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SW6190903_SW Report_20200102
Storm Water Design Calculations December 31, 2019 Short Stop Arabia Road Raeford, NC Hoke County Prepared for: Neal Holdings, LLC Attn. Chris Neal 1007 Aresenal Avenue Fayetteville, NC 28305 910-433-4490 Prepared by: Triangle Site Design, PLLC 4004 Barrett Drive, Suite 101 Raleigh, NC 27609 (919)553-6570 NC License#P-0619 TRIANGLE S I T E D E S I G N TABLE OF CONTENTS OVERVIEW STORMWATER NARRATIVE FIGURES SOILS SURVEY & SOIL INFORMATION USGS TOPOGRAPHIC MAP FEMA FIRM MAP WATER QUANTITY/QUALITY WET DETENTION POND DESIGN SUPPLEMENT CN VALUES PRE -DEVELOPMENT HYDROGRAPHS POST -DEVELOPMENT HYDROGRAPHS TIME VS. VOLUME (STORAGE) TIME VS. ELEVATION (STAGE) ELEVATION -VOLUME -FLOW SUMMARY POND OUTLET/STRUCTURE SUMMARY RIP -RAP APRON CALCULATION OVERVIEW Background This report contains the storm water calculations for the proposed Short Stop convenience store site. The project site is located on Arabia Road at the intersection with Davis Bridge Road. A portion of the site is currently developed as a convenience store. The existing store and portions of the associated paved areas will be demolished as part of the development of the site. The overall size of the development is 2.09 acres. The existing impervious area of the site is 17,236sf (0.40ac) which will be demolished. The proposed impervious area of the site is 37,848sf (0.86ac, 41.56%). The increase in impervious area for the property is 20,612sf (0.47ac). The proposed Short Stop parcel is located within a FEMA designated flood zone per FEMA FIRM 3710948300L with an effective date of January 1, 2007. There is a proposed storm water management facility (wet detention pond) for the site. The SCM is outlined in this report has been designed for post —development peak attenuation and water quality. The SCM is designed to capture a drainage area of 1.15 ac with an impervious area of 0.75 ac. The site grading and storm drainage systems are designed to convey stormwater runoff from the impervious areas of the site to the wet —detention pond. The wet detention pond is designed to provide peak flow attenuation for the 1, 2, 10 & 100 year storm events. The design storm for water quality is a 1.0" storm event. FIGURES Southeastern Soil & Environmental Associates, Inc. P.O. Box 9321 Fayetteville, NC 28311 Phone/Fax(910) 822-4540 Email mike@southeastemsoil.com February 18, 2019 Mr. Lee Humphry Double D Engineering, PLLC 110 Commerce Avenue Southern Pines, NC 28387 Re: Hydraulic conductivity (permeability) analysis & Seasonal High -Water Table determination (SHWT) for proposed stormwater retention/treatment area, Ratley Property, PIN 794830101216, Arabia Road, Hoke County, North Carolina Dear Mr. Humphry, An evaluation of soil properties and hydraulic conductivity (Ksat) has been conducted at your request on a portion of the aforementioned property. The purpose of the investigation was to determine soil water table depths (SHWT) based on soil profiles. In addition, Ksat was to be provided at a depth at least 2.0 feet above the SHWT elevation for use with stormwater retention basin design. Saturated hydraulic conductivity of the unsaturated zone was measured in a similar method as described in the Soil Science Society of America Journal, Vol. 53, no 5, Sept. - Oct. 1989, "A Constant Permeameter for Measuring Saturated Hydraulic Conductivity of the Vadose Zone" and Comparison of the Glover Solution with the Simultaneous Equations Approach for Measuring Hydraulic Conductivity." This consists of advancing a small diameter bore hole to a predetermined depth (typically 2 feet above SHWT). At this depth, a constant head (pressure) was established and maintained. Flow measurements were made at timed intervals after flow stabilized. Soils at the proposed basin site are most similar to the Candor soil series (see attached boring log). One boring was advanced to a depth of 10.50 feet below the soil surface. Seasonal High -Water Table (SHWT) as determined by evidence of colors of chroma 2 or less (and/or concentrations of high redox mottles) was encountered at a depth of 86 inches below the ground surface (see chart attached). SOIUSITE EVALUATION • SOIL PHYSICAL ANALYSIS • LAND USE/SUBDIVISION PLANNING • WETLANDS GROUNDWATER DRAINAGE/MOUNDING • SURFACE/SUBSURFACE WASTE TREATMENT SYSTEMS, EVALUATION & DESIGN One compact constant head permeameter (CCHP) test was conducted at a depth of 62 inches below the ground surface. The measured Ksat rate was 40.89 cm/hr (equivalent to 16.10 inches/hour). The attached map shows the location of the sample point as well as Ksat location. It should be noted that the reported SHWT does not necessarily reflect the elevation of static groundwater (due to variations in groundwater recharge rates, annual rainfall, drought conditions, etc.). The data presented in this report are limited by a number of considerations. The primary consideration is that soil formations can be highly variable. The soils found on this site can be subject to inclusions of other soil types, perched water, artesian conditions and/or layers of undulating low permeability clay seams. These and other soil conditions can have an effect on the steady state of groundwater flow. To the extent possible, we have identified the soil types that will impact the flow of groundwater, and have provided a professional opinion as to the depth of SHWT. I trust this is the information you require at this time. Sincerely, A4� Mike Eaker NC Licensed Soil Scientist #1030 Southeastern Soil & Environmental Associates, Inc. P.O. Box 932'1 Fayetteville, NC 28311 Phone/Fax (910) 822-4540 Email mike @southeastemsoil.com SHWT depths, Ratley Property, Arabia Road, Hoke County, North Carolina BORING SHWI' 1DEPTH_(inches) 86 Observed Water (inches) None SOIL/SITE EVALUATION • SOIL PHYSICAL ANALYSIS • LAND USE/SUBDIVISION PLANNING • WETLANDS GROUNDWATER DRAINAGE/MOUNDING • SURFACEISUBSURFACE WASTE TREATMENT SYSTEMS. EVALUATION R DFSIAN Southeastern Soil & Environmental Associates, Inc. P.O. Box 9321 Fayetteville, NC 28311 Phone/Fax (910) 822-4640 Email mike@southeasternsoil.com Measured Ksat Rate, Ratley Property, Arabia Road, Doke County, NC Ksa t Ksat Location Depth in cm/h r in/hr 1 62 40.89 16.10 SOIUSITE EVALUATION • SOIL PHYSICAL ANALYSIS • LAND USE/SUBDIVISION PLANNING • WETLANDS GROUNDWATER DRAINAGE/MOUNDING • SURFACE/SUBSURFACE WASTE TREATMENT SYSTEMS. EVALUATION & nFRIC;N Southeastern Soil & Environmental Associates, Inc. P.O. Box 9321 Fayetteville, NC 26311 Phone/Fax (910) 822-4540 Email mike@southeasternsoil.com Soil Boring Log, Ratley Property, Ratley Property, Arabia Road, Hoke County, NC This map unit consists of somewhat excessively drained soils that formed in sandy and loamy sediment on uplands. Slopes range from 3 to 6 percent. A - 0 to 4 inches; dark grayish brown (10YR 4/2) sand; weak fine granular structure; very friable; few fine roots; abrupt smooth boundary. E - 4 to 20 inches; light yellowish brown (2.5Y 6/3) loamy sand; weak fine granular structure; very friable; few fine roots; abrupt wavy boundary. Bt - 20 to 31 inches; light yellowish brawn (IOYR 6/4) sandy clay loam; weak fine subangular blocky structure; firm; gradual wavy boundary. E' - 31 to 73 inches; pale brown (10YR 6/3) coarse sand; single grained, loose; very friable; gradual diffuse boundary. C1 - 73 to 86 inches; yellow (IOYR 7/6) coarse sand; many medium prominent yellowish brown (IOYR 5/4) mottles; single grained; loose; very friable; gradual diffuse boundary. C2 - 86 to 130 inches; mottIed brownish yellow (I OYR 6/8) and gray (IOYR 6/1) coarse sand; very friable; massive structwwe. SHWT @ 86 inches (10YR 6/1) SOILISITE EVALUATION - SOIL PHYSICAL ANALYSIS - LAND USE/SUBDIVISION PLANNING - WETLANDS GROUNDWATER DRAINAGE/MOUNDING - SURFACE/SUBSURFACE WASTE TREATMENT SYSTEMS. EVAI I IATION P. nFsir.N r-off, -;)Sr .'%, S "Q �vp n� t LU O J�l �-3 44 L. v 0 KI I/ MALE .6L MAT£.6L Z M1 rgi � w M.TT,£ .61 C,0 O y 00 m o a *T irr Y �a d � ra �vr. •br:: • vr. v.:- u• sr.. m C 0 16 U L 0 O Z c 0 U (v Y O 2 r2^ V O cn U 0) O 0 -`o T 2 0 Z /W V W J a n E U f6 L _ a N 'p N m U O O V C U N O) U O O 7 C U O 16 0) QO_ O_ 67 l6 N N C N pm No Y O y M u d O C U 16 L N N E N 0 > y O O O) C N L C +O O L oa co aria a� T l] w 16 0 cu co E E O Ol 10 l6 m E�HN O C _ (n w E a) c a)-0 T105 m a ai 5 W E U N f`1 i N O O N a a> 6� � m a,a a_Ni a 3 c o U O U O a m1� I CO N O _C c wa v'r �� w rp rnE O C o T a .N O N 0 O '0 E In W L 6 0 m E 5 0.0 o N L 1O 0000 Z "' O_ N O N C 6f 0) 0) L U Q' C 00 O 5 O) co N VV01 a a f- Z v 10 Z Q 10 N U N 3 v u E 1n v_ L o '> m U W $ a m m 2 O �6O7 r�o mo L oT6NO3ld UNO n L a ocfn ad nE m U L 0 Z Ui 6 O O36s- O) C � OC O)- .� CC0 O_ N O O 6 E l m O d aN O OO E-0 0000 E Lo 7Z O ua m U O .a. dm nONo a -0� N 2 — Z O U iYNN N F 70%a'c0 J N Q O> o .0 Z E co-0C d n 67 6) N w .. 16 `1 N oN o '• aC O J d d f6 O) 61 N a 65 N Q m 0) E 0) a)7 O a d 16 7 'J 3 0 U D N C f0 16 E >, O) E ).2 +O+ C N E C f6 7 U cr 7 t`n >, N N 7 0 N a N N O a `l 2 O O C 0 0 0) 0) d O> Z a r O O N L 0 O (a in m m i U v �-0 O N U C E2 T CL m W o a o N L to aTi E C w W o 'a o rn- mm a E 000 U ii moin�8 as Q 61 r-t O o� cn U 0LO U— i6o O N soft F- U .- N A ca T 6 cc L 61 O' o U t @ C a � N O N a d O C 0 t m E m c a ca N a 6f cl In ` O N C U U 0 Z a! 65 O m 7 3 9 Q R C � N O 0 0 LL 0 1( r N l A . 16 1' A m s g N 0) O C N N O 0 0) V1 m ao 0 a 0 0 U c c Zi Q rn Q a co m U 0 Z rn Q < ..�� '0 N to Q N a 6 C O a % N � C 0 c IL 0 0 a m m o 0 0 z rn a a co m y ■ ■ i■ ■ rnv a 0 N N O 0) 00 m a M Z Hydrologic Soil Group —Hoke County, North Carolina Hydrologic Soil Group Map unit symbol I Map unit name BaB Blaney loamy sand, 2 to C 8 percent slopes JT Johnston loam A/D Totals for Area of Interest Description Rating I Acres in AOI I Percent of AOI 1.2 99.6% 0,0 0.4% 1.2 100.0% 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 USDA Natural Resources Web Soil Survey 8/10/2019 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Hoke County, North Carolina Component Percent Cutoff* None Specified Tie -break Rule: Higher � -Ni.,�, Natural Resources Web Soil Survey 8/10/2019 '0w Conservation Service National Cooperative Soil Survey Page 4 of 4 8/10/2019 Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 Location name: Lumber Bridge, North Carolina,� USA* Latitude: 34.9504*, Longitude:-79.0547* Elevation: 140.59 ft * NO '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) 1 2 5 10 25 50 100 200 500 1000 5-min D74-0 0: 95-0.481) (0: 67---0.56 0: 44 0 662) 0.602 04 33) (0. 8.1 0.72A fl 878 (0.765 0 937) (0.808-0 994)11(D.858-1?07j (0.897--12.12 0.695 0.821 0.960 1.06 1.18 1.27 1.36 1.44 1.54 1.61 10-min (0.631-0.768) (0.746-0.907) (0.872-1.06) (0.962-1.17) 1 (1.07-1.30) 1 (1.22-1A9) 1 (1.28-1.58) j(1.36-1,W (1.41-1.77) 0.868 1.03 1.21 1.34 1.60 1.61 1.72 1.81 1.94 2.02 15-min (0.789-0.959) 1 (0.38-1.14) 1 (1.22-1.48) (1.35-1.65) 1 (1.62-1.99) (1.71-2.12) j1.77-2.22) 30-min 1.08 1932 1.3041358 (1.577391 1.76 2.15) (2.00-2.44} (2. 9236 2.35-188 2.52-10 (2. 28 37 2.87 3 59 60-min 1.354864 (1.631998 (2.012144 (2.30280) 1 (2,67-3.26) 1 (2.96-3.61) (3.24-3.9 (3.53-4.34) (3.904484] (4.1975.24a 1.73 2.09 2.64 3.05 3.62 4.08 F 4.54 6.02 5.67 6.18 2-hr (1.55-1.95) 1 (1.88-2.36) 1 (2,74-3.44) 1 (3,23-4,08) 1 (3.62-4.58) (4.01-5.10 1 {4.40-5.63} (4,928.36) 1 (5.33-6.94) 3-hr 1.6582.07 1.99-2.51) 2.52 311 3-3.70) 3,50.4.43 3.954504 (4. 205.66 4.9068.33 .577 2 6.09.8.03) 2.18 2.65 3.35 3.92 4-12 6.39 6.09 6.83 7.89 1 8.76 6-hr 1.97-2.45) 1 (2.39-2.96) (3.02-3.74) (3.52-4.38) 1 (4,21-5.26} (4.77-5.99) 1 {5.35--6.75) 1 (5:84.7.56] (6,78-8.73) 7.44.9.68) 12atr (2.3252.89) 2.81-13.49) (3.5794.44) (4.865.22) 1 (5.036631) (5.25.21) 1 (6.44-818) 1 (7,20.9,23) (8.2810.8) (9. 3-12.0) 24a1r 2,8103.27 (3.41 3,96 4.3365.04] 5,0645.90 6.06578.10 6.87 88D 7.70 9?0 8.57410.1 1 9.75-81.6 10.7- 2.8 2iiay (3.27 3178) (3.95- 57) (4:9835 76j (5. 9-6.71) (6.90-8,04) (7.8049.11) (8.71 10.2) (9,66-161.4) (11 0-13.0) 1{12.0-14.3) 3.73 4.50 5.65 6.57 7.83 8.85 9.91 11.0 12.5 13.7 3�ay (3.49-4.00) (4.214.83) 1 (6,11-7.03) (7.268.39) (8.17-9.48) (10.1-11A) (11.4-13.5) 1 (12.4-14:8) 4 day (3.71-4.23) {q.46j5.D9 5.55 s,3 (6. 287..35Y (7.61-8,74) (8.55-D.86) (9,510131.0} (10.5- 2.2 1119-13.9 12.8-15.3 4.60 5.51 6.80 7.82 9.22 10.3 11.5 12.7 14.3 15.6 7�iay (4.30-4,92) (5A5-5.90) (6.34-718) (7.288.37) (8.56.9.86) (9,57-11.1) {10.6-12.3} (11.7-13.6) (13.1-15.4) (14.216.8) I5- 10�Jay 4.965.61 5.92.6.70 7.17 8413) 8.569.24 (9.45.10.8) l l7 5- .9 11 5� 3.2 12 4.4} 13.19-16.1 J 15.0.17.. 20�1ay {6.71 7.55 (7.96-&96) (9.4910.7) 10.7- 21) [12313.9) (1315- 5.3 (148 8.8) (1fi0- 8.3) (17.17--20A) J(19.0.22.0) 8.84 10.4 12.3 13.7 15.5 16.9 18.3 19.8 F 21.6 23.1 30�Jay (8.37-9.36) 1 (9.88-11.1) 11.6-13.D} (12.9-14.5) 1 (14.6-16A) 15.9-17.9) (17.2-19. (18.5-21.0) (20.1.23.0) (21.4-24.6) 45�1ay 1D8 .8 12.5-13.9 {14.4 S.0 15.8-17. (1778 9.8} 19 021.4) {2 5123. 218324.6} (23.6-20.7) (24?9. 8.3) 60�ay F;g1)]=J- 1710- 8.9) (187- 0.7) (207-23.0] {22?3-24.8) (23.826.5} [2522- 8.2) (27-0-30.4) (28A-32,1) 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/hdsc/pfds/pfds_printpage.htmI?Iat=34.9504&Ion=-79.0547&data=depth&units=english&series=pds 1 /4 i- b #fRqqH520Pp RD 9 _ ANID v `V 4 -- i02V Z ��flpFfE Rf1H'DRso Z F 4 W ' ` HILLCREEK DR--"—�- S;� 7 Y �y W W U- L cu J "2 O N (u O O LL O C O N Z / \} �- da ƒ�% | V7]77 ® \\}\j\ \ ) c \ 'As ƒ E \ © @ § 21 ƒ §a) � 9 / ) § - ,K o E E % - : 2 / d J / \ 3 \ } $ ƒ k � � I., mG WW E j m �y� Z1 3j 88 i € ^€ o 0 gQ Q < o^ m SUQL �ririri�0111 i g 4`�lT 9 m R!` -Y Y.'mNZ GN@Z's �� Z zi Imo m -� GiN°in Z aj'� Z W d oN o om o am 5a w a�p8'a- �v�¢�n N N H pn LL._. 0 (9 a V�4m U a Q m Bell � �.I I ..-, oll Y � w aF m ga k { j{ EllO N R„ I m 2� ��mN sl"s!I S zl a Ij ' R k _ � e 0 d � VO � Bi FY D s� m Yz a �v NR �'%lj� 4 =EWE. '�� 'spa 09� A Wa€ a8 OObl/ Sib O 0 Z � Q Q Z �3 a p Z w 5 aLU w d zae: w iY V1 J w W lY d Q Z 00 N U Q 0 0 d Z 0 Z z C140 ow 0 U-2 J J C z �M, All N9 0 a WATER QUALITY/QUANTITY Proposed Wet Pond Project Information Project Name: Short Stop Project #: Designed by: MEL Date: Revised by: Date. Checked by: Date: Site Information Sub Area Location: Drainage To Proposed Wet Pond Drainage Area (DA) = 1.15 Acres Impervious Area (IA) = 0.75 Acres Percent Impervious (1) = 64.87 % Required Surface Area Permament Pool Depth: 3.11 ft Non -Coastal county SA/DA = 2.23 Min Req'd Surface Area = 1,117 sf (at Permanent Pool Required WQv Storage Volume Design Storm = inch Non -Coastal County Determine Rv Value = 0.05 + .009 (1) = 0.634 in/in Storage Volume Required = 2,646 cf (above Permanent Pool Elevations Top of Pond Elevation = 134.00 ft Temporary Pool Elevation = 133.20 ft Permanent Pool Elevation = 132.50 ft Shelf Begining Elevation = 133.00 ft Forebay Weir = 131.00 ft Shelf Ending Elevation = 132.00 ft Bottom Elevation = 127.00 ft Permanent Pool Area Area @ Top of Permanent Pool = 2,380 sf Volume of Temporary Storage = 2,662 cf Is Permenant Pool Surface Area Sufficient (yes/no)? Yes ( 2380 > 1117 ) sf Volume of Storage for Design Storm = 2,662 Yes ( 2662 > 2646 ) cf Incremental Drawdown Time Project Information Project Nar Project #: asigned by: iecked by: STORMWATER POND INCREMENTAL DRAWDOWN METHOD -Water Quality Volume Date: Date: Water Quality Orifice . Incremental Determination of Water Quality Volume Drawdown Time Zone 3 Zone 2 Zone 1 1 Orifice Diameter (D) = Cd = Ei = Zone 1 Range = Zone 2 Range = Zone 3 Range = Q3 = 0.0437 Co' D2 (Z-D/24-Ei)A(ln) Q2 = 0.372 CD " D'(Z-Ei)A(312) Q,=0 0.75 in 0.6 132.5 Orifice Inv. 0.00 to 132.5 132.5 to 132.6 132.6 to 134 Incremental Drawdown Method Countour Contour Area Incremental Volume Stage, Z Zone Q Drawdown Time sq ft cu ft ft cfs min 132.50 3,195 0 0.00 2.00 0.000 -- 133.00 3990 1.796 0.50 3.00 0.010 2.964 133.20 4675 866 0.20 3.00 0.012 1.197 Total 2.662 -- -- 4.161 Drawdown Time = Incremental Volume / Q / 60sec/min Summary Total Volume = 2,662 cf Total Time = 4,161 min Total Time = 2.89 days 69.3505401 9/13/2019 Prop Wet Pond- new design.xls 1 of 1 Proposed Wet Pond #1 Project Information Project Name: Short Stop Project #: Designed by: M E L Date. Revised by: Date Checked by: Date Site Information Sub Area Location: Drainage to Proposed Pond Drainage Area (DA) = 1 15 Acres Impervious Area (IA) = 0.75 Acres Percent Impervious (1) = 64.87 % (Drainage Area) Orifice Sizing Orifice Size = 0.75 in (Diameter) Drawdown Time = 2.89 days (Incremental Draw Down Method) less than 5 days (yes/no) ? yes greater than 2 day (yes/no) ? yes Anti -Flotation Device 4' x 4' Outlet Structure Area: 16.0 sf Volume: 128.0 cf Weight: 7987 Ibs Factor of Safety 1.20 WT Req'd of Anti -Flotation Device: 9,585 Ibs Volume of Concrete Req'd: 63.9 cf (Water Displaced - Top of Pond to Bottom of Pond) (Unit WT of Concrete = 150 pcf) Volume Provided: 73.5 cf (4'x4' riser x 2.25' = 36cf, 5'x5' footing x 1.6=37.5cf) LJJ Q a W O U O LL N 11J H z LU 2 LU J a a D m 0) C a U o a) c rn G U m w c CL � aci 3 0 O Y C C C Y O LY O p E E •N N O m 2 m o c o w o r Q O N L O O "' C O E N ai N t' N L-� -O C LLLJ a c a) 0 p a w O 0 co ca oa w E o Z ai 3 oEicE°�—o' �o cn E +� to O a 0 0 g 4) 1D to H LO a '� E cu '� cn 0 ° cn N U t- v o n `° d a ca -� ac) cn c o - E m w a t = rn O Q U' z O -o 2 (0, -.—z: c a) D) C 0) O U In N v ) .> co c a) Lp M 'a -o n a o m a) c M c o m m` c N ca ncu o w I _ z Q a), mo a) c c o o n a) L p > O _ o c c C ^ O. (6 a) ca O f0 +L- f0 z V LT . � a) N a) E " C (a 01 N c (a .LO-. -o O w E o p COo c a E 3 w w a3o co c c rn d o cc T Q 4] 7 7 0 [a mN m N .2 cn u C m a .. i) co a) c [a U1 C c ,— f0 wc :E Z m L.. 6 3 p L E m E o a o o 'm c° E a) ca°o Q U U U a w U— .E — > of 0 --a a) 2 f t C O v) v) o U � a) O 3 a o ti c U v) O Ira O N 4 N M ` U N - U cj '� N 0 co - z c J O) m O) 0 C a5 L) V N EA a) .r c C Ol 0 U N 4� 6 m as E n _ 3 n U o o d f° 0 U o0. N ? o> O a cu .J E m U N N C7 n a) m 10 E .. v) i}.S � NJ a m cm 3 o f E U uiF- 0 w a U N ca U a a p c c C H c p �) E J O L O C cn 01 [aEn IL o z D U) U [t ui d v 0 Z O W j� Y liJ V o L O 1- N O C O' a V N N N m N m N N N m N N m E O t7 O N C VJ i0 N m m O N N N N m m N M coN N O pZp` V � O r E ° U n o h t ❑ n C � N � In E L N IM C O C � C L ❑ 0 Y c U 2❑ ❑ U n E m U o ° d C o O C •Q m ,p�■ 4J _' 0 - U w Q> L m2N •f 0. 7. 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E L) O _ Q d v rn d m W y `CP o d m N. « % Q m O o o N vi ❑ E a m N o `o `o N 5 o J N T m m m L m v ° J = v g Q' Q d v m Q m w° c .^N.. u a > r m N N o LL a! C o m o 0 Or 0 0 V m a m`o o m o° a 0 ? m `m v 3 j E m LL m o w o G o L L m ai E o m o= Z IM Q C m m m m O W O` N — m (� N n E V Q) m N L m Q• m O O O N C N L p d N m N 3 3 a) 3 (% n L co N c m m v {] '" J `o > c c c > S m 0 N O d m m m m Q Z U to U t0 m m m m Z v m m or 5 0 0 .6 o .� n 'm m m m `o 0 3 o Qi a, m L m N E m c ❑ o E m m m :Eani n - W __ a a 3 E n_ w L N L 3 o 0 Q b m> (n o > > a Q>i w -a>+ w N w v 0 N a 0 E o > ❑ C] o ❑� ami U� 3� ❑ ° O N O ° O N CJ t`J R O N N N N N (7 1 Project: Pond #1 Date: 1/1/2020 Main -Pond Contours -Volumes Elevation Main -Pond Incremental Vol. Accumulated Vol. Description 132.5 2,380 1,039 5,681 A2 (Perm —Pool) 132 1,775 1,588 4,643 Al (Bottom —Shelf) 131 1,400 1,225 3,055 130 1,050 895 1,830 129 740 600 935 128 460 335 335 127 210 125 0 A3 (Bottom —Pond) 126 40 0 0 18100 Forebay Contours -Volumes Elevation FB1 FB2 FB3 Total -Areas Incremental Vol. Accumulated Vol. 132.5 640 640 285 1,028 132 500 500 403 743 131 305 305 233 340 130 160 160 108 108 129 55 55 0 0 Forebay Volume Average Depth (Option 1) Average Depth Calculation (Option 2) Vpp permeter of shelf width of shelf Al (Bottom —Shelf): Average Depth = 18.1% *Between 15% & 20% 2.62 *At least 3' average depth 5,681 205 3 1,775 3.11 Triangle Site Design, PLLC Curve Number Calculation (CN) Pre -Developed Conditions Drainage Area (acres): 1.15 Existino Soil Groups: Soil Group Map Symbol Soil Description Acres Percent of DA C BaB Blaney Loamy Sand 1.15 100% Existing Land Uses: Land Use Description Existing Sail Group Acres Curve # Weighted CN Open space C 1.12 74 72.1 Impervious C 0.03 98 2.6 Cumulative Curve # = 74.6 Triangle Site Design, PLLC Curve Number Calculation (CN) Post -Developed Conditions Drainage Area (acres_, 1.15 & Ling SoilGrou s Soil Groua Man Symbol Soil Description Acres Percent of DA C BaB Blaney Loamy Sand 1.15 100% ftposed Land Uses_ Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Condition C 0.4 74 25.7 Impervious Area - Parking/Bldg C 0.75 98 63.9 Cumulative Curve # = 89.7 z � V) w � � z w m Q9 � z � � cl:f w � � � M Of 0 F- cn M z O 0- z O � z w F- w � � w GLn 12�E k§§§§ §§§§) mis e� =r. .W! ��� co §2k \( Q§�§ R\en cm ....= «��■- 2Lj $�§ §2 §§CS IS / CS ■ke STAGE/STORAGE TABLE STAGE ELEVATION CONTOUR INCREMENTAL TOTAL (FT) (FT) AREA (SF) STORAGE (CF) STORAGE (CF) 0.0 132.5 3195 0 0 0.5 133.0 3990 1796 1796 0.7 133.2 4675 867 2663 (WQv) 1.5 134.0 9325 5600 8263 W CIL- u Q U U J I _ f Gyp II O Z w 1 1 \ J 10 a a ' o z Z O w LO C7 Z V7 Q J x OEn _ Z� Q II �W J O TRASH RACK REFER TO DETAIL THIS SHEET 6' TOPSOIL ABOVE 6' CLAY LINER ON LITTORAL SHELF %LITTORAL' 6 IHV=132.5--, ELEV=129.5 ASTM C-923 SEAL BETWEEN BARREL A RISER. RISER BASE TO BE FILLED WITH CONC. TO INVERT OF BARREL IUIRED) TO ANCHOR RISER TO TS FROM ANGLE TO RISER AND LONG FROM ANGLE TO BASE. l WITH ZINC RICH PAINT AFTER :ED UNDER LOWER REINFORCING STEEL. TOP OF EMBANKMENT ELEVATION=134.0 100 YEAR STORM ELEVATION=133.97 REFER TO DETAIL i FOR INCREMENTAL WEIR - - PRECAST CONCRETE RISER (INSTALL STEPS AS NECESSARY) I< Lq 2 YEAR STORM ELEVATION=133.47 1 YEAR STORM ELEVATION=133.35 1.0-INCH STORM ELEVATION=132.81 p NORMAL POND ELEVATION=132.5 PVC ELBOW SEE DETAIL 2 1 CONCRETE SHALL BE r PLACED IN RISER AFTER ANGLES ARE SECURED TO BASE AND RISER. 5'x5'x1.5' CONC. BASE REINFORCE WITH 14 BARS AT 12" O.C. TOP AND BOTTOM OF EACH DIRECTION PROVIDE 3' MIN. CLEARANCE BETWEEN EDGE OF CONC. AND STEEL REINFORCING. EXISTING GRADE=138.Ot NOTE: PUMPS SHALL BE USED TO DRAIN THE POND WHEN NECESSARY. REFER TO DETAIL THIS SHEET FOR DEWATERING REQUIREMENTS. BOTTOM OF POND (TOP OF SEDIMENT STORAGE)=126.0 -- (BOTTOM OF SEDIMENT STORAGE)=125.0 6" CLAY SOIL LINER MAIN POOL NOTC 1. 2. TOP OE STRUCTURE NOT SHOWN FOR CLARITY (REMOVABLE TRASH RACK) RISER STRUCTURE A' PVC SCREW EAR' FOR ClFi1NINC ACCESS s rug FT TOTAL WEIR LENGTH 12' YIN. MEND 4• ( AT ELEV=133.2 MC THROUGH RISER STRUCTURE < fj 4•z4• PVC 7EE PEW. POINT cur: Tsss 12• YIN. OUTLET CONTROL STRUCTURE - INCREMENTAL WEIR R' TOPSOIL FOR ALL — AREAS ABOVE THE 1 NORMAL POND ELEVATION �I (' Dll HOLE DRUM INTO BOTTOM GAP FOREBAY FQ- _ 'I EOREBAY TOP EIEV= MO PVC DRAIN OUTLET I MOTH AT TOP = 2.0 IT Kl.ti, c• •roenn �mur� Pond Report Hydreflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc v6.066 Friday, Sep 13, 2019 Pond No. 1 - BMP Pond Pond Data Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 132.50 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cult) Total storage (cult) 0.00 132.50 3,195 0 0 0.50 133-00 3,990 1,796 1,796 0.70 133.20 4,675 867 2,663 1.50 134.00 9,325 5,600 8,263 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRSr] [A] [B] [C] [D] Rise (in) = 15.00 0.75 0.00 0,00 Crest Len (ft) = 9.00 7.00 0.00 0.00 Span (in) = 15.00 0.75 0.00 0.00 Crest El. (ft) = 133.20 133.50 0.00 0.00 No. Barrels = 1 1 0 0 Weir Coeff. = 3.33 260 3.33 3.33 Invert El. (ft) = 132.50 132.50 0.00 0.00 Weir Type = Rect Broad --- --- Length (ft) = 10.00 0.50 0.00 0.00 Multistage = Yes No No No Slope (%) = 1.00 1.00 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) Multistage = n/a Yes No No TW Elev. (ft) = 0.00 Stage (ft) Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (cc) control Weir risers checked for orifice conditions (ic) and submergence (s). Elev (ft) 2.00 134.50 1.80 134.30 1.60 - 134.10 1.40 133.90 1.20 133.70 1.00 133.50 0-80 133.30 0.60 133.10 0.40 132.90 0.20 - 132.70 0.00 - 132.50 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 Total Q Discharge (cfs) Stage / Discharge Hydrograph Summary Re p `� �ycraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cult) Inflow hyd(s) -- Maximum elevation (ft) Total strge used (cuft) f Hydrograph description 1 SCS Runoff 1.539 2 722 4,128 ------ BMP Pre -Developed 2 SCS Runoff 3.765 2 716 7,772 --- - — ------ BMP Post -Developed 3 Reservoir 1.387 2 724 7,291 2 13335 3,656 Post Through Pond 5 SCS Runoff 0.282 2 146 1,210 ---- ------ BMP Post -Developed 6 Reservoir 0.008 2 366 1,121 5 1 Year 132.81 1,127 1.0-in Storm Thru Pond ShortStop.gpw Return Period: Friday, Sep 13, 2019 2 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 BMP Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 3.03 in Storm duration = 24 hrs Q (cfs) 2.00 1.00 BMP Pre -Developed Hyd. No. 1 -- 1 Year 120 240 360 480 600 720 840 960 Hyd No. 1 Friday, Sep 13, 2019 Peak discharge = 1.539 cfs Time to peak = 722 min Hyd. volume = 4,128 cuft Curve number = 74.6 Hydraulic length = 0 ft Time of conc. (Tc) = 10.00 min Distribution = Type II Shape factor = 484 Q (cfs) 2.00 1.00 0.00 1080 1200 1320 1440 1560 Time (min) 3 Hydrograph Report Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 BMP Post -Developed Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 3.03 in Storm duration = 24 hrs Q (cfs) 4.00 3.00 2.00 1.00 0.00 0 120 240 Hyd No. 2 BMP Post -Developed Hyd. No. 2 -- 1 Year Friday, Sep 13, 2019 Peak discharge = 3.765 cfs Time to peak = 716 min Hyd. volume = 7,772 cuft Curve number = 89.7 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 360 480 600 720 840 960 Q (cfs) 4.00 3.00 2.00 1.00 0.00 1080 1200 1320 Time (min) 4 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Storm frequency = 1 yrs Time interval = 2 min Inflow hyd. No. = 2 - BMP Post -Developed Reservoir name = BMP Pond Storage Indication method used. Q (cfs) 4.00 3.00 2.00 1.00 Post Through Pond Hyd. No. 3 -- 1 Year 120 240 360 480 600 720 Hyd No. 3 Hyd No. 2 Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Friday, Sep 13, 2019 1.387 cfs = 724 min = 7,291 tuft = 133.35 ft = 3,656 tuft Q (cfs) 4.00 _C 11 2.00 1.00 0.00 840 960 1080 1200 1320 1440 1560 Total storage used = 3,656 cult Time (min) Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 5 BMP Post -Developed Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 1.00 in Storm duration = 6.00 hrs Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 BMP Post -Developed Hyd. No. 5 -- 1 Year 0 Friday, Sep 13, 2019 Peak discharge = 0.282 cfs Time to peak = 146 min Hyd. volume = 1,210 cuft Curve number = 89.7 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = SCS 6-Hr Shape factor = 484 60 120 180 240 300 360 Hyd No. 5 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 420 Time (min) 7 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066 Friday, Sep 13, 2019 Hyd. No. 6 1.0-in Storm Thru Pond Hydrograph type = Reservoir Peak discharge = 0.008 cfs Storm frequency = 1 yrs Time to peak = 366 min Time interval = 2 min Hyd. volume = 1,121 cuft Inflow hyd. No. = 5 - BMP Post -Developed Max. Elevation = 132.81 ft Reservoir name = BMP Pond Max. Storage = 1,127 cuft Storage Indication method used. Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 480 960 Hyd No. 6 1.0-in Storm Thru Pond Hyd. No. 6 -- 1 Year Q (cfs) 0.50 j - - 0.45 - 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 1440 1920 2400 2880 3360 3840 4320 4800 Time (min) — Hyd No. 5 ® Total storage used = 1,127 cult Hydrograph Summary Re p `i� dy raflow Hydrographs Extension for AutoCAD® Civil 3D®2009 by Autodesk, Inc. v6.066 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph description BMP Pre -Developed 1 SCS Runoff 2.286 2 722 6,015 - --- 2 SCS Runoff 4.828 2 716 10,095 ---- -- BMP Post -Developed 3 Reservoir 1.939 2 722 9,613 2 133.47 4,495 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 — -- ------ BMP Post -Developed 6 Reservoir 0.000 2 n/a 0 Return Period: 5 i 2 Year 132.50 0.000 Friday, Sep 1.0-in Storm Thru Pond ShortStop.gpw 13, 2019 10 Hydrograph Report HydraFlow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 BMP Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 3.67 in Storm duration = 24 hrs Q (cfs) 3.00 2.00 1.00 BMP Pre -Developed Hyd. No. 1 -- 2 Year 120 240 360 480 600 720 840 960 Hyd No. 1 Friday, Sep 13, 2019 Peak discharge = 2.286 cfs Time to peak = 722 min Hyd. volume = 6,015 cuft Curve number = 74.6 Hydraulic length = 0 ft Time of conc. (Tc) = 10.00 min Distribution = Type II Shape factor = 484 Q (cfs) 3.00 2.00 1.00 0.00 1080 1200 1320 1440 1560 Time (min) 11 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Friday, Sep 13, 2019 Hyd. No. 2 BMP Post -Developed Hydrograph type = SCS Runoff Peak discharge = 4.828 cfs Storm frequency = 2 yrs Time to peak = 716 min Time interval = 2 min Hyd. volume = 10,095 cuft Drainage area = 1.150 ac Curve number = 89.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 5.00 min Total precip. = 3.67 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (cfs) 5.00 G 11 3.00 2.00 1.00 120 240 Hyd No. 2 BMP Post -Developed Hyd. No. 2 -- 2 Year 360 480 600 720 840 Q (cfs) 5.00 4.00 R 11 1.00 0.00 960 1080 1200 1320 Time (min) 12 Hydrograph Report Hydraflow Hydrographs Extension for AutoCADO Civil 31DO 2009 byAutodesk, Inc v6.066 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Storm frequency = 2 yrs Time interval - 2 min Inflow hyd. No. = 2 - BMP Post -Developed Reservoir name - BMP Pond Storage Indication method used Q (cfs) 5.00 4.00 3.00 2.00 1.00 Post Through Pond Hyd. No. 3 -- 2 Year Friday, Sep 13, 2019 Peak discharge = 1.939 cfs Time to peak = 722 min Hyd. volume = 9,613 cuft Max. Elevation = 133.47 ft Max. Storage = 4,495 cuft Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 3 Hyd No. 2 FTotal storage used = 4,495 cult iU1 Hydrograph Summary Rep' 'yrraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) ------ Hydrograph description BMP Pre -Developed 1 SCS Runoff 4.646 2 720 12,050 - - ------ 2 SCS Runoff 7.805 2 716 16,822 - ------ ------ BMP Post -Developed 3 Reservoir 4.526 2 722 16,339 2 133.74 6,427 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ -- ------ BMP Post -Developed 6 Reservoir 0.000 2 n/a 0 5 132.50 0.000 Friday, Sep 1.0-in Storm Thru Pond ShortStop.gpw Return Period: 10 Year 13, 2019 16 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 BMP Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 5.47 in Storm duration = 24 hrs 4.00 KW 2.00 1.00 BMP Pre -Developed Hyd. No. 1 -- 10 Year 120 240 360 480 600 720 840 Hyd No. 1 Friday, Sep 13, 2019 Peak discharge = 4.646 cfs Time to peak = 720 min Hyd. volume = 12,050 cuft Curve number = 74.6 Hydraulic length = 0 ft Time of conc. (Tc) = 10.00 min Distribution = Type II Shape factor = 484 Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.00 960 1080 1200 1320 1440 1560 Time (min) 17 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 BMP Post -Developed Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 5.47 in Storm duration = 24 hrs Q (cfs) 8.00 . �� 4.00 2.00 M BMP Post -Developed Hyd. No. 2 -- 10 Year Friday, Sep 13, 2019 Peak discharge = 7.805 cfs Time to peak = 716 min Hyd. volume = 16,822 cuft Curve number = 89.7 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 120 240 360 480 600 720 840 960 Hyd No. 2 Q (cfs) 8.00 4.00 2.00 0.00 1080 1200 Time (min) 18 Hydrograph Report Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Storm frequency = 10 yrs Time interval = 2 min Inflow hyd. No. = 2 - BMP Post -Developed Reservoir name = BMP Pond Storage Indication method used. Q (cfs) 8.00 .M 4.00 2.00 Post Through Pond Hyd. No. 3 -- 10 Year 120 240 360 480 600 720 Hyd No. 3 Hyd No. 2 Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Friday, Sep 13, 2019 = 4.526 cfs = 722 min = 16,339 cuft 133.74 ft = 6,427 cuft Q (cfs) 8.00 M 4.00 2.00 0.00 840 960 1080 1200 1320 1440 1560 1 Total storage used = 6,427 cult Time (min) 21 Hydrograph Summary Re p `fl'yci`raflow Hydrographs Extension for AutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph description 1 SCS Runoff 8.855 2 720 23,137 -- - -- - BMP Pre -Developed 2 SCS Runoff 12.62 2 716 28,112 ---- -- BMP Post -Developed 3 Reservoir 9.843 2 720 27,627 2 133.97 7,998 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 - --- — - BMP Post -Developed 6 Reservoir 0.000 2 n/a 0 5 132.50 0.000 1.0-in Storm Thru Pond ShortStop.gpw Return Period: 100 Year Friday, Sep 13, 2019 22 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Friday, Sep 13, 2019 Hyd. No. 1 BMP Pre -Developed Hydrograph type = SCS Runoff Peak discharge = 8.855 cfs Storm frequency = 100 yrs Time to peak = 720 min Time interval = 2 min Hyd. volume = 23,137 cuft Drainage area = 1.150 ac Curve number = 74.6 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 10.00 min Total precip. = 8.42 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (cfs) 10.00 1 4.00 2.00 w BMP Pre -Developed Hyd. No. 1 -- 100 Year 120 240 360 480 600 720 840 Hyd No. 1 Q (cfs) 10.00 1 . IM 4.00 2.00 0.00 960 1080 1200 1320 1440 1560 Time (min) 23 Hydrograph Report Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 BMP Post -Developed Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 1.150 ac Basin Slope = 0.0 % Tc method = USER Total precip. = 8.42 in Storm duration = 24 hrs Q (cfs) 14.00 12.00 10.00 1 It 4.00 2.00 w BMP Post -Developed Hyd. No. 2 -- 100 Year 120 240 360 480 600 720 Hyd No. 2 Friday, Sep 13, 2019 Peak discharge = 12.62 cfs Time to peak = 716 min Hyd. volume = 28,112 cuft Curve number = 89.7 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Q (cfs) 14.00 12.00 10.00 ItX .W8 ItX 2.00 0.00 840 960 1080 1200 Time (min) 24 Hydrograph Report Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Storm frequency = 100 yrs Time interval = 2 min Inflow hyd. No. = 2 - BMP Post -Developed Reservoir name = BMP Pond Storage Indication method used. Q (cfs) 14.00 12.00 10.00 M . OX 4.00 IX W Post Through Pond Hyd. No. 3 -- 100 Year Friday, Sep 13, 2019 Peak discharge = 9.843 cfs Time to peak = 720 min Hyd. volume = 27,627 cuft Max. Elevation = 133.97 ft Max. Storage = 7,998 cuft Q (cfs) 14.00 12.00 10.00 MX . �� 4.00 2.00 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 3 Hyd No. 2 Total storage used = 7,998 cult Time (min) Project Name lliprap Dissipator #t l Date Short Stop Arabia Road Oct, 2019 DD Project No. Location Double D Engineering, PLLC DD1812 Hoke County, North Carolina 150 S. Page Street Calculated By Southern Pines, NC 28387 JLH (910) 684-8646 Checked By JLH STORM DESIGN: 10 Year BACKGROUND: Use the E&S Control Planning & Design Manual, Section 8.06. PREFERENCE: (NCDEQ, 2013) Step 1. Minimum Tailwater Condition Step 2. D-o = 15 in. Pipe diameter in inches D-o = 1.25 ft. Pipe diameter in feet Q-10 = 7.81 cfs Pipe outlet (from drainage calculations) d-50 = 0.4 ft from Figure 8.06 a L-a = 10 ft. from Figure 8.06 a Step 3. Step 4. Step 5. 3*D-o = 3.75 ft. W = 11.25 ft. d-max 0.60 ft. d-max 7 in. Thickness = 0.90 ft. Thickness = 11 in. DESIGN DIMENSIONS: 3 times the outlet pipe diameter Pipe diameter + Apron length Maximum Stone Diameter (1.5*d-50) in inches Maximum Stone Diameter (1.5*d-50) in feet Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches Apron Dimensions Rlprap Length Width 3"13-o Thick Class 10 12 4 241n. 1 TERMINOLOGY: Q10 = 10-Year Design Storm, Peak Discharge, (cfs) D-o = Pipe Diameter, (in. & ft.) d-50 = Mean Stone Diameter of Rip -Rap, (ft.) L-a = Length of Rip -Rap Apron, (ft.) 3*D-o = Width of Rip -Rap Apron @ Pipe Outlet, (ft.) W = Width of Rip -Rap Apron @ End of Apron, (ft.) d-max = Maximum Stone Diameter of Rip -Rap, (ft. & in.) Thickness = Thickness of Rip -Rap Apron With Filter Fabric, (ft. &in.)