.59
5.67
6.52
7.68
8.62
9.57
10.6
11.9
13.0
4tlay
(3.56-4.11)
1 (4.27-4.93)
1 (5.26-6.08)
1 (6.04-7.00)
1 (7.10-8.25)
1 (7.94-9.26)
1 (8.80-10.3)
1 (9.68-11.3)
1 (10.9-12.8)
(11.8-14.0)
7tlay
4.41
5.26
6.41
7.32
8.58
9.58
10.6
11.7
13.1
14.3
(4.13-4.71)
(4.93-5.62)
(6.00-6.84)
(6.84-7.82)
(7.99-9.16)
(8.90-10.2)
(9.83-11.3)
(10.8-12.5)
(12.1-14.1)
(13.1-15.3)
10-day
5.06
6.02
7.24
8.19
9.48
10.5
11.5
12.6
14.0
15.1
(4.76-5.39)
(5.65-6.41)
(6.79-7.70)
(7.68-8.72)
(8.86-10.1)
(9.79-11.2)
(10.7-12.3)
(11.7-13.4)
(12.9-14.9)
(13.9-16.1)
6.79
8.02
9.47
10.6
12.2
13.4
14.6
15.8
17.5
18.8
20-day
(6.42-7.18)
1 (7.58-8.48)
1 (8.94-10.0)
1 (10.0-11.2)
1 (12.5-14.1)
(13.7-15.4)
(14.8-16.8)
(16.3-18.6)
(17.4-20.0)
30-day
8.34
9.81
11.4
12.6
14.3
15.5
16.8
18.0
19.7
20.9
(7.90-8.80)
1 (9.30-10.3)
1 (10.8-12.0)
1 (12.0-13.3)
1 (13.5-15.1)
(14.6-16.4)
(15.8-17.7)
(16.9-19.1)
(18.4-20.8)
(19.5-22.2)
45-day
10.5
12.3
14.1
15.4
17.2
18.5
19.8
21.1
22.8
24.0
(10.0-11.0)
1 (11.7-12.9)
1 (13.4-14.7)
1 (14.7-16.2)
(16.3-18.0)
(17.5-19.4)
(18.7-20.8)
(19.9-22.1)
(21.4-23.9)
(22.5-25.3)
12.5
14.6
16.5
18.0
19.9
21.3
22.7
24.0
25.8
27.1
60-day
(12.0-13.1)
(14.0-15.3)
(15.8-17.3)
(17.2-18.8)
(19.0-20.8)
(20.3-22.3)
(21.6-23.7)
LEZ 8-25.2)
(24.4-27.0)
(25.6-28.4)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90 % confidence interval. The probability that precipitation frequency estimates
(for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds
are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
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Precipitation Frequency Data Server
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c
30
25
5
0
PF graphical
PD5-based depth -duration -frequency {DDT} curves
Latitude: 35.2199', Longitude:-30.5159'
C_
C_
C
C
C_
, 7, 7:.,
}, 7,
7, y,
E
E
1=
E
E
-0 -0-0
-0 -0
-0 -0
-0-0
u'S
OO
1A
rl
Q
m
O
O
lG
N rh
Lb N
�" 1
f+l
A f� V
M1 6
14
66
N n
LA 6rl
V ko
Duration
on
25
a
r 20
5
0
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
Nt7AA Atlas 14, Volume 2, Version 3 Created {Gh1T}: Mon Jun 22 13:26:55 2020
Back to Top
Ausrage recurrence
rnleNal
(yaars)
— 1
2
5
10
25
50
100
200
500
1000
Duration
— 5-min —
2-day
— 1 Dmin —
3-day
15min —
4-day
— 30-min —
7-day
— 6Dmin —
10-day
— 2fir —
20-day
— 3fir —
30-day
— 8-rr —
45-day
— 12-hr —
60-day
— 24-hr
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Precipitation Frequency Data Server
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Maps & aerials
Small scale terrain
i
I . Midland
M F
Urn
mi
Large scale terrain
I't' Bristol
a
}city 4 Winston -Sal en}
a Dwhan}
Green sbara '
,: r:11 r:•lira}ell � Ralei+
Ashevill-e NORTH CAROLINA
• CT ""tte Fayetteville a
•
Greenville +
L
SOUTH CAROLINA ilm
1OOkm�
60mi •
CoILII}}I:•I i
Large scale map
I - Johnson City
Winston-Salen} Greensboro
Durham
Raleil
Asheville North
Carolina
___ hajatte
ettevil
Greene",Ee
Okm
m6is
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Precipitation Frequency Data Server
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Back to Top
US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: HDSC.Questionsidnoaa.gov
Disclaimer
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APPENDIX B:
Water Quality Calculations

Sand Filter Design
Sand Filter
1=
Rv =
Rv =
WQ Rain
WQv =
Af = (WQv)(df) / ((k)(hf+df)(tf))
A=
WQv =
df =
k=
hf =
t=
Af (required) _
Af (provided) _
As (required) _
As (provided) _
Onsite Area
0.05+0.0091
Stage Discharge Calculation - Sand Filter Only
Qo = Af(k)(hf+df)/df
Af =
k=
hf =
df =
hf
0
0.10
0.20
0.30
0.40
0.50
0.75
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
Outlet Design
7.278 acres
76.5 %
0.74
1 "
19512 cu-ft
(required sand filter surface area)
7.278 acres
19512 cu-ft
(water quality volume)
2 ft
(optimal efficiency)
3.5 ft/day
0.71 ft
(24" max depth)
1.667 days
2469 sf
(required area)
2885 sf
1288 sf
4792 sf
2885 sf
(designed area)
3.5 ft/day
0.71 ft
2 ft
Elev.
Qo
(ft)
0
0 cfs
509.00
10601 cf/day
0.123 cfs
509.10
11106 cf/day
0.129 cfs
509.20
11611 cf/day
0.134 cfs
509.30
12115 cf/day
0.140 cfs
509.40
12620 cf/day
0.146 cfs
509.50
13882 cf/day
0.161 cfs
509.75
15144 cf/day
0.175 cfs
510.00
17668 cf/day
0.204 cfs
510.50
20192 cf/day
0.234 cfs
511.00
22717 cf/day
0.263 cfs
511.50
25241 cf/day
0.292 cfs
512.00
27765 cf/day
0.321 cfs
512.50
30289 cf/day
0.351 cfs
513.00
32813 cf/day
0.380 cfs
513.50
35337 cf/day
0.409 cfs
514.00
37861 cf/day
0.438 cfs
514.50

Top of Gravel
509.25 ft
Top of Sand
509 ft
Total Bottom Area
2885 sq-ft
Min Sand Area
2469 sq-ft
Actual Sand Area
2885 sq-ft
Static WQ elevation
510.42 ft
1-year storm elev
510.90 ft
2nd stage outlet elev
510.70 ft
2nd stage outlet
(2) 28" W x 6" H windows
Tailwater Control
18-inch outlet pipe
Top of Bank
514.5
bottom of sand elev
507
SHWT elevation
ft
Underdrain Calculation
WQv =
19512 cu-ft
Drawdown =
0.113 cfs
Length of Pipe =
50 ft
Perforations =
200 holes
50% clogged =
100 holes
Hole Diameter=
3/8"
Capacity =
0.009 cfs
Total Capacity =
0.860 cfs
Perforation Capacity is greater than filter media capacity
50-year Storm
Peak Elevation = 512.73
Top of Bank = 514.50
(48 hours)
(4 per ft)
(per hole)

7P
Sand Filter 01 WQ @
510.42
S4
Reach on L
ink
8P
Forebay

2020-0122 Pinnacle Cranes 2020-08-03
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Rainfall Events Listing
Event#
Event
Name
Storm Type Curve
Mode
Duration
(hours)
B/B
Depth
(inches)
AMC
1
1-year
Type II 24-hr
Default
24.00
1
2.91
2
2
2-year
Type II 24-hr
Default
24.00
1
3.51
2
3
10-year
Type II 24-hr
Default
24.00
1
5.12
2
4
25-year
Type II 24-hr
Default
24.00
1
6.09
2
5
50-year
Type II 24-hr
Default
24.00
1
6.86
2
6
100-year
Type II 24-hr
Default
24.00
1
7.65
2
7
WQ
Type II 24-hr
Default
24.00
1
1.00
2

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr WQ Rainfall=1.00"
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Summary for Pond 7P: Sand Filter 01 WQ @ 510.42
Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Outflow = 0.20 cfs @ 0.00 hrs, Volume= 0.455 af, Atten= 0%, Lag= 0.0 min
Primary = 0.20 cfs @ 0.00 hrs, Volume= 0.455 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Starting Elev= 510.42' Surf.Area= 0.473 ac Storage= 0.455 of
Peak Elev= 510.42' @ 0.00 hrs Surf.Area= 0.473 ac Storage= 0.455 of
Plug -Flow detention time= (not calculated: no plugs found)
Center -of -Mass det. time= (not calculated: no inflow)
Volume
Invert Avail.Storage Storage
Description
#1
509.00'
2.779 of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation
Surf.Area
Inc.Store
Cum.Store
(feet)
(acres)
(acre-feet)
(acre-feet)
509.00
0.066
0.000
0.000
510.00
0.454
0.260
0.260
511.00
0.500
0.477
0.737
512.00
0.547
0.524
1.261
513.00
0.595
0.571
1.832
514.00
0.644
0.620
2.451
514.50
0.669
0.328
2.779
Device Routing Invert Outlet Devices
#1 Primary 509.00' Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
Primary OutFlow Max=0.20 cfs @ 0.00 hrs HW=510.42' (Free Discharge)
L1=Sand Filter (Custom Controls 0.20 cfs)

2020-0122 Pinnacle Cranes 2020-08-03 Type // 24-hr WQ Rainfall=1.00"
Prepared by Symanetc Printed 8/4/2020
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Pond 7P: Sand Filter 01 WQ @ 510.42
Hydrograph
❑ Inflow
❑ Primary
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type // 24-hr WQ Rainfall=1.00"
Prepared by Symanetc Printed 8/4/2020
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Hydrograph for Pond 7P: Sand Filter 01 WQ @ 510.42
Time
Inflow
Storage
Elevation
Primary
(hours)
(cfs)
(acre-feet)
(feet)
(cfs)
0.00
0.00
0.455
510.42
0.20
2.00
0.00
0.422
510.35
0.20
4.00
0.00
0.390
510.28
0.19
6.00
0.00
0.359
510.22
0.19
8.00
0.00
0.328
510.15
0.18
10.00
0.00
0.298
510.08
0.18
12.00
0.00
0.269
510.02
0.18
14.00
0.00
0.240
509.95
0.17
16.00
0.00
0.212
509.89
0.17
18.00
0.00
0.184
509.82
0.16
20.00
0.00
0.157
509.75
0.16
22.00
0.00
0.131
509.67
0.16
24.00
0.00
0.106
509.59
0.15
26.00
0.00
0.081
509.50
0.15
28.00
0.00
0.057
509.40
0.14
30.00
0.00
0.035
509.29
0.13
32.00
0.00
0.013
509.14
0.13
34.00
0.00
0.001
509.02
0.02
36.00
0.00
0.000
509.00
0.00
38.00
0.00
0.000
509.00
0.00
40.00
0.00
0.000
509.00
0.00
42.00
0.00
0.000
509.00
0.00
44.00
0.00
0.000
509.00
0.00
46.00
0.00
0.000
509.00
0.00
48.00
0.00
0.000
509.00
0.00
50.00
0.00
0.000
509.00
0.00
52.00
0.00
0.000
509.00
0.00
54.00
0.00
0.000
509.00
0.00
56.00
0.00
0.000
509.00
0.00
58.00
0.00
0.000
509.00
0.00
60.00
0.00
0.000
509.00
0.00

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr WQ Rainfall=1.00"
Prepared by Symanetc Printed 8/4/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 6
Summary for Pond 8P: Forebay
Volume Invert Avail.Storaae Storaae Description
#1 510.00' 11,183 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic -feet) (cubic -feet)
510.00 4,792 0 0
511.00 5,578 5,185 5,185
512.00 6,417 5,998 11,183

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APPENDIX C:
HydroCAD Output

8S 3S
Pre NW Pre SE
5S 1S
Post NW - Undetained Post SE - To Sand Filter
d rives
2P
Sand Filter 01
Subcat Reach on Link Routing Diagram for 2020-0122 Pinnacle Cranes 2020-08-03
Prepared by Symanetc, Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC

2020-0122 Pinnacle Cranes 2020-08-03
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 2
Rainfall Events Listing
Event#
Event
Name
Storm Type Curve
Mode
Duration
(hours)
B/B
Depth
(inches)
AMC
1
1-year
Type II 24-hr
Default
24.00
1
2.91
2
2
2-year
Type II 24-hr
Default
24.00
1
3.51
2
3
10-year
Type II 24-hr
Default
24.00
1
5.12
2
4
25-year
Type II 24-hr
Default
24.00
1
6.09
2
5
50-year
Type II 24-hr
Default
24.00
1
6.86
2
6
100-year
Type II 24-hr
Default
24.00
1
7.65
2
7
WQ
Type II 24-hr
Default
24.00
1
1.00
2

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 24.40 cfs @ 11.98 hrs, Volume= 1.205 af, Depth= 1.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-year Rainfall=2.91"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
Subcatchment 1S: Post SE - To Sand Filter
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 3S: Pre SE
Runoff = 3.97 cfs @ 12.34 hrs, Volume= 0.464 af, Depth= 0.85"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-year Rainfall=2.91"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
Prepared by Symanetc Printed 8/5/2020
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Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 0.93 cfs @ 11.96 hrs, Volume= 0.044 af, Depth= 1.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-year Rainfall=2.91"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
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Summary for Subcatchment 8S: Pre NW
Runoff = 1.11 cfs @ 12.07 hrs, Volume= 0.071 af, Depth= 0.85"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 1-year Rainfall=2.91"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
Prepared by Symanetc Printed 8/5/2020
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Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 1.99" for 1-year event
Inflow =
24.40 cfs @
11.98 hrs,
Volume=
1.205 of
Outflow =
1.52 cfs @
12.73 hrs,
Volume=
1.146 af, Atten= 94%, Lag= 45.4 min
Primary =
1.52 cfs @
12.73 hrs,
Volume=
1.146 of
Secondary =
0.00 cfs @
0.00 hrs,
Volume=
0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 510.89' @ 12.73 hrs Surf.Area= 0.495 ac Storage= 0.685 of
Plug -Flow detention time= 867.7 min calculated for 1.146 of (95% of inflow)
Center -of -Mass det. time= 839.4 min ( 1,642.9 - 803.5 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 1-year Rainfall=2.91"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 8
Primary OutFlow Max=1.51 cfs @ 12.73 hrs HW=510.89' (Free Discharge)
L1=Culvert (Passes 1.51 cfs of 12.08 cfs potential flow)
2=Sand Filter (Custom Controls 0.23 cfs)
3=Windows (Orifice Controls 1.29 cfs @ 1.42 fps)
4=Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 30.87 cfs @ 11.98 hrs, Volume= 1.547 af, Depth= 2.55"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=3.51"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
Subcatchment 1S: Post SE - To Sand Filter
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 3S: Pre SE
Runoff = 6.08 cfs @ 12.33 hrs, Volume= 0.679 af, Depth= 1.25"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=3.51"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 11
Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 1.18 cfs @ 11.96 hrs, Volume= 0.056 af, Depth= 2.55"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=3.51"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 12
Summary for Subcatchment 8S: Pre NW
Runoff = 1.67 cfs @ 12.06 hrs, Volume= 0.104 af, Depth= 1.25"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=3.51"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 13
Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 2.55" for 2-year event
Inflow = 30.87 cfs @ 11.98 hrs, Volume= 1.547 of
Outflow = 4.38 cfs @ 12.22 hrs, Volume= 1.484 af, Atten= 86%, Lag= 14.8 min
Primary = 4.38 cfs @ 12.22 hrs, Volume= 1.484 of
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 511.12' @ 12.22 hrs Surf.Area= 0.506 ac Storage= 0.799 of
Plug -Flow detention time= 685.4 min calculated for 1.484 of (96% of inflow)
Center -of -Mass det. time= 661.6 min ( 1,458.1 - 796.5 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 2-year Rainfall=3.51"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 14
Primary OutFlow Max=4.38 cfs @ 12.22 hrs HW=511.12' (Free Discharge)
L1=Culvert (Passes 4.38 cfs of 12.93 cfs potential flow)
2=Sand Filter (Custom Controls 0.24 cfs)
3=Windows (Orifice Controls 4.14 cfs @ 2.09 fps)
4=Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 15
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 48.12 cfs @ 11.98 hrs, Volume= 2.486 af, Depth= 4.10"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=5.12"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
■ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 16
Summary for Subcatchment 3S: Pre SE
Runoff = 12.56 cfs @ 12.30 hrs, Volume= 1.340 af, Depth= 2.46"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=5.12"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
Subcatchment 3S: Pre SE
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 17
Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 1.83 cfs @ 11.96 hrs, Volume= 0.090 af, Depth= 4.10"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=5.12"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 18
Summary for Subcatchment 8S: Pre NW
Runoff = 3.36 cfs @ 12.06 hrs, Volume= 0.206 af, Depth= 2.46"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=5.12"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 19
Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 4.10" for 10-year event
Inflow = 48.12 cfs @ 11.98 hrs, Volume= 2.486 of
Outflow = 11.37 cfs @ 12.13 hrs, Volume= 2.416 af, Atten= 76%, Lag= 9.3 min
Primary = 11.37 cfs @ 12.13 hrs, Volume= 2.416 of
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 511.93' @ 12.13 hrs Surf.Area= 0.544 ac Storage= 1.222 of
Plug -Flow detention time= 448.2 min calculated for 2.416 of (97% of inflow)
Center -of -Mass det. time= 430.9 min ( 1,214.3 - 783.3 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type 1124-hr 10-year Rainfall=5.12"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 20
Primary OutFlow Max=11.37 cfs @ 12.13 hrs HW=511.93' (Free Discharge)
L1=Culvert (Passes 11.37 cfs of 15.17 cfs potential flow)
2=Sand Filter (Custom Controls 0.29 cfs)
3=Windows (Orifice Controls 11.09 cfs @ 4.75 fps)
4=Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 21
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 58.42 cfs @ 11.97 hrs, Volume= 3.060 af, Depth= 5.05"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-year Rainfall=6.09"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
Subcatchment 1S: Post SE - To Sand Filter
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 22
Summary for Subcatchment 3S: Pre SE
Runoff = 16.78 cfs @ 12.30 hrs, Volume= 1.776 af, Depth= 3.26"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-year Rainfall=6.09"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
1
1
1
1
1
1
1
N
1
3
0
LL
Subcatchment 3S: Pre SE
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
■ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 23
Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 2.22 cfs @ 11.96 hrs, Volume= 0.111 af, Depth= 5.05"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-year Rainfall=6.09"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 24
Summary for Subcatchment 8S: Pre NW
Runoff = 4.46 cfs @ 12.05 hrs, Volume= 0.273 af, Depth= 3.26"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 25-year Rainfall=6.09"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
❑ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 25
Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 5.05" for 25-year event
Inflow = 58.42 cfs @ 11.97 hrs, Volume= 3.060 of
Outflow = 14.23 cfs @ 12.13 hrs, Volume= 2.988 af, Atten= 76%, Lag= 9.1 min
Primary = 14.23 cfs @ 12.13 hrs, Volume= 2.988 of
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 512.41' @ 12.13 hrs Surf.Area= 0.567 ac Storage= 1.491 of
Plug -Flow detention time= 377.5 min calculated for 2.988 of (98% of inflow)
Center -of -Mass det. time= 363.0 min ( 1,140.8 - 777.8 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type/1 24-hr 25-year Rainfall=6.09"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 26
Primary OutFlow Max=14.17 cfs @ 12.13 hrs HW=512.41' (Free Discharge)
L1=Culvert (Passes 14.17 cfs of 16.29 cfs potential flow)
2=Sand Filter (Custom Controls 0.32 cfs)
3=Windows (Orifice Controls 13.58 cfs @ 5.82 fps)
4=Grate (Weir Controls 0.27 cfs @ 0.39 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 27
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 66.55 cfs @ 11.97 hrs, Volume= 3.518 af, Depth= 5.80"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-year Rainfall=6.86"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
Subcatchment 1S: Post SE - To Sand Filter
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 28
Summary for Subcatchment 3S: Pre SE
Runoff = 20.23 cfs @ 12.30 hrs, Volume= 2.136 af, Depth= 3.92"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-year Rainfall=6.86"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
Subcatchment 3S: Pre SE
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 29
Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 2.53 cfs @ 11.96 hrs, Volume= 0.127 af, Depth= 5.80"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-year Rainfall=6.86"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 30
Summary for Subcatchment 8S: Pre NW
Runoff = 5.35 cfs @ 12.05 hrs, Volume= 0.328 af, Depth= 3.92"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 50-year Rainfall=6.86"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
■ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 31
Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 5.80" for 50-year event
Inflow = 66.55 cfs @ 11.97 hrs, Volume= 3.518 of
Outflow = 17.03 cfs @ 12.12 hrs, Volume= 3.446 af, Atten= 74%, Lag= 8.8 min
Primary = 17.03 cfs @ 12.12 hrs, Volume= 3.446 of
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 512.76' @ 12.12 hrs Surf.Area= 0.583 ac Storage= 1.688 of
Plug -Flow detention time= 338.1 min calculated for 3.446 of (98% of inflow)
Center -of -Mass det. time= 324.9 min ( 1,099.0 - 774.1 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 50-year Rainfall=6.86"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 32
Primary OutFlow Max=17.03 cfs @ 12.12 hrs HW=512.76' (Free Discharge)
L1=Culvert (Inlet Controls 17.03 cfs @ 9.64 fps)
2=Sand Filter (Passes < 0.34 cfs potential flow)
3=Windows (Passes < 15.09 cfs potential flow)
4=Grate (Passes < 10.55 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 33
Summary for Subcatchment 1 S: Post SE - To Sand Filter
Runoff = 74.86 cfs @ 11.97 hrs, Volume= 3.990 af, Depth= 6.58"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=7.65"
Area (ac) CN Description
1.124 98 impervious area
4.444 96 Gravel surface, HSG C
0.319 70 Woods, Good, HSG C
1.391 74 >75% Grass cover, Good, HSG C
7.278 91 Weighted Average
6.154 84.56% Pervious Area
1.124 15.44% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.6 792 2.00 Direct Entry, Pipe flow
Subcatchment 1S: Post SE - To Sand Filter
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 34
Summary for Subcatchment 3S: Pre SE
Runoff = 23.82 cfs @ 12.30 hrs, Volume= 2.513 af, Depth= 4.61"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=7.65"
Area (ac) CN Description
0.487 70 Woods, Good, HSG C
6.050 74 Pasture/grassland/range, Good, HSG C
6.537 74 Weighted Average
6.537 100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
21.7
100
0.0183
0.08
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
12.9
552
0.0104
0.71
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
Subcatchment 3S: Pre SE
Hydrograph
■ Runoff
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 35
Summary for Subcatchment 5S: Post NW - Undetained drives
Runoff = 2.85 cfs @ 11.96 hrs, Volume= 0.144 af, Depth= 6.58"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=7.65"
Area (ac)
CN
Description
0.181
98
0.082
74
>75% Grass cover, Good, HSG C
0.263
91
Weighted Average
0.082
31.18% Pervious Area
0.181
68.82% Impervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
1.0
100
0.0261
1.60
Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.51"
0.3
53
0.0261
3.28
Shallow Concentrated Flow,
Paved Kv= 20.3 fps
3.7
Direct Entrv. to minimum
5.0 153 Total
❑ Runoff

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 36
Summary for Subcatchment 8S: Pre NW
Runoff = 6.28 cfs @ 12.05 hrs, Volume= 0.386 af, Depth= 4.61"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=7.65"
Area (ac)
CN
Description
0.979
74
Pasture/grassland/range, Good, HSG C
0.025
70
Woods, Good, HSG C
1.004
74
Weighted Average
1.004
100.00% Pervious Area
Tc
Length
Slope
Velocity Capacity
Description
(min)
(feet)
(ft/ft)
(ft/sec) (cfs)
13.2
100
0.0636
0.13
Sheet Flow,
Grass: Bermuda n= 0.410 P2= 3.51"
0.3
30
0.0729
1.89
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
13.5 130 Total
■ Runoff
N
U
3
0
LL

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 37
Summary for Pond 2P: Sand Filter 01
Inflow Area = 7.278 ac, 15.44% Impervious, Inflow Depth = 6.58" for 100-year event
Inflow = 74.86 cfs @ 11.97 hrs, Volume= 3.990 of
Outflow = 17.78 cfs @ 12.13 hrs, Volume= 3.916 af, Atten= 76%, Lag= 9.2 min
Primary = 17.78 cfs @ 12.13 hrs, Volume= 3.916 of
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.01 hrs
Peak Elev= 513.12' @ 12.13 hrs Surf.Area= 0.601 ac Storage= 1.901 of
Plug -Flow detention time= 308.0 min calculated for 3.916 of (98% of inflow)
Center -of -Mass det. time= 296.1 min ( 1,067.0 - 770.9 )
Volume Invert Avail.Storage
Storage Description
#1 509.00'
2.779
of Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet) (acres)
(acre-feet) (acre-feet)
509.00 0.066
0.000 0.000
510.00 0.454
0.260 0.260
511.00 0.500
0.477 0.737
512.00 0.547
0.523 1.261
513.00 0.595
0.571 1.832
514.00 0.644
0.619 2.451
514.50 0.669
0.328 2.779
Device Routing
Invert
Outlet Devices
#1 Primary
508.00'
18.0" Round Culvert
L= 37.295' RCP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 508.00' / 507.81' S= 0.0051 T Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1
509.00'
Sand Filter
Head (feet) 0.00 0.10 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Disch. (cfs) 0.000 0.123 0.129 0.134 0.140 0.146 0.161 0.175
0.204 0.234 0.263 0.292 0.321 0.351 0.380 0.409 0.438
#3 Device 1
510.70'
28.0" W x 6.0" H Vert. Windows X 2.00 C= 0.600
Limited to weir flow at low heads
#4 Device 1
512.40'
2.0" x 16.5" Horiz. Grate X 8.00 columns X 2 rows C= 0.600
Limited to weir flow at low heads
#5 Secondary
514.00'
35.0' 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

2020-0122 Pinnacle Cranes 2020-08-03 Type 11 24-hr 100-year Rainfall=7.65"
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 38
Primary OutFlow Max=17.78 cfs @ 12.13 hrs HW=513.12' (Free Discharge)
L1=Culvert (Inlet Controls 17.78 cfs @ 10.06 fps)
2=Sand Filter (Passes < 0.36 cfs potential flow)
3=Windows (Passes < 16.53 cfs potential flow)
4=Grate (Passes < 14.94 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=509.00' (Free Discharge)
L5= Broad -Crested Rectangular Weir ( Controls 0.00 cfs)
N
U
3
0
LL
Pond 2P: Sand Filter 01
Hydrograph
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Time (hours)
Mry

2020-0122 Pinnacle Cranes 2020-08-03 Multi -Event Tables
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 39
Events for Subcatchment 1S: Post SE - To Sand Filter
Event
Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-year
2.91
24.40
1.205
1.99
2-year
3.51
30.87
1.547
2.55
10-year
5.12
48.12
2.486
4.10
25-year
6.09
58.42
3.060
5.05
50-year
6.86
66.55
3.518
5.80
100-year
7.65
74.86
3.990
6.58

2020-0122 Pinnacle Cranes 2020-08-03 Multi -Event Tables
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 40
Events for Subcatchment 3S: Pre SE
Event
Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-year
2.91
3.97
0.464
0.85
2-year
3.51
6.08
0.679
1.25
10-year
5.12
12.56
1.340
2.46
25-year
6.09
16.78
1.776
3.26
50-year
6.86
20.23
2.136
3.92
100-year
7.65
23.82
2.513
4.61

2020-0122 Pinnacle Cranes 2020-08-03 Multi -Event Tables
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 41
Events for Subcatchment 5S: Post NW - Undetained drives
Event
Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-year
2.91
0.93
0.044
1.99
2-year
3.51
1.18
0.056
2.55
10-year
5.12
1.83
0.090
4.10
25-year
6.09
2.22
0.111
5.05
50-year
6.86
2.53
0.127
5.80
100-year
7.65
2.85
0.144
6.58

2020-0122 Pinnacle Cranes 2020-08-03 Multi -Event Tables
Prepared by Symanetc Printed 8/5/2020
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC Page 42
Events for Subcatchment 8S: Pre NW
Event
Rainfall
(inches)
Runoff
(cfs)
Volume
(acre-feet)
Depth
(inches)
1-year
2.91
1.11
0.071
0.85
2-year
3.51
1.67
0.104
1.25
10-year
5.12
3.36
0.206
2.46
25-year
6.09
4.46
0.273
3.26
50-year
6.86
5.35
0.328
3.92
100-year
7.65
6.28
0.386
4.61

2020-0122 Pinnacle Cranes 2020-08-03
Prepared by Symanetc
HydroCAD® 10.10-3a s/n 03828 © 2020 HydroCAD Software Solutions LLC
Multi -Event Tables
Printed 8/5/2020
Page 43
Events for Pond
2P:
Sand Filter 01
Event
Inflow
Outflow
Primary Secondary
Elevation
Storage
(cfs)
(cfs)
(cfs)
(cfs)
(feet) (acre-feet)
1-year
24.40
1.52
1.52
0.00
510.89
0.685
2-year
30.87
4.38
4.38
0.00
511.12
0.799
10-year
48.12
11.37
11.37
0.00
511.93
1.222
25-year
58.42
14.23
14.23
0.00
512.41
1.491
50-year
66.55
17.03
17.03
0.00
512.76
1.688
100-year
74.86
17.78
17.78
0.00
513.12
1.901

A legacy of experience. A reputation for excellence.
APPENDIX D:
Storm Sewer Calculations

User Input Data
Calculated Value
Reference Data
Designed By:
Mariah Anderson Date: 8/5/2020
Checked By:
Brian Rossi Date: -
Company:
EMHaT
Project Name:
Pinnacle Cranes
Project No.:
2020-0122
Site Location (City/Town) Town of Midland
Culvert Id. BMP 1
Total Drainage Area (acres) 7.278
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe. Lf the tailwater depth is less
than half the outlet pipe diameter. it is classified mitunxwt taihvater condition.
Wit is greater than half the pipe diameter. it is classified mn=im„m condition.
Pipes that outlet onto wide flat areas with no defined channel are assumed
to have a minimum tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter, Do (in.) 18
Tailwater depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.06a)
Discharge (cfs) 17.78
Velocity (ft./s) 5.27
Step 2. Based on the tailwater conditions determined in step 1, enter Figure
8.06a or Figtrre 8.06b. and determine d� riprap size and minimum apron length
(L)J The d., size is the median stone size in a well -grated nprap apron
Step 3. Determine apron width at the pipe outlet. the apron shape. and the
apron width at the outlet end from the same figure used in Step I -
Minimum TW Maximum TW
Figure 8.06a Figure 8.06b
Riprap d50, (ft.) 0.6
Minimum apron length, La (ft.) 16
Apron width at pipe outlet (ft.) 4.5 4.5
Apron shape Trapezoid
Apron width at outlet end (ft.) 17.5 1.5
Step 4- Detemme the maxinitun stone diameter
d,,,,, = 1.5 x d,a
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft.) 0.9 0
Step 5. Determine the apron thickness
Apron thickness = 1.5 x dr.,
Minimum TW Maximum TW
Apron Thickness(ft.) 1.35 0
Step 6. Fit the riprap apron to the site by malting it level for the minimum
length. L.. from Figure 8 06a or Figure 8-06b- Emend the apron farther
downstream and along channel banks until stability is assured. Keep the
apron m straight as possible and align it with the flow of the receiving stream.
.lake goy necessary alignment bends war the pipe outlet so that the Mittac:e
into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure
stability_
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary (Appendix 8.05). Where overfalls exist at
pipe outlets or flows are excessive, a plunge pool should be considered, see
page 8.06.8.

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Discharge (ft3/sec
Curves may not be extrapolated.
Figure 8.06a Cosign of outlet protection protcction from a round pipe flowing full• minimum tailwater condition (Tw c 0.6 diamel•r).
Rev. IIJ93 8.06.