YADKI-013 Final Report

DAM HYDRAULIC CAPACITY
ASSESSMENT REPORT
(DRAFT)
DEEP CREEK WS #24 (PL-566)
YADKI-013
YADKIN COUNTY, NC
PREPARED BY:
HDR Engineering Inc. of the
Carolinas under contract with
WOOD E&I Solutions
2020

EXECUTIVE SUMMARY
A hydraulic capacity analysis was completed for the Deep Creek WS #24 (Pl-566) in Yadkin County,
North Carolina. The purpose of the study was to analyze the existing potential of the dam for
overtopping during predetermined specified rainfall events using the North Carolina Dam Safety
defined process and templates. The analyses were completed using the United States Army Corps
of Engineers developed software Hydrologic Engineering Center – Hydrologic Modeling System
(HEC-HMS) in combination with Arc-GIS to develop required input parameters. The rainfall
events included in the analyses consist of 24-hour durations with return periods of 25 years, 50
years, 100 years, 200 years, 500 years and 1000 years. Results of the analyses indicate that this
structure is hydraulically adequate for 25 years, 50 years, 100 years, and 200 years rainfall events.
Data, input parameters, and final results can be found on the attached summary sheets and in
the appendices of this report as well as in the associated electronic file in which all program files
are stored.
Drainage Area (Sq. Mi.)=
Curve Number =
Lag Time (min.)=
Rainfall Distribution Methods =
417.0
325.5
339.7
354.3
369.4
384.8
400.7
892.2
892.7
893.2
893.7
894.2
ELEVATION
889.7
890.2
890.7
891.2
891.7
15.1
18.4
21.9
STORAGE (ACRE-FT)
0.0
1.5
3.1
4.9
7.0
9.5
12.2
873.7
870.7
871.2
871.7
872.2
872.7
873.2
882.2
885.2
ELEVATION
869.2
869.7
870.2
STORAGE (ACRE-FT)
285.2
298.3
311.7
68.69
62
SCS Type 2
SPILLWAY
Primary
Auxiliary
TYPE
Riser / Barrel
Grass Lined Trapezoidal Channel
ELEVATION
24 HOUR - 200 YEAR EVENT, 8.77 INCHES, ELEVATION 887.3 (0.4 FT FREE-BOARD)
24 HOUR - 100 YEAR EVENT, 7.86 INCHES, ELEVATION 886.5 (1.2 FT FREE-BOARD)
24 HOUR - 50 YEAR EVENT, 6.99 INCHES, ELEVATION 885.7 (2 FT FREE-BOARD)
24 HOUR - 25 YEAR EVENT, 6.16 INCHES, ELEVATION 884.2 (3.5 FT FREE-BOARD)
SUMMARY OF INPUT PARAMETERS
1.72
SUMMARY SHEET OF HYDRAULIC CAPACITY RESULTS
DEEP CREEK WS #24 (PL-566), YADKI-013
ANALYSIS PERFORMED BY: S. MURPHY, HDR
24 HOUR - 1000 YEAR EVENT, 11.1 INCHES, ELEVATION 888.7 (1 FT OVER-TOPPED)
24 HOUR - 500 YEAR EVENT, 10 INCHES, ELEVATION 888.1 (0.4 FT OVER-TOPPED)
TOP OF DAM ELEVATION = 887.7
YADKI-013DEEP CREEK WS #24 (PL-566)OCTOBER 27, 2020
1150.9
NOT TO SCALE
959.4
989.5
1020.3
1051.8
1084.0
1117.0
794.0
819.8
846.3
873.5
901.4
930.0
650.2
672.8
696.0
719.6
743.9
768.7
524.9
544.6
564.8
585.4
606.5
628.1
433.8
450.9
468.7
487.0
505.7
907.2
907.7
908.2
908.7
909.2
904.2
904.7
905.2
905.7
906.2
906.7
901.2
901.7
902.2
902.7
903.2
903.7
898.2
898.7
899.2
899.7
900.2
900.7
895.2
895.7
896.2
896.7
897.2
897.7
894.7
236.1
247.9
260.0
272.4
171.6
181.6
191.9
202.5
213.4
224.6
118.4
126.6
135.0
143.7
152.7
162.0
74.7
81.4
88.3
95.5
102.9
110.5
39.4
44.7
50.2
56.0
62.0
68.2
25.7
29.9
34.4
888.7
889.2
885.7
886.2
886.7
887.2
887.7
888.2
882.7
883.2
883.7
884.2
884.7
885.2
879.7
880.2
880.7
881.2
881.7
882.2
876.7
877.2
877.7
878.2
878.7
879.2
874.2
874.7
875.2
875.7
876.2
YADKI-013DEEP CREEK WS #24 (PL-566)OCTOBER 27, 2020

APPENDIX A
Watershed Boundary

Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P,NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea,Esri (Thailand), NGCC, (c) OpenStreetMap contributors, and theGIS User Community
Deep Creek WS #24 (PI-566) - YADKI-013 - Watershed Boundary
Legend
Longest FlowPath
Watershed Bound ary
0 0.65 1.30.325 Miles
Date: 10 /5/2020
/Drainage Area:1.72 Square MilesFlowpath Length: 2.5 miles

APPENDIX B

Lag Time Calculation
Dam No:YADKI-013 Date:10/23/2020
Dam Name:Deep Creek WS #24 (Pl-566)Engineer:K. Trefzger
Maximum Potential Retention (inches):S =(1000/cn')-10
Time of Concentration (hours):Tc =l0.8*(S+1)0.7
1140*Y0.5
Basin Data:Input Values in yellow
Curve Number CN =68.6914 from NRCS CN Calculation
S =4.55786 in.
Mean Basin Slope Y =11.3388 %from Watershed Mean slope
Longest Flowpath:2.53 mi.from Watershed Longest flowpath
Flow Length l =13358.4 ft.
Time of Concentration Tc =1.73 Hours Tc =104 mins
Lag Time TL =1.04 Hours TL =62 mins

APPENDIX C
NRCS Curve Number Summary Sheet

Change CN according to TR-55 (see tables below)
NLCD (2016) Landuse TR-55 Landuse HSG A (sq. ft.)CN HSG B (sq. ft.)CN HSG C (sq. ft.)CN HSG D (sq. ft.)CN
Open Water Not Available 0 100 0 107202 100 10720234 39082 100 3908165 589981 100 58998056
Developed, Open Space Open space - Fair condition (grass cover 50% to 75%)0 49 0 645470 69 44537421 670103 79 52938146 56165 84 4717824
Developed, Low Intensity Residential districts by average lot size: 1/3 acre 0 57 0 67462 72 4857255 188153 81 15240400 0 86 0
Developed, Medium Intensity Residential districts by average lot size: 1/8 acre 0 77 0 3373 85 286697 35378 90 3183988 0 92 0
Developed, High Intensity Urban districts - Commercial and business 0 89 0 0 92 0 0 94 0 0 95 0
Barren Land Newly graded areas 0 77 0 0 86 0 0 91 0 0 94 0
Deciduous Forest Woods - Fair 0 36 0 16260832 60 975649949 1978755 73 144449132 926194 79 73169316
Evergreen Forest Woods - Fair 0 36 0 879960 60 52797586 198181 73 14467219 31972 79 2525810
Mixed Forest Woods - Fair 0 36 0 3654990 60 219299377 664428 73 48503269 188111 79 14860757
Shrub/Scrub Brush - Fair 0 35 0 14194 56 794888 43917 70 3074190 0 77 0
Herbaceuous Herbaceuous - Fair 0 60 0 851967 71 60489679 172718 81 13990156 70026 89 6232340
Hay/Pasture Pasture - Fair 0 49 0 10750879 69 741810675 4589980 79 362608406 576091 84 48391631
Cultivated Crops Row crops (SR + CR) - Poor 0 71 0 1423531 80 113882517 2259952 87 196615807 0 90 0
Woody Wetlands Not Available 0 80 0 0 85 0 0 90 0 0 95 0
Emergent Herbaceuous Wetlands Not Available 0 80 0 0 85 0 0 90 0 0 95 0 Weighted CN=68.69
NOTE: Curve Numbers are from SCS TR-55 with the exception of assumed HSG A (CN=60) for Herbaceous,Open Water, Woody Wetlands, and Emergent Herbaceous
Wetlands.
NOTE: double-check all the land types are being calculated and texts are accurate
NOTE: double-check the exported attribute table has the same table format as the "Export_Output" table

APPENDIX D
Hyetograph Results Used for Analysis

0.0
2.0
4.0
6.0
8.0
10.0
12.0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Cumulative Depth (in)Time (hrs)
Hyetographs for 24-Hour SCS Type II Rainfall Distributions
25YR
50YR
100YR
200YR
500YR
1000YR

APPENDIX E
NOAA Atlas 14 Rainfall Table

Point precipitation frequency estimates (inches)
NOAA Atlas 14 Volume 2 Version 3
Data type: Precipitation depth
Time series type: Partial duration
Project area: Ohio River Basin
Location name (ESRI Maps): Boonville, North Carolina USA
Station Name: -
Latitude: 36.205018°
Longitude: -80.664415°
Elevation (USGS): 946.01 ft
PRECIPITATION FREQUENCY ESTIMATES
by
duration
for ARI
(years):1 2 5 10 25 50 100 200 500 1000
5-min:0.354 0.42 0.497 0.552 0.618 0.665 0.708 0.749 0.797 0.831
10-min:0.566 0.672 0.796 0.882 0.985 1.06 1.13 1.19 1.26 1.31
15-min:0.707 0.845 1.01 1.12 1.25 1.34 1.42 1.5 1.59 1.64
30-min:0.97 1.17 1.43 1.62 1.85 2.02 2.18 2.33 2.52 2.66
60-min:1.21 1.46 1.83 2.11 2.46 2.74 3 3.27 3.62 3.89
2-hr:1.43 1.74 2.19 2.54 3.01 3.37 3.74 4.11 4.62 5.01
3-hr:1.55 1.88 2.37 2.75 3.27 3.68 4.1 4.53 5.12 5.59
6-hr:1.92 2.32 2.93 3.4 4.05 4.57 5.11 5.66 6.43 7.04
12-hr:2.35 2.85 3.59 4.17 4.98 5.63 6.31 7.02 8.01 8.8
24-hr:2.85 3.46 4.39 5.13 6.16 6.99 7.86 8.77 10 11.1
2-day:3.38 4.08 5.13 5.95 7.08 7.97 8.9 9.85 11.2 12.2
3-day:3.6 4.34 5.43 6.27 7.44 8.37 9.32 10.3 11.7 12.7
4-day:3.81 4.59 5.72 6.6 7.8 8.76 9.75 10.8 12.2 13.3
7-day:4.37 5.23 6.39 7.29 8.51 9.48 10.5 11.5 12.8 13.9
10-day:4.99 5.96 7.18 8.13 9.39 10.4 11.4 12.4 13.7 14.7
20-day:6.7 7.94 9.41 10.5 12.1 13.2 14.4 15.6 17.2 18.4
30-day:8.31 9.79 11.3 12.5 13.9 15 16.1 17.1 18.5 19.5
45-day:10.5 12.3 14 15.2 16.8 18 19.1 20.2 21.6 22.6
60-day:12.5 14.6 16.4 17.8 19.6 20.9 22.1 23.3 24.8 25.9
Date/time (GMT): Fri Oct 23 15:00:47 2020
pyRunTime: 0.0364208221436

APPENDIX F
Outlet Works Rating Curves

Total outlet discharge from the spillway systemClient:NCEMDate:10/21/2020Project:Overtopping StudyEngineer:T.CarterDam:Deep Creek WS #24 (PI-566)Dam No.YADKI-013Reservior Water Level (RWS) Elevation (ft)Total discharge from the spillway system (cfs)(from Hydrocad)869.20.0870.05.2870.814.4871.620.7872.425.3873.229.2874.032.7874.835.8875.638.6876.441.3877.243.7878.046.1878.848.3879.650.5880.452.5881.254.5882.056.4882.880.6883.6137.0884.4150.2885.2153.0886.0298.9886.8575.7887.6950.7888.41414.9889.21964.4890.02597.7890.83177.0891.63614.6892.43993.6893.24334.8894.04648.4894.84940.5895.65215.2896.45475.4897.25723.2898.05960.3898.86188.0899.66407.3900.46619.2901.26824.3902.07023.3902.87216.7903.67404.9904.47588.4905.27767.5906.07942.5906.88113.6907.68281.2908.48445.4909.28606.40.01000.02000.03000.04000.05000.06000.07000.08000.09000.0865.0 870.0 875.0 880.0 885.0 890.0 895.0 900.0 905.0 910.0Total discharge from the spillway system (cfs)Reservior Water Level (RWS) Elevation (ft)The whole spillway system rating curve (cfs)
YADKI-013 Deep Creek WS #24 (PI-566)
Rainfall not specifiedYADKI-013
Printed 10/21/2020Prepared by HDR, Inc
Page 1HydroCAD® 10.00-25 s/n 07102 © 2019 HydroCAD Software Solutions LLC
Summary for Pond 1P: YADKI-013 Deep Creek WS #24 (PI-566)
Volume Invert Avail.Storage Storage Description
#1 869.20' 50,132,117 cf Custom Stage Data (Prismatic) Listed below (Recalc)
YADKI-013 Deep Creek WS #24 (PI-566)
Rainfall not specifiedYADKI-013
Printed 10/21/2020Prepared by HDR, Inc
Page 2HydroCAD® 10.00-25 s/n 07102 © 2019 HydroCAD Software Solutions LLC
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
869.20 123,320 0 0
869.70 130,693 63,503 63,503
870.20 148,623 69,829 133,332
870.70 172,217 80,210 213,542
871.20 200,049 93,067 306,609
871.70 224,316 106,091 412,700
872.20 248,047 118,091 530,791
872.70 271,709 129,939 660,730
873.20 292,510 141,055 801,785
873.70 317,920 152,608 954,392
874.20 348,018 166,485 1,120,877
874.70 379,238 181,814 1,302,691
875.20 415,176 198,604 1,501,294
875.70 445,693 215,217 1,716,511
876.20 470,947 229,160 1,945,671
876.70 493,428 241,094 2,186,765
877.20 514,912 252,085 2,438,850
877.70 534,004 262,229 2,701,079
878.20 553,193 271,799 2,972,878
878.70 571,934 281,282 3,254,160
879.20 591,973 290,977 3,545,137
879.70 613,818 301,448 3,846,585
880.20 633,848 311,917 4,158,501
880.70 654,902 322,188 4,480,689
881.20 676,895 332,949 4,813,638
881.70 699,121 344,004 5,157,642
882.20 722,920 355,510 5,513,152
882.70 746,855 367,444 5,880,596
883.20 769,727 379,146 6,259,741
883.70 795,059 391,197 6,650,938
884.20 825,674 405,183 7,056,121
884.70 856,084 420,440 7,476,561
885.20 883,203 434,822 7,911,382
885.70 909,482 448,171 8,359,554
886.20 935,107 461,147 8,820,701
886.70 961,416 474,131 9,294,832
887.20 988,193 487,402 9,782,234
887.70 1,014,668 500,715 10,282,949
888.20 1,042,373 514,260 10,797,209
888.70 1,070,176 528,137 11,325,347
889.20 1,097,861 542,009 11,867,356
889.70 1,125,898 555,940 12,423,296
890.20 1,154,072 569,993 12,993,288
890.70 1,185,625 584,924 13,578,212
891.20 1,219,521 601,287 14,179,499
891.70 1,255,586 618,777 14,798,276
892.20 1,292,148 636,934 15,435,209
892.70 1,328,662 655,203 16,090,412
893.20 1,364,951 673,403 16,763,815
YADKI-013 Deep Creek WS #24 (PI-566)
Rainfall not specifiedYADKI-013
Printed 10/21/2020Prepared by HDR, Inc
Page 3HydroCAD® 10.00-25 s/n 07102 © 2019 HydroCAD Software Solutions LLC
893.70 1,402,988 691,985 17,455,800
894.20 1,437,998 710,247 18,166,046
894.70 1,474,492 728,123 18,894,169
895.20 1,515,352 747,461 19,641,630
895.70 1,572,188 771,885 20,413,515
896.20 1,614,102 796,573 21,210,087
896.70 1,654,072 817,044 22,027,131
897.20 1,694,697 837,192 22,864,323
897.70 1,735,400 857,524 23,721,847
898.20 1,776,953 878,088 24,599,935
898.70 1,818,506 898,865 25,498,800
899.20 1,860,850 919,839 26,418,639
899.70 1,904,414 941,316 27,359,955
900.20 1,946,729 962,786 28,322,741
900.70 1,991,279 984,502 29,307,243
901.20 2,037,070 1,007,087 30,314,330
901.70 2,086,748 1,030,955 31,345,285
902.20 2,136,475 1,055,806 32,401,090
902.70 2,184,033 1,080,127 33,481,217
903.20 2,229,355 1,103,347 34,584,564
903.70 2,277,178 1,126,633 35,711,198
904.20 2,334,434 1,152,903 36,864,101
904.70 2,397,939 1,183,093 38,047,194
905.20 2,464,795 1,215,684 39,262,877
905.70 2,527,275 1,248,018 40,510,895
906.20 2,589,648 1,279,231 41,790,126
906.70 2,653,730 1,310,845 43,100,970
907.20 2,715,107 1,342,209 44,443,179
907.70 2,775,459 1,372,642 45,815,821
908.20 2,839,629 1,403,772 47,219,593
908.70 2,913,486 1,438,279 48,657,872
909.20 2,983,496 1,474,246 50,132,117
Device Routing Invert Outlet Devices
#1 Primary 862.40'36.0" Round 36" RCP
L= 208.0' RCP, sq.cut end projecting, Ke= 0.500
Inlet / Outlet Invert= 862.40' / 860.30' S= 0.0101 '/' Cc= 0.900
n= 0.013, Flow Area= 7.07 sf
#2 Device 1 869.20'27.0" W x 18.0" H Vert. Riser Orifice C= 0.600
#3 Device 1 882.20'90.0" W x 15.0" H Vert. Riser Weirs X 2.00 C= 0.600
#4 Secondary 885.20'Emergency Spillway, Cv= 3.10 (C= 3.88)
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00
Width (feet) 50.00 55.00 60.00 65.00 70.00 75.00
Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=0.00' TW=856.90' (Fixed TW Elev= 856.90')
1=36" RCP ( Controls 0.00 cfs)
2=Riser Orifice ( Controls 0.00 cfs)
3=Riser Weirs ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=0.00' (Free Discharge)
4=Emergency Spillway ( Controls 0.00 cfs)
YADKI-013 Deep Creek WS #24 (PI-566)
Rainfall not specifiedYADKI-013
Printed 10/21/2020Prepared by HDR, Inc
Page 4HydroCAD® 10.00-25 s/n 07102 © 2019 HydroCAD Software Solutions LLC
Stage-Discharge for Pond 1P: YADKI-013 Deep Creek WS #24 (PI-566)
Elevation
(feet)
Discharge
(cfs)
Primary
(cfs)
Secondary
(cfs)
869.20 0.00 0.00 0.00
869.60 1.83 1.83 0.00
870.00 5.17 5.17 0.00
870.40 9.49 9.49 0.00
870.80 14.39 14.39 0.00
871.20 17.87 17.87 0.00
871.60 20.69 20.69 0.00
872.00 23.13 23.13 0.00
872.40 25.34 25.34 0.00
872.80 27.35 27.35 0.00
873.20 29.23 29.23 0.00
873.60 30.99 30.99 0.00
874.00 32.66 32.66 0.00
874.40 34.24 34.24 0.00
874.80 35.75 35.75 0.00
875.20 37.20 37.20 0.00
875.60 38.60 38.60 0.00
876.00 39.95 39.95 0.00
876.40 41.25 41.25 0.00
876.80 42.51 42.51 0.00
877.20 43.74 43.74 0.00
877.60 44.93 44.93 0.00
878.00 46.09 46.09 0.00
878.40 47.22 47.22 0.00
878.80 48.33 48.33 0.00
879.20 49.41 49.41 0.00
879.60 50.47 50.47 0.00
880.00 51.51 51.51 0.00
880.40 52.52 52.52 0.00
880.80 53.52 53.52 0.00
881.20 54.50 54.50 0.00
881.60 55.46 55.46 0.00
882.00 56.40 56.40 0.00
882.40 61.64 61.64 0.00
882.80 80.62 80.62 0.00
883.20 107.29 107.29 0.00
883.60 136.99 136.99 0.00
884.00 148.76 148.76 0.00
884.40 150.19 150.19 0.00
884.80 151.61 151.61 0.00
885.20 153.01 153.01 0.00
885.60 204.20 154.40 49.80
886.00 298.85 155.78 143.07
886.40 424.06 157.15 266.92
886.80 575.72 158.50 417.22
887.20 751.69 159.84 591.85
887.60 950.71 161.18 789.53
888.00 1,171.94 162.50 1,009.45
888.40 1,414.86 163.81 1,251.05
888.80 1,679.09 165.11 1,513.98
889.20 1,964.40 166.40 1,798.00
Elevation
(feet)
Discharge
(cfs)
Primary
(cfs)
Secondary
(cfs)
889.60 2,270.62 167.68 2,102.95
890.00 2,597.68 168.95 2,428.73
890.40 2,919.40 170.21 2,749.19
890.80 3,176.95 171.46 3,005.48
891.20 3,405.27 172.70 3,232.56
891.60 3,614.59 173.94 3,440.65
892.00 3,809.74 175.16 3,634.57
892.40 3,993.61 176.38 3,817.23
892.80 4,168.16 177.59 3,990.58
893.20 4,334.81 178.79 4,156.02
893.60 4,494.61 179.98 4,314.63
894.00 4,648.40 181.16 4,467.23
894.40 4,796.84 182.34 4,614.51
894.80 4,940.50 183.51 4,756.99
895.20 5,079.82 184.67 4,895.15
895.60 5,215.19 185.82 5,029.37
896.00 5,346.95 186.97 5,159.98
896.40 5,475.37 188.11 5,287.26
896.80 5,600.70 189.24 5,411.46
897.20 5,723.17 190.37 5,532.80
897.60 5,842.96 191.49 5,651.47
898.00 5,960.26 192.60 5,767.66
898.40 6,075.21 193.71 5,881.50
898.80 6,187.95 194.81 5,993.14
899.20 6,298.60 195.90 6,102.70
899.60 6,407.29 196.99 6,210.30
900.00 6,514.11 198.08 6,316.04
900.40 6,619.16 199.15 6,420.01
900.80 6,722.53 200.22 6,522.30
901.20 6,824.29 201.29 6,623.00
901.60 6,924.52 202.35 6,722.17
902.00 7,023.28 203.40 6,819.88
902.40 7,120.65 204.45 6,916.20
902.80 7,216.68 205.49 7,011.18
903.20 7,311.42 206.53 7,104.89
903.60 7,404.92 207.56 7,197.36
904.00 7,497.24 208.59 7,288.65
904.40 7,588.41 209.61 7,378.80
904.80 7,678.48 210.63 7,467.85
905.20 7,767.49 211.64 7,555.85
905.60 7,855.47 212.65 7,642.82
906.00 7,942.47 213.65 7,728.82
906.40 8,028.51 214.65 7,813.86
906.80 8,113.62 215.65 7,897.97
907.20 8,197.84 216.64 7,981.20
907.60 8,281.19 217.62 8,063.57
908.00 8,363.69 218.60 8,145.09
908.40 8,445.38 219.58 8,225.81
908.80 8,526.28 220.55 8,305.73
909.20 8,606.41 221.52 8,384.89