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HomeMy WebLinkAboutSW5240603_Design Calculations_20240911 it PROJECT Eaddy Deivberry® IV' CLIENT CALCULATION SHEET TITLE Curve Number Calculations Designer SNT Reviewer DAR Sheet No. 1 Date 7/24/2024 Date Intensity oyea = 7.16 in/hr ED 1 Drainage Area Land Use Sq.Ft Acres C-Value Soil Type CN-Value Woods 0 0.00 0.15 B 60 Parking/Driveway/Sidewalk 335,881 7.71 0.95 D 98 Pervious/Landscaping(Open Space) 374,390 8.59 0.35 B 61 Cumulative: 710,271 16.31 0.63 78 Peak 10-year Flow 73.99 cfs PROPOSED DRAINAGE AREA PD 1 Drainage Area Land Use Sq.Ft Acres C-Value Soil Type CN-Value Woods 0 0.00 0.15 B 60 Parking/Driveway/Sidewalk 341,776 7.85 0.95 D 98 Pervious/Landscaping(Open Space) 368,495 8.46 0.35 B 61 Cumulative: 710,271 16.31 0.64 79 Peak 10-year Flow 74.57 cfs TR55 Tc Worksheet Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Hyd. No. 1 ED Description A B C Totals Sheet Flow Manning's n-value = 0.011 0.011 0.011 Flow length (ft) = 300.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.45 0.00 0.00 Land slope (%) = 3.50 0.00 0.00 Travel Time (min) = 2.25 + 0.00 + 0.00 = 2.25 Shallow Concentrated Flow Flow length (ft) = 773.00 0.00 0.00 Watercourse slope (%) = 2.80 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) =3.40 0.00 0.00 Travel Time (min) = 3.79 + 0.00 + 0.00 = 3.79 Channel Flow X sectional flow area (sqft) = 80.00 20.00 0.00 Wetted perimeter(ft) = 168.00 40.00 0.00 Channel slope (%) = 5.70 4.10 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =14.43 12.64 0.00 Flow length (ft) ({0})262.0 341.0 0.0 Travel Time (min) = 0.30 + 0.45 + 0.00 = 0.75 Total Travel Time, Tc 6.80 min TR55 Tc Worksheet Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Hyd. No. 2 PD Description A B C Totals Sheet Flow Manning's n-value = 0.011 0.011 0.011 Flow length (ft) = 300.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.45 0.00 0.00 Land slope (%) = 3.50 0.00 0.00 Travel Time (min) = 2.25 + 0.00 + 0.00 = 2.25 Shallow Concentrated Flow Flow length (ft) = 773.00 0.00 0.00 Watercourse slope (%) = 2.80 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) =3.40 0.00 0.00 Travel Time (min) = 3.79 + 0.00 + 0.00 = 3.79 Channel Flow X sectional flow area (sqft) = 80.00 20.00 0.00 Wetted perimeter(ft) = 168.00 40.00 0.00 Channel slope (%) = 5.70 4.10 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =14.43 12.64 0.00 Flow length (ft) ({0})262.0 341.0 0.0 Travel Time (min) = 0.30 + 0.45 + 0.00 = 0.75 Total Travel Time, Tc 6.80 min Hydraflow Table of Contents 2024.07.25-Eaddy Drainage.gpw Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Watershed Model Schematic 1 Hydrograph Return Period Recap 2 2 - Year Summary Report 3 Hydrograph Reports 4 Hydrograph No. 1, SCS Runoff, ED 4 Hydrograph No. 2, SCS Runoff, PD 5 10 - Year Summary Report 6 Hydrograph Reports 7 Hydrograph No. 1, SCS Runoff, ED 7 Hydrograph No. 2, SCS Runoff, PD 8 25 - Year Summary Report 9 Hydrograph Reports 10 Hydrograph No. 1, SCS Runoff, ED 10 Hydrograph No. 2, SCS Runoff, PD 11 100 - Year Summary Report 12 Hydrograph Reports 13 Hydrograph No. 1, SCS Runoff, ED 13 Hydrograph No. 2, SCS Runoff, PD 14 IDF Report 15 1 Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 1 2 C Legend Hyd. Origin Description 1 SCS Runoff ED 2 SCS Runoff PD Project: 2024.07.25- Eaddy Drainage.gpw Friday, 07/26/2024 2 Hydrograph Return Period Recap Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Hyd. Hydrograph Inflow Peak Outflow(cfs) Hydrograph No. type hyd(s) Description (origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr 1 SCS Runoff 37.76 70.33 90.99 124.26 ED 2 SCS Runoff 39.50 72.58 93.36 126.73 PD Proj. file: 2024.07.25- Eaddy Drainage.gpw Friday, 07/26/2024 3 Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 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 37.76 2 720 86,409 ED 2 SCS Runoff 39.50 2 720 90,421 PD 2024.07.25- Eaddy Drainage.gpw Return Period: 2 Year Friday, 07/26/2024 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 1 ED Hydrograph type = SCS Runoff Peak discharge = 37.76 cfs Storm frequency = 2 yrs Time to peak = 12.00 hrs Time interval = 2 min Hyd. volume = 86,409 cuft Drainage area = 16.310 ac Curve number = 78 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 3.45 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 ED Q (cfs) Hyd. No. 1 -- 2 Year Q (cfs) 40.00 40.00 30.00 I 30.00 20.00 20.00 10.00 10.00 J . , , 0.00 - - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time (hrs) 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 2 PD Hydrograph type = SCS Runoff Peak discharge = 39.50 cfs Storm frequency = 2 yrs Time to peak = 12.00 hrs Time interval = 2 min Hyd. volume = 90,421 cuft Drainage area = 16.310 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 3.45 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 PD Q (cfs) Hyd. No. 2 -- 2 Year Q (cfs) 40.00 40.00 30.00 30.00 20.00 20.00 10.00 10.00 J . . 0.00 - - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 2 Time (hrs) 6 Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 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 70.33 2 718 161,049 ED 2 SCS Runoff 72.58 2 718 166,382 PD 2024.07.25- Eaddy Drainage.gpw Return Period: 10 Year Friday, 07/26/2024 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 1 ED Hydrograph type = SCS Runoff Peak discharge = 70.33 cfs Storm frequency = 10 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 161,049 cuft Drainage area = 16.310 ac Curve number = 78 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 5.01 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 ED Q (cfs) Hyd. No. 1 -- 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 10.00 0.00 - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time (hrs) 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 2 PD Hydrograph type = SCS Runoff Peak discharge = 72.58 cfs Storm frequency = 10 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 166,382 cuft Drainage area = 16.310 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 5.01 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 PD Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs) 80.00 i 80.00 1 --- -- 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 J 0.00 - - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 2 Time (hrs) 9 Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 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 90.99 2 718 209,278 ED 2 SCS Runoff 93.36 2 718 215,213 PD 2024.07.25- Eaddy Drainage.gpw Return Period: 25 Year Friday, 07/26/2024 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 1 ED Hydrograph type = SCS Runoff Peak discharge = 90.99 cfs Storm frequency = 25 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 209,278 cuft Drainage area = 16.310 ac Curve number = 78 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 5.95 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 ED Q (cfs) Hyd. No. 1 -- 25 Year Q (cfs) 100.00 100.00 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 20.00 20.00 10.00 10.00 0.00 - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time (hrs) 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 2 PD Hydrograph type = SCS Runoff Peak discharge = 93.36 cfs Storm frequency = 25 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 215,213 cuft Drainage area = 16.310 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 5.95 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 PD Q (cfs) Hyd. No. 2 -- 25 Year Q (cfs) 100.00 100.00 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 20.00 20.00 10.00 10.00 0.00 - - 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 2 Time (hrs) 12 Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 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 124.26 2 718 288,674 ED 2 SCS Runoff 126.73 2 718 295,361 PD 2024.07.25- Eaddy Drainage.gpw Return Period: 100 Year Friday, 07/26/2024 13 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 1 ED Hydrograph type = SCS Runoff Peak discharge = 124.26 cfs Storm frequency = 100 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 288,674 cuft Drainage area = 16.310 ac Curve number = 78 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 7.44 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 ED Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs) 140.00 140.00 120.00 120.00 100.00 100.00 80.00 80.00 60.00 60.00 40.00 40.00 20.00 20.00 0.00 — 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 Hyd No. 1 Time (hrs) 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Hyd. No. 2 PD Hydrograph type = SCS Runoff Peak discharge = 126.73 cfs Storm frequency = 100 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 295,361 cuft Drainage area = 16.310 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 6.80 min Total precip. = 7.44 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 PD Q (cfs) Hyd. No. 2 -- 100 Year Q (cfs) 140.00 140.00 120.00 120.00 100.00 I 100.00 I I 80.00 80.00 60.00 60.00 40.00 40.00 20.00 20.00 0.00 — ' 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 Hyd No. 2 Time (hrs) 15 Hydraflow Rainfall Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Friday,07/26/2024 Return Intensity-Duration-Frequency Equation Coefficients(FHA) Period (Yrs) B D E (N/A) 1 64.6880 13.0000 0.9002 2 1961.3149 52.2998 1.5023 3 0.0000 0.0000 0.0000 5 76.7442 13.3000 0.8516 10 69.8886 12.3000 0.7995 25 63.5278 11.3000 0.7472 50 56.7195 10.2000 0.7002 100 52.5262 9.5000 0.6642 File name: Eaddy.IDF Intensity= B/(Tc+ D)^E Return Intensity Values(in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 4.80 3.85 3.22 2.78 2.45 2.19 1.98 1.81 1.67 1.55 1.45 1.36 2 4.48 3.95 3.52 3.16 2.86 2.60 2.38 2.19 2.02 1.88 1.75 1.63 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 6.46 5.25 4.45 3.88 3.44 3.10 2.82 2.60 2.41 2.24 2.10 1.98 10 7.15 5.84 4.97 4.34 3.87 3.50 3.20 2.95 2.75 2.57 2.41 2.28 25 7.89 6.46 5.52 4.85 4.34 3.94 3.62 3.35 3.13 2.93 2.77 2.62 50 8.44 6.91 5.92 5.22 4.69 4.27 3.93 3.65 3.42 3.22 3.04 2.89 100 8.89 7.30 6.28 5.55 5.00 4.57 4.22 3.93 3.69 3.48 3.30 3.14 Tc=time in minutes.Values may exceed 60. Precip.file name:Sample.pcp Rainfall Precipitation Table (in) Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 0.00 3.45 0.00 3.30 5.01 5.95 6.80 7.44 SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-1st 0.00 0.00 0.00 2.75 0.00 5.38 6.50 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 2.80 0.00 5.25 6.00 0.00 Channel/Swale Sizing Calculation 8/6/2024 Channel Type/Name: Temp./Perm.Diversion Ditch User Input Data Project: Eaddy Building Addition Calculated Value Location: RTP,Raleigh Reference Data Objective: Design channel to convey flow to temporary sediment trap References: (1) North Carolina Erosion and Sediment Control Planning and Design Manual (2) Elements of Urban Stormwater Design,H.R.Malcom. Procedure: Use procedures outlined in the above references.Rational Method will be used to calculate flows.Normal depth will be calculated using Mannings Equation.Water velocity will be calculated using the principle of continuity(Q= VA) Channels will be designed to carry flow generated by the 10-Year storm event using maximum slope. For Grass channels,a velocity below 5ft/sec NCDEQ Stormwater Manual 6.3 Calculations: Rational Method: Q=C*I*A Where Q=Flow(cfs) C=Runoff Coefficient Calculate'Weighted C'using Site Specific Data and Reference 2 I=Rainfall Intensity(in/hr) Find Intensity for 10-year event from A=Drainage Area(ac) NOAA Precipitation Intensity Data Source C= 0.63 110=7.16 Use min.allowed to=5 min Drainage area(A)(ac)= 1.17 Q(cfs)= 5.277636 Length(L)(ft)= 104 Calculations will be done using Manning's Equation to find normal depth Channel cross section and Continuity(Q=V*A)to find velocity. Q(cfs)= 5.28 Sm*x(ft/ft)=0.028 B(ft)= 0 M(ft)= 3 Calculate normal depth and velocity with bare earth as lining From Ref.2, n= 0.020 Flow(cfs)= 5.28 normal depth(ft)= 0.58 velocity(ft/s)= 5.26 Calculate normal depth and velocity with jute matting From Ref.2, n= 0.022 Flow(cfs)= 5.28 normal depth(ft)= 0.60 velocity(ft/s)= 4.90 Calculate normal depth and velocity with straw w/net lining From Ref.2, n= 0.033 Flow(cfs)= 5.28 normal depth(ft)= 0.70 velocity(ft/s)= 3.61 Calculate normal depth and velocity with grass as lining From Ref.2, n= 0.030 Flow(cfs)= 5.28 normal depth(ft)= 0.67 velocity(ft/s)= 3.88 Calculate shear stress T=yds y=62.4 d=0.67 s=0.028 T=1.17 Maximum permissible shear stress for: Straw with net 1.45 1 of 1 10/16/23,8:49 AM Precipitation Frequency Data Server NOAA Atlas 14,Volume 2,Version 3 `:%"°,4,, Location name: Raleigh,North Carolina,USA* r.,, "none . Latitude: 35.8143°,Longitude:-78.711° i illElevation:445 ft** �'f° +�u *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 I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval(years) Duration 1 2 5 10 25 50 100 200 500 1000 5-min 0.400 0.467 0.538 0.597 0.658 0.703 0.742 I 0.776 0.813 0.842 (0.367-0.436) (0.429-0.510) (0.495-0.586) (0.547-0.650) (0.601-0.716) (0.638-0.764) (0.670-0.807) (0.697-0.845) (0.724-0.885) (0.744-0.918) 10-min 0.639 0.747 0.861 0.954 1.05 1.12 1.18 1.23 1.29 1.32 (0.586-0.696) (0.686-0.816) (0.792-0.939) (0.875-1.04) (0.958-1.14) (1.02-1.22) (1.06-1.28) I (1.10-1.34) (1.15-1.40) (1.17-1.45) 15-min 0.799 0.939 1.09 1.21 1.33 1.42 1.49 1.55 1.62 1.66 (0.732-0.870) (0.863-1.02) (1.00-1.19) (1.11-1.31) (1.21-1.45) (1.29-1.54) (1.35-1.62) (1.40-1.69) (1.44-1.76) (1.47-1.82) 30-min 1.10 1.30 1.55 1.75 1.97 2.13 2.28 2.42 2.58 2.69 (1.00-1.19) (1.19-1.42) (1.42-1.69) (1.60-1.90) (1.80-2.14)_ (1.94-2.32) (2.06-2.48) (2.17-2.63) (2.30-2.80) (2.38-2.94) 60-min 1.36 1.63 1.98 2.28 2.62 2.89 3.14 3.39 3.69 3.93 (1.25-1.49) (1.50-1.78) (1.83-2.16) (2.09-2.48) (2.39-2.85) (2.63-3.14) (2.84-3.42) (3.04-3.69) (3.29-4.02) (3.48-4.29) 2-hr 1.59 1.90 2.34 2.70 3.15 3.52 3.86 4.21 4.66 5.02 (1.45-1.74) (1.74-2.08) (2.13-2.56) (2.46-2.96) (2.84-3.45) (3.16-3.84) (3.45-4.22) (3.74-4.60) (4.10-5.09) 1 (4.38-5.48) 3-hr 1.68 2.01 2.49 2.90 3.42 3.85 4.28 4.71 5.29 5.77 (1.54-1.84) (1.84-2.21) (2.27-2.73)_ (2.64-3.18) (3.09-3.73) (3.46-4.20) (3.81-4.66) (4.17-5.13) (4.64-5.77) (5.00-6.31) 6-hr 2.03 2.43 3.00 3.50 4.14 4.68 5.22 5.77 6.53 7.16 (1.86-2.22) (2.23-2.66) (2.75-3.28) (3.20-3.82) (3.76-4.50) (4.22-5.08) (4.67-5.66) (5.12-6.26)_ (5.71-7.07) (6.19-7.77) 12-hr 2.40 2.87 3.56 4.17 4.98 5.66 6.36 7.09 8.09 8.94 (2.20-2.62) (2.64-3.14) (3.27-3.89) (3.81-4.55) (4.52-5.41) (5.10-6.12) (5.66-6.87) (6.24-7.65) (7.01-8.72) (7.64-9.66) 24-hr 2.86 3.45 4.33 5.01 5.95 6.69 7.44 8.22 9.28 10.1 (2.67-3.08) (3.22-3.72) (4.04-4.65) (4.67-5.39) (5.52-6.39) (6.19-7.18) (6.87-8.00)_ (7.57-8.84) _(8.50-10.0) (9.23-10.9) 2-day 3.30 3.97 4.94 5.70 6.72 7.52 8.34 9.18 10.3 11.2 (3.07-3.55) (3.70-4.27) I (4.60-5.32), (5.30-6.12) (6.23-7.22) (6.96-8.09) (7.69-8.97) (8.44-9.88) (9.45-11.1) (10.2-12.1) 3-day 3.50 4.20 5.20 5.98 7.04 7.88 8.74 9.62 10.8 11.7 (3.26-3.75) (3.92-4.51) (4.85-5.58) (5.57-6.41) (6.54-7.56) (7.30-8.46) (8.07-9.38) (8.85-10.3) (9.91-11.6) (10.7-12.6) 4-day 3.69 4.43 5.46 6.27 7.37 8.25 9.14 10.1 11.3 12.3 (3.46-3.96) (4.14-4.74) (5.10-5.84) (5.85-6.71) (6.86-7.89) (7.65-8.83) (8.45-9.79) (9.27-10.8) (10.4-12.1) (11.2-13.2) 7-day 4.28 5.11 6.22 7.10 8.30 9.25 10.2 11.2 12.6 13.6 (4.02-4.57) (4.79-5.45) (5.82-6.63) (6.64-7.56) (7.74-8.84)_ (8.61-9.86) (9.48-10.9) (10.4-12.0) (11.6-13.5) (12.5-14.6) 10-day 4.88 5.80 6.97 7.89 9.13 10.1 11.1 12.1 13.4 14.5 (4.59-5.20) (5.45-6.18) (6.54-7.43) (7.39-8.40) (8.53-9.72)_ (9.42-10.8) (10.3-11.8) (11.2-12.9) (12.4-14.3) (13.3-15.5) 20-day 6.53 7.71 9.11 10.2 11.7 12.9 14.1 15.3 16.9 18.2 (6.14-6.96) (7.25-8.21) (8.56-9.70) (9.58-10.9) (11.0-12.5) (12.0-13.7) (13.1-15.0) (14.2-16.3) (15.6-18.1) (16.7-19.5) 30-day 8.11 9.54 11.1 12.3 13.9 15.1 16.3 17.5 19.1 20.4 (7.64-8.61) (8.98-10.1) (10.4-11.8) (11.6-13.1) (13.0-14.7) (14.1-16.0) (15.2-17.4) (16.3-18.7) (17.8-20.4) (18.8-21.7) 45-day 10.3 12.1 13.9 15.2 17.0 18.3 19.6 20.9 22.5 23.8 (9.82-10.9) (11.5-12.8) (13.1-14.6) (14.4-16.0) (16.0-17.9) (17.3-19.3) (18.5-20.7) (19.6-22.1) (21.1-23.9) (22.2-25.3) 60-day 12.4 14.5 16.4 17.8 19.7 21.1 22.4 23.8 25.5 26.7 (11.8-13.1) (13.8-15.2) (15.5-17.2) (16.9-18.8) (18.6-20.7) (19.9-22.2) (21.2-23.7) (22.4-25.1) (23.9-26.9) (25.1-28.3) 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. Back to Top PF graphical https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.8143&Ion=-78.7110&data=depth&units=english&series=pds 1/4 10/16/23,8:49 AM Precipitation Frequency Data Server PDS-based depth-duration-frequency (DDF) curves Latitude: 35.8143°, Longitude: -78.7110° Average recurrence 25 - interval (years) 20 - // — 1 L 2 a - 5 a) 15 - — 10 o — 25 y �i/ — 50 O. 100 10 - V - cu - 200 o_ =/ �� 500 5 - - �� �_ — 1000 0- r 1 I I - - I - - I rt-r- • E E E E E rann 6b N Tr v vv 7 v v v v v ,� ev in o m ID Duration `" "�' o N m v m 25 - III -•c 20 - Duration L O. -- 5 mm — 2-day c 15 C — 10-min — 3-day •y 15-min — 4-day ro a 10 �� — 30-min — 7-day �= — 60-mm — 10-day a - -- - 2-hr — 20-day 5 �,_— — 3-hr — 30-day — 6-hr — 45-day 0- •'� 12-hr — 60-day — 24-hr 1 2 5 10 25 50 100 200 500 1000 - Average recurrence interval (years) NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Mon Oct 16 12:48:32 2023 Back to Top Maps & aerials Small scale terrain https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.8143&Ion=-78.7110&data=depth&units=english&series=pds 2/4 7/22/24,4:04 PM Precipitation Frequency Data Server NOAA Atlas 14,Volume 2,Version 3 le "° Location name:Raleigh,North Carolina,USA* *: ' Latitude:35.8143°,Longitude:-78.711° Elevation:445 ft** a,gyp *source:ESRI Maps **source:USGS w*"`x""" POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches/hour)1 Average recurrence interval(years) Duration 1 2 5 10 25 50 100 200 500 1000 5-min 4.80 5.60 6.46 7.16 7.90 8.44 8.90 9.31 9.76 10.1 (4.40-5.23) (5.15-6.12) (5.94-7.03) (6.56-7.80) (7.21-8.59) (7.66-9.17) (8.04-9.68) (8.36-10.1) (8.69-10.6) (8.93-11.0) 10-min 3.83 4.48 5.17 5.72 6.29 6.71 7.07 7.38 7.72 7.95 (3.52-4.18) (4.12-4.90) (4.75-5.63) (5.25-6.23) (5.75-6.85) (6.10-7.30) (6.39-7.69) (6.63-8.03) (6.88-8.40) (7.03-8.68) 15-min 3.20 3.76 4.36 4.83 5.32 5.67 5.96 6.21 6.47 6.66 (2.93-3.48) (3.45-4.10) (4.01-4.75) (4.43-5.26) (4.86-5.78) (5.15-6.16) (5.39-6.48) (5.58-6.76) (5.77-7.05) (5.88-7.26) 30-min 2.19 2.60 3.10 3.50 3.94 4.27 4.57 4.83 5.15 5.39 (2.01-2.39) (2.38-2.83) (2.85-3.38) (3.21-3.81) (3.60-4.29) (3.88-4.64) (4.13-4.96) (4.34-5.26) (4.59-5.61) (4.76-5.88) 60-min 1.36 1.63 1.98 2.28 2.62 2.89 3.14 3.39 3.69 3.93 (1.25-1.49) (1.50-1.78) (1.83-2.16) (2.09-2.48) (2.39-2.85) (2.63-3.14) (2.84-3.42) (3.04-3.69) (3.29-4.02) (3.48-4.29) 2-hr 0.794 0.950 1.17 1.35 1.58 1.76 1.93 2.11 2.33 2.51 (0.723-0.872) (0.868-1.04) (1.07-1.28) (1.23-1.48) (1.42-1.72) (1.58-1.92) (1.72-2.11) (1.87-2.30) (2.05-2.54) (2.19-2.74) 3-hr 0.559 0.670 0.829 0.965 1.14 1.28 1.42 1.57 1.76 1.92 (0.511-0.614) (0.614-0.736)(0.756-0.910) (0.878-1.06) (1.03-1.24) (1.15-1.40) (1.27-1.55) (1.39-1.71) (1.54-1.92) (1.67-2.10) 6-hr 0.338 0.405 0.501 0.584 0.691 0.781 0.871 0.963 1.09 1.20 (0.311-0.370) (0.372-0.444)(0.459-0.548) (0.533-0.637) (0.627-0.752)(0.705-0.849) (0.779-0.945) (0.854-1.04) (0.953-1.18) (1.03-1.30) 12-hr 0.198 0.238 0.295 0.346 0.413 0.469 0.527 0.588 0.671 0.742 (0.182-0.217) (0.219-0.260)(0.271-0.322) (0.316-0.377) (0.374-0.448)(0.423-0.508) (0.470-0.570)(0.518-0.634) (0.581-0.724) (0.633-0.801) 24-hr 0.119 0.143 0.180 0.208 0.247 0.278 0.310 0.342 0.386 0.421 (0.111-0.128) (0.134-0.154)(0.168-0.193) (0.194-0.224) (0.229-0.266)(0.257-0.299) (0.286-0.333)(0.315-0.368) (0.354-0.416) (0.384-0.454) 2-day 0.068 0.082 0.102 0.118 0.139 0.156 0.173 0.191 0.215 0.233 (0.063-0.073) (0.077-0.089) (0.095-0.110) (0.110-0.127) (0.129-0.150)(0.144-0.168) (0.160-0.186)(0.175-0.205) (0.196-0.231) (0.213-0.252) 3-day 0.048 0.058 0.072 0.083 0.097 0.109 0.121 0.133 0.150 0.163 (0.045-0.052) (0.054-0.062)(0.067-0.077) (0.077-0.089) (0.090-0.104) (0.101-0.117) (0.112-0.130) (0.122-0.143) (0.137-0.161) (0.148-0.175) 4-day 0.038 0.046 0.056 0.065 0.076 0.085 0.095 0.104 0.117 0.127 (0.035-0.041) (0.043-0.049)(0.053-0.060) (0.060-0.069) (0.071-0.082)(0.079-0.091) (0.088-0.101) (0.096-0.112) (0.108-0.126) (0.116-0.137) 7-day 0.025 0.030 0.036 0.042 0.049 0.055 0.060 0.066 0.074 0.081 (0.023-0.027) (0.028-0.032)(0.034-0.039) (0.039-0.045) (0.046-0.052)(0.051-0.058) (0.056-0.064)(0.061-0.071) (0.068-0.080) (0.074-0.087) 10-day 0.020 0.024 0.029 0.032 0.038 0.042 0.046 0.050 0.055 0.060 (0.019-0.021) (0.022-0.025)(0.027-0.030) (0.030-0.035) (0.035-0.040)(0.039-0.044) (0.042-0.049)(0.046-0.053) (0.051-0.059) (0.055-0.064) 20-day 0.013 0.016 0.018 0.021 0.024 0.026 0.029 0.031 0.035 0.037 (0.012-0.014) (0.015-0.017)(0.017-0.020) (0.019-0.022) (0.022-0.025)(0.025-0.028) (0.027-0.031)(0.029-0.033) (0.032-0.037) (0.034-0.040) 30-day 0.011 0.013 0.015 0.017 0.019 0.020 0.022 0.024 0.026 0.028 (0.010-0.011) (0.012-0.014)(0.014-0.016) (0.016-0.018) (0.018-0.020)(0.019-0.022) (0.021-0.024)(0.022-0.025) (0.024-0.028) (0.026-0.030) 45-day 0.009 0.011 0.012 0.014 0.015 0.016 0.018 0.019 0.020 0.022 (0.009-0.010) (0.010-0.011) (0.012-0.013) (0.013-0.014) (0.014-0.016)(0.015-0.017) (0.017-0.019)(0.018-0.020) (0.019-0.022) (0.020-0.023) 60-day 0.008 0.010 0.011 0.012 0.013 0.014 0.015 0.016 0.017 0.018 (0.008-0.009) (0.009-0.010) (0.010-0.011) (0.011-0.013) (0.012-0.014)(0.013-0.015) (0.014-0.016)(0.015-0.017) (0.016-0.018) (0.017-0.019) t Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.8143&Ion=-78.7110&data=intensity&units=english&series=pds 1/3 7/22/24,4:04 PM Precipitation Frequency Data Server PD5-based intensity-duration-frequency(IDF)curves Latitude: 35.8143°,Longitude:-78.7110° 101 I I I I Average recurrence —____ interval (years) L ▪ 10° ��� 2 °ci — 10 — 25 o � — 50 % 10-1 '`,.,. . . — 100 'a._ — 200 v \\\ — 500 o \ — 1000 10-2- - . C C C C c L L L L L T T T T >, T T », E IS rp ro ro ro p ro O ro N ref lG O 7 V-O -O � V "O "O LA O i .,-, nl l0 Duration NI N n5 n- O N o in in cr lD 101 I �4 — 1 _c C Duration Z• 10° c — 5-mon — 2-day v — 10-min — 3-day c 15-min — 4-day 0 m 10-1- — 30-nln — 7-day aa9 — 60-min — 10-day . — 2-tor — 20-day o` — Er — 60-day I i i I I I — 24-hr 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval(years) NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Mon Jul 22 20:03:39 2024 Back to Top Maps &aerials Small scale terrain _ 11 ! 17 N. �51", e .2 1 Lak °pne'tt __,,: Agi--41 Wad �nar°, _Ye a -oorou9. s-i,sCd iMtllRd � Of V I? al - - = I 3.lkm T3 �_ _ I 2rmi Large scale terrain https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.8143&Ion=-78.7110&data=intensity&units=english&series=pds 2/3