SW1200501_SW Report_20200506

DESIGN REPORT
STORMWATER MANAGEMENT PLAN

Fairview Elementary School
Car Rider Road/School Expansion
Buncombe County, North Carolina
April 2020

_________________________________________
Scott E. Burwell, PE
NC Professional Engineer No. 039177

McGill Associates, P.A.
55 Broad Street
Asheville, NC 28801

License Number C-0459

APRIL 2020

STORMWATER MANAGEMENT PLAN
FAIRVIEW ELEMENTARY SCHOOL
CAR RIDER ROAD/SCHOOL EXPANSION
BUNCOMBE COUNTY, NORTH CAROLINA

1.1 PROJECT DESCRIPTION ................................................................................................. 3
1.2 SITE DESCRIPTION........................................................................................................... 3
1.3 ADJACENT PROPERTY .................................................................................................... 3
1.4 SOILS ................................................................................................................................. 3
1.5 STORMWATER CONTROL MEASURES.......................................................................... 3

APPENDICES

APPENDIX A SITE LOCATION MAP
APPENDIX B DEED(S)
APPENDIX C CALCULATIONS: BIO-RETENTION CELLS
APPENDIX D CALCULATIONS: PIPES
APPENDIX E CALCULATIONS: OUTLET PROTECTION
APPENDIX F CALCUALTIONS: RUNOFF
APPENDIX G RAINFALL AND SOILS DATA
APPENDIX H DRAINAGE AREA MAP

1.1 PROJECT DESCRIPTION

The project consists of the construction of an approximately 976 LF 22’ wide car rider lane. The
project is located at the Fairview Elementary School in Buncombe County, NC. The school has
had problems with cars blocking intersections while they wait to pick up the students when school
lets out. The new car rider lane sets up a queue for parents to wait until pick-up time that will not
impede other traffic.

Stormwater management for this project includes capturing runoff, including the runoff from all
proposed impervious areas, via a stormwater conveyance system. The stormwater conveyance
system will discharge to one of two permanent bio-retention cells, where the one-year storm will
be treated, and volume match will be achieved. All existing conveyances will remain active for the
remainder of the 26.72 acre property. Approximately 1.90 acres will be disturbed as part of this
project.

Project Contact:
Mr. Clark Wyatt, Director of Maintenance
Buncombe County Schools
175 Bingham Road
Asheville, North Carolina 28806
(828)-232-4244
1.2 SITE DESCRIPTION

The project site can be described as predominately grass and some wooden areas. The grading
operations will occur where proposed grades are shown on the plans. The site drains towards the
north and runoff will collect into proposed bio-retention cells before connecting into an existing
stormwater conveyance system. The average slope is 13%. The site is in the French Broad
Basin but does not reside in an area subject to Riparian Buffer requirements.

1.3 ADJACENT PROPERTY

The surrounding properties of both sites are best described as industrial developments and
residential, single-family lots.
1.4 SOILS

The extents of the project site contain soils with the following map unit names: Junaluska-
Brasstown complex, 2 to 8 percent slopes, group C (JbB), Junaluska- Brasstown complex, basin,
8 to 15 percent slopes, group C (JbC), Junaluska- Brasstown complex, basin, 15 to 30 percent
slopes, group C (JbD), Tate-Urban land complex, 8 to 15 percent slopes, group B (TmC),
Udorthents, loamy, group C (Ud), Udorthents-Urban land complex, 2 to 50 percent slopes, group
A (UhE), and Urban land (Ux).
1.5 STORMWATER CONTROL MEASURES

Two bio-retention cells were selected as the primary stormwater control measure for this project to
satisfy volume match requirements. Based on post-construction conditions, there are two drainage

areas located within the boundaries of the project. All runoff within these improved drainage areas
will be captured and detained in the proposed bio-retention cells. The bio-retention cells were sized
to treat the runoff from the one-year design storm from all proposed built-upon areas associated
with the project. All existing stormwater conveyances will be bypassed through the project area and
will not be treated.

APPENDIX A
SITE LOCATION MAP
© 2020 Microsoft Corporation © 2020 DigitalGlobe ©CNES (2020) Distribution Airbus DS © 2020 HERE
LOCATION MAP55 Broad Street
Asheville, NC 28801
828.252.0575
NC Firm License # C-0459
mcgillassociates.com BUNCOMBE COUNTY, NORTH CAROLINA
BUNCOMBE COUNTY SCHOOLS
CAR RIDER IMPROVEMENTS
FAIRVIEW ELEMENTARY SCHOOL DIVISION VALUE = FEETGRAPHIC SCALE
01000 500 1000 2000
1000
M. CATHEY
S. BURWELL
N. CROOM
N. SAWYER APRIL 2020 19.00154 N/A
EX-1FORREVIEWONLYPLAN
P:\2019\19.00154-BUNCOMBEBOE-FAIRVIEW ELEM CAR RIDER LANE\DRAWINGS\CIVIL\19.00154 EXHIBIT SHEETS.DWG PLOT DATE 4/13/2020 6:12 PM NATALIE CROOMNO.DATE BY DESCRIPTION
SHEET
OFFICE MANAGER
PROJECT MANAGER
DESIGNER
REVIEWER DATE PROJECT #FUNDING #19.00154 BUNCOMBE COUNTY SCHOOLS - FAIRVIEW ELEMENTARY SCHOOL - CAR RIDER IMPROVEMENTS

APPENDIX B
DEED(S)

APPENDIX C
BIO-RETENTION CELLS
CALCULATIONS
Stormwater Runoff Volume Calculation Bio Cell #1Reference: NCDENR Stormwater BMP ManualChapter 3.3 Runoff VolumeSimple Method (Proposed Conditions)Rv = 0.05+0.9*Ia = 0.95 Runoff coefficient [(storm runoff (in)/ storm rainfall(in)] unitlessIa = 1 Impervious Fraction [impervious portion of drainage area (ac)/ drainage area (ac)], unitlessV= 3630 * Rd * Rv * AVolume of Runoff for the design storm (cf)Rd = 2.67 Design storm rainfall depth (in) 1‐yr, 24‐hr eventA = 0.15 Watershed area (acres)6673 Impervious (Proposed Road) 6673V = 13820 Pervious (Proposed Road) 6673 TotalSimple Method (Existing)Rv = 0.05+0.9*Ia = 0.14 Runoff coefficient [(storm runoff (in)/ storm rainfall(in)] unitlessIa = 0.1 Impervious Fraction [impervious portion of drainage area (ac)/ drainage area (ac)], unitlessV= 3630 * Rd * Rv * AVolume of Runoff for the design storm (cf)Rd = 2.67 Design storm rainfall depth (in)A = 0.15 Watershed area (acres)6673 TotalV = 204669 Impervious (Existing Road)Pre. vs. Post. Volume Difference (cf) 11786004 Pervious (Existing Road)6673 TotalBuilt Upon Area Summary (sf)Pre‐DevelopmentBuilt Upon Area Summary (sf) Whole Site Area (sf)Post‐DevelopmentP:\2019\19.00154‐BuncombeBOE‐Fairview Elem Car Rider Lane\Design\Calcs\Stormwater\Simple Method Runoff Volume‐Cell 11 of 1
Stormwater Runoff Volume Calculation ‐ Bio Cell #2Reference: NCDENR Stormwater BMP ManualChapter 3.3 Runoff VolumeSimple Method (Proposed Conditions)Rv = 0.05+0.9*Ia = 0.95 Runoff coefficient [(storm runoff (in)/ storm rainfall(in)] unitlessIa = 1 Impervious Fraction [impervious portion of drainage area (ac)/ drainage area (ac)], unitlessV= 3630 * Rd * Rv * AVolume of Runoff for the design storm (cf)Rd = 2.67 Design storm rainfall depth (in) 1‐yr, 24‐hr eventA = 0.43 Watershed area (acres)18698 Impervious (Proposed Road) 18698V = 39600 Pervious (Proposed Road) 18698 TotalSimple Method (Existing)Rv = 0.05+0.9*Ia = 0.248 Runoff coefficient [(storm runoff (in)/ storm rainfall(in)] unitlessIa = 0.22 Impervious Fraction [impervious portion of drainage area (ac)/ drainage area (ac)], unitlessV= 3630 * Rd * Rv * AVolume of Runoff for the design storm (cf)Rd = 2.67 Design storm rainfall depth (in)A = 0.43 Watershed area (acres)18698 TotalV = 10344046 Impervious (Existing Road)Pre. vs. Post. Volume Difference (cf) 292614652 Pervious (Existing Road)18698 TotalBuilt Upon Area Summary (sf)Pre‐DevelopmentBuilt Upon Area Summary (sf) Whole Site Area (sf)Post‐DevelopmentP:\2019\19.00154‐BuncombeBOE‐Fairview Elem Car Rider Lane\Design\Calcs\Stormwater\Simple Method Runoff Volume‐Cell 21 of 1

APPENDIX D
PIPE CALCULATIONS
A1 CB #A1 EX CI #A2 2317.97 103 2313.00 2301.00 15 66661 1.53 0.30 7.90 3.63 3.63 A1 HDPE 0.011 11.65%4.97 1 0.0450 0.69 26.06 11.8 OK Inlet
A2 CI #A3 CI #A4 2317.13 24 2313.00 2312.00 15 3177 0.07 0.69 7.90 0.40 0.40 A2 HDPE 0.011 4.17%4.13 1 0.0450 0.69 15.58 10.5 OK Inlet
A3 CI #A4 FES #A5 2317.03 110 2311.90 2306.00 15 2294 0.05 0.95 7.90 0.40 0.80 A3 HDPE 0.011 5.36%5.13 1 0.0450 0.69 17.68 12.0 OK Inlet
A4 OCS #A6 EX CI #A7 2307.00 13 2303.50 2303.25 15 20549 0.47 0.30 7.90 1.12 1.91 A4 HDPE 0.011 1.92%3.50 1 0.0450 0.69 10.59 9.4 OK Inlet
B1 HW #B1 HW #B2 2329.00 52 2327.00 2322.35 15 68889 1.58 0.30 7.90 3.75 3.75 B1 HDPE 0.011 8.94%2.00 1 0.0450 0.69 22.83 6.3 OK Inlet
C1 CI #C1 CI #C2 2302.47 24 2298.00 2297.50 15 47857 1.10 0.43 7.90 3.71 3.71 C1 HDPE 0.011 2.08%4.47 1 0.0450 0.69 11.02 11.0 OK Inlet
C2 CI #C2 JB #C3 2303.00 60 2297.40 2294.70 15 8876 0.20 0.95 7.90 1.53 5.24 C2 HDPE 0.011 4.50%5.60 1 0.0450 0.69 16.19 12.6 OK Inlet
C3 JB #C3 JB #C4 2298.97 89 2294.60 2287.50 15 0 0.00 0.00 7.90 0.00 5.24 C3 HDPE 0.011 7.98%4.37 1 0.0450 0.69 21.56 10.9 OK Inlet
C4 JB #C4 JB #C5 2295.49 70 2287.40 2285.40 15 0 0.00 0.00 7.90 0.00 5.24 C4 HDPE 0.011 2.86%8.09 1 0.0450 0.69 12.90 15.6 OK Manning's
C5 JB #C5 FES #C6 2291.75 136 2285.30 2270.00 15 0 0.00 0.00 7.90 0.00 5.24 C5 HDPE 0.011 11.25%6.45 1 0.0450 0.69 25.61 13.8 OK Inlet
D1 OCS #D1 EX CI #D2 2271.00 72 2268.00 2263.00 15 44690 1.03 0.39 7.90 3.13 8.37 D1 HDPE 0.011 6.94% 3.00 1 0.0450 0.69 20.12 8.5 OK Inlet
Notes:
* Outflow based on pond routing calculations.
1 RCP, Square edge w/headwall
2 RCP, Groove w/headwall
3 RCP, Groove End Projecting
4 CMP, Headwall
5 CMP, Mitered to Slope
6 CMP, Projecting
7 Circular, Beveled Ring, 45o Bevel
8 Circular, Beveled Ring, 37o Bevel
HDS-5
Inlet
Ref. No.
Pipe
Material
Controlling
Factor
Headwater
Available
(FT)
1. Inlet control capacities are calculated using Equation 28 located in the Federal Highway Administration publication HDS-5 - Hydraulic Design of Highway Culverts
2. Calculations do not take into account reduced flow on account of oversized pipe and outlet control structure.
3. HDS-5 Inlet Reference Numbers are as follows:
Pipe ID
Inlet Control
Capacity
(CFS)
Length
(FT)
Pipe Characteristics
Upstream
Structure ID
Upstream
Structure
Rim
Rational Method Calculation Q = CiA
Total (CFS)Roughness
Coef. (n)Pipe Slope
Weighted
Runoff
Coef. (C)
Design Outcomes
Manning's
Capacity
(CFS)
Inlet
Constant
(c)
Pipe Size
Adequacy
Comment
Inlet
Constant
(y)
STORM DRAIN PIPES
Pipe ID
Manning's and Inlet Control Values
Incremental
(CFS)
Downstream
Structure ID Diameter (IN)
Drainage
Area
(AC)
Inv. OutInv. In Drainage Area (SF)
Rainfall
Intensity
(IN/HR)
P:\2019\19.00154-BuncombeBOE-Fairview Elem Car Rider Lane\Design\Calcs\Stormwater\19.00154 - Pipe calcs
STORM DRAIN PIPE SCHEDULE STRUCTURE SCHEDULE
Shape & Material Ref. No.Nomograph Inlet Edge Description Equation K M C Y References
1 1 Square edge w/headwall 1 0.0098 2 0.0398 0.67 (56) (57)
2 2 Groove w/headwall 1 0.0018 2 0.0292 0.74 (56) (57)
3 3 Groove End Projecting 1 0.0045 2 0.0317 0.69 (56) (57)
4 1 Headwall 1 0.0078 2 0.0379 0.69 (56) (57)
A1 103 2313.00 2301.00 15 21.2 11.65%CB #A1 2317.97 2313.00 4.97
A2 24 2313.00 2312.00 15 12.7 4.17%CI #A3 2317.13 2313.00 4.13
A3 110 2311.90 2306.00 15 14.4 5.36%CI #A4 2317.03 2311.90 5.13
A4 13 2303.50 2303.25 15 8.6 1.92%OCS #A6 2307.00 2303.50 3.50
B1 52 2327.00 2322.35 15 18.6 8.94%HW #B1 2329.00 2327.00 2.00
C1 24 2298.00 2297.50 15 9.0 2.08%CI #C1 2302.47 2298.00 4.47
C2 60 2297.40 2294.70 15 13.2 4.50%CI #C2 2303.00 2297.40 5.60
C3 89 2294.60 2287.50 15 17.6 7.98%JB #C3 2298.97 2294.60 4.37
C4 70 2287.40 2285.40 15 10.5 2.86%JB #C4 2295.49 2287.40 8.09
C5 136 2285.30 2270.00 15 20.9 11.25%JB #C5 2291.75 2285.30 6.45
D1 72 2268.00 2263.00 15 16.4 6.94% OCS #D1 2271.00 2268.00 3.00
Pipe ID
Structure Characteristics
Structure ID Rim/ Grate
Elevation
Structure
Depth
Bottom
ElevationInv. In
Pipe Characteristics
Diameter (IN)
Stormwater Culvert Sizing Calculation for Inlet Control
Circular Concrete
Pipe SlopeLength (FT)
Circular Corrugated Metal
Inv. Out Full Flow
Velocity
P:\2019\19.00154-BuncombeBOE-Fairview Elem Car Rider Lane\Design\Calcs\Stormwater\19.00154 - Pipe calcs

APPENDIX E
OUTLET PROTECTION CALCULATIONS
Guide to Color Key: User Input Data Calculated Value Reference Data
Designed By:N Sawyer Date:4/14/2020
Checked By:S Burwell Date:4/14/2020
Company:McGill Associates
Project Name:Fairview Elementary Car-Rider Lane
Project No.:19.00154
Site Location (City/Town)Fairview, NC
Culvert Id.Pipe A3
Estimation of Stone Size and Dimensions For Culvert Aprons
Velocity (ft/s) 7.3
Opening type Pipe Culvert
Single or multiple openings? Single
Outlet pipe diameter, Do (ft)1.25
NOTE 2: If multiple openings, Do=1.25 x Do of single culvert.
Zone 1 Figure 8.06c
Will apron have >/=10% grade? No
Apron length (ft) 5 Figure 8.06d
Max. stone size (in.) 8 Figure 8.06e
Min. & max range of stones (lbs) 25-150 Figure 8.05f
Weight range of 75% of stones (lbs) 50-150 Figure 8.05f
New York DOT Dissipator Method For Use in Defined Channels
Determination of Stone Sizes For Dumped Stone Channel Linings and
Revetments
NOTE: For apron slopes equal to or greater than 10%, use next higher Zone in Figure 8.06d to determine
apron length.
NOTE 1: If opening type is anything other than "Pipe Culvert", Do=Ao (Cross-
sectional area of flow at outlet).
e
f
Guide to Color Key: User Input Data Calculated Value Reference Data
Designed By:N Sawyer Date:4/14/2020
Checked By:S Burwell Date:4/14/2020
Company:McGill Associates
Project Name:Fairview Elementary Car-Rider Lane
Project No.:19.00154
Site Location (City/Town)Fairview, NC
Culvert Id.Pipe B1
Estimation of Stone Size and Dimensions For Culvert Aprons
Velocity (ft/s) 13.05
Opening type Pipe Culvert
Single or multiple openings? Single
Outlet pipe diameter, Do (ft)1.25
NOTE 2: If multiple openings, Do=1.25 x Do of single culvert.
Zone 2 Figure 8.06c
Will apron have >/=10% grade? Yes
Apron length (ft) 10 Figure 8.06d
Max. stone size (in.) 24 Figure 8.06e
Min. & max range of stones (lbs) 5-1000 Figure 8.05f
Weight range of 75% of stones (lbs) 250-1000 Figure 8.05f
New York DOT Dissipator Method For Use in Defined Channels
Determination of Stone Sizes For Dumped Stone Channel Linings and
Revetments
NOTE: For apron slopes equal to or greater than 10%, use next higher Zone in Figure 8.06d to determine
apron length.
NOTE 1: If opening type is anything other than "Pipe Culvert", Do=Ao (Cross-
sectional area of flow at outlet).
e
f
Guide to Color Key: User Input Data Calculated Value Reference Data
Designed By:N Sawyer Date:4/14/2020
Checked By:S Burwell Date:4/14/2020
Company:McGill Associates
Project Name:Fairview Elementary Car-Rider Lane
Project No.:19.00154
Site Location (City/Town)Fairview, NC
Culvert Id.Pipe C5
Estimation of Stone Size and Dimensions For Culvert Aprons
Velocity (ft/s) 17.4
Opening type Pipe Culvert
Single or multiple openings? Single
Outlet pipe diameter, Do (ft)1.25
NOTE 2: If multiple openings, Do=1.25 x Do of single culvert.
Zone 3 Figure 8.06c
Will apron have >/=10% grade? Yes
Apron length (ft) 12.5 Figure 8.06d
Max. stone size (in.) 36 Figure 8.06e
Min. & max range of stones (lbs) 100-2700 Figure 8.05f
Weight range of 75% of stones (lbs) 800-2700 Figure 8.05f
New York DOT Dissipator Method For Use in Defined Channels
Determination of Stone Sizes For Dumped Stone Channel Linings and
Revetments
NOTE: For apron slopes equal to or greater than 10%, use next higher Zone in Figure 8.06d to determine
apron length.
NOTE 1: If opening type is anything other than "Pipe Culvert", Do=Ao (Cross-
sectional area of flow at outlet).
e
f

APPENDIX F
RUNOFF CALCULATIONS
Ditch total area (acres) total area (sf) Impervious Wooded Lawns, Heavy Soil, Steep (>7%) Bare Packed Soil C Q10 Q25 Q50 Q100Skimmer Basin0.60 26019 4223 0 0 19886 0.613 2.52 2.89 3.17 3.46Permanent Ditch #1 (west)1.46 63561 3482 27765 32314 0 0.270 2.71 3.11 3.41 3.72Permanent Ditch #2 (middle)0.46 20008 1700 1242 17066 0 0.346 1.09 1.26 1.38 1.50Permanent Ditch #3 (east)1.09 47617 4624 0 42993 0 0.363 2.73 3.14 3.44 3.75Permanent Ditch #4 (north)1.69 73833 6324 1242 66267 0 0.353 4.12 4.73 5.18 5.65Temporary Ditch #10.08 3314 0 0 0 3314 0.600 0.31 0.36 0.40 0.43Temporary Ditch #20.16 7007 0 0 0 7007 0.600 0.66 0.76 0.84 0.91Description rational runoff coefficientsUnimproved Areas 0.35Asphalt 0.9519.00154Concrete 0.95By: NLCBrick 0.85Date: 4/13/2020Roofs, Inclined 1Roofs, Flat 0.9Lawns, Sandy Soil, Flat (<2%) 0.1Lawns, Sandy Soil, Average (2‐7%) 0.15Lawns Sandy Soil, Steep (>7%) 0.2Lawns, Heavy Soil, Flat (<2%) 0.15Lawns, Heavy Soil, average (2‐7%) 0.2Lawns, Heavy Soil, Steep (>7%) 0.3Bare Packed Soil 0.6Wooded Areas 0.1510 Year intensity (in/hr) 6.88 Taken From NOAA (10 yr, 5 min duration)25 Year intensity (in/hr) 7.9 Taken From NOAA (25 yr, 5 min duration)50 Year intensity (in/hr) 8.66 Taken From NOAA (50 yr, 5 min duration)100 Year intensity (in/hr) 9.44 Taken From NOAA (100 yr, 5 min duration)Ditch ‐ Rational Method Hydrology
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Apr 13 2020
PD #1
Trapezoidal
Bottom Width (ft) = 1.00
Side Slopes (z:1) = 2.00, 2.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 100.00
Slope (%) = 0.08
N-Value = 0.020
Calculations
Compute by: Known Q
Known Q (cfs) = 2.71
Highlighted
Depth (ft) = 0.82
Q (cfs) = 2.710
Area (sqft) = 2.16
Velocity (ft/s) = 1.25
Wetted Perim (ft) = 4.67
Crit Depth, Yc (ft) = 0.46
Top Width (ft) = 4.28
EGL (ft) = 0.84
0 1 2 3 4 5 6 7
Elev (ft)Depth (ft)Section
99.50 -0.50
100.00 0.00
100.50 0.50
101.00 1.00
101.50 1.50
102.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Apr 13 2020
PD #2
Trapezoidal
Bottom Width (ft) = 1.00
Side Slopes (z:1) = 2.00, 2.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 100.00
Slope (%) = 0.08
N-Value = 0.020
Calculations
Compute by: Known Q
Known Q (cfs) = 1.09
Highlighted
Depth (ft) = 0.54
Q (cfs) = 1.090
Area (sqft) = 1.12
Velocity (ft/s) = 0.97
Wetted Perim (ft) = 3.41
Crit Depth, Yc (ft) = 0.28
Top Width (ft) = 3.16
EGL (ft) = 0.55
0 1 2 3 4 5 6 7
Elev (ft)Depth (ft)Section
99.50 -0.50
100.00 0.00
100.50 0.50
101.00 1.00
101.50 1.50
102.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Apr 13 2020
PD #3
Trapezoidal
Bottom Width (ft) = 1.00
Side Slopes (z:1) = 2.00, 2.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 100.00
Slope (%) = 0.06
N-Value = 0.020
Calculations
Compute by: Known Q
Known Q (cfs) = 2.73
Highlighted
Depth (ft) = 0.88
Q (cfs) = 2.730
Area (sqft) = 2.43
Velocity (ft/s) = 1.12
Wetted Perim (ft) = 4.94
Crit Depth, Yc (ft) = 0.46
Top Width (ft) = 4.52
EGL (ft) = 0.90
0 1 2 3 4 5 6 7
Elev (ft)Depth (ft)Section
99.50 -0.50
100.00 0.00
100.50 0.50
101.00 1.00
101.50 1.50
102.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Apr 13 2020
PD #4
Trapezoidal
Bottom Width (ft) = 1.00
Side Slopes (z:1) = 2.00, 2.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 100.00
Slope (%) = 0.13
N-Value = 0.020
Calculations
Compute by: Known Q
Known Q (cfs) = 4.12
Highlighted
Depth (ft) = 0.89
Q (cfs) = 4.120
Area (sqft) = 2.47
Velocity (ft/s) = 1.67
Wetted Perim (ft) = 4.98
Crit Depth, Yc (ft) = 0.57
Top Width (ft) = 4.56
EGL (ft) = 0.93
0 1 2 3 4 5 6 7
Elev (ft)Depth (ft)Section
99.50 -0.50
100.00 0.00
100.50 0.50
101.00 1.00
101.50 1.50
102.00 2.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Apr 13 2020
Temp Ditch
Triangular
Side Slopes (z:1) = 2.00, 2.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 100.00
Slope (%) = 0.10
N-Value = 0.020
Calculations
Compute by: Known Q
Known Q (cfs) = 0.66
Highlighted
Depth (ft) = 0.59
Q (cfs) = 0.660
Area (sqft) = 0.70
Velocity (ft/s) = 0.95
Wetted Perim (ft) = 2.64
Crit Depth, Yc (ft) = 0.37
Top Width (ft) = 2.36
EGL (ft) = 0.60
0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5
Elev (ft)Depth (ft)Section
99.50 -0.50
100.00 0.00
100.50 0.50
101.00 1.00
101.50 1.50
102.00 2.00
Reach (ft)

APPENDIX G
RAINFALL AND SOILS DATA
Hydrologic Soil Group—Buncombe County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/23/2020
Page 1 of 4393160039317003931800393190039320003932100393220039315003931600393170039318003931900393200039321003932200371900372000372100372200372300372400
371900 372000 372100 372200 372300 372400
35° 31' 33'' N 82° 24' 49'' W35° 31' 33'' N82° 24' 25'' W35° 31' 7'' N
82° 24' 49'' W35° 31' 7'' N
82° 24' 25'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 150 300 600 900
Feet
0 50 100 200 300
Meters
Map Scale: 1:3,880 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:12,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Buncombe County, North Carolina
Survey Area Data: Version 16, Sep 16, 2019
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Nov 23, 2011—Nov
28, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Buncombe County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/23/2020
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
CuB Clifton-Urban land
complex, 2 to 8
percent slopes
B 0.4 0.6%
CuC Clifton-Urban land
complex, 8 to 15
percent slopes
B 0.6 0.9%
CuD Clifton-Urban land
complex, 15 to 30
percent slopes
B 1.8 2.8%
JbB Junaluska-Brasstown
complex, 2 to 8
percent slopes
C 3.2 4.9%
JbC Junaluska-Brasstown
complex, basin, 8 to
15 percent slopes
C 15.1 23.3%
JbD Junaluska-Brasstown
complex, basin, 15 to
30 percent slopes
C 15.2 23.5%
TmC Tate-Urban land
complex, 8 to 15
percent slopes
B 4.0 6.1%
Ud Udorthents, loamy C 4.3 6.7%
UhE Udorthents-Urban land
complex, 2 to 50
percent slopes
A 6.8 10.4%
UnB Unison loam, 2 to 8
percent slopes
B 0.0 0.0%
UnC Unison loam, 8 to 15
percent slopes
B 5.6 8.7%
Ux Urban land 7.9 12.2%
Totals for Area of Interest 64.9 100.0%
Hydrologic Soil Group—Buncombe County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/23/2020
Page 3 of 4
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Buncombe County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/23/2020
Page 4 of 4
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=depth&units=english&series=pds 1/6
NOAA Atlas 14, Volume 2, Version 3
Location name: Fairview, North Carolina, USA*
Latitude: 35.5229°, Longitude: -82.4109°
Elevation: 2296.54 ft**
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF_tabular | PF_graphical | Maps_&_aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Duration Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
5-min 0.356
(0.323‑0.393)
0.423
(0.385‑0.467)
0.508
(0.461‑0.561)
0.573
(0.518‑0.632)
0.658
(0.591‑0.725)
0.722
(0.645‑0.796)
0.787
(0.699‑0.868)
0.851
(0.750‑0.942)
0.935
(0.815‑1.04)
1.00
(0.865‑1.12)
10-min 0.569
(0.516‑0.628)
0.677
(0.616‑0.747)
0.814
(0.738‑0.898)
0.916
(0.828‑1.01)
1.05
(0.942‑1.16)
1.15
(1.03‑1.27)
1.25
(1.11‑1.38)
1.35
(1.19‑1.49)
1.48
(1.29‑1.65)
1.58
(1.36‑1.77)
15-min 0.711
(0.645‑0.784)
0.851
(0.774‑0.939)
1.03
(0.933‑1.14)
1.16
(1.05‑1.28)
1.33
(1.19‑1.46)
1.46
(1.30‑1.60)
1.58
(1.40‑1.74)
1.70
(1.50‑1.88)
1.86
(1.62‑2.07)
1.98
(1.71‑2.22)
30-min 0.974
(0.885‑1.08)
1.18
(1.07‑1.30)
1.46
(1.33‑1.62)
1.68
(1.52‑1.85)
1.97
(1.77‑2.17)
2.19
(1.96‑2.42)
2.42
(2.15‑2.67)
2.65
(2.34‑2.93)
2.96
(2.58‑3.30)
3.21
(2.77‑3.59)
60-min 1.22
(1.10‑1.34)
1.48
(1.34‑1.63)
1.88
(1.70‑2.07)
2.19
(1.98‑2.41)
2.62
(2.36‑2.89)
2.97
(2.65‑3.27)
3.33
(2.96‑3.68)
3.72
(3.28‑4.11)
4.25
(3.70‑4.73)
4.68
(4.04‑5.24)
2-hr 1.40
(1.27‑1.55)
1.70
(1.55‑1.88)
2.16
(1.96‑2.38)
2.53
(2.29‑2.79)
3.05
(2.73‑3.36)
3.48
(3.09‑3.83)
3.92
(3.46‑4.33)
4.39
(3.85‑4.86)
5.06
(4.38‑5.63)
5.60
(4.79‑6.27)
3-hr 1.49
(1.35‑1.65)
1.79
(1.63‑1.99)
2.26
(2.05‑2.50)
2.65
(2.39‑2.93)
3.21
(2.88‑3.55)
3.68
(3.28‑4.07)
4.18
(3.69‑4.63)
4.73
(4.12‑5.25)
5.51
(4.73‑6.16)
6.16
(5.22‑6.92)
6-hr 1.82
(1.67‑2.00)
2.16
(1.98‑2.37)
2.68
(2.44‑2.94)
3.12
(2.84‑3.42)
3.77
(3.40‑4.12)
4.32
(3.86‑4.73)
4.91
(4.35‑5.39)
5.55
(4.87‑6.11)
6.49
(5.59‑7.18)
7.27
(6.17‑8.07)
12-hr 2.25
(2.07‑2.46)
2.68
(2.46‑2.93)
3.30
(3.02‑3.60)
3.80
(3.48‑4.15)
4.50
(4.10‑4.91)
5.08
(4.60‑5.54)
5.67
(5.11‑6.20)
6.28
(5.61‑6.89)
7.12
(6.31‑7.87)
7.78
(6.83‑8.65)
24-hr 2.67
(2.47‑2.91)
3.22
(2.98‑3.51)
4.02
(3.71‑4.37)
4.65
(4.28‑5.05)
5.52
(5.06‑5.99)
6.21
(5.69‑6.75)
6.93
(6.32‑7.53)
7.67
(6.96‑8.33)
8.69
(7.84‑9.45)
9.49
(8.52‑10.3)
2-day 3.18
(2.95‑3.44)
3.82
(3.54‑4.13)
4.73
(4.37‑5.11)
5.43
(5.01‑5.87)
6.40
(5.89‑6.91)
7.16
(6.57‑7.74)
7.94
(7.27‑8.59)
8.74
(7.96‑9.47)
9.84
(8.90‑10.7)
10.7
(9.63‑11.6)
3-day 3.39
(3.15‑3.65)
4.06
(3.77‑4.38)
4.98
(4.62‑5.37)
5.70
(5.27‑6.14)
6.67
(6.16‑7.19)
7.44
(6.85‑8.02)
8.22
(7.54‑8.87)
9.02
(8.24‑9.74)
10.1
(9.17‑10.9)
10.9
(9.89‑11.9)
4-day 3.60
(3.34‑3.87)
4.30
(4.00‑4.63)
5.24
(4.86‑5.63)
5.97
(5.53‑6.42)
6.95
(6.43‑7.48)
7.73
(7.12‑8.31)
8.51
(7.81‑9.15)
9.29
(8.51‑10.0)
10.4
(9.43‑11.2)
11.2
(10.2‑12.1)
7-day 4.19 5.00 6.03 6.84 7.92 8.77 9.63 10.5 11.6 12.5
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=depth&units=english&series=pds 2/6
(3.92‑4.50)(4.67‑5.37)(5.63‑6.48)(6.37‑7.34)(7.35‑8.49)(8.12‑9.40)(8.88‑10.3)(9.64‑11.3)(10.7‑12.5)(11.4‑13.5)
10-day 4.79
(4.50‑5.11)
5.69
(5.34‑6.07)
6.78
(6.36‑7.24)
7.63
(7.15‑8.13)
8.76
(8.19‑9.33)
9.64
(8.98‑10.3)
10.5
(9.77‑11.2)
11.4
(10.5‑12.2)
12.6
(11.6‑13.4)
13.4
(12.3‑14.4)
20-day 6.47
(6.09‑6.87)
7.63
(7.18‑8.10)
8.92
(8.40‑9.48)
9.92
(9.33‑10.5)
11.2
(10.5‑11.9)
12.2
(11.5‑13.0)
13.2
(12.4‑14.1)
14.2
(13.2‑15.1)
15.4
(14.3‑16.5)
16.4
(15.2‑17.5)
30-day 8.00
(7.58‑8.46)
9.39
(8.89‑9.93)
10.8
(10.2‑11.4)
11.8
(11.1‑12.4)
13.1
(12.3‑13.8)
14.0
(13.2‑14.8)
14.9
(14.0‑15.8)
15.8
(14.8‑16.7)
16.9
(15.8‑17.9)
17.7
(16.5‑18.8)
45-day 10.1
(9.64‑10.7)
11.9
(11.3‑12.5)
13.4
(12.7‑14.1)
14.5
(13.7‑15.2)
15.8
(15.0‑16.6)
16.8
(15.9‑17.7)
17.7
(16.8‑18.6)
18.5
(17.5‑19.5)
19.5
(18.5‑20.6)
20.3
(19.1‑21.4)
60-day 12.2
(11.6‑12.8)
14.2
(13.5‑15.0)
15.9
(15.1‑16.7)
17.1
(16.3‑18.0)
18.6
(17.7‑19.6)
19.7
(18.7‑20.7)
20.7
(19.6‑21.8)
21.6
(20.5‑22.8)
22.7
(21.5‑23.9)
23.4
(22.2‑24.8)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for
a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are
not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
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PF graphical
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=depth&units=english&series=pds 3/6

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Maps & aerials
Small scale terrain
3/20/2020 Precipitation Frequency Data Server
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Large scale terrain
Large scale map
+
–
3km
2mi
+
–
100km
60mi
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=depth&units=english&series=pds 5/6
Large scale aerial
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+
–
100km
60mi
+
–
100km
60mi
3/20/2020 Precipitation Frequency Data Server
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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
Disclaimer
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=intensity&units=english&series=pds 1/6
NOAA Atlas 14, Volume 2, Version 3
Location name: Fairview, North Carolina, USA*
Latitude: 35.5229°, Longitude: -82.4109°
Elevation: 2296.54 ft**
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF_tabular | PF_graphical | Maps_&_aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Duration Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
5-min 4.27
(3.88‑4.72)
5.08
(4.62‑5.60)
6.10
(5.53‑6.73)
6.88
(6.22‑7.58)
7.90
(7.09‑8.70)
8.66
(7.74‑9.55)
9.44
(8.39‑10.4)
10.2
(9.00‑11.3)
11.2
(9.78‑12.5)
12.0
(10.4‑13.5)
10-min 3.41
(3.10‑3.77)
4.06
(3.70‑4.48)
4.88
(4.43‑5.39)
5.50
(4.97‑6.06)
6.29
(5.65‑6.93)
6.90
(6.16‑7.60)
7.50
(6.66‑8.28)
8.09
(7.14‑8.96)
8.87
(7.73‑9.88)
9.47
(8.17‑10.6)
15-min 2.84
(2.58‑3.14)
3.40
(3.10‑3.76)
4.12
(3.73‑4.54)
4.64
(4.19‑5.11)
5.32
(4.78‑5.86)
5.82
(5.20‑6.42)
6.32
(5.61‑6.98)
6.81
(6.00‑7.54)
7.45
(6.49‑8.28)
7.92
(6.84‑8.87)
30-min 1.95
(1.77‑2.15)
2.35
(2.14‑2.60)
2.93
(2.65‑3.23)
3.36
(3.04‑3.70)
3.94
(3.54‑4.34)
4.39
(3.92‑4.83)
4.84
(4.30‑5.34)
5.30
(4.67‑5.87)
5.92
(5.16‑6.59)
6.41
(5.53‑7.18)
60-min 1.22
(1.10‑1.34)
1.48
(1.34‑1.63)
1.88
(1.70‑2.07)
2.19
(1.98‑2.41)
2.62
(2.36‑2.89)
2.97
(2.65‑3.27)
3.33
(2.96‑3.68)
3.72
(3.28‑4.11)
4.25
(3.70‑4.73)
4.68
(4.04‑5.24)
2-hr 0.702
(0.637‑0.774)
0.851
(0.774‑0.939)
1.08
(0.978‑1.19)
1.27
(1.14‑1.39)
1.53
(1.37‑1.68)
1.74
(1.55‑1.92)
1.96
(1.73‑2.17)
2.20
(1.93‑2.43)
2.53
(2.19‑2.82)
2.80
(2.40‑3.13)
3-hr 0.496
(0.451‑0.550)
0.597
(0.542‑0.661)
0.753
(0.683‑0.833)
0.882
(0.796‑0.974)
1.07
(0.957‑1.18)
1.23
(1.09‑1.36)
1.39
(1.23‑1.54)
1.57
(1.37‑1.75)
1.83
(1.58‑2.05)
2.05
(1.74‑2.30)
6-hr 0.304
(0.278‑0.333)
0.361
(0.330‑0.396)
0.447
(0.408‑0.490)
0.521
(0.474‑0.570)
0.629
(0.567‑0.689)
0.721
(0.645‑0.789)
0.820
(0.726‑0.900)
0.928
(0.813‑1.02)
1.08
(0.933‑1.20)
1.21
(1.03‑1.35)
12-hr 0.187
(0.172‑0.204)
0.222
(0.204‑0.243)
0.274
(0.251‑0.299)
0.315
(0.288‑0.344)
0.374
(0.340‑0.408)
0.421
(0.382‑0.460)
0.470
(0.424‑0.514)
0.521
(0.466‑0.572)
0.591
(0.523‑0.653)
0.645
(0.567‑0.718)
24-hr 0.111
(0.103‑0.121)
0.134
(0.124‑0.146)
0.167
(0.154‑0.182)
0.194
(0.178‑0.210)
0.230
(0.211‑0.250)
0.259
(0.237‑0.281)
0.289
(0.263‑0.314)
0.320
(0.290‑0.347)
0.362
(0.327‑0.394)
0.396
(0.355‑0.431)
2-day 0.066
(0.061‑0.072)
0.080
(0.074‑0.086)
0.098
(0.091‑0.106)
0.113
(0.104‑0.122)
0.133
(0.123‑0.144)
0.149
(0.137‑0.161)
0.165
(0.151‑0.179)
0.182
(0.166‑0.197)
0.205
(0.185‑0.222)
0.223
(0.201‑0.242)
3-day 0.047
(0.044‑0.051)
0.056
(0.052‑0.061)
0.069
(0.064‑0.075)
0.079
(0.073‑0.085)
0.093
(0.086‑0.100)
0.103
(0.095‑0.111)
0.114
(0.105‑0.123)
0.125
(0.114‑0.135)
0.140
(0.127‑0.152)
0.152
(0.137‑0.165)
4-day 0.037
(0.035‑0.040)
0.045
(0.042‑0.048)
0.055
(0.051‑0.059)
0.062
(0.058‑0.067)
0.072
(0.067‑0.078)
0.080
(0.074‑0.087)
0.089
(0.081‑0.095)
0.097
(0.089‑0.104)
0.108
(0.098‑0.116)
0.117
(0.106‑0.126)
7-day 0.025 0.030 0.036 0.041 0.047 0.052 0.057 0.062 0.069 0.075
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=intensity&units=english&series=pds 2/6
(0.023‑0.027)(0.028‑0.032)(0.033‑0.039)(0.038‑0.044)(0.044‑0.051)(0.048‑0.056)(0.053‑0.061)(0.057‑0.067)(0.063‑0.075)(0.068‑0.080)
10-day 0.020
(0.019‑0.021)
0.024
(0.022‑0.025)
0.028
(0.027‑0.030)
0.032
(0.030‑0.034)
0.036
(0.034‑0.039)
0.040
(0.037‑0.043)
0.044
(0.041‑0.047)
0.047
(0.044‑0.051)
0.052
(0.048‑0.056)
0.056
(0.051‑0.060)
20-day 0.013
(0.013‑0.014)
0.016
(0.015‑0.017)
0.019
(0.017‑0.020)
0.021
(0.019‑0.022)
0.023
(0.022‑0.025)
0.025
(0.024‑0.027)
0.028
(0.026‑0.029)
0.030
(0.028‑0.031)
0.032
(0.030‑0.034)
0.034
(0.032‑0.036)
30-day 0.011
(0.011‑0.012)
0.013
(0.012‑0.014)
0.015
(0.014‑0.016)
0.016
(0.015‑0.017)
0.018
(0.017‑0.019)
0.019
(0.018‑0.021)
0.021
(0.019‑0.022)
0.022
(0.021‑0.023)
0.023
(0.022‑0.025)
0.025
(0.023‑0.026)
45-day 0.009
(0.009‑0.010)
0.011
(0.010‑0.012)
0.012
(0.012‑0.013)
0.013
(0.013‑0.014)
0.015
(0.014‑0.015)
0.016
(0.015‑0.016)
0.016
(0.016‑0.017)
0.017
(0.016‑0.018)
0.018
(0.017‑0.019)
0.019
(0.018‑0.020)
60-day 0.008
(0.008‑0.009)
0.010
(0.009‑0.010)
0.011
(0.011‑0.012)
0.012
(0.011‑0.013)
0.013
(0.012‑0.014)
0.014
(0.013‑0.014)
0.014
(0.014‑0.015)
0.015
(0.014‑0.016)
0.016
(0.015‑0.017)
0.016
(0.015‑0.017)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
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PF graphical
3/20/2020 Precipitation Frequency Data Server
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Maps & aerials
Small scale terrain
3/20/2020 Precipitation Frequency Data Server
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Large scale terrain
Large scale map
+
–
3km
2mi
+
–
100km
60mi
3/20/2020 Precipitation Frequency Data Server
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.5229&lon=-82.4109&data=intensity&units=english&series=pds 5/6
Large scale aerial
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+
–
100km
60mi
+
–
100km
60mi
3/20/2020 Precipitation Frequency Data Server
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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
Disclaimer

APPENDIX H
DRAINAGE AREA MAP
#################
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#
############DIVERSION DITCHES
DRAINAGE AREAS MAP55 Broad Street
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40 0 20 40 80
40
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M. CATHEY
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EX-3FORREVIEWONLYPLAN
P:\2019\19.00154-BUNCOMBEBOE-FAIRVIEW ELEM CAR RIDER LANE\DRAWINGS\CIVIL\19.00154 EXHIBIT SHEETS.DWG PLOT DATE 4/13/2020 6:12 PM NATALIE CROOMNO.DATE BY DESCRIPTION
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############
#######STORMWATER PIPES
DRAINAGE AREAS MAP55 Broad Street
Asheville, NC 28801
828.252.0575
NC Firm License # C-0459
mcgillassociates.com BUNCOMBE COUNTY, NORTH CAROLINA
BUNCOMBE COUNTY SCHOOLS
CAR RIDER IMPROVEMENTS
FAIRVIEW ELEMENTARY SCHOOL DIVISION VALUE = FEETGRAPHIC SCALE
60 0 30 60 120
60
0
M. CATHEY
S. BURWELL
N. CROOM
N. SAWYER APRIL 2020 19.00154 N/A
EX-4FORREVIEWONLYPLAN
P:\2019\19.00154-BUNCOMBEBOE-FAIRVIEW ELEM CAR RIDER LANE\DRAWINGS\CIVIL\19.00154 EXHIBIT SHEETS.DWG PLOT DATE 4/13/2020 6:13 PM NATALIE CROOMNO.DATE BY DESCRIPTION
SHEET
OFFICE MANAGER
PROJECT MANAGER
DESIGNER
REVIEWER DATE PROJECT #FUNDING #19.00154 BUNCOMBE COUNTY SCHOOLS - FAIRVIEW ELEMENTARY SCHOOL - CAR RIDER IMPROVEMENTS