20141276 Ver 1_Stormwater Management Report_20141211 (4)

WITHERS & RAVENEL
STORMWATER MANAGEMENT
REPORT
HOWARD /EMERSON TRACT - COMMERCIAL
Cary, North Carolina
Prepared For:
NORTHWEST COMMUNITY CHURCH
7712 CARPENTER FIRE STATION RD
CARY NC 27519
ATTN: MR. JOEL CARPENTER
Prepared By:
WITHERS & RAVENEL, INC
115 MacKenan Drive
Cary, North Carolina 27511
Revised October 2014
W &R Project No. 02130427
"w1 frr
� N CAR"',
,,• F S�jQ•.•r
to. Z. Iq
Jennifer C. Diaz, PE
Clay Parrish, El

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
INTRODUCTION
The proposed Howard /Emerson Tract development is located southwest of the intersection of
Morrisville Parkway and White Oak Church Road in Cary, NC. The 20.07 acre development is proposed
as a church with associated parking and infrastructure. It is less than 24% and is therefore considered
low density.
The site in its existing conditions is approximately 80% wooded with some open space and
impervious area. The site is bound by White Oak Church Road to west, Morrisville Parkway to the north
and the American Tobacco Trail to the east — all of which are higher than the site. The site drains
towards the center and is collected via an unregulated stream feature which exits the site along the
southern boundary. The site is comprised of HSG "D" soils. A soils map is provided in the Background
Data portion of this report.
Site outlined in blue.
The impacts of the increased runoff from the development will be mitigated with a wet pond. The BMP
will be oversized in order to accommodate future development. Although the proposed development
is low density, the proposed BMP and storm drain network are designed to capture the proposed
impervious area to the maximum extent practical in anticipation that future development would
increase impervious area above 24% thereby making the site high density in the future.
STORMWATER MANAGEMENT REQUIREMENTS
The proposed development is with the Jordan Lake, Lower New Hope watershed. The site must
therefore meet Town requirements relating to town wide ordinances and policies for stormwater
NWCC - Commercial 1 W &R Project 02130427
Stormwater Management Plan Revised October 2014

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
compliance. To meet these requirements the Nitrogen export rates from the site are to be reduced to
4.4 lbs /ac /yr; Phosphorus export rates to 0.78 lbs /ac /yr.
This is accomplished through the use of a wet pond. Additionally, peak flows at the point of analysis
shall be reduced to predevelopment levels for the 1 -year storm and larger storms must also be
controlled to within the anticipated flows from R -40 zoning or 1o% of predevelopment flows,
whichever is less.
METHODOLOGY
The stormwater study was conducted using the natural drainage features as depicted by LIDAR
topography and existing field surveys. Proposed drainage areas were based on field survey data and
proposed development within the drainage areas.
The scope of work included the following analyses:
Hydrology
❑ Simulation of the 1 -year, 2 -year, 5 -year, 10 -year, and loo -year rainfall events for the Cary,
NC area
❑ Formulation of the 1 -year, 2 -year, 5 -year, 10 -year, and loo -year flood hydrographs for the
pre- and post- development drainage areas
Hydraulic
❑ Routing the 1 -year, 2 -year, 5 -year, so -year,
predevelopment runoff from the site.
❑ Routing the 1 -year, 2 -year, 5 -year, 10 -year, and
development runoff through the stormwater BMP.
❑ Analyzing results at the analysis point
and soo -year flood hydrographs for
soo -year flood hydrographs for post-
The results of the hydrology calculations are used in the hydraulic analyses. The hydraulic design
requires the development of stage- storage and stage- discharge functions for the BMP. The
rainfall /runoff hydrographs, stage- storage, and stage- discharge functions have been compiled to
create a computer routing simulation model using Bentley Systems PondPack v1o.o software. This
PondPack model was then used to assess the peak water surface elevations in the BMP forthe design
rainfall events. The PondPack modeling results are provided as appendices to this report.
HYDROLOGY
The SCS Method, in conjunction with NOAA Atlas 14 rainfall data for Raleigh- Durham International
Airport, was used to develop runoff hydrographs for the storm events. This method requires three
basic parameters: a curve number (CN), time of concentration (tc), and drainage area.
Curve numbers were based on soil type and land use. Soil types were delineated from the Soil Survey
of Wake County, North Carolina (November 1970). The curve numbers used in this study are listed in
the PondPack section of this report.
Time of concentration for pre- and post- development drainage areas were developed using the TR -55
method. A minimum time of concentration of 5 minutes was used for the proposed piped drainage
systems.
NWCC - Commercial 2 W &R Project 02130427
Stormwater Management Plan Revised October 2014

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
HYDRAULICS
Computer simulated reservoir routing of the 1 -year, 2 -year, 5 -year, io -year, and loo -year design storms
utilized stage- storage and stage- discharge functions. Stage- storage functions were derived from the
proposed geometry of the BMP. A non - linear regression relation for surface area versus elevation was
derived for each BMP. This relation estimates the incremental volume of the basin to the stage or
elevation of the basin. Stage- discharge functions were developed to size the proposed outlet
structures for the BMP.
NITROGEN EXPORT
The Nitrogen and Phosphorus export rates for the development were calculated using Jordan/ Falls
Lake Stormwater Nutrient Load Accounting Tool. All onsite drainage areas, including roadway and
driveway improvements, were used in the nutrient export analysis. The worksheet used to calculate
the nutrient export loading rate can be found in the appendices.
CONCLUSIONS
Quality
Based upon the routing study, the proposed stormwater management plan has sufficient measures
to provide the necessary removal of nutrients as required by Town policy.
The proposed stormwater wet pond has been designed to store and treat the water quality volume
(runoff associated with the first 1" of rainfall, WQv) generated by the contributing drainage area, and
draw down that volume in at least z days, but no slower than 5 days.
Because the runoff resulting from the first i" of rainfall is being discharged perthe NCDENR standards
for a wet pond, the appropriate reduction credits were taken for the area draining through the BMP.
The BMP treatment resulted in bringingthe total site's Nitrogen and Phosphorus export down to below
target levels.
Quantity
The peak flows from the site have been attenuated for predevelopment levels. Furthermore, the
proposed BMP has sufficient storage to safely pass the loo -year storm event without overtopping.
Future Expansion
The proposed SWMP and BMP have been designed with possible future development in mind. The
BMP has been sized to accommodate an additional 2.5 acres of impervious area for both water quality
and quantity control. This analysis of future impervious assumes that all of it drains to the BMP
without additional bypass.
Although this SWMP and BMP have accounted for future impervious area in this study, any expansion
to the site will still be subject to Town of Cary standards at the time of site plan submittal.
NWCC - Commercial 3 W &R Project 02130427
Stormwater Management Plan Revised October 2014

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
DESIGN SUMMARY
BMP #1 - WET POND
DRAINAGE AREA =16.10 ACRES
PERCENT IMPERVIOUS AREA = 44% (INCLUDES OFFSITE AND FUTURE DEVELOPMENT)
• 2.5" DRAWDOWN ORIFICE AT EL 351.0
• 2 -3' WIDE PEAK CONTROL WEIRS AT EL = 352.5
5'x5' RISER, CREST EL = 353.5
36" 0 -RING RCP OUTLET EL = 344.00
Top OF DAM EL = 356.00
BMP #1- Wet Pond Routing Summary
Storm Event
Peak Water Surface
Elevation
Freeboard
Qpeak Outflow
(total)
(ft)
(ft)
(cfs)
1 -Year
353.30
2.70
13.17
2 -Year
353.70
2.30
27.88
5 -Year
354.03
1.97
50.28
10 -Year
354.20
1.8o
64.3
loo -Year
354.51
1.49
90.54
PEAK ATTENUATION SUMMARY
NWCC - Commercial 4 W &R Project 02130427
Stormwater Management Plan Revised October 2014
Pre Development
Post Development
Net Change
Net Change
Peak Flow
Peak Flow w /BMP
(cfs)
NO
Storm Event
(cfs)
(cfs)
1 -Year
35.91
17.45
-18.46
-51%
2 -Year
52.36
36.24
-16.12
-31%
5 -Year
71.30
64.62
-6.68
-9%
10 -Year
86.36
84.33
-2.03
-2%
loo -Year
125.04
119.24
-5.8o
-5%
NWCC - Commercial 4 W &R Project 02130427
Stormwater Management Plan Revised October 2014

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
BACKGROUND INFORMATION
NWCC - Commercial W &R Project 02130427
Stormwater Management Plan Revised October 2014

35° 47 41" N
35° 47 23" N
3 Hydrologic Soil Group —Wake County, North Carolina 3
(NWCC - Commercial) N
m m
687430 697450 687550 6976.10 687670 687730 68877%
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3
Map Scale: 1:2,600 if printed on A portrait (8.5" x 11 ") sheet.
N — ,Meters
n 0 35 70 140 210
0 100 200 400 600
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
U Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
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Page 1 of 3
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Hydrologic Soil Group —Wake County, North Carolina
Hydrologic Soil Group
NWCC - Commercial
Hydrologic Soil Group— Summary by Map Unit— Wake County, North Carolina (NC183)
Map unit symbol Map unit name Rating Acres in AOI I Percent of AOI
CrB
Creedmoor sandy loam,
D
2 to 6 percent slopes
CrB2
Creedmoor sandy loam,
D
2 to 6 percent slopes,
moderately eroded
CrC
Creedmoor sandy loam,
D
6 to 10 percent slopes
CrC2
Creedmoor sandy loam,
D
6 to 10 percent slopes,
moderately eroded
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Creedmoor sandy loam,
D
10 to 20 percent
slopes
WyA
Worsham sandy loam, 0
D
to 3 percent slopes
Totals for Area of Interest
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie -break Rule: Higher
0.2
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0.2
9.7
Iff
1.1
20.1
1.1%
38.4%
1.1%
48.3%
5.5%
5.7%
100.0%
USDA Natural Resources Web Soil Survey 7/8/2014
Conservation Service National Cooperative Soil Survey Page 3 of 3

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
BMP SIZING
CALCULATIONS
NWCC - Commercial W &R Project 02130427
Stormwater Management Plan Revised October 2014

Project Name: Howard /Eemerson Tract - Commercial
City /State: Cary, NC
BMP #1
Project #: 2130427
Date: 1- Oct -14
Table 10.3 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 90% Pollutant
Removal Efficiency in the Piedmont
% Impervious
Permanent Pool Depth
3.0 4.0 5.0 6.0
(feet)
7.0 8.0 9.0
10
0.9
0.8
0.6
0.5
0.5
0.4
0.4
20
1.5
1.1
1.0
0.9
0.8
0.7
0.7
30
1.9
1.7
1.4
1.3
1.0
0.9
0.9
40
2.5
2.0
1.8
1.6
1.5
1.2
1.1
50
3.0
2.5
2.0
1.9
1.7
1.5
1.5
60
3.5
2.8
2.5
2.2
1.9
1.8
1.7
70
4.0
3.3
2.8
2.5
2.2
2.0
1.9
80
4.5
3.8
3.3
2.8
2.6
2.1
2.0
90
5.0
4.0
3.5
3.0
2.8
2.5
2.4
Source: NCDENP/DWQ Stormwater Best Management Practices, pg. 10 -15, July 2007 rev. 6/16/09
STORMWATER BMP #1- STORMWATER WET POND (25% TN Removal)
Land Use
Area
(ac)
% IA
Imp. Area
(ac)
Impervious
3.44
100
3.44
Open Space
8.36
0
0.00
Future Impervious
2.50
100
2.50
OFFSITE impervious
1 1.80
1 60
1.08
Totals
1 16.10
1
1 7.02
Total % Impervious Surface Area = 43.6 %
Surface Area of Permanent Pool:
Average depth = 5.00 ft
SA/DA ratio = 1.87 From Table 10.3
Minimum pond surface area (SA) = (DA * SA/DA ratio) /100
SA = 0.301 acres
13133 sq. ft.
Normal pool elevation = 351.0 feet
Surface area provided = 0.377 acres
16428 sq. ft.
1 -Inch Runoff Volume Calculation
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv = Runoff coefficient, in. /in.
I = Percent impervious
Rv = 0.44 in. /in.
Total runoff volume from 1 -inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.594 acre -ft
25871 cu. ft.
Water quality pool elevation=
352.38
feet
Overflow elevation=
352.50
feet
Storage volume provided =
0.653
acre -ft
28445
cu.ft.
K: \13 \13- 0420 \130427 - Northwest Community Church \H -H \Commercial \BMP #1 BMP #1 - Pond Design

Project Name: Howard /Eemerson Tract - Commercial Project #: 2130427
City /State: Cary, NC BMP #1 Date: 1- Oct -14
STORMWATER BMP #1- STORMWATER WET POND (25% TN Removal)
AVERAGE DEPTH
Per NCDENR "Stormwater Best Management Practices ", the average depth of a wet pond is to be calculated by one
of these two options:
K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \BMP #1 BMP #1 - Basin Sizing
Incremental
Accumulated
Below Normal Contour
Contour
Contour
Pool Contours Area
Volume
Volume
(feet) (SF)
(CF)
(CF)
343.00 5809
Abot_ pond
344.00 6613
6207
6207 — Sediment Storage Volume
346.00 8366
14945
21151
350.00 12457
41375
62527
Abot shelf
350.50 13737
6546
69073
Aperm pool
351.00 16428
7531
76604 —Total Pond Volume
PPS = Total Volume - Sediment Storage Volume = 70,397 cf
OPTION 1:
Average Depth = Permanent
Pool Volume / Surface Area
PPV =
70,397
cf
SA =
16,428
sf
day =
4.29 ft
OPTION 2:
Use the following equation:
da„ = 0.25 x (1 + Abot_ shelf )+ (Abot_ shelf + Abot_oond)
x Depth
Aperm_ pool
2
Abot shelf
day, = (0.25 x (1 + 13737
)) + ( 13737+
5473 ) x 6.5
16428
2
13737
day =
5.27 ft
Use Average Depth =
5.00 ft
OPTION 2
K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \BMP #1 BMP #1 - Basin Sizing

Project Name: Howard /Eemerson Tract - Commercial Project #: 2130427
City /State: Cary, NC BMP #1 Date: 1- Oct -14
STORMWATER BMP #1- STORMWATER WET POND (25% TN Removal)
Orifice Calculator
Q = Cd *A *(2gh)'(1/2)
1" WATER QUALITY STORM VOLUME
Variables Constants
WQ Volume: 0.594 Acre -ft 25871 cf g = 32.2 ft/s2
Head / Driving Head: 1.38 ft 0.46 ft Cd= 0.6
Draw down time: 65 hrs 234099 s
Orifice Area = 0.034 sq. ft
Orifice Diameter = 2.491 in
USE 2.5 INCH DIAMETER ORIFICE
4.873 sq. in
K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \BMP #1 BMP #1- Orifice Calculator

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
NITROGEN LOADING
CALCULATIONS
NWCC - Commercial W &R Project 02130427
Stormwater Management Plan Revised October 2014

Jordan Lake Developer Nutrient Reporting Form
Please complete and submit the following information to the local government permitting your development project to
characterize it and assess the need to purchase nutrient offsets. Contact and rule implementation information can be
found online at http: / /Dortal.ncdenr.org/ web /wq /ps /nps /nutrientoffsetintro.
PROJECT INFORMATION (for Jordan Lake)
Applicant Name:
Northwest Community Church
Project Name:
Howard /Eemerson Tract - Commercial
Project Address (if available): Street: City /Town: County:
Morrisville Parkway and White Oak Church Road, Cary, Wake
Date: (mo/d/yr) Project Lat: (decimal degrees) Long: (decimal degrees)
7/10/2014 Location : 35.791340° 1 - 78.925725°
Is this Redevelopment? Yes
Development Type (Please check all that apply)
X No
Impervious Cover ( %): 1 % HIndustrial Commercial Mixed -Use Single Fam. Residential
(Pre- Construction) Duplex Residential HMulti-Fam. Residential
Impervious Cover ( %): 19% Institutional
(Post- Construction) I H
JORDAN WATERSHED INFORMATION
Small Watershed ID (6 digits): (See next page or online map.) New Development Load Requirements (See individual rules
60150 for a full description of nutrient requirements.)
Jordan Subwatershed (Please check one) Loading Rate Targets Offsite Thresholds
Nitrogen (N) & Phosphorus (P)
Z.Z N iDiaciyr
0.82 P Ib /ac /yr
4.4 N Ib /ac /yr
0.78 P Ib /ac /yr
he offsite thresholds — see above)
6 N Ibs /ac Residential;
10 N Ibs /ac Commercial
(must meet all onsite treatment
requirements)
(D)
Upper New Hope
EX
Lower New Hope
NUTRIENT OFFSET REQUEST(Must meet t
Nitrogen Loading
/ Offset Needs
(A)
(B)
(C)
Untreated
Treated
Loading Rate
Loading Rate
Loading Rate
Target
(Ibs /ac /yr)
(Ibs /ac /yr)
(Ibs /ac /yr)
3.52
2.41
4.40
Phosphorus Loading / Offset
Needs
Z.Z N iDiaciyr
0.82 P Ib /ac /yr
4.4 N Ib /ac /yr
0.78 P Ib /ac /yr
he offsite thresholds — see above)
6 N Ibs /ac Residential;
10 N Ibs /ac Commercial
(must meet all onsite treatment
requirements)
(D)
(E)
(F)
(G)
Reduction Need
Project
Offset
Delivery
(Ibs /ac /yr)
Size (ac)
Duration (yrs)
Factor ( %)
B -C
Control of Peak
Stormwater Flow
(1 year 24 hour design storm)
0.00
20.07
30
88%
(A)
Untreated
Loading Rate
(Ibs /ac /yr)
(B)
Treated
Loading Rate
(Ibs /ac /yr)
(C)
Loading Rate
Target
(Ibs /ac /yr)
(D)
Reduction Need
(Ibs /ac /yr)
B - C
(E)
Project
Size (ac)
(F)
Offs
Duration
0.83
0.49
0.78
0.00
20.07
30
Control of Peak
Stormwater Flow
(1 year 24 hour design storm)
Calculated Predevelopment Peak Flow
35.91
Calculated Post Development Peak Flow
17.45
(H)
State Buy Down
Amount (Ibs)
D`E'F`G
0
(G) (H)
et Delivery State Buy Down
(yrs) Factor ( %) Amount (Ibs)
D "E'F`G
91% 0
Flow Control Method
Wet Detention Pond
Authorizing Local Government Name: Town of Cary
Staff Name: I Matt Flynn
Staff Email: matt.flynn @townofcary.org Phone: [phone]
Jordan Nutrient Load Reporting Form. September 12, 2012

Physiographic /Geologic Region:
Piedmont
Soil Hydrologic Group
D
Precipitation location:
Raleigh
COLUMN 1 -- NON- RESIDENTIAL LAND USES
874,191
TN EMC I TP EMC
(rng /L) (mg /L)
COMMERCIAL
Howard /Eemerson Tract - Commercial
Post -
Development
(ftz)
Pre-
Development
(ftz)
Parking lot
1.44
0.16
-ac lots
111,302
Roof
1.08
0.15
18,594
Open /Landscaped
2.24
0.44
1 -ac lots
INDUSTRIAL
Parking lot
1.44
0.39
2-ac lots
Roof
1.08
0.15
Multi- family
Open /Landscaped
2.24
0.44
Townhomes
TRANSPORTATION
High Density (interstate, main)
3.67
0.43
Custom Lot Size
Low Density (secondary, feeder)
1.4
0.52
PART B
Roadway
Rural
1.14
0.47
12,900
1.0
1.44
Parking lot
Sidewalk
1.4
1.16
32,000
Sidewalk /Patio
PERVIOUS
Lawn
Managed pervious
3.06
0.59
3.06
416,523
1.47
Unmanaged (pasture)
3.61
1.56
244,917
Open water*
Forest
1.47
0.25
616,374
295,772
JURISDICTIONAL LANDS*
Natural wetland
Riparian buffer
Open water
LAND TAKEN UP BY BMPs
1.08
0.15
*Jurisdictional land uses are not included in nutrient /flow calculations.
Total Development Area (ft 2):
874,191
Development Name:
Howard /Eemerson Tract - Commercial
Model Prepared By:
JCD
COLUMN 2 -- RESIDENTIAL LAND USES
Custom Age TN EMC TP EMC Pre- Post -
Lot Size Development Development
(ac) (yrs) (mg /L) (mg /L) (ftz) (ftz)
PART A
%-ac lots
-ac lots
Y. -ac lots
1 -ac lots
2-ac lots
Multi- family
Townhomes
Custom Lot Size
PART B
Roadway
1.4
0.52
0.39
0.39
0.15
1.16
0.44
0.59
0.25
--
0.15
Driveway
1.0
1.44
Parking lot
1.44
Roof
1.08
Sidewalk /Patio
1.4
Lawn
2.24
Managed pervious
3.06
Forest
1.47
Natural wetland*
Riparian buffer*
Open water*
LAND TAKEN UP BY BMPs
--
1.0.0 8
LAND USE AREA CHECK
Total Development Area Entered (ft'): 874,191
Total Pre - Development Calculated Area (ft): 874,191
Total Post - Development Calculated Area (ftz): 874,191

Type of BMP:
If BMP is undersized, indicate the BMP's size
relative to the design size required to capture
the designated water quality depth (i.e. 0.75
= BMP is 75% of required design size):
*For water harvesting BMP, enter percent
volume reduction in decimal form.
Catchment 1:
Catchment 2:
Catchment 3:
Catchment 4:
Catchment 5:
Catchment 6:
Drainage Area Land Use
MMERCIAL
Parking lot
Roof
Open /Landscaped
)USTRIAL
Parking lot
Roof
Open /Landscaped
ANSPORTATION
High Density (interstate, main)
Low Density (secondary, feeder)
Rural
Sidewalk
SC. PERVIOUS
2 -ac lots (New)
2 -ac lots (Built after 1995)
2 -ac lots (Built before 1995)
1 -ac lots (New)
1 -ac lots (Built after 1995)
1 -ac lots (Built before 1995)
-ac lots (New)
% -ac lots (Built after 1995)
% -ac lots (Built before 1995)
Y -ac lots (New)
Y -ac lots (Built after 1995)
X -ac lots (Built before 1995)
% -ac lots (New)
A -ac lots (Built after 1995)
%-ac lots (Built before 1995)
Townhomes (New)
Townhomes (Built after 1995)
Townhomes (Built before 1995)
Multi- family (New)
Multi- family (Built after 1995)
Multi- family (Built before 1995)
Custom Lot Size (New)
Custom Lot Size (Built after 1995)
Custom Lot Size (Built before 1995)
Sidewalk
Lawn
Managed pervious
Forest
NO TAKEN UP BY BMP
TOTAL AREA TREATED BY BMP (ftz):
TOTAL AREA TREATED BY SERIES (ft):
.......................""
BMP #1
Wet Detention
Pond
CATCHMENT 1 -----------------------------
BMP #2 BMP #3
no
no
no
no
no
no
no
no
no
no
no
no
no no no
Area treated Area treated
Area Treated by BMP #3 that is not
by BMP by BMP #2 that is not treated by BMPs #1
treated by BMP #1
(ft z) or #2
1ft' 1 (ft)
106,300
16,042
16,042
325,907
158,617
622,908 0 0
622,908

3. Development Summary
Development: Howard /Eemerson Tract - Commercial
Prepared By: JCD
Date: October 2, 2014
WATERSHED SUMMARY Ver2.0
REGION:
Piedmont
TOTAL DEVELOPMENT AREA (ft ):
874,191
Percent Impervious ( %)
17%
17%
0%
Pre - Development Conditions
Post - Development Conditions
Post - Development w/ BMPS
Percent Impervious
1,5%
18.5%
1815%
( %)
Total Nitrogen Loading (lb /ac /yr)
189%
98%
Annual Runoff Volume
Total Phosphorus EMC (mg/L)
-18%
-59%
(c.f.)
209,338
716,782
657,865
Total Nitrogen EMC
0.26
1.08
0.15
(mg/L)
1.87
1.58
1.18
Total Nitrogen Loading
1.20
0.15
Permeable
(lb /ac/yr)
1.22
3.52
2.41
0%
1.44
0.39
Total Phosphorus EMC
(mg /L)
0.59
0.48
0.24
user defined
1.08
0.15
Total Phosphorus Loading
(lb /ac /yr)
0.38
0.83
0.49
Percent Difference Between:
Negative percent difference values indicate a decrease in runoff volume, pollutant concentration or pollutant loading. Positive values indicate an increase.
BMP SUMMARY Ver2.0
BMP VOLUME REDUCTIONS /EFFLUENT CONCENTRATIONS
Pre -Dev. &
Post -Dev. without BMPs
Pre - Development &
Post - Development with BMPs
Post -Dev without BMPs &
Post -Dev with BMPs
Percent Impervious ( %)
17%
17%
0%
Annual Runoff Volume (c.f.)
242%
214%
-8%
Total Nitrogen EMC (mg/L)
-16%
-37%
-25%
Total Nitrogen Loading (lb /ac /yr)
189%
98%
-32%
Total Phosphorus EMC (mg/L)
-18%
-59%
-50%
Total Phosphorus Loading (lb /ac /yr)
1 117%
1 29%
1 -41%
Negative percent difference values indicate a decrease in runoff volume, pollutant concentration or pollutant loading. Positive values indicate an increase.
BMP SUMMARY Ver2.0
BMP VOLUME REDUCTIONS /EFFLUENT CONCENTRATIONS
`if treating commercial parking lot, TP effluent concentration = 0.16 mg/L
Return to Instructions
[ Return to Watershed Characteristics I
Return to BMP Characteristics
l Print Summary I
CATCHMENT 1
Volume Reduction TN Effluent Concen.
TP Effluent Concen.
CATCHMENT 4
(%) (mg/L)
(mg/L)
Bioretention with
BMP1
BMP2
BMP3
MIS
50%
0.95
0.12
Bioretention without
BMP3
BMP1
BMP2
MIS
35%
1.00
0.12
Dry Detention Pond
0%
1.20
0.20
Grassed Swale 0%
1.21
0.26
1.08
0.15
Green Roof 50%
Level Spdr, Filter
40%
Strip
1.20
0.15
Permeable
Pavement*
0%
1.44
0.39
Sand Filter
5%
0.92
0.14
Water Harvesting
user defined
1.08
0.15
Wet Detention Pond
10%
1.01
0.11
Wetland
20%
1.08
0.12
`if treating commercial parking lot, TP effluent concentration = 0.16 mg/L
Return to Instructions
[ Return to Watershed Characteristics I
Return to BMP Characteristics
l Print Summary I
CATCHMENT 1
CATCHMENT 2
CATCHMENT 3
CATCHMENT 4
CATCHMENTS
CATCHMENT 6
BMP1 BMP2 BMP3
BMP1
BMP2
BMP3
BMP1
BMP2
BMP3
BMP1
BMP2
BMP3
BMP1
BMP2
BMP3
BMP1
BMP2
BMP3
39%
-
--
--
-
--
Catchment Outflow Phosphorus EMC
(mg/L)
0.134
Wet Detention
Pond
Catchment Outflow
Total Phosphorus (lb /ac /yr)
0.311
-
-
--
Total Area Treated
-
Percent Reduction in Phosphorus Load ( %)
61%
-
--
--
-
--
Total Inflow Volume
589,161
-
-
--
-
--
--
-
-
-
--
-
--
-
-
-
-
-
(c.f.)
Percent Volume Reduced
10%
Inflow Nitrogen EMC
(mg/L)
1.57
Total Inflow Nitrogen
(lb /ac /yr)
4.04
-
-
--
-
--
Inflow Phosphorus EMC
(mg/L)
0.306
--
-
Total Inflow Phosphorus
(lb /ac /yr)
0.79
BMP Outflow
Nitrogen (Ibs /ac /yr)
2.48
-
-
--
-
-
-
--
-
-
--
-
--
-
-
-
-
-
BMP Outflow
Phosphorus (Ibs /ac /yr)
0.31
-
-
--
-
-
-
-
-
-
--
-
--
-
-
-
--
-
Catchment Outflow Nitrogen EMC (mg/L)
1.07
-
-
--
-
-
Catchment Outflow
2.48
-
-
-
-
Total Nitrogen (lb /ac /yr)
Percent Reduction in Nitrogen Load ( %)
39%
-
--
--
-
--
Catchment Outflow Phosphorus EMC
(mg/L)
0.134
_
Catchment Outflow
Total Phosphorus (lb /ac /yr)
0.311
-
-
--
-
-
Percent Reduction in Phosphorus Load ( %)
61%
-
--
--
-
--

HOWARD /EMERSON TRACT
NORTHWEST COMMUNUNITY CHURCH - COMMERCIAL
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
PONDPACK ROUTING
CALCULATIONS
NWCC - Commercial W &R Project 02130427
Stormwater Management Plan Revised October 2014

pre
R
Q
Q
5'
O
to bmp
Q
Q
x
N
O
A w
bmp
PRE
�©v
76
bypass
Q
Q
W
O
A&
o

Job File: K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC- COMM.PPW
Rain Dir: K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial\
JOB TITLE
Project Date: 7/9/2014
Project Engineer: jdiaz
Project Title: 2130427
Project Comments:
Revised 10/1/14
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Table of Contents
Table of Contents
i
* * * * * * * * * * * * * * * * * * * * ** MASTER SUMMARY * * * * * * * * * * * * * * * * * * * * **
Watershed....... Master Network Summary ............. 1.01
* * * * * * * * * * * * * * * * ** DESIGN STORMS SUMMARY * * * * * * * * * * * * * * * * * **
RDU 24 Hour Desi Design Storms ...................... 2.01
* * * * * * * * * * * * * * * * * * * * ** TC CALCULATIONS * * * * * * * * * * * * * * * * * * * **
BYPASS.......... Tc Calcs ........................... 3.01
PRE ............. Tc Calcs ........................... 3.03
TO BMP.......... Tc Calcs ........................... 3.05
* * * * * * * * * * * * * * * * * * * * ** CN CALCULATIONS * * * * * * * * * * * * * * * * * * * **
BYPASS.......... Runoff CN -Area ..................... 4.01
PRE ............. Runoff CN -Area ..................... 4.02
TO BMP.......... Runoff CN -Area ..................... 4.03
* * * * * * * * * * * * * * * * * * * * * ** POND VOLUMES * * * * * * * * * * * * * * * * * * * * * **
BMP ............. Vol: Elev -Area ..................... 5.01
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Table of Contents
Table of Contents (continued)
ii
* * * * * * * * * * * * * * * * * * ** OUTLET STRUCTURES * * * * * * * * * * * * * * * * * * * **
Outlet 1........ Outlet Input Data .................. 6.01
Composite Rating Curve ............. 6.04
SIN: Bentley Systems, Inc.
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Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC- comm.ppw
MASTER DESIGN STORM SUMMARY
Network Storm Collection: RDU 24 Hour Desi
Total
Depth
Return Event in
1
2.8300
2
3.4400
5
4.3000
10
4.9800
100
7.3700
Rainfall
Type
--------------- -
Time -Depth Curve
Time - Depth Curve
Time -Depth Curve
Time -Depth Curve
Time -Depth Curve
RNF ID
RDU NOAA lyr
RDU NOAA 2yr
RDU NOAA 5yr
RDU NOAA 10yr
RDU NOAA 100yr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
( *Node= Outfall; +Node = Diversion;)
(Trun= HYG Truncation: Blank =None; L =Left; R =Rt; LR= Left &Rt)
SIN:
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Max
Return
HYG Vol
Qpeak
Qpeak
Max WSEL
Pond Storage
Node ID
Type
Event
ac -ft
Trun
hrs
cfs
ft
ac -ft
-----------
BMP
- - - - --
IN
- - --
POND
- - - - --
1
---- - - - - --
2.238
--
--- - - - - --
12.1000
-- - - - - --
48.71
-- - - - - --
------ - - - - --
BMP
IN
POND
2
2.971
12.1000
63.51
BMP
IN
POND
5
4.037
12.1000
78.65
BMP
IN
POND
10
4.898
12.1000
90.47
BMP
IN
POND
100
7.988
12.1000
118.20
BMP
OUT
POND
1
2.216
R
12.3000
13.17
353.30
1.054
BMP
OUT
POND
2
2.948
R
12.2500
27.88
353.70
1.265
BMP
OUT
POND
5
4.012
R
12.2000
50.28
354.03
1.443
BMP
OUT
POND
10
4.872
R
12.1500
64.39
354.20
1.538
BMP
OUT
POND
100
7.961
R
12.1500
90.54
354.51
1.715
BYPASS
AREA
1
.512
12.1000
10.98
BYPASS
AREA
2
.731
12.1000
15.79
BYPASS
AREA
5
1.063
12.1000
21.27
BYPASS
AREA
10
1.339
12.1000
25.62
BYPASS
AREA
100
2.368
12.1000
36.67
SIN:
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Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC- comm.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
( *Node = Outfall; +Node = Diversion;)
(Trun= HYG Truncation: Blank =None; L =Left; R =Rt; LR= Left &Rt)
SIN:
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Max
Return
HYG Vol
Qpeak
Qpeak Max WSEL Pond Storage
Node ID
----------- - -
Type
- - -- - - --
Event
- - - - --
ac -ft
---- - - - - --
Trun
--
hrs
--- - - - - --
cfs ft ac -ft
-- - - - - -- -- - - - - -- ------ - - - - --
*POST
JCT
1
2.728
R
12.2000
17.45
*POST
JCT
2
3.678
R
12.2000
36.24
*POST
JCT
5
5.075
R
12.1500
64.62
*POST
JCT
10
6.211
R
12.1500
84.33
*POST
JCT
100
10.328
R
12.1500
119.24
PRE
AREA
1
1.688
12.1000
35.91
PRE
AREA
2
2.428
12.1000
52.36
PRE
AREA
5
3.561
12.1000
71.30
PRE
AREA
10
4.507
12.1000
86.36
PRE
AREA
100
8.048
12.1000
125.04
*PRE
JCT
1
1.688
12.1000
35.91
*PRE
JCT
2
2.428
12.1000
52.36
*PRE
JCT
5
3.561
12.1000
71.30
*PRE
JCT
10
4.507
12.1000
86.36
*PRE
JCT
100
8.048
12.1000
125.04
TO BMP
AREA
1
2.238
12.1000
48.71
TO BMP
AREA
2
2.971
12.1000
63.51
TO BMP
AREA
5
4.037
12.1000
78.65
TO BMP
AREA
10
4.898
12.1000
90.47
TO BMP
AREA
100
7.988
12.1000
118.20
SIN:
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Type.... Design Storms
Name.... RDU 24 Hour Desi
Page 2.01
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
Title... Project Date: 7/9/2014
Project Engineer: jdiaz
Project Title: 2130427
Project Comments:
Revised 10/1/14
DESIGN STORMS SUMMARY
Design Storm File,ID = RDU 24 Hour Desi
Storm Tag Name = 1
---------------------------------------------------------------- - - - - --
Data Type, File, ID = Time -Depth Curve RDU NOAA 1yr
Storm Frequency = 1 yr
Total Rainfall Depth= 2.8300 in
Duration Multiplier = 1
Resulting Duration = 23.9999 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9999 hrs
Storm Tag Name = 2
Data Type, File, ID = Time -Depth Curve RDU NOAA 2yr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.4400 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 5
Data Type, File, ID = Time -Depth Curve RDU NOAA 5yr
Storm Frequency = 5 yr
Total Rainfall Depth= 4.3000 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 10
Data Type, File, ID = Time -Depth Curve RDU NOAA 10yr
Storm Frequency = 10 yr
Total Rainfall Depth= 4.9800 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 100
Data Type, File, ID = Time -Depth Curve RDU NOAA 100yr
Storm Frequency = 100 yr
Total Rainfall Depth= 7.3700 in
Duration Multiplier = 1
Resulting Duration = 23.9990 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9990 hrs
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Tc Calcs
Name.... BYPASS
Page 3.01
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
.......................................... ...............................
......................................... ...............................
TIME OF CONCENTRATION CALCULATOR
......................................... ...............................
......................................... ...............................
Segment #1: Tc: Kirpich (TN)
Hydraulic Length 841.00 ft
Slope .042000 ft /ft
Multiplier 1.000 (Tc Adjustment)
Avg.Velocity 2.97 ft /sec
Segment #1 Time: .0787 hrs
------------------------------------------------------------------ - - - - --
------------------ - - - - --
Total Tc: .0787 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
SIN: Bentley Systems, Inc.
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Type.... Tc Calcs
Name.... BYPASS
Page 3.02
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------ - - - - --
Kirpich (TN)
Tc = 0.00013 * (Lf* *0.77) * (Sf * *- 0.385) * Mt
Where: Tc = Time of concentration, hrs
Lf = Flow length, ft
Sf = Slope, ft /ft
Mt = Tc Multiplier (Tc adjustment)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Tc Calcs
Name.... PRE
Page 3.03
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
.......................................... ...............................
......................................... ...............................
TIME OF CONCENTRATION CALCULATOR
......................................... ...............................
......................................... ...............................
Segment #1: Tc: Kirpich (TN)
Hydraulic Length 841.00 ft
Slope .042000 ft /ft
Multiplier 1.000 (Tc Adjustment)
Avg.Velocity 2.97 ft /sec
Segment #1 Time: .0787 hrs
------------------------------------------------------------------ - - - - --
------------------ - - - - --
Total Tc: .0787 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Tc Calcs
Name.... PRE
Page 3.04
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------ - - - - --
Kirpich (TN)
Tc = 0.00013 * (Lf* *0.77) * (Sf * *- 0.385) * Mt
Where: Tc = Time of concentration, hrs
Lf = Flow length, ft
Sf = Slope, ft /ft
Mt = Tc Multiplier (Tc adjustment)
SIN: Bentley Systems, Inc.
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Type.... Tc Calcs
Name.... TO BMP
Page 3.05
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
.......................................... ...............................
......................................... ...............................
TIME OF CONCENTRATION CALCULATOR
......................................... ...............................
......................................... ...............................
Segment #1: Tc: User Defined
Segment #1 Time: .0833 hrs
------------------------------------------------------------------ - - - - --
------------------- - - - - --
Total Tc: .0833 hrs
Calculated Tc < Min.TC:
Use Minimum Tc...
Use Tc = .0833 hrs
------------------ - - - - --
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Tc Calcs
Name.... TO BMP
Page 3.06
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------ - - - - --
User Defined
Tc = Value entered by user
Where: Tc = Time of concentration
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Runoff CN -Area
Name.... BYPASS
Page 4.01
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
RUNOFF CURVE NUMBER DATA
........................................... ...............................
........................................... ...............................
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Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014
Impervious
Area
Adjustment
Adjusted
Soil /Surface Description
CN
acres
%C %UC
CN
-------------------------- - - - - --
open
- - --
80
--- - - - - --
2.710
- - - -- - - - --
- - - - --
80.00
woods
77
2.820
77.00
Impervious Areas
98
.240
98.00
COMPOSITE AREA & WEIGHTED CN - - ->
............................................
............................................
5.770
...............................
...............................
79.28 (79)
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Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Runoff CN -Area
Name.... PRE
Page 4.02
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
RUNOFF CURVE NUMBER DATA
........................................... ...............................
........................................... ...............................
Impervious
Area Adjustment Adjusted
Soil /Surface Description CN acres %C %UC CN
open 80 5.920 5.00 80.45
woods 77 14.150 77.00
COMPOSITE AREA & WEIGHTED CN - - -> 20.070 78.02 (78)
............................................ ...............................
............................................ ...............................
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Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Runoff CN -Area
Name.... TO BMP
Page 4.03
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
RUNOFF CURVE NUMBER DATA
........................................... ...............................
........................................... ...............................
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014
Impervious
Area
Adjustment
Adjusted
Soil /Surface Description
CN
acres
%C %UC
CN
-------------------------- - - - -
impervious
-- - - --
98
--- - - - - --
3.440
- - - -- - - - --
- - - - --
98.00
open
80
8.360
80.00
Future
98
2.500
98.00
Off -Site
80
1.800
60.00
90.80
COMPOSITE AREA & WEIGHTED CN -
- ->
16.100
87.85 (88)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Vol: Elev -Area
Name.... BMP
Page 5.01
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
Elevation Planimeter
Area
Al +A2 +sgr(A1 *A2)
Volume
Volume Sum
(ft) (sq.in)
------------------------------------------------------------------------
(sq.ft)
(sq.ft)
(ac -ft)
(ac -ft)
351.00 - - - --
16428
0
.000
.000
352.00 - - - --
20161
54788
.419
.419
353.00 - - - --
21974
63183
.483
.903
354.00 - - - --
23843
68706
.526
1.429
355.00 - - - --
25769
74399
.569
1.998
356.00 - - - --
27751
80262
.614
2.612
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2 -EL1) * (Areal + Area2 + sq.rt.(Areal *Area2))
where: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for EL1, EL2, respectively
Volume = Incremental volume between EL1 and EL2
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Type.... Outlet Input Data
Name.... Outlet 1
Page 6.01
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 351.00 ft
Increment = .20 ft
Max. Elev.= 356.00 ft
OUTLET CONNECTIVITY
- - -> Forward Flow Only (UpStream to DnStream)
< - -- Reverse Flow Only (DnStream to UpStream)
< - - -> Forward and Reverse Both Allowed
Structure
----------- - - - - --
No.
- - --
Outfall
- - - - - --
E1, ft
--- - - - - --
E2, ft
--- - - - - --
Weir- Rectangular
WO
- - -> CO
352.500
356.000
Inlet Box
RO
- - -> CO
353.500
356.000
Orifice - Circular
00
- - -> CO
351.000
356.000
Culvert - Circular
CO
- - -> TW
344.000
356.000
TW SETUP, DS Channel
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Outlet Input Data
Name.... Outlet 1
Page 6.02
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID
Structure Type
-------- - - - - --
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
WO
Weir - Rectangular
----------------
1
352.50 ft
6.00 ft
3.100000
Weir TW effects (Use adjustment equation)
Structure ID
= RO
Structure Type
= Inlet Box
------------------------------------
# of Openings
= 1
Invert Elev.
= 353.50 ft
Orifice Area
= 25.0000 sq.ft
Orifice Coeff.
_ .600
Weir Length
= 14.00 ft
Weir Coeff.
= 3.100
K, Reverse
= 1.000
Mannings n
= .0000
Kev,Charged Riser
= .000
Weir Submergence
= No
Structure ID = 00
Structure Type = Orifice- Circular
------------------------------------
# of Openings = 1
Invert Elev. = 351.00 ft
Diameter = .2083 ft
Orifice Coeff. _ .600
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Type.... Outlet Input Data
Name.... Outlet 1
Page 6.03
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID
= CO
Structure Type
= Culvert - Circular
------------------------------------
No. Barrels
= 1
Control K =
Barrel Diameter
= 3.0000
ft
Upstream Invert
= 344.00
ft
Dnstream Invert
= 342.15
ft
Horiz. Length
= 187.00
ft
Barrel Length
= 187.01
ft
Barrel Slope
= .00989
ft /ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000
Kb = .007228
Kr = .5000
HW Convergence = .001
INLET
CONTROL DATA...
Equation
form =
1
Inlet
Control K =
.0098
Inlet
Control M =
2.0000
Inlet
Control c =
.03980
Inlet
Control Y =
.6700
T1 ratio (HW /D) =
1.155
T2 ratio (HW /D) =
1.302
Slope
Factor =
-.500
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/- ft
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 347.47 ft - - -> Flow = 42.85 cfs
At T2 Elev = 347.91 ft - - -> Flow = 48.97 cfs
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum
Iterations=
40
Min.
TW
tolerance =
.01
ft
Max.
TW
tolerance =
.01
ft
Min.
HW
tolerance =
.01
ft
Max.
HW
tolerance =
.01
ft
Min.
Q
tolerance =
.00
cfs
Max.
Q
tolerance =
.00
cfs
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Type.... Composite Rating Curve
Name.... Outlet 1
Page 6.04
File.... K: \13 \13- 0420 \130427- Northwest Community Church \H -H \Commercial \NWCC - comm.ppw
* * * ** COMPOSITE OUTFLOW SUMMARY * * **
WS Elev,
Total Q
Notes
----------
- - - - --
-- - - - -
-- Converge
-------------------------
Elev.
Q
TW Elev
Error
ft
cfs
ft
+ / -ft
Contributing
Structures
-- - - - - --
351.00
- - - - - --
.00
-- - - - -
Free
-- - - - --
Outfall
--------------------------
(no Q: WO,RO,OO,CO)
351.20
.05
Free
Outfall
OO,CO (no Q:
WO,RO)
351.40
.09
Free
Outfall
OO,CO (no Q:
WO,RO)
351.60
.11
Free
Outfall
OO,CO (no Q:
WO,RO)
351.80
.14
Free
Outfall
OO,CO (no Q:
WO,RO)
352.00
.15
Free
Outfall
OO,CO (no Q:
WO,RO)
352.20
.17
Free
Outfall
OO,CO (no Q:
WO,RO)
352.40
.19
Free
Outfall
OO,CO (no Q:
WO,RO)
352.50
.19
Free
Outfall
OO,CO (no Q:
WO,RO)
352.60
.79
Free
Outfall
WO,OO,CO (no
Q: RO)
352.80
3.24
Free
Outfall
WO,OO,CO (no
Q: RO)
353.00
6.70
Free
Outfall
WO,OO,CO (no
Q: RO)
353.20
10.88
Free
Outfall
WO,OO,CO (no
Q: RO)
353.40
15.65
Free
Outfall
WO,OO,CO (no
Q: RO)
353.50
18.23
Free
Outfall
WO,OO,CO (no
Q: RO)
353.60
22.32
Free
Outfall
WO,RO,OO,CO
353.80
33.78
Free
Outfall
WO,RO,OO,CO
354.00
48.08
Free
Outfall
WO,RO,OO,CO
354.20
64.56
Free
Outfall
WO,RO,OO,CO
354.40
82.95
Free
Outfall
WO,RO,OO,CO
354.60
96.48
Free
Outfall
WO,RO,OO,CO
354.80
101.89
Free
Outfall
WO,RO,OO,CO
355.00
104.87
Free
Outfall
WO,RO,OO,CO
355.20
106.56
Free
Outfall
WO,RO,OO,CO
355.40
107.61
Free
Outfall
WO,RO,OO,CO
355.60
108.65
Free
Outfall
RO,CO (no Q:
WO,O0)
355.80
109.69
Free
Outfall
RO,CO (no Q:
WO,O0)
356.00
110.71
Free
Outfall
RO,CO (no Q:
WO,O0)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 4:59 PM 10/1/2014

Appendix A
Index of Starting Page Numbers for ID Names
- - - -- B -----
BMP... 5.01
BYPASS... 3.01, 4.01
- - - -- 0 - - - --
Outlet 1... 6.01, 6.04
- - - -- P -----
PRE ... 3.03, 4.02
- - - -- R - - - --
RDU 24 Hour Desi... 2.01
- - - -- T - - - --
TO BMP... 3.05, 4.03
- - - -- W -----
Watershed ... 1.01
A -1
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