20150600 Ver 1_Stormwater Info_20150615

Stormwater Impact Analysis
Site Plan Submittal
For the proposed
Crystal Lake Subdivision at Croasdaile Farm
Durham, North Carolina
Prepared By
Stewart Inc.
e
STEWART
March 3, 2015

Table of Contents
1.
Table of Contents & Narrative
2.
Site Information
a.
QUAD Map
b.
FEMA Map
c.
Soils Map
3.
Quantity Calculations
a.
1 -Year Peak Flow Analysis
b.
2 and 10 Year Peak Flow Analysis
c.
Detention Basin Sizing
4.
Nutrient Loading Calculations
a.
Jordan Lake Accounting Tool
b.
City of Durham Nutrient Reporting Form
c.
TSS Summary
5.
Plan
Sheets
a.
SW1.0 - Existing Impervious Areas
b.
SW2.0 - Proposed Impervious Areas
c.
SW3.0 - 1 Year Pre - Development Drainage Area Map
d.
SW4.0 - 2/10 Year Pre Development Drainage Area Map
e.
SW5.0 - Post Development Drainage Area Map
6.
Miscellaneous Information
a.
Wetlands Study
b.
City of Durham Site Plan Checklist

STORMWATER IMPACT ANALYSIS
CRYSTAL LAKE SUBDIVISION AT CROASDAILE FARM
DURHAM, NORTH CAROLINA
Site Description:
Project Location: Garden View Realty is planning to construct a residential subdivision containing
single family homes and townhomes on 2 existing contiguous lots totaling approximately 150 -acres of
land located north of the intersection of Croasdaile Farm Parkway and Hillandale Road. See Figure 1.0
below.
Figure 1.0 - Vicinity Map for Crystal Lake Subdivision
Site Characteristics: The site is currently vacant and mostly wooded. There is an existing house and
associated driveway directly north of Crystal Lake. There are regulated streams in the southwest
portion of the site but will not be impacted by this development.
Drainage Area A: There is a ridge that runs the divides the area west of Hillendale into two areas. The
northern portion drains to an existing stream that drains in to the Crystal Lake. The southern portion
also drains to the existing stream that runs south, and drains in to the Crystal Lake. There is an third
drainage area, bordered by Trail Wood Dr, Croasdaile Farm Pkwy and Hillendale Rd, that drains
directly in to the Crystal Lake. There is approximately 150 feet of fall across the site with slopes
ranging from 10 -20 percent. The western side of the site drains to the stream buffer to the south
and will not be affected by this development.
Soil Type: ApB, ApC, CfE, CrB, GrB, IrB, IrC, MfB, MfC, PfE, WmD, WxE - Mostly Hydraulic Soil Group
B, with some Hydraulic Soil Group D and Hydraulic Soil Group C. See attached Soils Map from Durham
County Soils Survey (USDA, SCS - 1971) sheets 16 -17.
River Basin: Neuse
Watershed: Falls Lake

Water Quantity Analysis (Q1 /Q2 /Q10 /Q100):
No new development can increase the peak runoff rate from the 1 -yr storm events where it leaves the
property. The 1 -yr analysis point and drainage area can be found on sheet SW3.0. There is an
existing culvert that runs underneath Ashburn Lane that will be affected by this project. This point was
chosen as the 2 and 10 -yr analysis point. The pre and post development drainage areas can be found
on sheets SW4.0 and SW5.0 within this report.
The SCS method and TR -55 segmental Time of Concentration was used to calculate peak flows for all
storm events. For the proposed conditions, a Time of Concentration of 5 minutes was assumed.
Composite curve numbers (CN) were calculated using curve numbers for open space, wooded and
impervious surfaces. Within the SCS stormwater impact analysis model, Durham County precipitation
data and a Type II rainfall distribution were used.
Once the pre - development and post - development flow rates were calculated it was determined that a
detention basin is necessary to attenuate the post development 1 -year storms back to pre -
development conditions at the 1 -year storm analysis point. Additionally, 2 and 10 -year detention will
be provided to attenuate the post development peak flow to pre - development conditions at the
existing culvert.
Summary of Water Quantity Results:
The following tables summarize the results from the pre and post development, 1 -year, 2 -year, 10-
year pre & post development peak flow rates. Additionally, each table summarizes if detention is
required.
Wetland A:
Table 1.0 — Pre and )ost Peak Flow Rates: 2 Year Storm Event
Post -
Pre- Development: Detention Post -
Development No Detention Required Development: Increase /Decreas
Sub -Basin # (cfs) (cfs) (Y/ N) Detention (cfs) e after Detention
At Analysis Point 33.34 60.68 Y 22.33 -33%
Table 2.0 — Pre and Post Peak Flow Rates: 10 Year Storm Event
Wetland B:
Post -
Pre-
Development:
Detention Post -
Development
No Detention
Required Development:
Increase /Decrease
Sub -Basin # (cfs)
(cfs)
(Y /N) Detention (cfs)
after Detention
At Analysis Point 63.79
108.12
Y 67.34
5.3%
Wetland B:
Table 3.0 — Pre and Post Peak Flow Rates: 1 Year 4naiysis
Post -
Pre-
Development:
Detention
Post -
Development
No Detention
Required
Development:
Increase /Decreas
Sub -Basin # (cfs)
(cfs)
(Y /N)
Detention (cfs)
e after Detention
1 -Year Analysis
Point 27.83
101.63
Y
25.64
-7.9%

Table 4.0 — Pre and
Post Peak Flow Rates:
2 Year Storm Event
Post -
Post -
Post Peak Flow Rates: 2 Year
Pre-
Development:
Pre-
Development:
Detention
Post -
No Detention
Development
No Detention
Required
Development:
Increase /Decreas
Sub -Basin # (cfs)
(cfs)
(Y/ N)
Detention (cfs)
e after Detention
At Analysis Point 116.85
128.16
Y
84.56
-27.6%
Table 5.0 — Pre and Post Peak Flow Rates: 10 Year Storm Event
Post -
Table 6.0 — Pre and
Post Peak Flow Rates: 2 Year
Pre-
Development:
Detention
Post -
Development
No Detention
Required
Development:
Increase /Decrease
Sub -Basin # (cfs)
(cfs)
(Y /N)
Detention (cfs)
after Detention
At Analysis Point 221.69
216.53
Y
141.44
-36.2%
Wetland C:
Post -
Table 6.0 — Pre and
Post Peak Flow Rates: 2 Year
Storm Event
Development:
Detention
Post -
Development
No Detention
Pre-
Development:
Detention
Post -
(cfs)
Development
No Detention
Required
Development:
Increase /Decreas
Sub -Basin # (cfs)
(cfs)
(Y /N)
Detention (cfs)
e after Detention
At Analysis Point 114.04
111.36
Y
76.62
-32.8%
Table 3.0 — Pre and Post Peak Flow Rates: 10 Year Storm Event
Post -
Pre-
Development:
Detention
Post -
Development
No Detention
Required
Development:
Increase /Decrease
Sub -Basin # (cfs)
(cfs)
(Y /N)
Detention (cfs)
after Detention
At Analysis Point 207.04
203.08
Y
179.53
-13.3%
Water Quality Analysis (TSS & Nutrient Removal):
The site meets the requirement to be classified as a low density project (below 16% in the Falls basin)
therefore the project is not required to construct SCMs except for all piped conveyed areas.
The site is located within the Upper Falls Basin of the Falls of the Neuse watershed. Per the City of
Durham Stormwater Performance Standards the total post development nitrogen export must be
limited to 2.2 Ibs /ac /yr and the post development phosphorus export must be limited to 0.33
Ibs /ac /yr. This can be achieved through a combination of onsite removal and purchasing offsite
credits. Also, 85% of all TSS from new impervious surface must be removed.
In order to meet the onsite removal requirements as well as the TSS requirement, a water quality
stormwater control measures has been proposed. Three constructed wetlands are proposed to
capture all of the runoff within proposed drainage area as shown on sheet SW5.0. The wetlands have
been sized to remove 90 %.
Engineer's Conclusion:
Because of the increase in the peak flows from the new development three Stormwater Control
Measures are needed to attenuate the flows to the pre - development levels at the 1 -yr and 2 /10 -yr
analysis points. Three constructed wetlands will capture and treat the site runoff.

The proposed SCMs will be designed per NCDENR requirements in order to receive the nutrient and
TSS reduction requirements. All peak flow and nutrient calculations have been included within this
report.
Attachments
Miscellaneous Maps
• USGS 7.5 Minute Map
• Durham County Soils Map
• FEMA Floodway ]-Series Maps
Support Documents — Pre - Development
• SCS Pre Development Flow rates
• Composite CN Values
• TR -55 Time of Concentration
Support Documents — Post Development
• SCS Post Development Flow rates
• Composite CN Values
• TR -55 Time of Concentration
Support Documents — Nitrogen Loading
• City of Durham Nitrogen Worksheet
• Jordan Lake Tool
Plan Sheets
• Pre - Development Conditions
• Post - Development Conditions
Submitted 3`d day of March 2015 by STEWART
tl`et'tltiu�lrrr►►4
s Li /I v
AW - AL
6
Aaron Hutchens = ;
Ariel Gamboa, PIE
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Appendix 2
2. Site Information
a. QUAD Map
b. FEMA Map
C. Soils Map

`���� U.S. DEPARTMENT
S. GEOLOGIC ERIOR
ALSURVEY
science for a changing world
79 °00'
36 °07'?
39990[
5'
10a
820
F
36 °00'
7u -uu, -
Produced by the United States Geological Survey
North American Datum of 1983 (NAD83)
World Geodetic System of 1984 (WGS84). Projection and
1 000 -meter grid: Universal Transverse Mercator, Zone 17S
10 000 -foot ticks: North Carolina Coordinate System of 1983
The National Map
USTopo
57'30" 55'
NORTHWEST DURHAM QUADRANGLE
NORTH CAROLINA
7.5- MINUTE SERIES
78 °52'30"
36 °07'30"
Imagery .........................
..........................NAIP, May 2012
Roads .........................
.....................02006 -2012 TomTom
Names ...........................
............................... GNIS, 2012
Hydrography ....................National
Hydrography Dataset, 2012
Contours ..... .......................National
Elevation Dataset, 2008
Boundaries ....................Census,
IBWC, IBC, USGS, 1972 - 2012
8° 57'
159 MILS (N
1° 13'
22 MILS
UTM GRID AND 201 = MAGNETIC NORTH
DECLINATION AT CENTER OF SHEET
U.S. National Grid
100,000 -ra Square ID
PV
Grid Zone Designation
17S
-
SCALE 1:24 000
1 0.5 0 KILOMETERS 1 2
1000 500 0 METERS 1000 2000
1 0.5 0 1
MILES
1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
~ FEET
CONTOUR INTERVAL 10 FEET
NORTH AMERICAN VERTICAL DATUM OF 1988
This map was produced to conform with the
National Geospatial Program US Topic, Product Standard, 2011.
A metadata file associated with this product is draft version 0.6.11
55'
N-RTH ■
,fCANA
QUADRANGLE LOCATION
Caldwell Rougemont Lake
Michie
Hillsborough Northwest Northeast
Durham Durham
Chapel Southwest Southeast
Hill Durham Durham
ADJOINING 7.5' QUADRANGLES
99
60 000
=ET
98
97
96
5'
95
94
93
92
191
2'30"
190
189
188
187000"N
36 °00'
is °5x30"
ROAD CLASSIFICATION
Expressway Local Connector
Secondary Hwy Local Road
Ramp 4WD
• Interstate Route 0 US Route O State Route
NORTHWEST DURHAM, NC
2013

850000 FEET
840000 FEET
2010000 FEET
Ki:3ilRil]IW
101MlB71101
KI:i�lYli17Y►1
78 °57'30 "W
78 °57'0 "W
78 °56'30 "W
2020000 FEET
78 °56'0 "W
2010000 FEET
FLOOD HAZARD INFORMATION
SEE FIS REPORT FOR ZONE DESCRIPTIONS AND INDEX MAP
THE INFORMATION DEPICTED ON THIS MAP AND SUPPORTING
DOCUMENTATION ARE ALSO AVAILABLE IN DIGITAL FORMATAT
HTTP: / /FRIS.NC.GOV /FRIS
Hydrographic Feature
OTHER Limit of Study
FEATURES Jurisdiction Boundary
78 °57'30 "W
NOTES TO USERS
78 °57'0 "W
For information and questions about this map, available products associated with this FIRM including
historic versions of this FIRM, how to order products or the National Flood Insurance Program in general,
please call the FEMA Map Information eXchange at 1- 877 -FEMA -MAP (1- 877 - 336 -2627) or visit the FEMA Map
Service Center website at http: / /msc.fema.gov. An accompanying Flood Insurance Study report, Letter of Map
Revision (LOMR) or Letter of Map Amendment (LOMA) revising portions of this panel, and digital versions of this
FIRM may be available. Visit the North Carolina Floodplain Mapping Program website at http: / /www.ncf[oodmaps.com
or contact the FEMA Map Service Center.
Communities annexing land on adjacent FIRM panels must obtain a current copy of the adjacent panel as well as
the current FIRM Index. These may be ordered directly from the Map Service Center at the number listed above.
For community and countywide map dates refer to the Flood Insurance Study report for this jurisdiction.
To determine if flood insurance is available in the community, contact your Insurance agent or call the National
Flood Insurance Program at 1- 800 - 638 -6620.
Base map information shown on this FIRM was provided in digital format by the North Carolina Floodplain
Mapping Program (NCFMP). The source of this information can be determined from the metadata available in the
digital FLOOD database and in the Technical Support Data Notebook (TSDN).
ACCREDITED LEVEE NOTES TO USERS: If an accredited levee note appears on this panel check with your local
community to obtain more information, such as the estimated level of protection provided (which may exceed the
1- percent - annual- chance level) and Emergency Action Plan, on the levee system(s) shown as providing protection.
To mitigate flood risk in residual risk areas, property owners and residents are encouraged to consider flood
insurance and floodproofing or other protective measures. For more information on flood insurance, interested
parties should visit the FEMA Website at http: / /www.fema.gov /business /nfip /index.shtm.
PROVISIONALLY ACCREDITED LEVEE NOTES TO USERS: If a Provisionally Accredited Levee (PAL) note
appears on this panel, check with your local community to obtain more information, such as the estimated level of
protection provided (which may exceed the 1- percent - annual- chance level) and Emergency Action Plan, on the
levee system(s) shown as providing protection. To maintain accreditation, the levee owner or community is
required to submit the data and documentation necessary to comply with Section 65.10 of the NFIP regulations.
If the community or owner does not provide the necessary data and documentation or if the data and documentation
provided indicates the levee system does not comply with Section 65.10 requirements, FEMA will revise the flood
hazard and risk information for this area to reflect de- accreditation of the levee system. To mitigate flood risk in
residual risk areas, property owners and residents are encouraged to consider flood insurance and floodproofing
or other protective measures. For more information on flood insurance, interested parties should visit the FEMA
Website at http: / /www.fema.gov /business /nfip /index.shtm.
LIMIT OF MODERATE WAVE ACTION NOTES TO USERS: For some coastal flooding zones the AE Zone
category has been divided by a Limit of Moderate Wave Action (LiMWA). The LiMWA represents the approximate
landward limit of the 1.5 -foot breaking wave. The effects of wave hazards between the VE Zone and the LiMWA
(or between the shoreline and the LiMWA for areas where VE Zones are not identified) will be similar to, but less
severe than those in the VE Zone.
Limit of Moderate Wave Action (LiMWA)
COASTAL BARRIER RESOURCES SYSTEM (CBRS) NOTE
This map may include approximate boundaries of the CBRS for informational purposes only. Flood insurance is not
available within CBRS areas for structures that are newly built or substantially improved on or after the date(s)
indicated on the map. For more information see http:// www. fws. gov/ habitatconservation /coastal_barrier.htmi, the
FIS Report, or call the U.S. Fish and Wildlife Service Customer Service Center at 1- 800 - 344 -WILD.
CBRS Area r,\ � \ ; ,\r Otherwise Protected Area
78 °56'30 "W
SCALE
Map Projection:
North Carolina State Plane Projection Feet (Zone 3200)
Datum: NAD 1983 (Horizontal), NAVD 1988 (Vertical)
1 inch = 500 feet 1:6,000
0 250 500 1,000
Feet
Meters
0 75 150 300
PANEL LOCATOR
PERSON COUNTY
0940
0910 i��'�i�i� I G73.
1
0819
!- 0828 0848
1b818
st
0807 J 0817 0827 0837 0847 085+ GRANVILLE COUNTY
08061 0816 0826 0836 0846 085:
--i
0805 0815 0825 0835 0845 085, 0865
ORANGE COUNTY �N
0804 U8d4 0824 0834 0844 0854 0864 -0 &74 -�
0903 0813 0823 0833 0843 0853 0863 0873 0883
0812 0822 0832 0842 0852 0862
0811 0821 0831 0841 0851 0861 0871
989010800 0810 0820 0830 0840 0850 0860 0870
979911I0709
Without Base Flood Elevation (BFE)
0729 0739
Zone A, V, A99
9798 0708
With BFE or Depth zone AE, A0, AH, VE, AR
SPECIAL FLOOD
Regulatory Floodway
HAZARD AREAS
0.2% Annual Chance Flood Hazard, Areas
9797 0707
of 1% Annual Chance Flood with Average
0727 0737
Depth Less Than One Foot or With Drainage
Areas of Less Than One Square Mile zone x
0716
Future Conditions 1% Annual
Chance Flood Hazard zone x
OTHER AREAS OF
�_
Area with Reduced Flood Risk due to Levee
FLOOD HAZARD
See Notes zone x
OTHER
Areas Determined to be Outside the
AREAS
0.2% Annual Chance Floodplain zone x
------- - - - - --
Channel, Culvert, or Storm Sewer
' ' ' ' ' ' ' ' ' • 1
Accredited or Provisionally Accredited
GENERAL
Levee, Dike, or Floodwall
STRUCTURES
Non - accredited Levee, Dike, or Floodwall
BM5510 X
North Carolina Geodetic Survey bench mark
BM5510 ®
National Geodetic Survey bench mark
BM5510�
Contractor Est. NCFMP Survey bench mark
Cross Sections with 1% Annual Chance
Water Surface Elevation (BFE)
sa - - - - -
Coastal Transect
- -- - --
Coastal Transect Baseline
Profile Baseline
Hydrographic Feature
OTHER Limit of Study
FEATURES Jurisdiction Boundary
78 °57'30 "W
NOTES TO USERS
78 °57'0 "W
For information and questions about this map, available products associated with this FIRM including
historic versions of this FIRM, how to order products or the National Flood Insurance Program in general,
please call the FEMA Map Information eXchange at 1- 877 -FEMA -MAP (1- 877 - 336 -2627) or visit the FEMA Map
Service Center website at http: / /msc.fema.gov. An accompanying Flood Insurance Study report, Letter of Map
Revision (LOMR) or Letter of Map Amendment (LOMA) revising portions of this panel, and digital versions of this
FIRM may be available. Visit the North Carolina Floodplain Mapping Program website at http: / /www.ncf[oodmaps.com
or contact the FEMA Map Service Center.
Communities annexing land on adjacent FIRM panels must obtain a current copy of the adjacent panel as well as
the current FIRM Index. These may be ordered directly from the Map Service Center at the number listed above.
For community and countywide map dates refer to the Flood Insurance Study report for this jurisdiction.
To determine if flood insurance is available in the community, contact your Insurance agent or call the National
Flood Insurance Program at 1- 800 - 638 -6620.
Base map information shown on this FIRM was provided in digital format by the North Carolina Floodplain
Mapping Program (NCFMP). The source of this information can be determined from the metadata available in the
digital FLOOD database and in the Technical Support Data Notebook (TSDN).
ACCREDITED LEVEE NOTES TO USERS: If an accredited levee note appears on this panel check with your local
community to obtain more information, such as the estimated level of protection provided (which may exceed the
1- percent - annual- chance level) and Emergency Action Plan, on the levee system(s) shown as providing protection.
To mitigate flood risk in residual risk areas, property owners and residents are encouraged to consider flood
insurance and floodproofing or other protective measures. For more information on flood insurance, interested
parties should visit the FEMA Website at http: / /www.fema.gov /business /nfip /index.shtm.
PROVISIONALLY ACCREDITED LEVEE NOTES TO USERS: If a Provisionally Accredited Levee (PAL) note
appears on this panel, check with your local community to obtain more information, such as the estimated level of
protection provided (which may exceed the 1- percent - annual- chance level) and Emergency Action Plan, on the
levee system(s) shown as providing protection. To maintain accreditation, the levee owner or community is
required to submit the data and documentation necessary to comply with Section 65.10 of the NFIP regulations.
If the community or owner does not provide the necessary data and documentation or if the data and documentation
provided indicates the levee system does not comply with Section 65.10 requirements, FEMA will revise the flood
hazard and risk information for this area to reflect de- accreditation of the levee system. To mitigate flood risk in
residual risk areas, property owners and residents are encouraged to consider flood insurance and floodproofing
or other protective measures. For more information on flood insurance, interested parties should visit the FEMA
Website at http: / /www.fema.gov /business /nfip /index.shtm.
LIMIT OF MODERATE WAVE ACTION NOTES TO USERS: For some coastal flooding zones the AE Zone
category has been divided by a Limit of Moderate Wave Action (LiMWA). The LiMWA represents the approximate
landward limit of the 1.5 -foot breaking wave. The effects of wave hazards between the VE Zone and the LiMWA
(or between the shoreline and the LiMWA for areas where VE Zones are not identified) will be similar to, but less
severe than those in the VE Zone.
Limit of Moderate Wave Action (LiMWA)
COASTAL BARRIER RESOURCES SYSTEM (CBRS) NOTE
This map may include approximate boundaries of the CBRS for informational purposes only. Flood insurance is not
available within CBRS areas for structures that are newly built or substantially improved on or after the date(s)
indicated on the map. For more information see http:// www. fws. gov/ habitatconservation /coastal_barrier.htmi, the
FIS Report, or call the U.S. Fish and Wildlife Service Customer Service Center at 1- 800 - 344 -WILD.
CBRS Area r,\ � \ ; ,\r Otherwise Protected Area
78 °56'30 "W
SCALE
Map Projection:
North Carolina State Plane Projection Feet (Zone 3200)
Datum: NAD 1983 (Horizontal), NAVD 1988 (Vertical)
1 inch = 500 feet 1:6,000
0 250 500 1,000
Feet
Meters
0 75 150 300
PANEL LOCATOR
PERSON COUNTY
0940
0910 i��'�i�i� I G73.
1
0819
!- 0828 0848
1b818
st
0807 J 0817 0827 0837 0847 085+ GRANVILLE COUNTY
08061 0816 0826 0836 0846 085:
--i
0805 0815 0825 0835 0845 085, 0865
ORANGE COUNTY �N
0804 U8d4 0824 0834 0844 0854 0864 -0 &74 -�
0903 0813 0823 0833 0843 0853 0863 0873 0883
0812 0822 0832 0842 0852 0862
0811 0821 0831 0841 0851 0861 0871
989010800 0810 0820 0830 0840 0850 0860 0870
979911I0709
0719
0729 0739
0749 0759 0769 0,779 0789
9798 0708
0718
0728 0738
0748 07j58 0768 0778
/
9797 0707
0717
0727 0737
0747 ,0757 WAKE COUNTY
9796 0706
0716
I
CHATHAM COUNTY
i
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W
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0• w
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KZ:3�.'YIlY►1
36 °4'30 "N
36 °4'0 "N
36 °3'30 "N
78 °56'0 "W
2020000 FEET
OR7 11CAROt.I\ l
' Cooperatin "f'ee�linical Stake
850000 FEET
840000 FEET
This digital Flood Insurance Rate Map (FIRM) was produced through a unique
cooperative partnership between the State of North Carolina and the Federal
Emergency Management Agency (FEMA). The State of North Carolina has
implemented a long term approach to floodplain management to decrease the
costs associated with flooding. This is demonstrated by the State's commitment
to map flood hazard areas at the local level. As a part of this effort, the State of
North Carolina has joined in a Cooperating Technical State agreement with
FEMA to produce and maintain this digital FIRM.
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NORTH CAROLINA FLOODPLAIN MAPPING PROGRAM
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Panel Contains:
COMMUNITY
DURHAM COUNTY
DURHAM, CITY OF
CID PANEL SUFFIX
370085 0814 J
370086 0814 J
MAP NUMBER
3720081400J
MAP REVISED
05/02/06

840000 FEET
830000 FEET
2010000 FEET
1011- SY1}Y►1
KI:3i�aBi�lY►1
Ki:Vxljii►
78 °57'30 "W
78 °57'0 "W
78 °56'30 "W
2020000 FEET
78 °56'0 "W
2010000 FEET
FLOOD HAZARD INFORMATION
78 °57'30 "W
NOTES TO USERS
78 °57'0 "W
SCALE
78 °56'30 "W
SEE FIS REPORT FOR ZONE DESCRIPTIONS AND INDEX MAP For information and questions about this map, available products associated with this FIRM including
historic versions of this FIRM, how to order products or the National Flood Insurance Program in general, Map Projection:
THE INFORMATION DEPICTED ON THIS MAP AND SUPPORTING please call the FEMA Map Information eXchange at 1- 877 -FEMA -MAP (1- 877 - 336 -2627) or visit the FEMA Map North Carolina State Plane Projection Feet (Zone 3200)
DOCUMENTATION ARE ALSO AVAILABLE IN DIGITAL FORMATAT Service Center website at http: / /msc.fema.gov. An accompanying Flood Insurance Study report, Letter of Map Datum: NAD 1983 (Horizontal), NAVD 1988 (Vertical)
Revision (LOMR) or Letter of Map Amendment (LOMA) revising portions of this panel, and digital versions of this
H 1 T 1 T P: / /FRIS.NC.GOV /FRIS FIRM may be available. Visit the North Carolina Floodplain Mapping Program website at http: / /www.ncf[oodmaps.com 1 inch = 500 feet 1'6 000
or contact the FEMA Map Service Center. ,
Without Base Flood Elevation (BFE) Communities annexing land on adjacent FIRM panels must obtain a current copy of the adjacent panel as well as 250 500 1 ,000
Zone A, V, A99 the current FIRM Index. These may be ordered directly from the Map Service Center at the number listed above.
With BFE or Depth zone AE, AO, AH, VE, AF? Feet
For community and countywide map dates refer to the Flood Insurance Study report for this jurisdiction. Meters FLOOD
Regulatory Floodway To determine if flood insurance is available in the community, contact your Insurance agent or call the National 0 75 150 300
HAZARD AREAS Flood Insurance Program at 1 -800- 638 -6620.
0.2% Annual Chance Flood Hazard, Areas Base map information shown on this FIRM was provided in digital format by the North Carolina Floodplain
Mapping Program (NCFMP). The source of this information can be determined from the metadata available in the PANEL LOCATOR
of 1% Annual Chance Flood with Average digital FLOOD database and in the Technical Support Data Notebook (TSDN).
Depth Less Than One Foot or With Drainage ACCREDITED LEVEE NOTES TO USERS: If an accredited levee note appears on this panel check with your local
Areas of Less Than One Square Mile zone X community to obtain more information, such as the estimated level of protection provided (which may exceed the
1- percent - annual- chance level) and Emergency Action Plan, on the levee system(s) shown as providing protection. PERSON COUNTY
o To mitigate flood risk in residual risk areas, property owners and residents are encouraged to consider flood
Future Conditions 1 /o Annual insurance and floodproofing or other protective measures. For more information on flood insurance, interested
U'
OTHER AREAS OF y�� ���.�
Chance Flood Hazard zone X parties should visit the FEMA Website at http: / /www.fema.gov /business /nfip / index.shtm. oy :.tr 1 0940
�',. ' I
Area with Reduced Flood Risk due to Levee PROVISIONALLY ACCREDITED LEVEE NOTES TO USERS: If a Provisionally Accredited Levee (PAL) note
FLOOD HAZARD appears on this panel, check with your local community to obtain more information, such as the estimated level of
See Notes Zone X protection provided (which may exceed the 1- percent - annual- chance level) and Emergency Action Plan, on the 0819
OTHER levee system(s) shown as providing protection. To maintain accreditation, the levee owner or community is -r— 0828 0848
Areas Determined to be Outside the required to submit the data and documentation necessary to comply with Section 65.10 of the NFIP regulations. 19818
AREAS o If the community or owner does not provide the necessary data and documentation or if the data and documentation
0.2 /o Annual Chance Floodplain zone X provided indicates the levee system does not comply with Section 65.10 requirements, FEMA will revise the flood GRANVILLE COUNTY
hazard and risk information for this area to reflect de- accreditation of the levee system. To mitigate flood risk in 10807,"0817 0827 0837 0847 085 Channel Culvert or Storm Sewer s s residual risk areas, property owners and residents are encouraged to consider flood insurance and floodproofing
' ' ' ' ' ' ' ' ' ' ' ' Accredited or Provisionally Accredited or other protective measures. For more information on flood insurance, interested parties should visit the FEMA 08061 0816 0826 0836 0846 085
Website at http: / /www.fema.gov /business /nfip /index.shtm. —j
GENERAL Levee, Dike, or Floodwall 0805 0815 0825 0835 0845 085 0865
LIMIT OF MODERATE WAVE ACTION NOTES TO USERS: For some coastal flooding zones the AE Zone
STRUCTURES Non- accredited Levee, Dike, or Floodwall category has been divided by a Limit of Moderate Wave Action (LiMWA). The LiMWA represents the approximate ORANGE COUNTY 1 �N ___ —_`
landward limit of the 1.5 -foot breaking wave. The effects of wave hazards between the VE Zone and the LiMWA 0804 0814 0824 0834 0844 0854 0864, -0 8&-74
BM5510 X North Carolina Geodetic Survey bench mark (or between the shoreline and the LiMWA for areas where VE Zones are not identified) will be similar to, but less 1
severe than those in the VE Zone. 0903 @81 0823 0833 0843 0853 0863 0873 0883
BM5510 ® National Geodetic Survey bench mark
f
Limit of Moderate Wave Action (LiMWA)
BM5510 Contractor Est. NCFMP Survey bench mark 802 0812 0822 0832 0842 0852 0862 0872 08821
� 1
012 1.8.2— Cross Sections with 1% Annual Chance COASTAL BARRIER RESOURCES SYSTEM (CBRS) NOTE 6801 0811 0821 0831 0841 0851 0861 0871 08s1
This map may include approximate boundaries of the CBRS for informational purposes only. Flood insurance is not
Water Surface Elevation (BFE) available within CBRS areas for structures that are newly built or substantially improved on or after the date(s) 9890 0800 0810 0820 0830 0840 0850 0860 0870 0880
indicated on the map. For more information see http:// www. fws. gov/ habitatconservation /coastal_barrier.html, the
sa - - - - - Coastal Transeet FIS Report, or call the U.S. Fish and Wildlife Service Customer Service Center at 1- 800 - 344 -WILD. j
\ \ 9799 0709 0719 0729 0739 0749 0759 0769 0,779 0789
- -- - -- Coastal Transect Baseline ������� CBRS Area �r Otherwise Protected Area I
9798 0708 0718 0728 0738 0748 07j58 0768 0778
Profile Baseline 1 1
9797 0707 0717 0727 0737 0747 ,0757 WAKE COUNTY
Hydrographic Feature 1 9796 0706 0716 j
OTHER Limit of Study CHATHAM COUNTY I j
/
FEATURES Jurisdiction Boundary
1<
W
w
0* AA,
7
36 °3'0 "N
36 °2'30 "N
36 °2'0 "N
78 °56'0 "W
2020000 FEET
,jam V 1RHiC:tROf-D l
I` Cooperating "Fedinical State
840000 FEET
830000 FEET
This digital Flood Insurance Rate Map (FIRM) was produced through a unique
cooperative partnership between the State of North Carolina and the Federal
Emergency Management Agency (FEMA). The State of North Carolina has
implemented a long term approach to floodplain management to decrease the
costs associated with flooding. This is demonstrated by the State's commitment
to map flood hazard areas at the local level. As a part of this effort, the State of
North Carolina has joined in a Cooperating Technical State agreement with
FEMA to produce and maintain this digital FIRM.
r--
r'�
M
�W
0
CL
V
0
0
0
■�
Z
NORTH CAROLINA FLOODPLAIN MAPPING PROGRAM
NATIONAL FLOOD INSURANCE PROGRAM
FLOOD INSURANCE RATE MAP
NORTH CAROLINA ep�
PANEL 0813'
�Ft-IND Skc'��.
EEN1.A
Panel Contains:
COMMUNITY
DURHAM COUNTY
DURHAM, CITY OF
CID PANEL SUFFIX
370085 0813 1
370086 0813 1
MAP NUMBER
3720081300J
MAP REVISED
05/02/06

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Appendix 3
3. Quantity Calculations
a. 1 -Year Peak Flow Analysis
b. 2 and 10 Year Peak Flow Analysis
c. BMP Sizing for peak flow and water
quality.

Year Peak Flow Analysis

Hydrograph
Summary
Report
2
726
279,788
- - - - --
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
86.83
2
726
279,788
- - - - --
- - - - --
- - - - -- Pre Development DA'B'
2
SCS Runoff
27.83
2
728
99,307
- - - - --
- - - - --
- - - - -- Pre Dev DA'B' 1 -YR
4
SCS Runoff
73.49
2
716
153,094
- - - - --
- - - - --
- - - - -- Post Development DA'B'
5
SCS Runoff
41.97
2
726
135,223
- - - - --
- - - - --
- - - - -- POST DEV AREA —B BYPASS
7
Reservoir
25.64
2
724
149,876
4
357.98
52,858 Constructed Wetland
8
Combine
67.48
2
724
285,098
5,7
- - - - --
- - - - -- COMBINE
10
Combine
101.63
2
718
288,317
4, 5,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost B Site Plan.gpw Return Period: 1 Year ` Tuesday, 03 / 3 / 2015

STFWART
Project: Crystal Lake Date: 03.03.15
Project No: C 13098 By: ACH
Composite CN Values - Drainage Area 'B' 1 -YR Pre Development Analysis
lPre- Development 1 -Year Analysis
Surface SCS CN
Impervious 98
Open Space 80
lWooded 77
_> Total Area
11 => Composite SCS CN Value
Area (ac) Comments
0.96 assume good condition
0.10 assume good condition
22.75 assume good condition
23.81 ac
78 i+

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area B Culvert
Checked By AG Revised -
Flow length, L in ft
Pre - development Condition 1 Year Storm Analysis
Sheet Flow
0.036
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.040
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.132 0.132
Shallow Concentrated Flow
7
8
9
10
11
Segment ID
2
Surface description (paved or unpaved)
Unpaved
Flow length, L in ft
2662
Watercourse slope, s in ft/ft
0.036
Average velocity, V in ft/s (figure 3 -1)
3
Tt= L /3600V in hr
0.246 0.246
Channel Flow
Segment ID
12 Cross Sectional flow area, a in ftA2
13 Wetted perimeter, pw in ft
14 Hydraulic radius, r =a /pw in ft
15 Channel slope, s in ft/ft
16 Manning's roughness, n
17 V= 1.49xrA0.667xsA0.5/n in ft/s
18 Flow length, L in ft
19 Tt= L/3600V, in hr 0.000
20 Watershed total Tc in hours 0.379
21 Watershed total Tc in minuets 22.7
See page 30 of TR -55 Manual. 2662
Pre Area B 1 -YR J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 2
Pre Dev DA 'B' 1 -YR
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 23.810 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.00 in
Distribution
Storm duration
= 24 hrs
Shape factor
Pre Dev DA W 1 -YR
Q (cfs) Hyd. No. 2 -- 1 Year
28.00
24.00
20.00
16.00
12.00
11
4.00
Monday, 03 / 2 / 2015
= 27.83 cfs
= 728 min
= 99,307 cuft
= 78
= Oft
= 22.70 min
= Type II
= 484
0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2
Q (cfs)
28.00
24.00
20.00
16.00
12.00
F-WIT11
4.00
,%- 0.00
1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 4
Post Development DA 'B'
Hydrograph type
= SCS Runoff
Peak discharge
= 73.49 cfs
Storm frequency
= 1 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 153,094 cuft
Drainage area
= 21.720 ac
Curve number
= 91 *
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.00 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 21.720
Post Development DA W
Q (cfs) Hyd. No. 4 -- 1 Year Q (cfs)
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 ii 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4 Monday, 03 / 2 / 2015
Hyd. No. 7
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
= 25.64 cfs
Storm frequency
= 1 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 149,876 cuft
Inflow hyd. No.
= 4 - Post Development DA'B'
Max. Elevation
= 357.98 ft
Reservoir name
= POND B
Max. Storage
= 52,858 cuft
Storage Indication method used
Constructed Wetland
Q (cfs) Hyd. No. 7 -- 1 Year Q (cfs)
80.00 80.00
1
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 i 30.00
20.00 20.00
10.00 i i 10.00
S
0.00 i - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 111111-1 Hyd No. 4 1����� Total storage used = 52,858 Cuft

21 10 Year Peak Flow Analysis

1
SCS Runoff
33.34
1
Hydrograph
Summary
Report
- - - - --
- - - - -- Pre Development DA W
3
SCS Runoff
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
33.34
2
722
87,393
- - - - --
- - - - --
- - - - -- Pre Development DA W
3
SCS Runoff
46.24
2
716
93,423
- - - - --
- - - - --
- - - - -- Post Development DA W
4
SCS Runoff
16.22
2
722
42,519
- - - - --
- - - - --
- - - - -- POST DEV AREA —A BYPASS
6
Reservoir
6.695
2
728
93,402
3
398.51
40,505 Constructed Wetland
7
Combine
22.33
2
722
135,921
4,6
- - - - --
- - - - -- COMBINE
9
Combine
60.68
2
718
135,942
3, 4,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost A Site Plan.gpw Return Period: 2 Year ` Tuesday, 03 / 3 / 2015

STEWART
Project: Crystal Lake Date: 03.03.15
Project No: C13098 By: ACH
Development Composite CN Values - Drainage Area'A'Pre
Pre- Development Area A
Surface SCS CN Area (ac) Comments
Impervious 98 0 assume good condition
Open Space 80 0.00 assume good condition
l Wooded 77 16.32 assume good condition
_> Total Area 16.32 ac
11 => Composite SCS CN Value 77 J

STFWART
Project: Crystal Lake Date: 03.03.15
Project No: C 13098 By: ACH
Composite CN Values - Drainage Area 'A' Post Development Bypass Analysis
Post Development Bypass Analysis
Surface
SCS CN
Area (ac)
Comments
Impervious
98
3.75
assume good condition
Open Space
80
12.50
assume good condition
l Wooded
77
28.14
assume good condition
_> Total Area
44.39
ac
11 => Composite SCS CN Value 80 1

rou"'Aw
STEWART
Proj:cl: Crystal Lake Date: 03.03.15
Proj C, No: C13098 By: ACH
Composite CN Values - Drainage Area to POND A Post Development Analysis
Post Development Analysis POND
Surface
SCS CN
Area lac)
Comments
Impervious
98
2.42
assume good condition
Open Space
80
7.94
assume good condition
l Wooded
77
5.04
assume good condition
=> Total Area
15.40
ac
11 => Composite SCS CN Value 82

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area A
Checked By AG Revised -
Flow length, L in ft
Pre - development Condition -2 and 10 Year Storm Analysis
Sheet Flow
0.054
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
7
8
9
10
11
Segment ID
2
Surface description (paved or unpaved)
Unpaved
Flow length, L in ft
1347
Watercourse slope, s in ft/ft
0.054
Average velocity, V in ft/s (figure 3 -1)
3.8
Tt= L /3600V in hr
0.098 0.098
Channel Flow
Segment ID
12 Cross Sectional flow area, a in ftA2
13 Wetted perimeter, pw in ft
14 Hydraulic radius, r =a /pw in ft
15 Channel slope, s in ft/ft
16 Manning's roughness, n
17 V= 1.49xrA0.667xsA0.5/n in ft/s
18 Flow length, L in ft
19 Tt= L/3600V, in hr 0.000
20 Watershed total Tc in hours 0.199
21 Watershed total Tc in minuets 11.9
See page 30 of TR -55 Manual.
Pre Area A J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area A
Checked By AG Revised -
Flow length, L in ft
Post development Condition -2 and 10 Year Storm Analysis - Bypass
Sheet Flow
0.054
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
7
8
9
10
11
Segment ID
2
Surface description (paved or unpaved)
Unpaved
Flow length, L in ft
2091
Watercourse slope, s in ft/ft
0.054
Average velocity, V in ft/s (figure 3 -1)
3.8
Tt= L /3600V in hr
0.153 0.153
Channel Flow
Segment ID
12 Cross Sectional flow area, a in ftA2
13 Wetted perimeter, pw in ft
14 Hydraulic radius, r =a /pw in ft
15 Channel slope, s in ft/ft
16 Manning's roughness, n
17 V= 1.49xrA0.667xsA0.5/n in ft/s
18 Flow length, L in ft
19 Tt= L/3600V, in hr 0.000
20 Watershed total Tc in hours 0.253
21 Watershed total Tc in minuets 15.2
See page 30 of TR -55 Manual.
POST Area A J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 1
Pre Development DA W
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 16.320 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 16.320
Q (cfs)
35.00
30.00
25.00
15.00
10.00
5.00
0.00
0 120 240
Hyd No. 1
Pre Development DA W
Hyd. No. 1 -- 2 Year
Monday, 03 / 2 / 2015
= 33.34 cfs
= 722 min
= 87,393 cuft
= 77*
= Oft
11.90 min
= Type II
= 484
Q (cfs)
35.00
30.00
25.00
' 20.00
15.00
10.00
5.00
0.00
360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 3
Post Development DA W
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.400 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 15.400
Post Development DA W
Q (cfs) Hyd. No. 3 -- 2 Year
50.00
40.00
30.00
20.00
10.00
0.00
0
120 240 360 480 600 720 840 960
Hyd No. 3
Monday, 03 / 2 / 2015
= 46.24 cfs
= 716 min
= 93,423 cuft
= 82*
= Oft
= 5.00 min
= Type II
= 484
Q (cfs)
50.00
40.00
30.00
20.00
10.00
U.UU
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 4
POST DEV AREA A BYPASS
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.940 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
POST DEV AREA_A BYPASS
Q (cfs) Hyd. No. 4 -- 2 Year
18.00
15.00
Monday, 03 / 2 / 2015
= 16.22 cfs
= 722 min
= 42,519 cuft
= 77
= Oft
11.90 min
= Type II
= 484
Q (cfs)
18.00
15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 6
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 3 - Post Development DA W
Max. Elevation
Reservoir name
= POND A
Max. Storage
Storage Indication method used.
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
0 240
Hyd No. 6
Constructed Wetland
Hyd. No. 6 -- 2 Year
Monday, 03 / 2 / 2015
= 6.695 cfs
= 728 min
= 93,402 cuft
= 398.51 ft
= 40,505 cuft
480 720 960 1200 1440 1680
Hyd No. 3 111111-1 Total storage used = 40,505 cuft
Q (cfs)
50.00
40.00
30.00
20.00
10.00
- 0.00
1920
Time (min)

1
SCS Runoff
63.79
2
Hydrograph
Summary
Report
- - - - -- Pre Development DA W
3
SCS Runoff
81.05
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
63.79
2
720
165,370
- - - - -- - - - - --
- - - - -- Pre Development DA W
3
SCS Runoff
81.05
2
716
166,064
- - - - -- - - - - --
- - - - -- Post Development DA W
4
SCS Runoff
31.04
2
720
80,456
- - - - -- - - - - --
- - - - -- POST DEV AREA —A BYPASS
6
Reservoir
36.64
2
722
166,043
3 399.31
63,444 Constructed Wetland
7
Combine
67.34
2
722
246,499
4,6 - - - - --
- - - - -- COMBINE
9
Combine
108.12
2
718
246,520
3, 4, - - - - --
- - - - -- POST DEV NO DETENTION
PrePost A Site Plan.gpw Return Period: 10 Year ` Tuesday, 03 / 3 / 2015

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 1
Pre Development DA W
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 16.320 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 5.10 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 16.320
Q (cfs)
70.00
.1 11
50.00
F 1 11
30.00
20.00
10.00
0.00
0 120 240
Hyd No. 1
Pre Development DA W
Hyd. No. 1 -- 10 Year
Monday, 03 / 2 / 2015
= 63.79 cfs
= 720 min
= 165,370 cuft
= 77*
= Oft
11.90 min
= Type II
= 484
Q (cfs)
70.00
.1 11
50.00
F4, 11
30.00
20.00
10.00
0.00
360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 3
Post Development DA W
Hydrograph type
= SCS Runoff
Peak discharge
= 81.05 cfs
Storm frequency
= 10 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 166,064 cuft
Drainage area
= 15.400 ac
Curve number
= 82*
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 5.10 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 15.400
Post Development DA W
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
90.00 1 90.00
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 — � 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 4
POST DEV AREA A BYPASS
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.940 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 5.10 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
POST DEV AREA_A BYPASS
Hyd. No. 4 -- 10 Year
Monday, 03 / 2 / 2015
= 31.04 cfs
= 720 min
= 80,456 cuft
= 77
= Oft
11.90 min
= Type II
= 484
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00 5.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4 Monday, 03 / 2 / 2015
Hyd. No. 6
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
= 36.64 cfs
Storm frequency
= 10 yrs
Time to peak
= 722 min
Time interval
= 2 min
Hyd. volume
= 166,043 cuft
Inflow hyd. No.
= 3 - Post Development DA W
Max. Elevation
= 399.31 ft
Reservoir name
= POND A
Max. Storage
= 63,444 cuft
Storage Indication method used
Constructed Wetland
Q (cfs) Hyd. No. 6 -- 10 Year Q (cfs)
90.00 90.00
I
80.00 80.00
70.00 70.00
50.00
40.00
30.00
20.00
10.00
50.00
40.00
30.00
20.00
10.00
0.00 - 1 ' - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 111111-1 Hyd No. 3 1����� Total storage used = 63,444 Cuft

Hydrograph
Summary
Report
2
724
371,134
- - - - --
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
116.85
2
724
371,134
- - - - --
- - - - --
- - - - -- Pre Development DA'B'
2
SCS Runoff
37.45
2
728
131,730
- - - - --
- - - - --
- - - - -- Pre Dev DA'B' 1 -YR
4
SCS Runoff
89.18
2
716
187,830
- - - - --
- - - - --
- - - - -- Post Development DA'B'
5
SCS Runoff
56.47
2
724
179,370
- - - - --
- - - - --
- - - - -- POST DEV AREA —B BYPASS
7
Reservoir
28.09
2
724
184,609
4
358.19
64,852 Constructed Wetland
8
Combine
84.56
2
724
363,979
5,7
- - - - --
- - - - -- COMBINE
10
Combine
128.16
2
718
367,200
4, 5,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost B Site Plan.gpw Return Period: 2 Year ` Tuesday, 03 / 3 / 2015

STEWART
Project: Crystal Lake Date: 03.03.15
Project No: C13098 By: ACH
Development Composite CN Values - Drainage Area'B' Pre
lPre- Development 1 -Year Analysis
Surface SCS, CN Area (ac) Comments
Impervious 98 2.93 assume good condition
Open Space 80 7.71 assume good condition
l Wooded 77 57.64 assume good condition
_> Total Area 68.28 ac
11 => Composite SCS CN Value 78 1+

STFWART
Project: Crystal Lake Date: 03.03.15
Project No: C 13098 By: ACH
Composite CN Values - Drainage Area 'B' Post Development Bypass Analysis
Post Development Bypass Analysis
Surface
SCS CN
Area (ac)
Comments
Impervious
98
1.25
assume good condition
Open Space
80
4.81
assume good condition
l Wooded
77
26.94
assume good condition
_> Total Area
33.00
ac
11 => Composite SCS CN Value 78 1

rou"'Aw
STEWART
Proj:ct: Crystal Lake Date: 03.03.15
Composite CN Values - Drainage Area to POND B Post Development Analysis
Post Development Analysis POND
Surface
SCS CN
Area (ac)
Comments
Impervious
98
14.22
assume good condition
Open Space
80
2.72
assume good condition
l Wooded
77
4.78
assume good condition
=> Total Area
21.72
ac
11 => Composite SCS CN Value 91

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area B
Checked By AG Revised -
Cross Sectional flow area, a in ftA2
Pre - development Condition -2 and 10 Year Storm Analysis
Sheet Flow
14
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
Segment ID
7 Surface description (paved or unpaved)
8 Flow length, L in ft
9 Watercourse slope, s in ft/ft
10 Average velocitv, V in ft/s (figure 3 -1)
11 Tt= L /3600V in hr
Channel Flow
Paved
Segment ID
12
Cross Sectional flow area, a in ftA2
13
Wetted perimeter, pw in ft
14
Hydraulic radius, r =a /pw in ft
15
Channel slope, s in ft/ft
16
Manning's roughness, n
17
V= 1.49xrA0.667xsA0.5/n in ft/s
18
Flow length, L in ft
19
Tt= U3600V, in hr
20
Watershed total Tc in hours
21
Watershed total Tc in minuets
See page 30 of TR -55 Manual.
Unpaved
Paved
Unpaved
Unpaved
327
38
203
2349
0.035
0.061
0.084
0.032
3
5
4.7
3.9
0.030
0.002
0.012
0.167
1.77
2.36
0.75
0.0313
0.013
11.04
57
0.212
0.313
18.8
Pre Area B J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area B
Checked By AG Revised -
Cross Sectional flow area, a in ftA2
Pre - development Condition -2 and 10 Year Storm Analysis - Bypass
Sheet Flow
14
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
Segment ID
7 Surface description (paved or unpaved)
8 Flow length, L in ft
9 Watercourse slope, s in ft/ft
10 Average velocitv, V in ft/s (figure 3 -1)
11 Tt= L /3600V in hr
Channel Flow
Paved
Segment ID
12
Cross Sectional flow area, a in ftA2
13
Wetted perimeter, pw in ft
14
Hydraulic radius, r =a /pw in ft
15
Channel slope, s in ft/ft
16
Manning's roughness, n
17
V= 1.49xrA0.667xsA0.5/n in ft/s
18
Flow length, L in ft
19
Tt= U3600V, in hr
20
Watershed total Tc in hours
21
Watershed total Tc in minuets
See page 30 of TR -55 Manual.
Unpaved
Paved
Unpaved
Unpaved
327
38
203
2349
0.035
0.061
0.084
0.032
3
5
4.7
3.9
0.030
0.002
0.012
0.167
1.77
2.36
0.75
0.0313
0.013
11.04
57
0.212
0.313
18.8
POST Area B J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 1
Pre Development DA 'B'
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 68.280 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 68.280
Pre Development DA 'B'
Q (cfs) Hyd. No. 1 -- 2 Year
120.00 I
1
100.00
80.00
60.00
40.00
20.00
Monday, 03 / 2 / 2015
= 116.85 cfs
= 724 min
= 371,134 cuft
= 78*
= Oft
18.80 min
= Type II
= 484
Q (cfs)
120.00
100.00
•1 11
FA�
20.00
0.00 L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 2
Pre Dev DA 'B' 1 -YR
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 23.810 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
40.00
30.00
20.00
10.00
0.00
0 120 240
Hyd No. 2
Pre Dev DA W 1 -YR
Hyd. No. 2 -- 2 Year
I
Monday, 03 / 2 / 2015
= 37.45 cfs
= 728 min
= 131,730 cuft
= 78
= Oft
= 22.70 min
= Type II
= 484
Q (cfs)
40.00
30.00
20.00
10.00
0.00
360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 4
Post Development DA 'B'
Hydrograph type
= SCS Runoff
Peak discharge
= 89.18 cfs
Storm frequency
= 2 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 187,830 cuft
Drainage area
= 21.720 ac
Curve number
= 91 *
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.50 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 21.720
Post Development DA W
Q (cfs) Hyd. No. 4 -- 2 Year Q (cfs)
90.00 90.00
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
i
20.00 20.00
10.00 10.00
i
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4 Monday, 03 / 2 / 2015
Hyd. No. 5
POST DEV AREA —B BYPASS
Hydrograph type
= SCS Runoff
Peak discharge
= 56.47 cfs
Storm frequency
= 2 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 179,370 cuft
Drainage area
= 33.000 ac
Curve number
= 78
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 18.80 min
Total precip.
= 3.50 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
POST DEV AREA_B BYPASS
Q (cfs) Hyd. No. 5 -- 2 Year Q (cfs)
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 5 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 7
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 4 - Post Development DA'B'
Max. Elevation
Reservoir name
= POND B
Max. Storage
Storage Indication method used
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
Constructed Wetland
Hyd. No. 7 -- 2 Year
Monday, 03 / 2 / 2015
= 28.09 cfs
= 724 min
= 184,609 cuft
= 358.19 ft
= 64,852 cuft
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 — - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 111111-1 Hyd No. 4 1����� Total storage used = 64,852 Cuft

Hydrograph
Summary
Report
2
724
693,203
- - - - --
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
221.69
2
724
693,203
- - - - --
- - - - --
- - - - -- Pre Development DA'B'
2
SCS Runoff
71.21
2
726
246,044
- - - - --
- - - - --
- - - - -- Pre Dev DA'B' 1 -YR
4
SCS Runoff
139.04
2
716
301,519
- - - - --
- - - - --
- - - - -- Post Development DA'B'
5
SCS Runoff
107.15
2
724
335,028
- - - - --
- - - - --
- - - - -- POST DEV AREA B BYPASS
7
Reservoir
34.30
2
724
298,291
4
358.90
105,622 Constructed Wetland
8
Combine
141.44
2
724
633,318
5,7
- - - - --
- - - - -- COMBINE
10
Combine
216.53
2
718
636,547
4, 5,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost B Site Plan.gpw Return Period: 10 Year ` Tuesday, 03 / 3 / 2015

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 1
Pre Development DA 'B'
Hydrograph type
= SCS Runoff
Peak discharge
= 221.69 cfs
Storm frequency
= 10 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 693,203 cuft
Drainage area
= 68.280 ac
Curve number
= 78*
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 18.80 min
Total precip.
= 5.10 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 68.280
Pre Development DA 'B'
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
240.00 240.00
i
210.00 210.00
180.00 180.00
150.00 150.00
120.00 120.00
90.00 90.00
60.00 60.00
30.00 30.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 2
Pre Dev DA 'B' 1 -YR
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 23.810 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 5.10 in
Distribution
Storm duration
= 24 hrs
Shape factor
Pre Dev DA W 1 -YR
Monday, 03 / 2 / 2015
= 71.21 cfs
= 726 min
= 246,044 cuft
= 78
= Oft
= 22.70 min
= Type II
= 484
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
80.00 80.00
70.00 70.00
60.00 i 60.00
50.00 50.00
40.00 40.00
30.00 i 30.00
20.00 20.00
10.00 i 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 4
Post Development DA 'B'
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 21.720 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 5.10 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 21.720
Q (cfs)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
I
0.00
0
Post Development DA W
Hyd. No. 4 -- 10 Year
Monday, 03 / 2 / 2015
= 139.04 cfs
= 716 min
= 301,519 cuft
= 91*
= Oft
= 5.00 min
= Type II
= 484
Q (cfs)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 5
POST DEV AREA —B BYPASS
Hydrograph type
Storm frequency
Time interval
Drainage area
Basin Slope
Tc method
Total precip.
Storm duration
Q (cfs)
120.00
100.00
:1 11
.1 11
i 1 11
20.00
1 11
0 120 240
Hyd No. 5
= SCS Runoff
Peak discharge
= 10 yrs
Time to peak
= 2 min
Hyd. volume
= 33.000 ac
Curve number
= 0.0%
Hydraulic length
= User
Time of conc. (Tc)
= 5.10 in
Distribution
= 24 hrs
Shape factor
POST DEV AREA_B BYPASS
Hyd. No. 5 -- 10 Year
360 480 600 720 840 960 1080 1200
Monday, 03 / 2 / 2015
= 107.15 cfs
= 724 min
= 335,028 cuft
= 78
= Oft
18.80 min
= Type II
= 484
Q (cfs)
120.00
100.00
:1 11
•1 11
i 1 11
20.00
%� 0.00
1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 7
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 4 - Post Development DA'B'
Max. Elevation
Reservoir name
= POND B
Max. Storage
Storage Indication method used
Q (cfs)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
Constructed Wetland
Hyd. No. 7 -- 10 Year
Monday, 03 / 2 / 2015
= 34.30 cfs
= 724 min
= 298,291 cuft
= 358.90 ft
= 105,622 cuft
Q (cfs)
140.00
120.00
100.00
.1 11
40.00
20.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 111111-1 Hyd No. 4 1����� Total storage used = 105,622 cuft

Hydrograph
Summary
Report
2
718
261,182
- - - - --
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
114.04
2
718
261,182
- - - - --
- - - - --
- - - - -- Pre Development DA'C'
3
SCS Runoff
41.93
2
716
85,012
- - - - --
- - - - --
- - - - -- Post Development DA'C'
4
SCS Runoff
70.48
2
720
161,337
- - - - --
- - - - --
- - - - -- POST DEV AREA C BYPASS
6
Reservoir
6.870
2
726
84,984
3
367.06
37,395 Constructed Wetland
7
Combine
76.62
2
720
246,321
4,6
- - - - --
- - - - -- COMBINE
9
Combine
111.36
2
718
246,349
3, 4,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost C Site Plan.gpw Return Period: 2 Year I Monday, 03 / 2 / 2015

STEWART
Project: Crystal Lake Date: 03.03.15
Project No: C13098 By: ACH
Development Composite CN Values - Drainage Area'C' Pre
lPre- Development 1 -Year Analysis
Surface SCS CN
Impervious 98
Open Space 80
lWooded 77
_> Total Area
11 => Composite SCS CN Value
80 1
Area (ac)
Comments
4.17
assume good condition
13.00
assume good condition
26.80
assume good condition
43.97
ac
80 1

rou"'Aw
STEWART
Proj:ct: Crystal Lake Date: 03.03.15
Composite CN Values - Drainage Area 'C' Post Development Bypass Analysis
Post Development Bypass Analysis
Surface
SCS CN
Area (ac)
Comments
Impervious
98
assume good condition
Open Space
80
assume good condition
l Wooded
77
31.07
assume good condition
_> Total Area
31.07
ac
11 => Composite SCS CN Value 77

,"�A
STEWART
r
Composite CN Values - Drainage Area to POND C Post Development Analysis
Post Development Analysis POND
Surface
SCS CN
Area Jac)
Comments
Impervious
98
4. 9
assume pood condition
�O an $ace
D p
80
2.18
assume good and n
J/
Wooded
77
6.53
assume pood on 't,
_> Total Area
12.90 ac
IF-=> Composite SCS CN Value
84 iI

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area C
Checked By AG Revised -
Surface description (paved or unpaved)
Pre - development Condition -2 and 10 Year Storm Analysis
Sheet Flow
Unpaved
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
7
8
9
10
11
Segment ID
2
3
4
Surface description (paved or unpaved)
Unpaved
Paved
Unpaved
Flow length, L in ft
219
42
603
Watercourse slope, s in ft/ft
0.055
0.039
0.093
Average velocitv. V in ft/s (figure 3 -1)
3.8
4
4.8
Tt= L /3600V in hr
0.016
0.003
0.035 0.054
Channel Flow
Segment ID
12 Cross Sectional flow area, a in ftA2
13 Wetted perimeter, pw in ft
14 Hydraulic radius, r =a /pw in ft
15 Channel slope, s in ft/ft
16 Manning's roughness, n
17 V= 1.49xrA0.667xsA0.5/n in ft/s
18 Flow length, L in ft
19 Tt= L/3600V, in hr 0.000
20 Watershed total Tc in hours 0.154
21 Watershed total Tc in minuets 9.2
See page 30 of TR -55 Manual.
Pre Area C J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

,"�il
S T E'WA R T TR 55 Time of Concentration Worksheet
Project Crystal Lake
Calculated By AH Date 03.03.15
Location Area C
Checked By AG Revised -
Surface description (paved or unpaved)
Pre - development Condition -2 and 10 Year Storm Analysis - Bypass
Sheet Flow
Unpaved
Segment ID
1 Subtotal
1 Surface Description
Open Space
2 Mannings Roughness, n
0.23
3 Flow Length, L in ft (max 300')
75
4 Two -year 24 -hr rainfall, P2 in inches
3.5
5 Land Slope, s in ft/ft
0.080
6 Tt = 0.007x(nL) ^0.8 /(P2A0.5xsA0.4) in hr
0.100 0.100
Shallow Concentrated Flow
7
8
9
10
11
Segment ID
2
3
4
Surface description (paved or unpaved)
Unpaved
Paved
Unpaved
Flow length, L in ft
219
42
603
Watercourse slope, s in ft/ft
0.055
0.039
0.093
Average velocitv. V in ft/s (figure 3 -1)
3.8
4
4.8
Tt= L /3600V in hr
0.016
0.003
0.035 0.054
Channel Flow
Segment ID
12 Cross Sectional flow area, a in ftA2
13 Wetted perimeter, pw in ft
14 Hydraulic radius, r =a /pw in ft
15 Channel slope, s in ft/ft
16 Manning's roughness, n
17 V= 1.49xrA0.667xsA0.5/n in ft/s
18 Flow length, L in ft
19 Tt= L/3600V, in hr 0.000
20 Watershed total Tc in hours 0.154
21 Watershed total Tc in minuets 9.2
See page 30 of TR -55 Manual.
POST Area C J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \C13098_Tc.xls

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4
Hyd. No. 1
Pre Development DA 'C'
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 43.970 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 43.970
Pre Development DA V
Q (cfs) Hyd. No. 1 -- 2 Year
120.00 J
100.00
:1 11
.1 11
i 1 11
20.00
0.00
0 120 240
Hyd No. 1
Monday, 03 / 2 / 2015
= 114.04 cfs
= 718 min
= 261,182 cuft
= 80*
= Oft
= 9.20 min
= Type II
= 484
Q (cfs)
120.00
100.00
:1 11
•1 11
i 1 11
20.00
0.00
360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 3
Post Development DA 'C'
Hydrograph type
= SCS Runoff
Peak discharge
= 41.93 cfs
Storm frequency
= 2 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 85,012 cuft
Drainage area
= 12.900 ac
Curve number
= 84*
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.50 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 12.900
Post Development DA V
Q (cfs) Hyd. No. 3 -- 2 Year Q (cfs)
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 4
POST DEV AREA C BYPASS
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 31.070 ac
Curve number
Basin Slope
= 0.0%
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.50 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
80.00
70.00
.1 11
50.00
rd�
30.00
20.00
10.00
0.00
0 120 240 360 480
Hyd No. 4
POST DEV AREA_C BYPASS
Hyd. No. 4 -- 2 Year
Monday, 03 / 2 / 2015
= 70.48 cfs
= 720 min
= 161,337 cuft
= 77
= Oft
= 9.20 min
= Type II
= 484
Q (cfs)
80.00
70.00
I 60.00
50.00
40.00
30.00
20.00
10.00
0.00
600 720 840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 6
Constructed Wetland
Hydrograph type = Reservoir Peak discharge
Storm frequency = 2 yrs Time to peak
Time interval = 2 min Hyd. volume
Inflow hyd. No. = 3 - Post Development DA'C' Max. Elevation
Reservoir name = POND C Max. Storage
Storage Indication method used
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
0
240
Hyd No. 6
Constructed Wetland
Hyd. No. 6 -- 2 Year
480 720
- Hyd No. 3
Monday, 03 / 2 / 2015
= 6.870 cfs
= 726 min
= 84,984 cuft
= 367.06 ft
= 37,395 cuft
Q (cfs)
50.00
1 11
30.00
20.00
10.00
- 0.00
960 1200 1440 1680 1920
Time (min)
II T T T— l ll Total storage used = 37,395 cuft

Hydrograph
Summary
Report
2
718
475,686
- - - - --
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D@2015 by Autodesk, Inc. v10.4
Hyd. Hydrograph Peak
Time Time to
Hyd.
Inflow Maximum Total Hydrograph
No. type flow
interval Peak
volume
hyd(s) elevation strge used Description
(origin) (cfs)
(min) (min)
(cuft)
(ft) (cuft)
1
SCS Runoff
207.04
2
718
475,686
- - - - --
- - - - --
- - - - -- Pre Development DA'C'
3
SCS Runoff
71.44
2
716
147,594
- - - - --
- - - - --
- - - - -- Post Development DA'C'
4
SCS Runoff
133.40
2
718
305,292
- - - - --
- - - - --
- - - - -- POST DEV AREA C BYPASS
6
Reservoir
47.29
2
720
147,566
3
367.82
52,504 Constructed Wetland
7
Combine
179.53
2
720
452,858
4,6
- - - - --
- - - - -- COMBINE
9
Combine
203.08
2
718
452,886
3, 4,
- - - - --
- - - - -- POST DEV NO DETENTION
PrePost C Site Plan.gpw Return Period: 10 Year ` Monday, 03 / 2 / 2015

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 1
Pre Development DA 'C'
Hydrograph type
= SCS Runoff
Peak discharge
= 207.04 cfs
Storm frequency
= 10 yrs
Time to peak
= 718 min
Time interval
= 2 min
Hyd. volume
= 475,686 cuft
Drainage area
= 43.970 ac
Curve number
= 80*
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 9.20 min
Total precip.
= 5.10 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(4.670 x 77) + (6.820 x 80) + (0.410 x 98)] / 43.970
Pre Development DA V
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
210.00 210.00
180.00
150.00
120.00
•1 11
•1 11
�I
180.00
150.00
120.00
•1 11
•1 11
30.00 30.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. 00.4 Monday, 03 / 2 / 2015
Hyd. No. 3
Post Development DA 'C'
Hydrograph type
= SCS Runoff
Peak discharge
= 71.44 cfs
Storm frequency
= 10 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 147,594 cuft
Drainage area
= 12.900 ac
Curve number
= 84*
Basin Slope
= 0.0%
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 5.10 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area /CN) = [(10.510 x 98) + (9.230 x 80) + (0.770 x 77)] / 12.900
Post Development DA V
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 i 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 4
POST DEV AREA —C BYPASS
Hydrograph type
Storm frequency
Time interval
Drainage area
Basin Slope
Tc method
Total precip.
Storm duration
Q (cfs)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
= SCS Runoff
Peak discharge
= 10 yrs
Time to peak
= 2 min
Hyd. volume
= 31.070 ac
Curve number
= 0.0%
Hydraulic length
= User
Time of conc. (Tc)
= 5.10 in
Distribution
= 24 hrs
Shape factor
POST DEV AREA_C BYPASS
Hyd. No. 4 -- 10 Year
Monday, 03 / 2 / 2015
= 133.40 cfs
= 718 min
= 305,292 cuft
= 77
= Oft
= 9.20 min
= Type II
= 484
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 4
Q (cfs)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Hyd. No. 6
Constructed Wetland
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 3 - Post Development DA'C'
Max. Elevation
Reservoir name
= POND C
Max. Storage
Storage Indication method used
Constructed Wetland
Q (cfs) Hyd. No. 6 -- 10 Year
80.00
70.00
.1 11
50.00
i 1 11
30.00
20.00
10.00
Monday, 03 / 2 / 2015
= 47.29 cfs
= 720 min
= 147,566 cuft
= 367.82 ft
= 52,504 cuft
Q (cfs)
80.00
70.00
•1 11
50.00
i 1 11
30.00
20.00
10.00
0.00 __.1.. , - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 111111-1 Hyd No. 3 1����� Total storage used = 52,504 Cuft

BMP Sizing for Peak Flow and Water Quality

rmqw;j
STEWART
Project: Crystal Lake Date: 03.03.15 Revision -
Project No: C13098 By: ACH
Constructed . . Calcukifions
Input values in red
Drainage Area: A
Drainage
JTotal Drainage Area (sf) 720,787
IOn-site Drainage Area �sf) 597,845
Off -site Drainage Area s) 97,806
Impervious Surface Area
6.59 ac
On -site Buildings /Lots (sf)
120,000
JOn -site Streets (sf)
86,625
On -site Parking (sf)
0
On -site Sidewalks (sf)
80,150
Other On -site (sf)
76
Future (sf)
0
Off -site sf
0
Existing A* (sf)
0
JTotal Impervious Area (sf)
286,851
Total Drainage Area = 16.55 ac
Total Impervious Area =
6.59 ac
Percent Impervious =
39.80%
Design Rainfall Depth =
1 in
Allowed Ponding Depth =
12 in
Required Surface Area = 24517 sf
Required Storage Area =
Provided Surface Area =
Wetland Zone Type
Deep Water (Forebay)
Shallow Water
Shallow Land
Deep Water (non - Forebay)
24517 SF
25136 SF
Managed Pervious Area (sf)
JUnmanged Pervious Area (pasture) (sf)
Forest (sf)
JTotal Pervious Area (sf)
228,202
0
180,598
408,800
* = Report only amount of existing BUA that will remain after
development. Do not report any existing BUA that is to be
removed and which will be replaced by new BUA
Simple Method
Rv = 0.05 + 0.009(I)
I = % impervious = 40%
Rv = 0.41 in
Required Volume = 24517 cf
% of Total
Surface
Surface
Wetland
Area
Area
Surface
Required
Zone
Provided
Area
(sf)
Depth
(sf)
% of Total
10%
2,514
18 -36"
5,323
21.2%
40%
10,054
3 -6"
21,291
84.7%
40%
10,054
12"
21,291
84.7%
10%
2,514
18 -36"
5,323
21.2%

STEWART
Project: Crystal Lake
Proiect No: C13098
Input values in red
Drainage Area: A
Date: 03.03.15
Bv: ACH
Storage Volume Required (Simple Method) Basin Characteristics
Revision -
Total Drainage Area =
16.55 ac
Wetland Invert =
395.50 ft
Total Impervious Area =
6.59 ac
Normal Pool Elevation =
397.00 ft
Percent Impervious =
40%
Next available Outlet =
398.00 ft
Storage Depth =
1.00 ft
Rv = 0.05 + 0.009(I)
Driving Head (H /3)=
0.33 ft
I = % impervious =
40%
Rv =
0.41 in
Runoff Vol. Req'= 24517 cf
Temporary Storage Volume = 25136 cf
Temporary Storage Surface Area = 25136 sf
Find orifice size for 2 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.1455 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.05233 ft2
7.53497 in
Orifice Size (2 day) = 3.10 in (dia)
Find orifice size for 5 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.0568 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.02042 ft2
2.93978 in
Orifice Size (5 day) = 1.93 in (dia)
Select orifice size between 2 and 5 day size
Actual Drawdown Time
Volume = 25136 cf
Pipe Size = 2.5 "dia
Area = 0.03409 ft2
Flow Rate = 0.09476 cfs
STRONGER BY DESIGN 421 FAYETTEVILLE ST. SUITE 400 RALEIGH, NC 27603 T 919.380.8750 F 919.380.8752

Pond Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Monday, 03 / 2 / 2015
Pond No. 1 - POND A
[C]
[PrfRsr]
Pond Data
[B]
[C]
[D]
Contours - User - defined contour areas.
Average end area method
used for volume calculation. Begining Elevation = 397.00 ft
Stage / Storage Table
0.00
Crest Len (ft)
= 20.00
Stage (ft) Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00 397.00
25,136
0
0
1.00 398.00
27,141
26,139
26,139
2.00 399.00
29,204
28,173
54,311
3.00 400.00
31,322
30,263
84,574
4.00 401.00
33,498
32,410
116,984
Culvert / Orifice Structures Weir Structures
Stage (ft)
4.00
3.00
f 1117
1.00
0.00
0.00 7.00
Total Q
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
14.00 21.00 28.00 35.00 42.00 49.00 56.00 63.00
Elev (ft)
401.00
400.00
16DR- [1111
398.00
397.00
70.00
Discharge (cfs)
[A]
[B]
[C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in)
= 36.00
6.00
6.00
0.00
Crest Len (ft)
= 20.00
40.00
0.00
0.00
Span (in)
= 36.00
6.00
24.00
0.00
Crest El. (ft)
= 398.60
399.40
0.00
0.00
No. Barrels
= 1
4
1
0
Weir Coeff.
= 3.33
3.33
3.33
3.33
Invert El. (ft)
= 395.50
397.00
398.00
0.00
Weir Type
= 1
Ciplti
- --
- --
Length (ft)
= 68.00
0.00
0.00
0.00
Multi -Stage
= Yes
Yes
No
No
Slope ( %)
= 0.50
0.00
0.00
n/a
N -Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in /hr)
= 0.000 (by
Contour)
Multi -Stage
= n/a
Yes
Yes
No
TW Elev. (ft)
= 0.00
Stage (ft)
4.00
3.00
f 1117
1.00
0.00
0.00 7.00
Total Q
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
14.00 21.00 28.00 35.00 42.00 49.00 56.00 63.00
Elev (ft)
401.00
400.00
16DR- [1111
398.00
397.00
70.00
Discharge (cfs)

rmqw;j
STEWART
Project: Crystal Lake Date: 03.03.15 Revision -
Project No: C13098 By: ACH
Constructed Wetland . Calculations
Input values in red
Drainage Area: B
Drainage Area Pervious Surface Area
JTotal Drainage Area (sf) 998,529 1Managed Pervious Area (sf) 118,314
JOn -site Drainage Area �sf) 945,817 JUnmanged Pervious Area (pasture) (sf) 0
lOff -site Drainage Area s) 0 1 Forest (sf) 208,231
JTotal Pervious Area (sf) 326,545
Impervious Surface Area
14.22 ac
On -site Buildings /Lots (sf)
272,500
JOn -site Streets (sf)
134,508
JOn -site Parking (sf)
25,640
lOn -site Sidewalks (sf)
159,813
10ther On -site (sf)
26,811
Future (sf)
0
JOff -site (sf)
0
lExisting BUA* (sf)
0
JTotal Impervious Area (sf)
619,272
Total Drainage Area = 22.92 ac
Total Impervious Area =
14.22 ac
Percent Impervious =
62.02%
Design Rainfall Depth =
1 in
Allowed Ponding Depth =
12 in
Required Surface Area = 50606 sf
Required Storage Area =
Provided Surface Area =
Wetland Zone Type
Deep Water (Forebay)
Shallow Water
Shallow Land
Deep Water (non - Forebay)
50606 SF
52712 SF
* = Report only amount of existing BUA that will remain after
development. Do not report any existing BUA that is to be
removed and which will be replaced by new BUA
Simple Method
Rv = 0.05 + 0.009(I)
I = % impervious = 62%
Rv = 0.61 in
Required Volume = 50606 cf
% of Total
Surface
Surface
Wetland
Area
Area
Surface
Required
Zone
Provided
Area
(sf)
Depth
(sf)
% of Total
10%
5,271
18 -36"
5,323
10.1%
40%
21,085
3 -6"
21,291
40.4%
40%
21,085
12"
21,291
40.4%
10%
5,271
18 -36"
5,323
10.1%

-A
STEWART
Project: Crystal Lake
Proiect No: C13098
Input values in red
Drainage Area: B
Storage Volume Required (Simple Method)
Date: 03.03.15
Bv: ACH
Basin Characteristics
Revision -
Total Drainage Area =
22.92 ac
Wetland Invert =
355.50 ft
Total Impervious Area =
14.22 ac
Normal Pool Elevation =
357.00 ft
Percent Impervious =
62%
Next available Outlet =
358.00 ft
Storage Depth =
1.00 ft
Rv = 0.05 + 0.009(I)
Driving Head (H /3)=
0.33 ft
I = % impervious =
62%
Rv =
0.61 in
Runoff Vol. Req'= 50606 cf
Temporary Storage Volume = 52712 cf
Temporary Storage Surface Area = 52712 sf
Find orifice size for 2 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.3050 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.10973 ft2
15.80137 in
Orifice Size (2 day) = 4.49 in (dia)
Find orifice size for 5 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.1171 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.04214 ft2
6.06802 in
Orifice Size (5 day) = 2.78 in (dia)
Select orifice size between 2 and 5 day size
Actual Drawdown Time
Volume = 52712 cf
Pipe Size = 3.5 "dia
Area = 0.066813 ft2
Flow Rate = 0.185736 cfs
STRONGER BY DESIGN 421 FAYETTEVILLE ST. SUITE 400 RALEIGH, NC 27603 T 919.380.8750 F 919.380.8752

Pond Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Monday, 03 / 2 / 2015
Pond No. 1 - POND B
[C]
[PrfRsr]
Pond Data
[B]
[C]
[D]
Contours - User - defined contour areas.
Average end area method
used for volume calculation. Begining Elevation = 357.00 ft
Stage / Storage Table
0.00
Crest Len (ft)
= 20.00
Stage (ft) Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00 357.00
52,712
0
0
1.00 358.00
55,594
54,153
54,153
2.00 359.00
58,534
57,064
111,217
3.00 360.00
61,529
60,032
171,249
4.00 361.00
64,582
63,056
234,304
Culvert / Orifice Structures Weir Structures
Stage (ft)
4.00
3.00
f 1111
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
1.00 r
Elev (ft)
361.00
360.00
[CM111I11
358.00
0.00 357.00
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00
Total Q Discharge (cfs)
[A]
[B]
[C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in)
= 30.00
1.50
6.00
0.00
Crest Len (ft)
= 20.00
40.00
0.00
0.00
Span (in)
= 30.00
1.50
24.00
0.00
Crest El. (ft)
= 357.10
357.90
0.00
0.00
No. Barrels
= 1
1
3
0
Weir Coeff.
= 3.33
3.33
3.33
3.33
Invert El. (ft)
= 355.50
357.00
358.00
0.00
Weir Type
= 1
Ciplti
- --
- --
Length (ft)
= 103.00
0.00
0.00
0.00
Multi -Stage
= Yes
Yes
No
No
Slope ( %)
= 2.72
0.00
0.00
n/a
N -Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in /hr)
= 0.000 (by
Contour)
Multi -Stage
= n/a
Yes
Yes
No
TW Elev. (ft)
= 0.00
Stage (ft)
4.00
3.00
f 1111
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
1.00 r
Elev (ft)
361.00
360.00
[CM111I11
358.00
0.00 357.00
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00
Total Q Discharge (cfs)

_ I
STEWART
Project: Crystal Lake Date: 03.03.15 Revision -
Project No: C13098 By: ACH
Constructed Wetland . Calculations
Input values in red
Drainage Area: C
- _, .
JTotal Drainage Area (sf) 578,329
IOn-site Drainage Area �sf) 321,093
Off -site Drainage Area s) 240,728
Impervious Surface Area
4.19 ac
On -site Buildings /Lots (sf)
21,314
JOn -site Streets (sf)
52,657
On -site Parking (sf)
0
On -site Sidewalks (sf)
24,357
Other On -site (sf)
200
Future (sf)
0
Off -site sf
84,054
Existing A* (sf)
0
JTotal Impervious Area (sf)
182,582
Total Drainage Area = 13.28 ac
Total Impervious Area =
4.19 ac
Percent Impervious =
31.57%
Design Rainfall Depth =
1 in
Allowed Ponding Depth =
12 in
Required Surface Area = 16103 sf
1.
Managed Pervious Area (sf) 94,810
JUnmanged Pervious Area (pasture) (sf) 0
1 Forest (sf) 284,429
JTotal Pervious Area (sf) 379,239
* = Report only amount of existing BUA that will remain after
development. Do not report any existing BUA that is to be
removed and which will be replaced by new BUA
Simple Method
Rv = 0.05 + 0.009(I)
I = % impervious = 32%
Rv = 0.33 in
Required Volume = 16103 cf
Required Surface Area ..
Required Storage Area = 16103 SF
Provided Surface Area = 16508 SF
% of Total
Surface
Surface
Wetland
Area
Area
Surface
Required
Zone
Provided
Wetland Zone Type
Area
(sf)
Depth
(sf)
% of Total
Deep Water (Forebay)
10%
1,651
18 -36"
5,323
32.2%
Shallow Water
40%
6,603
3 -6"
21,291
129.0%
Shallow Land
40%
6,603
12"
21,291
129.0%
Deep Water (non - Forebay)
10%
1,651
18 -36"
5,323
32.2%

-A
STEWART
Project: Crystal Lake
Proiect No: C13098
Input values in red
Drainage Area: C
Storage Volume Required (Simple Method)
Date: 03.03.15
Bv: ACH
Basin Characteristics
Revision -
Total Drainage Area =
13.28 ac
Wetland Invert =
363.50 ft
Total Impervious Area =
4.19 ac
Normal Pool Elevation =
365.00 ft
Percent Impervious =
32%
Next available Outlet =
366.00 ft
Storage Depth =
1.00 ft
Rv = 0.05 + 0.009(I)
Driving Head (H /3)=
0.33 ft
I = % impervious =
32%
Rv =
0.33 in
Runoff Vol. Req'= 16103 cf
Temporary Storage Volume = 16508 cf
Temporary Storage Surface Area = 16508 sf
Find orifice size for 2 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.0955 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.03437 ft2
4.94857 in
Orifice Size (2 day) = 2.51 in (dia)
Find orifice size for 5 -day drawdown time
Flow Rate = Volume (cf) / Time (sec)
0.0373 cfs
Q= CD *A *(2 *g *h) ^(1/2) (Orifice Equation - solve for A (area))
A= 0.01341 ft2
1.93091 in
Orifice Size (5 day) = 1.57 in (dia)
Select orifice size between 2 and 5 day size
Actual Drawdown Time
Volume = 16508 cf
Pipe Size = 2 "dia
Area = 0.021817 ft2
Flow Rate = 0.060649 cfs
STRONGER BY DESIGN 421 FAYETTEVILLE ST. SUITE 400 RALEIGH, NC 27603 T 919.380.8750 F 919.380.8752

Pond Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2015 by Autodesk, Inc. v10.4
Monday, 03 / 2 / 2015
Pond No. 1 -
POND C
Pond Data
Contours - User - defined contour areas.
Average end area method used
for volume calculation.
Begining Elevation = 365.00 ft
Stage / Storage
Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00
365.00
16,508
0
0
1.00
366.00
18,081
17,295
17,295
2.00
367.00
19,711
18,896
36,191
3.00
368.00
21,397
20,554
56,745
4.00
369.00
23,140
22,269
79,013
Culvert / Orifice Structures
Weir Structures
[A]
[B] [C]
[PrfRsr]
[A] [B]
[C]
[D]
Rise (in)
= 48.00
6.00 6.00
0.00
Crest Len (ft)
= 20.00 40.00
0.00
0.00
Span (in)
= 48.00
6.00 24.00
0.00
Crest El. (ft)
= 367.10 367.90
0.00
0.00
No. Barrels
= 1
2 1
0
Weir Coeff.
= 3.33 3.33
3.33
3.33
Invert El. (ft)
= 363.00
365.00 366.00
0.00
Weir Type
= 1 Ciplti
- --
- --
Length (ft)
= 86.00
0.00 0.00
0.00
Multi -Stage
= Yes Yes
No
No
Slope ( %)
= 6.98
0.00 0.00
n/a
N -Value
= .013
.013 .013
n/a
Orifice Coeff.
= 0.60
0.60 0.60
0.60
Exfil.(in /hr)
= 0.000 (by Contour)
Multi -Stage
= n/a
Yes Yes
No
TW Elev. (ft)
= 0.00
Note: Culvert/Orifice outflows are analyzed
under inlet (ic) and outlet
(oc) control. Weir risers checked for orifice conditions
(ic) and submergence (s).
Stage (ft)
4.00
3.00
41111
1.00
Stage / Discharge
Elev (ft)
369.00
368.00
1911*I[1I11
366.00
0.00 365.00
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0
Total Q Discharge (cfs)

Appendix 4
4. Nutrient Loading Calculations
a. Jordan Lake Accounting Tool
b. City of Durham Nutrient Reporting
Form
c. TSS Summary

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
A I B I C I D E F I G I11IIII K L I M I N 1 O 1 P I O I R I S I T I U
Watershed Characteristics Ver2.0 Clear All Values _j IReturn to Instructions J Proceed to BMP Characteristics L Skip to Development Summary
Instructions
1. Select your physiographic /geologic region. (see map on 'instructions' page)
2. Enter the area of the entire development in square feet (ft).
3. Select the location that is most representative of the site's precipitation characteristics. (see map on 'instructions' page)
4. For each applicable land use, enter the total area of that land use that lies within the development under pre - development conditions.
5. For each applicable land use, enter the total area of that land use that lies within the development under post - development conditions, before BMP implementation.
6. Ensure that the sum of pre- and post - development areas entered equal the orginal development area.
7. Continue to "BMP Characteristics" tab.
Additional Guidelines
- For non - residential watersheds, indicate acreages of each land use type in Column 1 for both pre- and post - development conditions.
- For residential watersheds, complete the required information in Column 2 for both pre- and post - development conditions.
- If a given land use is not present in the given watershed, leave the cell blank or enter a zero.
- Ensure that land use areas entered for both pre- and post - development conditions match the total development area entered in cell 021.
- Residential areas may be entered by average lot size (column, part A), or may be separated into individual land uses (column 2, part B) -- do NOT list out individual land uses within an
area already described by lot size.
- Unless runoff flowing onto the development from offsite is routed separately around or through the site, the offsite catchment area draining in must be included in the acreage
values of the appropriate land use(s) and treated.
Physiographic /Geologic Region: Piedmont
Soil Hydrologic Group B
Precipitation location: Carrboro
Total Development Area (ft`): 6,510,557
Development Name: Crystal Lake
I
Model Prepared By: A. Hutchens
COLUMN 1 -- NON- RESIDENTIAL LAND USES
COLUMN 2 -- RESIDENTIAL LAND USES
Pre-
Post-
Custom
Pre- Post -
TN EMC
TP EMC
Development
Development
Age TN EMC
Lot Size
TP EMC
Development Development
(mg/L)
(mg/L) (ftz)
(ftz)
(ac) (yrs) (mg/L)
(mg/L)
(ftz) Ihzl
COMM ERCIAL
I PART A
Parking lot
1.44
0.16
M -ac lots
-- -
-
Roof
1.08
0.15
I Y -ac lots
-- --
--
I�4 Open/Landscaped
2.24
0.44
INDUSTRIAL
1 -ac lots
-
Parking lot
1.44
0.39
2 -ac lots
-- -
-
Roof
1.08
0.15
Multi - family
-- --
--
Open /Landscaped
2.24
0.44
Townhomes
-- --
--
�TRANSPORTATION
Custom Lot Size
--
--
Higli Density (interstate, main)
3.67
0.43
PART B
Low Density (secondary, feeder)
1.4
0.52
Roadway
-- 1.4
0.52
286,702
Rural
1.14
0.47
Driveway
1.0 1.44
_
0.39
20,000 75,856
Sidewalk
1.4
1.16
Parking lot
- 1.44
0.39
276
PERVIOUS
Roof
-- 1.08
0.15
4,430 402,304
Managed pervious
3.06
0.59
Sidewalk /Patio
-- 1.4
1.16
268,742
Unmanaged (Pasture)
3.61
1.56
I Lawn
-- 2.24
0.44
Forest
1.47
0.25
I Managed pervious
-- 3.06
0.59
395,463 441,301
JURISDICTIONAL LANDS*
I Forest
-- 1.47
_
0.25
4,325,364 3,175,720
Natural wetland.
-
--
I Natural wetland*
-- --
_
--
Riparian buffer
--
--
Riparian buffer*
- -
_
-
1,271,195 1,271,195
Open water
-
Open water*
- --
--
494,105 494,105
LAND TAKEN UP BY BMPs
1.08
0.15
ILAND TAKEN UP BY BMPs
-- 1.08
0.15 I
94,356
*Jurisdictional land uses are not included
in nutrient /flow calculations.
LAND USE AREA CHECK
Total Development Area Entered (ftz):
6,510,557
Total Pre - Development Calculated Area (ft):
6,510,557
Total Post - Development
Calculated Area (ftz):
6,510,557

BMP Characteristics Ver2.0 I Remmto water shed Frppeed ep Deyelplwmentl:
Clear All Values I Return to Instructions Characteristics Summary
Instructions '� I\
1. Select the type of BMP for each catchment.
z Enter the area of each land use type in the contributing drainage area for each BMP.
3. Continue to "Development Summary" tab.
Additional Guidelines
-This spreadsheet allows the development to be divided into as many as 6 smaller catchments.
- BMPs 1, 2, and 3 for a given catchment are assumed to operate in series, with the outflow from I serving as the inflow to 2, etc.
- If the outflow from an entire catchment (including outflow from selected BMPs) drains to another BMP, indicate this in the drop down menu below the BMP type and leave all cells for individual land uses blank
- Nat all BMP or catchments must be utilized. Simply leave fields blank in the columns not needed.
- Leave cells blank or insert zeroes if a land use is not present in the area draining to the BMP.
- For water harvesting BMPs, be sure to enter the percent volume reduction that will be achieved by your system. Volume detention (catch- and - release mechanisms) will not be considered -only proven volume reductions are valid inputs.
The BMP undersizing option should only be used for existing development or retrofit sites.
- Volume reduction efficiencies for undersized BMPs are calculated based on a 1:1 ratio (a BMP that is 60 % smaller than the required design size is assigned a removal efficiency equal to 60% of the standard efficiency
value). Effluent concentrations remain the same as full -sized BMPS.
- IMPORTANT: for the land area calculation checks to occur, you MUST press enter after entering a value for area to be treated by a BMP )not just click on the next cell).
-See User's Manual far instructions on modeling oversized BMPs.
Type of BMP:
If BMP is undersized, Indicate the BMP's:
relative to the designs I,, required to
capture the designated water quality del
(i.e. 0.75 = BMP is 75% of required cash
size):
'For water harvesting BMP, enter pert e
volume reduction In decimal form.
Catchment 1:
Catchment 2:
Catchment 3:
Catchment 4:
Catchment s: 2
Drainage Area Land Use
{COMMERCIAL
Parking lot
Roof
Open /Landscaped
)INDUSTRIAL
Parking lot
Roof
Open / Landscaped
(TRANSPORTATION
High DenyIinterstate, main`
Low Density secondary, feeder)
Rural
Sidewalk
MISC. PERVIOUS
Managed pervious
Unmanaged (pasture)
Forest
RESIDENTIAL
2 -ac lots (New)
I 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)
Y2 Y -ac lots lNew)
Y -ac lots l Built after 1995)
Y -ac lots +Built before 1995)
Y. -ac lots
(New)
% -ac lots (Built after 1995)
Y. -ac lots Built before 1995)
Y -ac lotsSNew)
lots (Built after 1995)
Y -ac lots (Built before 1995)
Townhomes(New)
Townhomes (Built after 1995)
Townhomes Built before 1995)
Multi - family New)
Mufti - family (Built after 1995)
Multi- family (Built before 1995)
Custom LOt Size INIW I
Custom Lot Size Built after 1995)
Custom Lot Size (Built before 1995)
Roadway
Driveway
Parking of
Roof
Sidewalk
Lawn
Man cl pervious
Forest
LAND TAKEN UP BY BMP
BMP DETAILS
BMP Volume Reduction ( %) TN Effluent Concert. TP Effluent Concert.
(mg/L) (mg/L)
Green Roof
50%
1.08
0.15
Level Spreader, Filter Strip
40%
1.20
0.15
Permeable Pavements
0%
1.44
0.39
Sand Filter
5%
g1 g1 or N2
0.92
0.14
Water Harvesting
u ser defined
1.08
0.15
We Mention Pond
30%
1
1.01
0.11
Wetland
20%
1
1.08
0.12
•if treating commercial parking lot, TP effluent
concentration = 0.16 mg/L
----- - - - - -- CATCHMENT1 CATCHMENT2 CATCHMENTS ----- - - - --- CATCHMPNT4 . CATCHMENTS
Does BMP accept the outflow f
no no no
no no no -- -- no no no I no no no
no no no I no no no
no no no I no no no
no no no no no no
Area treated Area treated Area treated Area treated
Area Treated by BMP p2 that is by BMP 43 that is Area Treated by BMP #2 that is by BMP e3 that is
by BMP not treated by BMP not treated by BMPS by BMP nottreated by BMP nottreated by BMP,
(ft') #1 al or g2 (W) g1 #1 or e2
w lft'1 Ift'1 � Ift'1 (ft'1
I w
I
TOTAL AREA TREATED BY BMP (ft): 720,787 998,529 578,329 0 0
TOTAL AREA TREATED BY SERIES (ft 2): 11 2,297,645 0
om another Catchment? Use, indicate which one(s).(Land use a
no no
no no
no no no
no no no
no no no
Area treated Area treated
Area Treated by BMP g2 that is by BMP e3 that is
by BMP not treated by BMP not treated by BMPs
(ft2) g1 #1 or a2
(ft') (ft)
I
I
-eas entered below are in addition to the watershed areas treated by contributing catchments).)
no no no no no
1 no no no II no no
no no no II no no
-- -- -- I no no
no no no I -- --
no no no II no no
Area treated Area treated Area treated
Area Treated by BMP p2 that is by BMP p3 that is Area Treated by BMP 42 that
by BMP "or treated by BMP nottreated by BMPS by BMP not treated by BI
(H') #1 41 or p2 (k') #1
(ft ') (k') (ft')
I
II
I
0
CATCHMENT6
no
no
no
no
no
Area treated
I no
I no
I no
I no
no
I —
no no
no no
no no
no no
no no
Area treated Area treated
Total Land Use
BMP 43 that is
Area Treated
by BMP p2 that is by BMP p3 that is
Area Treated By
treated by BMP s
by BMP
nottreated by BMP nottreated by SNIPS
pg BMPs
ff1 or 42
(ft')
g1 g1 or N2
Ik )
(ft')
(ft') (ft')
.I p
II
II
II
I�
II
�I
i II
�I
II
�I
II
II
II
II
II
II
)
II
II
II
II
II
II
II
„
II
9 IIuII 0
7
8'
I
C
Allowable Total Land
Use Area to be
Treated Based on
Post -Dev. Areas
(W)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
286,702
75,856
276
402,304
268,742
0
441,301
3 175,720
C;, 75

3. Development Summary
BMP3
Development:
Crystal Lake
Prepared By:
A. Hutchens
Date:
March 3, 2015
WATERSHED SUMMARY Ver2.0
BMP VOLUME REDUCTIONS /EFFLUENT
CONCENTRATIONS
REGION:
Piedmont
TOTAL DEVELOPMENT AREA (ft`):
6,510,557
Volume Reduction
TN Effluent Concen.
TP Effluent Concen.
Pre - Development Conditions Post - Development Conditions
Post - Development w /BMPs
( %)
(mg /L)
(mg /L)
Percent Impervious
Bioretention with
( %)
0.5%
23.8%
23.8%
IWS
50%
0.95
0.12
Return to Instructions
Annual Runoff Volume
Bioretention
(c.f.)
1,001,785
4,840,546
3,183,061
without IWS
35%
1.00
0.12
Return to Watershed Characteristics
Total Nitrogen EMC
(mg /L)
1.58
1.32
1.13
Dry Detention Pond
0%
1.20
0.20
Total Nitrogen Loading
L Return to BMP Characteristics
(lb /ac /yr)
0.91
3.66
2.06
Grassed Swale
0%
1.21
0.26
Total Phosphorus EMC
0.28
0.47
0.11
Green Roof
50%
1.08
0.15
Print Summary
(mg /L)
Total Phosphorus Loading
Level Spdr, Filter
(lb /ac /yr)
0.16
1.31
0.21
Strip
40%
1.20
0.15
Permeable
Percent Difference Between:
Pavement*
0%
1.44
0.39
Pre -Dev. &
Pre - Development &
Post -Dev without BMPs &
Post -Dev. without BMPs
Post - Development with BMPs
Post -Dev with BMPs
Sand Filter
5%
0.92
0.14
Percent Impervious (%)
23%
23%
0%
Water Harvesting
user defined
1.08
0.15
Annual Runoff Volume (c.f.)
383%
218%
-34%
Total Nitrogen EMC (mg /L)
-17%
-28%
-14%
Wet Detention Pond
10%
1.01
0.11
Total Nitrogen Loading (Ib /ac /yr)
303%
127%
-44%
Total Phosphorus EMC (mg /L)
65%
-60%
-76%
Total Phosphorus Loading (Ib /ac /yr)
699%
27%
-84%
Wetland
20%
1.08
0.12
*Negative percent difference values indicate a decrease in runoff
volume, pollutant concentration or pollutant
loading. Positive values indicate an increase.
*if treating commercial
parking lot, TP effluent
concentration =
0.16 mg /L
BMP SUMMARY Ver2.0
CATCHMENT 1
CATCHMENT 2
CATCHMENT 3
CATCHMENT 4
CATCHMENT 5
CATCHMENT 6
BMP1 BMP2 BMP3
BMP1 BMP2
BMP3 BMP1
BMP2 BMP3
BMP1 BMP2
BMP3
BMP1
BMP2
BMP3 BMP1 BMP2
Wetland Wetland Wetland
-- --
-- --
-- --
-- --
--
--
--
-- -- --
Total Area Treated
16.55 39.47 5175
-- --
-- --
-- --
-- --
--
--
Total Inflow Volume
1,229,131 3,523,406 3,626,037
- -
- -
- -
- -
-
-
-
- - -
Percent Volume Reduced
20% 20% 20%
Inflow Nitrogen EMC
(mg /L)
1.32 1.22 1.15
-- --
-- --
-- --
-- --
--
--
-
-- -- --
Total Inflow Nitrogen
(Ib /ac /yr)
6.13 6.82 4.98
- -
- -
- -
- -
Inflow Phosphorus EMC
(mg /L)
0.506 0.380 0.220
- -
- -
- -
- -
Total Inflow Phosphorus
(lb /ac /yr)
2.35 2.18 1.04
-- --
-- --
-- --
-- --
--
--
BMP Outflow
Nitrogen (Ibs /ac /yr)
. '
BMP Outflow
Phosphorus (Ibs /ac /yr)
. '
Catchment Outflow Nitrogen EMC (mg /L)
1.09
-
-
-
-
-
Catchment Outflow
Total Nitrogen (lb /ac /yr)
3.73
-
-
-
-
-
Percent Reduction in Nitrogen Load ( %)
36%
-
-
-
-
-
Catchment Outflow Phosphorus EMC
(mg /L)
0.130
Catchment Outflow
Total Phosphorus (lb/ac/yr)
0.445
--
--
--
--
--
Percent Reduction in Phosphorus Load ( %)
73%
--
--
--
--
--
BMP3

DURHAM
CITY OF DURHAM Neuse, Falls Lake and Jordan Lake Developer Nutrient Reporting Form
Please complete and submit the following information to the City of Durham Stormwater Services to
1869 characterize your project and assess the need to purchase nutrient offsets. See the
CM OF NT:DKWE Citv Stormwater Performance Standards. For nutrient offset information, see nutrient offset intro
PROJECT INFORMATION
Applicant Name: Prepared by
Garden View Realty, INC Aaron Hutchens
Project Name (& Previous name, if applicable): (Site Plan #:
Crystal Lake Subdivision at Croasdaile Farm
Project Address (if available): Street: City /Town: County:
Hillandale Rd Durham Durham
Date: (mo/d/yr)
Project
(dec. degrees)
IN:
Long: (dec. degrees)
PIN /PID #s:
3/3/2015
Locat'n:
ILat:
36.0544746
(For the Jordan, Falls, and Neuse /Outside of Falls Watershed areas)
- 78.939669
173133
Is this Redevelopment? I ❑ Yes ❑ No
Development
Type (Please check all that apply)
Impervious Cover ( %) Pre - Construction:
❑
Commercial ❑ Duplex Residential
0.5
❑
Industrial F�] Single - Family Residential
Impervious Cover ( %) Post - Construction:
❑
Institutional ❑ Multi - Family Residential
15.9
(E)
Mixed Use
WATERSHED INFORMATION (See online map or alternative source for 12 -digit and 6 -digit IDS)
❑ Upper Falls Basin, 12 -digit Watershed ID:
Applicable)
030202010304
I Jordan Lake Delivery Factors ( %)
❑ Lower Falls Basin, 12 -digit Watershed ID:
Reduction Needed
Nitrogen
Phosphorus
❑ Neuse /Outside of Falls Basin, 03020201
State Buy Down
Additional
Site:
Bank:
Site:
Bank:
❑ Jordan Lake (Upper New Hope) 6 -digit Small
Offset
Amount Delivered
5% if bank
Total Delivered
Watershed ID:
Rate
Target
Name of Bank
Name of Bank
Neuse /Falls Lake Delivery Factors: There are no delivery factors, so the Delivery Factor = 1.
DURHAM STORMWATER PERFORMANCE STANDARDS FOR DEVELOPMENT COMPLIANCE ALTERNATIVE
Nutrient loading limits and on -site treatment minimum (Sections 70- 740(a) and Sections 70- 741(a))
Off -site treatment threshold ( %):
IN:
I 50 IP: 150 (Required on -site reduction achieved?
IN:
IYESIP: IYEE
NUTRIENT OFFSET REQUEST (Must meet the offsite thresholds — see above)
Loading
Loading
Nitrogen Loading / Offset Needs
(For the Jordan, Falls, and Neuse /Outside of Falls Watershed areas)
Rate
Target
0.00
0.00
0.00
PE #:
Phone #:
41363
stew rt i n c. c
(1) (Where
(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
Applicable)
0)
Untreated
Treated
Reduction Needed
State Buy Down
Additional
Loading
Loading
Load Rate
(Ibs /ac /yr)
Offset
Amount Delivered
5% if bank
Total Delivered
Rate
Rate
Target
(from Compl.
Project Size
Duration
Site Delivery
(Ibs)
not in City
(Ibs)
(Ibs /ac /yr)
(Ibs /ac /yr)
(Ibs /ac /yr)
worksheet)
(square feet)
(yrs)
Factor
D * E * F * G
limits (Ibs)
H + 1
3.66
2.06
2.20
0.00
I 6,510,557
I 30
1.00
0.00
0.00
0.00
Phosphorus Loading / Offset Needs (For the Jordan and Falls Watershed areas)
(A)
(B)
(C)
Untreated
Treated
Factor
Loading
Loading
Load Rate
Rate
Rate
Target
(Ibs /ac /yr) (Ibs /ac /yr) (Ibs /ac /yr)
1.31 0.21 1 0.33
Responsible Professional En
(D) (E)
Reduction
Needed
(Ibs /ac /yr)
(from Compl. Project Size
Worksheet) (square feet)
0.00 6,510,557
gineer's Name: 1A
(F)
(G) I (H)
Offset
Additional
Duration
Site Deliv
(yrs)
Factor
30
1.00
I Gamboa
D * E * F * G
Staff Name: (Aaron Hutchens (Staff e-mail: ahutcilens@
July 30, 2014 Version
(1) (Where
Applicable)
0)
State Buy Down
Additional
Amount Delivered
5% if bank
Total Delivered
.ry (Ibs)
not in City
(Ibs)
D * E * F * G
limits(lbs)
H + I
0.00
0.00
0.00
PE #:
Phone #:
41363
stew rt i n c. c
919- 866 -4793

COMPLIANCE WORKSHEET
Watershed (Select from Menu)
Falls Lake Basin Note that if a nutrient bank is used to buy offset credits
Jordan Lake Basin in order to achieve compliance with the alternative
selected below, the bank must be located in the same
Lower Neuse Basin watershed as the project site.
Compliance Alternative (Pick one alternative, see descriptions and calculations below)
1 Nutrient loading limits and on -site treatment minimum (Sections 70- 740(a) and Sections 70- 741(a))
O Alternative percentage reduction option for Redevelopment that increases impervious area (Section 70-
0 740(b))
O Alternative percentage reduction option for Redevelopment that does not increase impervious area
0 (Section 70- 740(c))
O 0 Alternative for low impact development in Falls Basin.
O Exempt from Stormwater Pollutant standards (Section 70 -739)
Project Area Disturbance (Fill in yellow cell below)
1,488,829 square feet 34.179 acres
TABLE 1 THRESHOLDS FOR APPLICATION OF STORMWATER
POLLUTANT REQUIREMENTS
Project Location Land Disturbance
Limited Residential Multifamily & Other
Jordan Basin 1 acre 0.5 acres
Falls Basin 0.5 acres 12,000 square feet
Lower Neuse Basin 1 acre 0.5 acres
Note: Thresholds are based upon land disturbance since the
applicable basin Baseline date.
The Project is Located Outside the Downtown Area (select from menu list)
Per Section 70 -736, Downtown Area means the Downtown Tier, Compact Neighborhoods,
and Suburban Transit Zones as shown on the Durham Comprehensive Land Use Plan most
recently approved by the Durham City Council.
The Project Type is Limited Residential (select from menu list)
Per Section 70 -736,
Limited Residential means single family and duplex residential and recreational development.
Multifamily and Other Development means development not included in Limited Resdiential, and
includes but is not limited to multifamily and townhomes, and office, industrial, institutional (including local
government institutional), and commercial development.
Other key definitions from Section 70 -736:
Development means Land Disturbance which increases impervious surface on a property, or
alters its location, or results in an increase in runoff from a property or a decrease in infiltration
of precipitation into the soil. It includes both existing development and new development. It
does not include agriculture, mining, or forestry activities.
Redevelopment means Development on a site where structures or impervious surface
already exists. It is a category of new development.
Version 2 DRAFT, April 5,2013

Nutrient Loading Limits and On -Site Treatment Minimum
ORDINANCE REQUIREMENTS
Sec. 70 -740.
(a) Nutrient Loading Rate Limits. Development not exempt under subsection 70 -739 shall
construct and implement SCMs so as to limit the post construction loading rate of nitrogen
and phosphorus from the project area to the limits set forth in Table 2 below, or shall
comply with an allowed alternative as set forth in (b) through (d) below. A portion of the
reduction requirements for nitrogen and phosphorus may be met through off site
measures or payments as set forth in 70 -741.
TABLE 2 NUTRIENT EXPORT LOADING RATE LIMITS
Project Location Export Limit Ibs /acre /year
Nitrogen Phosphorus
Jordan Basin 2.2 0.82
Falls Basin 2.2 0.33
Lower Neuse Basin 3.6 not required
Sec. 70 -741
(a) On site nutrient treatment requirements. Nitrogen and phosphorus reduction
requirements may be met, in part, through offsite management measures or the
purchase of nutrient credits. At a minimum, however, in the Jordan and Falls Basins a
percentage of the required nitrogen and phosphorus reductions must be achieved through
onsite treatment, in the amount shown in Table 4 below. In addition to meeting the
percentage reductions below, in the Jordan and Lower Neuse Basins, nitrogen export
load from the site must not exceed 6 Ibs. per acre per year for Limited Residential, and
and 10 Ibs per acre per year for Multifamily and Other.
(Note: offsite credit purchases do not meet TSS removal requirements, which must be
met onsite.)
TABLE 4 ONSITE NUTRIENT TREATMENT REQUIREMENTS
Project
Jordan - General
Falls - General
Falls and Jordan within
Downtown Area
Minimum Onsite Nutrient Treatment
Nitrogen Phosphorus
*40% of required *40% of required
reduction reduction
*50% of required
reduction
*30% of required
reduction
*50% of required
reduction
*30% of required
reduction
Version 2 DRAFT, April 5,2013

Falls and Jordan exceeding
thresholds but with less than 1 *30% of required *30% of required
acre land disturbance reduction reduction
Lower Neuse
No percentage
reductions apply, but
the 6/10 nitrogen
export limit described
in paragraph (a)
above must be met
No percentage
reductions apply, but
the 6/10 nitrogen
export limit described
in paragraph (a)
above must be met
*The "required reduction" is the difference between the post development loading in
pounds per acre per year multiplied by the site area in acres before treatment minus the
loading target, in pounds per acre per year multiplied by the acres. The percentage shown in
the chart above is applied to that difference and the resulting number is the amount in
pounds /year of nutrient reduction that must be achieved onsite.
CALCULATIONS - ENTER VALUES IN YELLOW CELLS
Nitrogen
Post Loading Rate
Untreated (Ibs /ac /yr)
3.66
Post Loading Rate
Untreated (Ibs /ac /yr)
1.31
Post Loading Rate Load Rate Target
Treated (Ibs /ac /yr) (Ibs /ac /yr)
2.06 2.2
Phosphorus
Post Loading Rate Load Rate Target
Treated (Ibs /ac /yr) (Ibs /ac /yr)
0.21 0.33
Reduction Needed
(Ibs /ac /yr)
0.00
Reduction Needed
(Ibs /ac /yr)
0.00
ONSITE CALCULATIONS - ENTER VALUE IN YELLOW CELLS BASED ON TABLE 4
Onsite Reduction Required Onsite Reduction Achieved?
Required ( %) Nitrogen Phosphorus
50 YES I YES
In the Jordan and Lower Neuse Basins, the nitrogen export loading rate from the
site does not exceed 6 Ib /ac /yr for Limited Residential, or 10 Ib /ac /yr for Multifamily
and Other.
Version 2 DRAFT, April 5,2013
N/A

Alternative percentage reduction option for Redevelopment that increases impervious area
ORDINANCE REQUIREMENTS
Sec. 70 -740.
(b) Alternative percentage reduction option for Redevelopment that increases impervious
area.
As an alternative to meeting the loading rate reductions described in (a) above, Redevelopment
not exempt under 70 -739 that increases impervious area may reduce the pre - development
nutrient loading rate from the entire project site for nitrogen and phosphorus by the percentage
loading rate reduction shown in Table 3 below. The pre - development nutrient loading rate is
calculated as of the Applicable Baseline Date. Load reductions already achieved shall be credited.
TABLE 3 PERCENTAGE REDUCTION OPTION FOR REDEVELOPMENT.
Project Location
Percent Loading Rate Reduction from Pre -Dev Loading Rate
Nitrogen Phosphorus
Jordan 35% 5%
Falls 40% 77%
Lower Neuse 30% Not applicable
CALCULATIONS - ENTER VALUES IN YELLOW CELLS
Nitrogen
Pre -Dev Loading Post Loading Rate Load Rate Target Reduction Needed
Rate* (Ibs /ac /yr) Treated (Ibs /ac /yr) (Ibs /ac /yr) (Ibs /ac /yr)
0.00 NONE
Phosphorus
Pre -Dev Loading Post Loading Rate Load Rate Target Reduction Needed
Rate* (Ibs /ac /yr) Treated (Ibs /ac /yr) (Ibs /ac /yr) (Ibs /ac /yr)
0.00 NONE
* As of the Applicable Baseline Date.
ONSITE CALCULATIONS - ENTER VALUE IN YELLOW CELLS BASED ON TABLE 4, above
Onsite N Reduction Onsite P Reduction Required Onsite Reduction Achieved?
Required ( %) Required ( %) Nitrogen Phosphorus li
YES YES
In Jordan and Lower Neuse Basins, the nitrogen export loading rate from the site
does not exceed 6 Ib /ac /yr for Limited Residential, or 10 Ib /ac /yr for Multifamily and
Other.
Version 2 DRAFT, April 5,2013
[Hill

Alternative Percentage Reduction Option for Redevelopment that does not Increase Impervious Area
ORDINANCE REQUIREMENTS
Sec. 70 -740.
(c) Alternative percentage reduction option for Redevelopment that does not increase
impervious area. Redevelopment not exempt under 70 -739 that is outside the Downtown
Area and that does not increase impervious area shall reduce the pre - development nutrient
loading rate, calculated as of the Applicable Baseline Date, by 10% if reductions are achieved
entirely onsite, and by 15% if reductions cannot be entirely achieved onsite. Table 4 is not
applicable to this alternative.
CALCULATIONS - ENTER VALUES IN YELLOW CELLS
Nitrogen
Pre -Dev Loading Post Loading Rate Load Rate Target
Rate* (Ibs /ac /yr) Treated (Ibs /ac /yr) (Ibs /ac /yr)
0.00
Phosphorus
Pre -Dev Loading Post Loading Rate Load Rate Target
Rate* (Ibs /ac /yr) Treated (Ibs /ac /yr) (Ibs /ac /yr)
0.00
* As of the Applicable Baseline Date.
Draft Reduction Needed ( %)
Nitrogen Phosphorus
10 1 10
Draft Reduction
Needed (Ibs /ac /yr)
none
Draft Reduction
Needed (Ibs /ac /yr)
none
Is N reduced by at least 10 %? YES Is P reduced by at least 10 %? YES
If either N or P is not reduced by at least 10% on site, a 15% reduction is required for both.
Final Reduction Required
Nitrogen Phosphorus
/o Ibs /ac /yr /o Ibs /ac /yr
10 1 NONE 10 1 NONE
Alternative for Low Impact Development in Falls Basin
ORDINANCE REQUIREMENTS
Sec. 70 -740.
(d) Alternative for low impact development in Falls basin. Development in the Falls Basin
will be considered compliant with the nutrient reduction obligations of this Section 70 -740 if it
demonstrates that it meets the post development hydrologic criteria set forth in Chapter 2 of the
North Carolina Low Impact Development Guidebook dated June of 2009, as it may be amended
from time to time.
❑ This development meets the post - development hydrologic criteria in Chapter 2 of the
North Carolina Low Impact Development Guidebook dated June 2009, as amended.
NO NUTRIENT OFFSET REPORT IS NEEDED WITH THIS ALTERNATIVE.
Version 2 DRAFT, April 5,2013

Exempt from Stormwater Pollutant standards (Section 70 -739)
ORDINANCE REQUIREMENTS
Sec. 70 -739.
(a) Exemptions for limited disturbances. Development in which Land Disturbance,
calculated cumulatively as of the Applicable Baseline Date, is less than the thresholds in Table 1
below is exempt from the standards in subsections 70 -740 and 70 -741, subject to paragraphs (1)
and (2) below.
TABLE 1 THRESHOLD FOR APPLICATION OF STORMWATER POLLUTANT
REQUIREMENTS
Project Location Land Disturbance
Limited Residential Multifamily & Other
Jordan Basin 1 acre 0.5 acre
Falls Basin 0.5 acre 12,000 sq. ft
Lower Neuse Basin 1 acre 0.5 acre
(1) Common Plan of Development. Development that is part of a Common Plan of
Development shall be included in the calculation. If the applicable threshold set forth in
Table 1 is exceeded, all other portions of the Common Plan are subject to the requirements
of this Article;
(2) Redevelopment and Existing Development, maintenance of treatment.
Redevelopment and Existing Development that are exempt under these thresholds must
continue to maintain and reconstruct all SCMs in compliance with approved plans, prior
ordinance requirements, and City Standards.
(b) Other exemptions. Additionally, Development is exempt if:
A. it qualifies in its entirety as Existing Development; or
B. it is located in the Downtown Area and does not increase impervious area over
the Applicable Baseline Date; or
C. it is undertaken by a state or federal entity. (Note: Review and approval by
the state must be demonstrated); or
D. it is a City transportation project in the Jordan basin.
❑ This project is exempt because it is below the applicable land disturbance threshold.
❑ This project is exempt because it qualifies entirely as Existing Development.
❑ This project is exempt because
• It is located in the Downtown Area and
• It does not increase impervious area over the Applicable Baseline Date.
❑ This project exempt because
• It is undertaken by a state or federal entity, and
• A demonstration of review and approval by the state has been provided.
❑ This project is exempt because it is a City transportation project in the Jordan Basin.
Version 2 DRAFT, April 5,2013

STEWART
Project: Crystal Lake Subdivision Date: 03.03.15
Project No: C13098 By: ACH
Total New Impervious Area
Type of Land Cover Area (ac)
New Impervious (current project) 23.73
Required treatment area 20.17
FDA to SCM Treatment Device
Device #1 -Level Spreader and EFS 90%
Impervious Surface to SCM (ac) 24.99
Provided treatment (ac) 22.49
Total Treatment Provided 22.49
Weighted TSS Runoff Calculation 95%
J: \C13098 - Croasdaile Farm SF \CALCS AND DATA \Stormwater \Spreadsheets \Cl3098_TSS Calculations.xlsx TSS

Appendix 5
5. Plan Sheets
a. SW1.0 - Existing Impervious Areas
b. SW2.0 - Proposed Impervious
Areas
c. SW3.0 - 1 Year Pre - Development
Drainage Area Map
d. SW4.0 - 2/10 Year Pre
Development Drainage Area Map
e. SW5.0 - Post Development
Drainage Area Map

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STEWART
101 WEST MAIN STREET
DURHAM, NC 27701
T 919.380.8750
Client:
FIRM LICENSE #: C -1051
www.stewartinc.com
PROJECT #: C13098
GARDEN VIEW REALTY, INC
2451 CROASDAILE FARM PARKWAY, SUITE 101
DURHAM, NC 27705
ATTN: MR. DAVID BEISCHER
PHONE (919) 383 - 5575
dbeischer @gardenviewrealty.com
Project:
CRYSTAL LAKE
SUBDIVISION AT
CROASDAILE FARM
Vicinity map:
Seal:
Issued for:
N CARP''%
,........ ! ,
,,.•oFFSSioti.,N
)RTON RD
Of`S'um lot S
PRELIMINARY - DO NOT USE
FOR CONSTRUCTION
No. Date
SITE PLAN
SUBMITTAL
Description
0 100 200 400
Scale: 1 " = 200'
Title:
EXISTING
IMPERVIOUS
AREAS
0
Cn
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AN
Project number: C13098 Sheet:
Date: 03/03/2015
Drawn by: AH SW1.0
Approved by: AG

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,P/*
STEWART
101 WEST MAIN STREET
DURHAM, NC 27701
T 919.380.8750
Client:
FIRM LICENSE #: C -1051
www.stewartinc.com
PROJECT #: C13098
GARDEN VIEW REALTY, INC
2451 CROASDAILE FARM PARKWAY, SUITE 101
DURHAM, NC 27705
ATTN: MR. DAVID BEISCHER
PHONE (919) 383 - 5575
dbeischer @gardenviewrealty.com
Project:
CRYSTAL LAKE
SUBDIVISION AT
CROASDAILE FARM
Vicinity map:
Seal:
I I �
Issued for:
N CARP%
••'•p0- ss /oti'••, Ly
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PRELIMINARY - DO NOT USE
FOR CONSTRUCTION
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Scale
Title.
� 1 1
SITE PLAN
SUBMITTAL
Description
100 200
1" =200'
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U)
w
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400 NORTH
PROPOSED
IMPERVIOUS
AREAS
Project number: C13098 Sheet:
J� Date: 03/03/2015
Drawn by: BL SW2.0
Approved by: TS

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1 �/
STEWART
101 WEST MAIN STREET
DURHAM, NC 27701
T 919.380.8750
Client:
FIRM LICENSE #: C -1051
www.stewartinc.com
PROJECT #: C13098
GARDEN VIEW REALTY, INC
2451 CROASDAILE FARM PARKWAY, SUITE 101
DURHAM, NC 27705
ATTN: MR. DAVID BEISCHER
PHONE (919) 383 - 5575
dbeischer @gardenviewrealty.com
Project:
CRYSTAL LAKE
SUBDIVISION AT
CROASDAILE FARM
Vicinity map:
Seal:
•�N CARD
`.••FESSio •� "'L,
)RTON RD
6143u= S
PRELIMINARY - DO NOT USE
FOR CONSTRUCTION
Issued for:
SITE PLAN
SUBMITTAL
No. Date Description
0
o!
U)
Lu
W
0
0 100 200 400 NORTH
Scale: 1" = 200'
Title:
1 YEAR STORM
PRE DEVELOPMENT
DRAINAGE AREA MAP
Project number: C13098 Sheet:
Date: 03/03/2015
Drawn by: AH SW3.0
Approved by: TS

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STEWART
101 WEST MAIN STREET
DURHAM, NC 27701
T 919.380.8750
Client:
FIRM LICENSE #: C -1051
www.stewartinc.com
PROJECT #: C13098
GARDEN VIEW REALTY, INC
2451 CROASDAILE FARM PARKWAY, SUITE 101
DURHAM, NC 27705
ATTN: MR. DAVID BEISCHER
PHONE (919) 383 - 5575
dbeischer @gardenviewrealty.com
Project:
CRYSTAL LAKE
SUBDIVISION AT
CROASDAILE FARM
Vicinity map:
N
Seal:
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OIJA 0' Q201 S
PRELIMINARY - DO NOT USE
FOR CONSTRUCTION
Issued for:
SITE PLAN
SUBMITTAL
No. Date Description
0
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LU
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Scale: 1" = 200'
Title:
2/10 YEAR STORM
PRE DEVELOPMENT
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Project number: C13098 Sheet:
Date: 03/03/2015
Drawn by: AH SW4.0
Approved by: TS

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ALI/ �
STEWART
101 WEST MAIN STREET
DURHAM, NC 27701
T 919.380.8750
Client:
FIRM LICENSE #: C -1051
www.stewartinc.com
PROJECT #: C13098
GARDEN VIEW REALTY, INC
2451 CROASDAILE FARM PARKWAY, SUITE 101
DURHAM, NC 27705
ATTN: MR. DAVID BEISCHER
PHONE (919) 383 - 5575
dbeischer @gardenviewrealty.com
Project:
CRYSTAL LAKE
SUBDIVISION AT
CROASDAILE FARM
Vicinity map:
Seal:
.0N CARD
•oFESSioti., "'k
)RTON RD-
Of`S'u+�"at S
PRELIMINARY - DO NOT USE
FOR CONSTRUCTION
Issued for:
SITE PLAN
SUBMITTAL
No. Date Description
U)
W
0
0 100 200 400 NORTH
Scale: 1" = 100'
Title:
POST DEVELOPMENT
DRAINAGE AREA MAP
Project number: C13098 Sheet:
Date: 03/03/2015
Drawn by: AH SW5.0
Approved by: TS

Appendix 6
6. Miscellaneous Information
a. Wetlands Study
b. City of Durham Site Plan Checklist

A tip
V-
NCDENR
North, Carolina, Department of Environment and Natural Resources
Pat McCrory
Governor
r
June 18, 2014
S &EC
Steven Ball;
8412 Falls -of the Neuse S_ uite'104_
Raleigh', NC:27615
John E. Skvarla, III
Secretary
Subject: ,Surface Water Determination
NBRRO #14 -169
Wake County
Determination, Type:
Buffer Call Isolated,or EIP'Call
'® Neuse (15A NCAC 2B :0233)
❑ ,Tian- Pamlico (15AN- A 2B )0259) El Ephemeral /Intermitt'ent/Perendial Determination
❑ Isolated 'Wetland Determination
❑ Jordan (15A NCAC 2B, 0267)
Projeci'Name: Lakefield Farm'Hillend'ale Road Tracts
Location/Directionsa Property is located Hillendale and Guess, road in Durham
Subject Stream:' UT'to Eno, River
befeirminafion •Date: June 3', 2014 Staff: James Graham
Feature/Flag Not
Subject
E/IYP *'
Start@
Stop@
Soil USGS
Subject
To;
Survey Topo
to
Buffers
,Buffers
A
X
P
throughout;
throughout
X' X.
B
X
P•
throughout
_ throughout
X
C
X
P,
throughout
throughout
X
D X
•E
X -
;E,
X
P
throughout,
throughout
X
F
X
I
na,S01
throughout
X
Pond
X
-X X _
*E!T - Ephemeral/IntermitteriUPerennial
None Carolina
-
- -
atura!!r�
North Carolina Division of Water Resources, 1628 Mail Service,Center
Raleigh, NC'27699 -1628 Phone (91'9),791--4200,
Internet - www ncwateroualb -or4
Location 3800 Barrett•Drive Raleigh, NC 27609 Faz
(91,9) 788 -7159
AwEqual Opportunity /Affirmative Action Employer
-.50% Recycled /10 %PostConsumer Paper

Lakefield Farm Hillendale Road Tracts
Durham County
June 18, 2014
Page 2 of 2
Explanation: The feature(s) listed above has or have been located on the Soil Survey of Wake County, North
Carolina or the most recent copy of the USGS Topographic map at a 1:24,000 scale. Each feature that is checked
"Not Subject" has been determined not to be a stream or is not present on the property. Features that are checked
"Subject" have been located on the property and possess characteristics that qualify it to be a stream. There may be
other streams located on your property that do not show up on the maps referenced above but, still may be
considered jurisdictional according to the US Army Corps of Engineers and/or to the Division of Water Resources
(DWR).
This on -site determination shall expire five (5) years from the date of this letter. Landowners or affected parties that
dispute a determination made by the DWR or Delegated Local Authority may request a determination by the
Director. An appeal request must be made within sixty (60) days of date of this letter or from the date the affected
party (including downstream and /or adjacent owners) is notified of this letter. A request for a determination by the
Director shall be referred to the Director in writing c/o Karen Higgins, DWR WeBSCaPe Unit, 1650 Mail Service
Center, Raleigh, NC 27699.
This determination is final and binding unless, as detailed above, you ask for a hearing or appeal within sixty (60)
days.
The owner /future owners should notify the Division of Water Resources (including any other Local, State, and
Federal Agencies) of this decision concerning any future correspondences regarding the subject property (stated
above). This project may require a Section 404/401 Permit for the proposed activity. Any inquiries should be
directed to the Division of Water Resources (Central Office) at (919)- 807 -6300, and the US Army Corp of Engineers
(Raleigh Regulatory Field Office) at (919) -554 -4884.
If you have questions regarding this determination, please feel free to contact James Graham at (919) 791 -4256.
Res6ehtfully,
Danny Smi , Supervisor
Water Quality Section
Raleigh Regional Office
cc: RRO /SWP File Copy

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Project No. Figure 2 -NRCS
10656.W?! Soil Survey Map
Project Mgr.: Croasdaile Apts
SB Crystal Lake Site Soil bF Environmental Consultants, PA
Scale: Durham County, NC g411F&Ihof'— Rwd.Suiu 104 Mcigh S(' 27613• Phone<919)84&5%0-1u(919)94(9460
..nde..�
1" = 1320'
Durham County Soil Survey
515114 Sheet 16
i ue1 ..J• 1 011111 mill 1 1.11 iii L

Soil & Environmental Consultants, PA
8412 Falls of Neuse Road, Suite 104, Raleigh, NC 27615 • Phone: [phone] • Fax: [phone]
sandec.com
May 9, 2014
S &EC Project No.: 10856.W7
Lakefield Farm, LLC
Attn: David Beischer
2451 Croadaile Farm Pkwy, Suite 101
Durham, NC 27705
Re: Detailed Wetland Delineation and Stream Buffer Evaluation
Lakefield Farm Crystal Lake Site
Durham County, NC
Mr. Beischer:
On May 8, 2014, S &EC personnel completed the wetland delineation and stream buffer evaluation on the
Lakefield Farm Crystal Lake Site is Durham County. You will find the attached report detailing our
findings. Maps that further document the wetland and stream related site characteristics are also attached.
Please review this information and call our office if you have questions.
The next step in the wetland and stream verification process is to perform a site visit with the Army Corps
of Engineers' agent for Durham County. In addition, a site meeting will also need to be conducted with
the NC -DWR agent for Durham County and possibly the local municipality representative. Please contact
S &EC is you are interested in proceeding with these verification meetings.
As you move forward in planning your development, S &EC personnel are available for site plan review
and permit consultation services. Please contact S &EC if you have any questions related to wetland and
stream regulations or if you need clarification of the attached report.
since ly,
Steven Ball, RF
Project Manager
Attachments:
1) Wetland Delineation Report
2) USGS site vicinity map
3) NRCS Soil Survey
4) Wetland & Stream Sketch Map
5) Requirements for Delineation Maps
6) Agent Authorization Form

S& Soil & Environmental Consultants, PA
EC 8412 Falls of Neuse Road, Suite 104, Raleigh, NC 27615 • Phone: [phone] • Fax: [phone]
sandec.com
DETAILED WETLAND DELINEATION & NEUSE RIVER STREAM BUFFER
EVALUATION REPORT FOR THE LAKEFIELD FARM CRYSTAL LAKE SITE
On May 8, 2014, S &EC personnel completed a detailed wetland delineation and Neuse
River stream buffer evaluation on the Lakefield Farm Crystal Lake Site. Please see the attached
sketch map for evaluation area. The subject property is located on the west side of Hillandale
Rd. approximately 2 miles and 1.5 miles north of I -85, respectively. Figure 1 and Figure 2 show
the location of the site on a USGS topographic quadrangle and Durham County Soil Survey.
EXECUTIVE SUMMARY
We have determined that jurisdictional streams and a number of wetland areas generally account
for the jurisdictional waters observed on the site. The attached wetland sketch map depicts the
approximate location of the streams and wetlands identified during our evaluation. Please refer
to the sketch map and the results and recommendations section below for more detailed
information.
SCOPE OF WORK
The detailed wetland delineation consisted of traversing the property on foot to examine soils,
vegetation, and hydrology across the site to identify areas that meet the criteria for jurisdictional
wetlands as described by the procedures set forth in the Coms of Enaineers Wetlands
Delineation Manual (January 1987 — Final Rebort). Areas on the site with positive indicators of
hydric soils, evidence of wetland hydrology, and presence of hydrophytic vegetation were
flagged and approximately sketched on a topographic map. Proof of wetland hydrology would
be the existence of hydric soils with oxidized root channels in the upper 12 inches of the soil
profile, water borne deposits, drift lines, scour marks, drainage patterns, regional indicators of
soil saturation, etc. Surface waters such as intermittent and perennial stream channels, ponds,
and lakes, which are also subject to regulation by the US Army Corps of Engineers (USACE) as
waters of the US, were also identified. These surface waters may also be referred to as
jurisdictional waters to indicate that they are within the jurisdiction of the USACE. It is
important to note that wetlands are also classified as waters of the US and regulated by the
USACE.
S &EC's Neuse River stream buffer evaluation consisted of examining each feature on the site
that is shown on the most recent version of the US Geological survey's 7.5 Minute Quadrangle
or Durham County soil survey for applicability to the Neuse River Basin riparian buffer rule
using NC -DWR stream evaluation techniques. Figure 2 shows the location of the site on the
relevant Durham County Soil Survey map.

May 13, 2015
S &EC Project #: 10856.w7
Page 2 of 4
RESULTS & RECOMMENDATIONS
The result of the wetland delineation and Neuse River Buffer evaluation is discussed below.
Wetlands and Jurisdictional Waters:
We have determined that jurisdictional waters (i.e., streams and wetlands) exist on the site.
Please refer to the attached "Wetland Sketch Map" for approximate locations.
Three jurisdictional streams were observed during the site evaluation, the approximate locations
of which are illustrated on the attached wetland sketch map. Streams identified on -site include:
• Feature A (Mill Creek) is perennial throughout the property. Below the dam of
Crystal Lake, there is a spillway and main channel. Both of these will likely be
perennial.
• Feature B (UT to Mill Creek) will likely be perennial from the property line to its
confluence with feature A.
• Feature C (UT to Mill Creek) is a perennial channel that flows from the southern
property boundary to a confluence with feature A.
■ Feature D (UT to Mill Creek) is believed to a broken segment of linear wetlands.
■ Feature E (UT to Mill Creek) originates off property and then flows into feature A.
This feature will likely be considered perennial.
■ Feature F (UT to Mill Creek) is an intermittent channel that originates at flag S01
and flows south into Feature A. There is a marginal stream above flag S01 that will
need to be reviewed by the regulatory agencies.
Surface waters on this site flow into Mill Creek in the Neuse River Basin, which has been
classified in NC -DWQ's "Classification and Water Quality Standards Applicable to Surface
Waters and Wetlands of North Carolina" as WS -IV; NSW.
The wetlands onsite were identified as being a Bottomland Hardwood Forest wetland type as
outlined in the publication "'A Field Guide To North Carolina Wetlands." This wetland type is
common throughout the piedmont region of North Carolina and is found mainly along headwater
streams like the one onsite. The USACE should verify our wetland delineation.
Water Supply Water Rules:
The surface waters on -site (i.e. perennial stream) potentially subject to the Water Supply Water
Rules includes Feature A (Mill Creek) below the dam. No other surface waters are indicated as
perennial features on the most recent USGS Topographic Quadrangle. A representative from the
NC -DWR must confirm our determination regarding the subjectivity of the aforementioned
channel(s) in order for our determination to be valid.
1 "A Field Guide To North Carolina Wetlands "; Department of Environment, Health and Natural
Resources, January 1996.

May 13, 2015
S &EC Project #: 10856.w7
Page 3 of 4
Neuse Buffer Subjectivity:
The surface waters on site (i.e., intermittent stream, perennial stream) potentially subject to the
Neuse River Buffers include features, A, B, C, D, E, F and Crystal Lake. Features A, B, C and E
will likely be subject throughout. Feature F will likely begin at flag SOL S &EC does not
believe feature D should be subject. A meeting with the NC -DWR will be necessary to confirm
the subjectivity of these features as well as the required buffer width.
Please also note that this site is located within Durham Watershed Protection Overlay E -B. All
perennial streams (A (including Crystal Lake), B, C and E) onsite will likely contain a 100 foot
buffer per City of Durham UDO.
Regulations
A general list of regulations that apply to jurisdictional wetlands and waters present on the site
are discussed below. Please be aware that other local, state, and federal regulations not included
in this list may also apply. S &EC personnel are available to discuss these regulations as they
apply to your project.
Neuse River Buffer Rules:
The Neuse River Basin: Nutrient Sensitive Waters Management Strateav: Protection and
Maintenance of Riparian Areas with Existing Forest Vegetation 115A NCAC 2B.0233) rules
apply to 50 -foot wide riparian buffers directly adjacent to surface waters in the Neuse River
Basin (intermittent streams, perennial streams, lakes, ponds, and estuaries), excluding wetlands.
The rule defines surface waters as features approximately shown on either the most recent
version of the soil survey map prepared by the Natural Resource Conservation Service (MRCS)
of the US Department of Agriculture (USDA) or the 7.5- minute quadrangle topographic maps
prepared by the US Geologic Survey (USGS). Surface waters that appear on these maps are not
subject only if an on -site determination by the NC Division of Water Quality (NC -DWQ) shows
that they fall into one of the following categories:
1) Ditches and manmade conveyances other than modified natural streams;
2) Manmade ponds and lakes that are located outside natural drainage ways; or
3) Ephemeral (stormwater) streams.
Water Supply Waters Rules:
Mill Creek (A) is mapped as a perennial stream below the dam on the USGS topographic
quadrangle. Those perennial streams identified on the USGS within a classified water supply
watershed require a 100 -foot buffer for new development activities with greater than 24 percent
"built upon" area (i.e., percent covered by impervious or partially impervious cover) and a 30-
foot buffer for activities with less than 24 percent built upon area by the NC -DWQ. (These
buffers are in addition to the any other stream buffers. The stricter of the two buffers applies to
these stream channels.)

May 13, 2015
S &EC Project #: 10856.w7
Page 4 of 4
Wetland Permitting:
The current Nationwide Permits were issued by the USACE on March 19, 2012. The USACE
Wilmington District issued revised Regional Conditions for the 2012 Nationwide Permits. We
recommend you forward a conceptual site plan to our office for review by one of our permitting
specialist, who can best advise you of the specific permitting needs as you progress through the
planning process.
Generally, wetland impact permits are issued on a per - project basis as determined by the
USACE. The USACE has determined that impacts on parcels sub - divided from larger tracts are
sometimes considered to be cumulative to existing impacts for the large tract. If this is the case,
then thresholds for notification may not apply to your project and impacts to streams /wetlands
must be considered in light of existing permits.
Limitations
Our evaluations, conclusions, and recommendations are based on project and site information
available to us at the time of this report and may require modification if there are any changes in
the project or site conditions, or if additional data about the project or site becomes available in
the future. This report is intended for use by Lakefield Farm LLC on this project. These
findings are not intended or recommended to be suitable for reuse on extensions of the project or
on any other project. Reuse on extensions of this project or on any other project shall be done
only after written verification or adaptation by SOIL & ENVIRONMENTAL CONSULTANTS,
PA, for the specific purpose intended.
CONCLUSION
The Lakefield Farm Crystal Lake Site evaluated by S &EC during May 2014, contains both
jurisdictional streams and wetlands that would require preconstruction authorization for impacts
(i.e. road construction, lot fill, stormwater pond construction, etc.). The next step in obtaining
jurisdictional feature approvals is to conduct a site meeting with NCDWR and USACE to
confirm our buffer start points, as well as the wetland delineation.

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10856.W11 I Soil Survey Map
Project Mgr.: Croasdaile Apts
SB Crystal Lake Site Soil i Environmental Consultants, PA
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Detailed Delineation of Waters of the US
Suitable for Preliminary Planning Only
S&-EC reserves the right to rl this map based on more fieldwork,
.0 0 1 and any other additional information. Approximations were mapped using
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l detailed delineation should be approved and
to be disturbed, S&
14 permit te d by the U. S. Army Corp s of Engi neers as requ ired. If the u ser oL_
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Jurisdictional Determination Request
REQUESTS FOR CORPS APPROVAL OF SURVEY PLAT
Prior to final production of a Plat, the Wilmington District recommends that the Land
Surveyor electronically submit a draft of a Survey Plat to the Corps project manager for
review.
Due to storage limitations of our administrative records, the Corps requires that all hard -
copy submittals include at least one orir-inai Plat (to scale) that is no larger than l 1 "xl7"
(the use of match lines for larger tracts acceptable). Additional copies of a plat, including
those larger than 11 "x17', may also be submitted for Corps signature as needed. The
Corps also accepts electronic submittals, of plats, such as those transmitted as a Portable
Document Format (PDF) file. Upon verification, the Corps can electronically sign these
plats and return them via e-mail to the requestor.
(1) PLATS SUMUTTED FOR APPROVAL
Must be sealed and signed by a licensed professional land surveyor
0 Must be to scale (all maps must include both a graphic scale and a verbal scale)
Must be legible
E] Must include a North Arrow, Scale(s). Title, Property Information
Must include a legible WoUS Delineation Table of distances and bearings /metes
and bounds /GPS coordinates of all surveyed delineation points
Must clearly depict surveyed property or project boundaries
ElMust clearly identify the known surveyed point(s) used as reference (e.g. property
comer, USGS monument)
F] NVhen wetlands are depicted:
• Must include acreage (or square footage) of wetland polygons
• Must identify each wetland polygon using an alphanumeric system
Version: December 2013 Page 8

Jurisdictional Determination Request
When tributaries are depicted:
• Must include either a surveyed, approximate centerline of tributary with
approximate width of tributary OR surveyed Ordinary High Water Marks
(OHNIr'M) of tributary
• Must identify each tributary using an alphanumeric system
• Must include linear footage of tributaries and calculated area (using approximate
widths or surveyed OHWM)
• Must include name of tributary (based on the most recent USGS topographic
map) or, when no USGS name exists, identify as "unnamed tributary"
all depicted WoUS (wetland polygons and tributary Ivies) must intersect or tie -to
sluveyed project/property boundaries
Must include the location of wetland data points and/or tributary assessment
reaches
Must include, label accordingly, and depict acreage of all waters not currently
subject to the requirements of the CWA (e.g. "isolated wetlands ", "non -
jurisdictional waters "). NOTE: An approved JD must be conducted in order to
make an official Corps determination that a particular waterbody or wetland is not
jurisdictional.
Must include and survey all existing conveyances (pipes, culverts, etc.) that
transport WoUS
Version: December 2013 Page 9

Jurisdictional Determination Request 11
(2) CERTIFICATION LANGUAGE
F] When the entire actual Jiuisdictional Boundary is depicted:
include the following Corps Certification language:
"This certifies that this copy of this plat accurately depicts the boundary of the jurisdiction
of Section 404 of the Clean Water Act as determined by the undersigned on this date.
Unless there is a change in the law or our published regulations, the determination of
Section 404 jurisdiction maybe relied upon for a period not to exceed five (5) years from
this date. The undersigned completed this determination utilizing the appropriate Regional
Supplement to the 1987 U.S. Army Corps of Engineers Wetlands Delineation Manual."
Regulatory Official..
Title:
Date:
USAGE Action ID No.:
When uplands maybe present within a, d picted Jurisdictional Boundarv:
include the following Corps Certification language:
"This certifies that this copy of this plat identifies all areas of waters of the United States
regulated pursuant to Section 404 of the Clean Water Act as determined by the
undersigned on this date. Unless there is change in the law or our published regulations,
this determination of Section 404 jurisdiction may be relied upon for a period not to exceed
five years from this date. The undersigned completed this determination utilizing the
appropriate Regional Supplement to the 1987 U.S. Army Corps of Engineers Wetlands
Delineation Manual."
Regulatory Official:
Title:
Date:
USACE Action 1D No.:
Version: December 2013 - Page 10

Jurisdictional Determination Request
(3) GPS SURVEYS
For Surveys prepared using a Global Positioning System (('rPS). the Survey must include
all of the above, as well as:
be at sub -meter accuracy at each survey point.
0 include an accuracy verification:
One or more known points (property comer, monument) shall be located with the
GPS and cross- referenced with the existing traditional property survey (metes and
bounds).
Rinclude a brief description of the GPS equipment utilized.
Version - December
2013 -_ Page it

Soil & Environmental Consultants, PA
8412 Falls of Neuse Road, Suite 104, Raleigh, NC 27615 • Phone: [phone] • Fax: [phone]
smidec.com
PROPERTY OWNER CERTIFICATION / AGENT AUTHORIZATION
Project Name/Description: S &EC Project #
Date:
The Department of the Army
U.S. Army Corps of Engineers, Wilmington District
69 Darlington Avenue
Wilmington, NC 28403
Attn: Field Office:
I, the undersigned, a duly authorized owner of record of the property/properties identified
herein, do authorize representatives of the Wilmington District, U.S. Army Corps of Engineers
(Corps) and Soil & Environmental Consultants, PA (S &EC) staff, as my agent, to enter upon the
property herein described for the purpose of conducting on -site investigations and issuing a
determination associated with Waters of the U.S. subject to Federal jurisdiction under Section
404 of the Clean Water Act and /or Section 10 of the Rivers and Harbors Act of 1899. This
document also authorizes S &EC, as my agent, to act on my behalf and take all actions
necessary for the processing, issuance and acceptance of a permit or certification and any and
all associated standard and special conditions.This notification supersedes any previous
correspondence concerning the agent for this project.
NOTICE: This authorization, for liability and professional courtesy reasons, is valid only for
government officials to enter the property when accompanied by S &EC staff. You should call
S &EC to arrange a site meeting prior to visiting the site.
PARCEL INFORMATION:
Parcel Index Number(s) (PIN):
Site Address:
City, County, State:
PROPERTY OWNER INFORMATION:
Property Owner (please print)
Property Owner Signature
Date
We hereby certify the above information submitted in this application is true and accurate to
the best of our knowledge.

Soil & Environmental Consultants PA
8412 Falls of Neuse Road, Suite 104, Raleigh, ITC 27615 • Phone: [phone] • Fax: ()19) 846 -9467
sandec.com
June 9, 2014
S &EC Project # 10856.W12
Lakefield Farm, LLC
Attn: David Beischer
2451 Croadaile Farm Pkwy, Suite 101
Durham, NC 27705
Re: Division of Water Resources / Water Quality Programs(DWR/WQP) Verification Meeting of the
Neuse Buffer Rules for the property known as Hillandale Road (Crystal Lake property) ( + / -115 acres);
Durham County, North Carolina
Dear Mr. Beischer:
On June 3, 2014, James Graham (DWR/WQP) and I reviewed the features potentially subject to the Neuse
Buffer Rules on the property. Mr. Graham agreed with our determination that feature D is not subject
to the Neuse Buffer Rule. Feature F will be subject beginning at flag SOL All other features will be
subject throughout. Please refer to the attached maps showing the approximate location of stream buffer
origins. Please note that the stream origin points and top of bank should be surveyed throughout the project
for accurate location. Mr. Graham will send written confirmation of our findings.
Neuse River Buffer Rules
The Neuse River Buffer rules protect up to 50 feet from the edge of existing "surface waters" (intermittent
streams, perennial streams, lakes, ponds and estuaries) found within the Neuse River Basin. The 50 -foot
buffer basically consists of two zones. The first zone is measured 30 feet landward from the top bank of
streams and intended to contain an undisturbed- forested area. The second zone is measured 20 feet from
the edge of the first zone and is intended to contain a vegetated buffer. A couple of notable points of the
rules include; the allowance of grading with re- vegetating within Zone 2 (the outer 20 feet) and the
requirement of mitigation for road crossings greater than 150 feet in width and utility lines running parallel
and within Zone 1 of the buffers. Please call if you would like to discuss the rules in more detail.
Additional Services
If the buffer determination described above interferes with your site plan, please contact S &EC to discuss
the possibility of a stream buffer appeal. An appeal with DWR/WQP must be filed within 30 days of the
determination. Please call or write if you have further questions. We will gladly make time to discuss any
permitting issues that may arise from this or other wetland/stream determinations.
Sincerely,
even Ball, RF
Project Manager
Attachments: 1) Site Map

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Detailed Delineation of Waters of the US
Suitable for Preliminary- Planning, Oniv
S &EC reserves the ri,ht to modify this map based on more fieldwork.
and any other additional information. Approximations were mapped using
topographic maps, air photos and ground truthing. If the site is going
to be disturbed. S &EC's detailed delineation should be approved and
permitted by the U.S. Arm} Corps of Engineers as required. If the user of
this work desires an accurate map of the regulated features flagged by
S &EC, they- should retain a NC Registered Professional Land Survevor to
locate Sa -EC's flagging.
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Soil & Environmental Consultants, PA
8412 Falls of Neuse Road, Suite 104, Raleigh, NC 27615 • Phone: [phone] • Fax: [phone]
sandec.com
June 19, 2014
S &EC Project # 10856.W13
Lakefield Farm, LLC
Attn: David Beischer
2451 Croadaile Farm Pkwy, Suite 101
Durham, NC 27705
Re: U.S. Army Corps of Engineers (USACE) Site Meeting to verify the Wetlands and
Waters of the U.S. for Hillandale Rd /Crystal Lake Site, Durham County, North
Carolina
Dear Mr. Beischer:
On June 17, 2014, Mr. Eric Alsmeyer of the USACE and I reviewed the areas on the site
potentially subject to USACE jurisdiction. Mr. Alsmeyer determined that feature F will begin at
flag SO1. The upstream wetland will be jurisdictional. The drainage within feature D will also be
considered non jurisdictional. Mr. Alsmeyer agreed with our delineation through the remainder
of the property. Please see the attached sketch map for determinations.
Impacts to "important streams" count toward the maximum 300' allowable under a Nationwide
permit. If a project exceeds 300' of important stream impacts, the responsible party must apply
for an Individual permit. The USACE has a 45 -day maximum review period to evaluate a
Nationwide permit. However, an Individual permit has no maximum review period. Streams
deemed to have `.`important aquatic function" may also require mitigation by the USACE for any
impact and will require mitigation by DWQ if impacts exceed 150'. Unimportant streams require
impact justification but do not require USACE mitigation.
The next step in this process is to generate a wetland delineation map for submission to the
USACE for approval and permitting. S &EC has not received a draft copy for a sign -off map to
date. If you choose to have S &EC submit a map on the owner's behalf, please contact us or send
a draft map for our review.
Sincerely, _
Steven Ball, RF
Project Manager
Attachments:
1) Site Map
S &EC Project #: 10856.W13
June 19, 2014

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7URHAM CITY OF DURHAM — STORMWATER SERVICES SITE PLAN SUBMITTAL CHECKLIST
Department of Public Works
101 City Hall Plaza I Durham, NC 27701
919.560.4326 1 F 919.560.4316
Date: 03/03/2015
1869 www.durhamnc.aov
❑iY OF MEMNE
PROJECT INFORMATION
Project Name: Crystal Lake Subdivision at Croasdaile Farm
Phase:
Previous Project Name(s): N/A
PIN (s ): 0813 -16 -68 -9042
Contact Person: Aaron Hutchens
Company: STEWART
Email Address: ahutchens @stewartinc.com
Planning Case Number: D150OXX
Phone: [phone]
Fax:
For each review submittal, including re- submittals, the entire Stormwater Impact Analysis (SIA) and
submittal checklist shall be submitted. Partial SIA and checklist will result in notification of an
incomplete submittal with no review performed.
Contact Stormwater Services regarding redevelopment or expansion projects for modified requirements.
The following checklist outlines submittal requirements. Initial in the space provided to indicate the
following submittal requirements have been met and supporting documentation is attached.
Initials
AH (Check One) r INSIDE I_ OUTSIDE Watershed Protection Overlay (WPO).
Indicate the WPO(s) where the project is located:
(Check all that apply) _ F /J -A _ F /J -B _ E -A ✓ E -B _ M /LR -A _ M /LR -B
If inside WPO, notation of WPO Standards is required on plans.
AH (Check all that apply) _ Jordan Basin ✓ Falls Basin _ Lower Neuse Basin
AH A legible copy of the United States Geological Survey 7.5 Minute Quadrangle map is provided,
including map reference, with site boundary clearly shown and labeled. The map clearly shows
all streams.
AH A legible copy of the published Durham County Soil Survey is provided, including map reference,
with the site boundary clearly shown and labeled. The map clearly shows all streams, soil types
and soil type boundaries.
AH Tops of banks for the streams are shown on the plan. [Contact the North Carolina Department of
Environment and Natural Resources for stream identifications in the Neuse River Basin (Falls
and Lower Neuse Basins). Stream determinations in the Jordan Basin shall be submitted per the
Letter to Industry found on Stormwater Development Reviews' web site at New Stream Buffer
Reauirements [First Revision to LTI 07 -03 -081 (25Auaust2011)1.
AH All Watershed Protection Overlay, Neuse River Basin, Jordan Basin, and City riparian buffers,
measured from the tops of the stream banks, are shown on the plan.
Page 1 of 6

AH The 10 -foot no build setback, measured from all riparian buffers, is shown on the plan.
AH Diffuse flow is achieved into riparian buffers.
AH (Check One) f � Yes F No Regulated floodplain located on site.
AH A legible copy of the effective Federal Emergency Management Agency National Flood
Insurance Program Flood Insurance Rate Map is provided. Map number, map date, and site
boundary are clearly shown and labeled. [This map is required regardless of whether floodplain
is located on the site.] The effective and /or future FEMA 100 -year floodplain, with base flood
elevations (if applicable), are shown on the plan.
AH All applicable notes, per the Standard Notes section of the Reference Guide for Development,
have been added to the plan.
AH Stormwater Impact Analysis (SIA) sealed and signed by a registered North Carolina Professional
Engineer (NCPE) is provided, including narrative report and drainage calculations. Note: If a site
is exempt from stormwater requirements then a narrative advising of the exemption can be
submitted by any designer.
Initials
AH An introductory narrative describing pre- and post - development site conditions and site
improvement changes, is provided. Note: The baseline conditions for the 1 -year event varies
based upon the regulatory basin in which the project is located.
AH Drainage area maps (one map for pre- development and one map for post - development) are
provided with the following items:
X Scale and north arrow (Note: Except in the instance of site -to- drainage area maps, the
scale of each drainage area map shall not exceed 1" = 30').
X Sub -basin area(s) delineated with area(s) in acres indicated.
X Analysis points clearly identified and labeled.
X Segmented TR -55 time of concentration flow paths showing and labeling each segment.
AH Methodologies and procedures are fully described.
AH A site plan with contour lines or grading plan identifying pre- and post - development drainage
patterns is provided.
AH Pre- and post - development times of concentration, calculated by TR -55 segmented approach,
are provided.
AH Calculations for the pre- and post - development peak discharge rates are provided for the 1 -, 2 -,
10 -, and 100 -year, 24 -hour storm using TR -55, TR -20, HEC -HMS, HEC -1 or Rational Method as
applicable. Note: The Rational Method is not accepted for the 1 -year analysis, areas that drain
more than 50 acres, or watersheds that are not homogeneous.
Page 2 of 6

AH A Summary of Results is provided in the following format:
Site Analvsis Point #
Site Condition Storm Event (cfs)
1 -year (cfs) 2 -year (cfs) 10 -year (cfs) 100 -year (cfs) -year (cfs)
Pre - Development
Post - Development
without Detention
Post - Development
with Detention
AH Conclusions providing detailed findings are provided.
AH Stormwater control measure(s) (SCM[s]) are provided (indicate number of each type of SCM):
Level Spreader w/ Vegetative Filter Strip 3 Stormwater Wetland
Wet Detention Basin Sand Filter Bioretention Grassed Swale
Restored Riparian Buffer Dry Extended Detention Basin
Permeable Pavement Green Roof Disconnected Impervious Surface
Rainwater Harvesting System
Proprietary Systems or Other
Not required (provide explanation):
AH The SCM(s) indicated above are required to control the following peak discharge rates:
1 -year 2 -year 10 -year X 100 -year Other
AH A downstream analysis in accordance with the Reference Guide for Development is provided
with findings, or is
Not required (provide explanation):
Initials
N/A The project is exempt based upon cumulative land disturbance as of the applicable baseline
date.
AH The proposed project is >_ 16% impervious (Falls and Jordan Basins) / >_ 24%
impervious (Lower Neuse Basin), 85% Total Suspended Solids (TSS) removal is provided for
this project, and all the impervious area as reasonably practical is treated by an SCM.
OR
The proposed project is X <16% impervious (Falls and Jordan Basins) / <24%
impervious (Lower Neuse Basin), 85% Total Suspended Solids (TSS) removal for all runoff from
non - vegetated conveyances is provided for this project, and all the impervious area as
reasonably practical is treated by an SCM.
N/A The project is low density without non - vegetated conveyances, thus TSS removal is not
required.
Page 3 of 6

N/A SCMs for TSS removal are provided (indicate number of each type of SCM): Note: Not all of the
SCMs listed below provide 85% TSS removal as a stand -alone SCM and must be used in series
with other SCMs to achieve the minimum TSS removal of 85 %.
Level Spreader w/ Vegetative Filter Strip Stormwater Wetland
Wet Detention Basin Sand Filter Bioretention Grassed Swale
Restored Riparian Buffer Dry Extended Detention Basin
Permeable Pavement Green Roof Disconnected Impervious Surface
Rainwater Harvesting System
Proprietary Systems or Other
Not required (provide explanation):
AH Both hard copies, and Excel- format electronic copies on a DVD or compact disc, of the following:
• Pre- and post - development nutrient calculations using the Jordan /Falls Lake Stormwater
Nutrient Load Accounting Tool found at
: http: / /portal.ncdenr.orq/ web /iordanlake /implementation - auidance- archive
or http: / /durhamnc.gov /ich /op /pwd /storm /Pages /SWDevReview.aspx
Note: Nutrient calculations are always required regardless if the project is exempt from
treatment requirements.
• The Nutrient Reporting Form (including the Compliance Worksheet tab) per the 3/7/2013
Letter to Industry http: / /durhamnc.gov /ich /op /pwd/ storm /Pages /LTI- SWDevReview.asiDx
AH Pre- and post - development land use area maps that correspond to the categories used in the
Jordan /Falls Lake Stormwater Nutrient Load Accounting Tool for the nutrient calculations, to
scale no smaller than 1 inch = 100 feet. The maps shall show the map scale, north arrow, and
are to have the different land uses either hatched or shaded with areas indicated in a legend on
the maps. Note: The land use area maps are always required regardless if the project is exempt
from treatment requirements.
Page 4 of 6

AH SCMs for nutrient control are provided (indicate number of each type of SCM):
Level Spreader w/ Vegetative Filter Strip 3 Stormwater Wetland
Wet Detention Basin Sand Filter Bioretention Grassed Swale
Restored Riparian Buffer Dry Extended Detention Basin
Permeable Pavement Green Roof Disconnected Impervious Surface
Rainwater Harvesting System
Proprietary Systems or Other
Not required (provide explanation):
N/A After meeting the minimum on -site treatment requirements, additional treatment and /or offsite
credit purchases, if needed, is provided by:
Additional SCMs
Nutrient Offset Payment to the North Carolina Ecosystem Enhancement Program
Nutrient Offset Payment to an Approved Nutrient Bank
Land Bank Credit Transfer (Commitments shall be made prior to October 1, 2015)
N/A The project site is located in an area subject to a state - approved Total Maximum Daily Load
(TMDL) for bacteria. (As of April 2014, only Northeast Creek has a TMDL for bacteria).
N/A SCMs rated as medium or high for bacterial removal are provided (indicate number of each type
of SCM):
Bioretention Area Stormwater Wetlands
Wet Detention Basin Sand Filter
Level Spreader w/ Vegetative Filter Strip Restored Riparian Buffer
Dry Extended Detention Basin Permeable Pavement
Other (specify)
Not required (provide explanation):
Page 5 of 6

Initials
N/A 85% Total Suspended Solids (TSS) removal is required for this project, and 100% of the
impervious area will be treated by an SCM. Note: Not all of the SCMs listed below provide 85%
TSS removal as a stand -alone SCM and must be used in series with other SCMs to achieve the
minimum TSS removal of 85 %.
N/A SCM for TSS removal are provided (indicate number of each type of SCM):
,Level Spreader w/ Vegetative Filter Strip Stormwater Wetland
Wet Detention Basin Sand Filter Bioretention Grassed Swale
.Restored Riparian Buffer Dry Extended Detention Basin
Permeable Pavement Rooftop Runoff Management
Disconnected Impervious Surface Rainwater Harvesting System
Proprietary Systems or Other
Not required (provide explanation):
Page 6 of 6