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HomeMy WebLinkAboutSW6220505_Design Calculations_20230414Sformwoler Monogemenf Reporf April 12, 2023 Utility Improvements to Serve Shahbain Reserve —Phase 1 Rockfish Road Raeford, Hoke County, NC Prepared for: D&L Engineering, PLLC 150 S. Page Street Southern Pines, NC 28387 910-684-8646 Prepared by: Bowman North Carolina, Ltd. 4006 Barrett Drive, Suite 104 Raleigh, NC 27609 (919) 553-6570 Firm#F-1445 Bowman \\O, t"C AIR 1 f ll � _ SEAS. Q5 571 OVERVIEW FIGURES SOILS SURVEY & SOIL INFORMATION USGS TOPOGRAPHIC MAP FEMA FIRM MAP WATER SURFACE CLASSIFICATIONS HUG NOAA POINT PRECIPITATION FREQUENCY ESTIMATES SHWT REPORT WATER QUANTITY -WET POND SCM 1 DRAINAGE AREA MAP DESIGN SUPPLEMENT CN VALUES PRE -DEVELOPMENT HYDROGRAPHS POST -DEVELOPMENT HYDROGRAPHS TIME VS. VOLUME (STORAGE) TIME VS. ELEVATION (STAGE) ELEVATION -VOLUME-FLOW SUMMARY SCM SUMMARY TIME OF CONCENTRATION WATER QUANTITY -INFILTRATION BASIN SCM 2 DRAINAGE AREA MAP DESIGN SUPPLEMENT CN VALUES PRE -DEVELOPMENT HYDROGRAPHS POST -DEVELOPMENT HYDROGRAPHS TIME VS. VOLUME (STORAGE) TIME VS. ELEVATION (STAGE) ELEVATION -VOLUME-FLOW SUMMARY SCM SUMMARY TIME OF CONCENTRATION WATER QUANTITY -WET POND SCM 3 DRAINAGE AREA MAP DESIGN SUPPLEMENT CN VALUES PRE -DEVELOPMENT HYDROGRAPHS POST -DEVELOPMENT HYDROGRAPHS TIME VS. VOLUME (STORAGE) TIME VS. ELEVATION (STAGE) ELEVATION -VOLUME-FLOW SUMMARY SCM SUMMARY TIME OF CONCENTRATION WATER QUANTITY -WET POND SCM 4 DRAINAGE AREA MAP DESIGN SUPPLEMENT CN VALUES PRE -DEVELOPMENT HYDROGRAPHS POST -DEVELOPMENT HYDROGRAPHS TIME VS. VOLUME (STORAGE) TIME VS. ELEVATION (STAGE) ELEVATION -VOLUME-FLOW SUMMARY SCM SUMMARY TIME OF CONCENTRATION OVERVIEW This report contains the storm water management overview for the residential project Utility Improvements to Serve Shahbain Reserve — Phase 1 on Rockfish Road in Hoke County. The project site is currently undeveloped. The proposed site consists of 115.32 acres. The proposed site is located in Flood Zone `X' as shown on FEMA FIRM Panel 3710947500K with an effective date of 1/5/07. Flood zones are subject to change by FEMA. There are existing stream or wetland features on the proposed property. There are four proposed storm water management facilities (three wet ponds and one infiltration basin) outlined in this report and have been designed for post —development peak attenuation to treat the impervious areas of the development. The Wet Pond SCM 1 is designed to capture a drainage area of 20.29 ac with an impervious area of 8.53 ac. The Infiltration Basin SCM 2 is designed to capture a drainage area of 9.05 ac with an impervious area of 3.93 ac. The Wet Pond SCM 3 is designed to capture a drainage area of 4.06 ac with an impervious area of 1.99 ac. The Wet Pond SCM 4 is designed to capture a drainage area of 20.08 ac with an impervious area of 8.06 ac. The balance of the site is open space and will by—pass the proposed SCMs. The SCMs are designed to treat a 1.0" storm event. Impervious Area Summary — Wet Pond SCM 1 Roadway 71,993 sf 1.65 ac Sidewalk 27,645 sf 0.64 ac Roof 68 lots @ 4,000 sf/lot 272,000 sf 6.24 ac Total IA to Pond 371,638 sf 8.53 ac Impervious Area Summary — Infiltration Basin SCM 2 Roadway 43,779 sf 1.01 ac Sidewalk 15,376 sf 0.35 ac Roof 28 lots @ 4,000 sf/lot 112,000 sf 2.57 ac Total IA to Pond 171,155 sf 3.93 ac Impervious Area Summary — Wet Pond SCM 3 Roadway 17,073 sf 0.39 ac Sidewalk 5,672 sf 0.13 ac Roof 16 lots @ 4,000 sf/lot 64,000 sf 1.47 ac Total IA to Pond 86,745 sf 1.99 ac Impervious Area Summary — Wet Pond SCM 4 Roadway 82,159 sf 1.89 ac Sidewalk 26,880 sf 0.62 ac Roof 58 lots @ 4,000 sf/lot 232,000 sf 5.32 ac Pool Kiosk 9 920 sf 0.23 ac Total IA to Pond 350,959 sf 8.06 ac Soils The County Soils Survey indicates that Blaney Loamy Sand, Johnston Loam, Norfolk Loamy Sand and Wagram Loamy Sand soils are present on the site. FIGURES Hydrologic Soil Group —Hoke County, North Carolina a - v 674300 674400 6745M 674600 674700 674800 674900 675000 675100 675200 34° 59' 46" N ,� � \ ems, + y, � + �< . � 34° 59' 46" N L C> T 1^ Vf k v ., A — r 8 r m � g M r J F2 ✓ is � - �� ,.., r � 5 Ae ►-. . - 1 4y i ,1 � ._ � ::1L +.r H d r 4 r FFT r r Soil Map may not he valiel at this scale. 34° 59' 0" N 34° 59' 0" N 674300 674400 674500 674600 674700 674800 674900 675000 675100 675200 Map Scale: 1:6,810 if printed on A portrait (8.5" x 11") sheet. a Meters N 0 100 200 400 600 Feet 0 300 600 1200 1800 Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84 usoA Natural Resources Web Soil Survey 4/4/2022 Conservation Service National Cooperative Soil Survey Pagel of 4 Hydrologic Soil Group —Hoke County, North Carolina MAP LEGEND Area of Interest (AOI) 0 Area of Interest (AOI) Soils Soil Rating Polygons 0 A 0 A/D 0 B 0 B/D C 0 C/D 0 D 0 Not rated or not available Soil Rating Lines r 0 A r 0 A/D B B/D N 0 C r 0 C/D r 0 D r 0 Not rated or not available Soil Rating Points 0 A 0 A/D 0 B 0 B/D ❑ C 0 C/D 0 D ❑ Not rated or not available Water Features Streams and Canals Transportation — Rails ­0 Interstate Highways US Routes Major Roads Local Roads Background D6 Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. 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: Hoke County, North Carolina Survey Area Data: Version 19, Jan 21, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 1, 2018—Jul 31, 2018 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. usoA Natural Resources Web Soil Survey 4/4/2022 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group —Hoke County, North Carolina Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI BaD Blaney loamy sand, 8 to 15 percent slopes C 42.6 37.1 % JT Johnston loam A/D 5.3 4.6% NoB Norfolk loamy sand, 2 to 6 percent slopes A 44.6 38.8% WaB Wagram loamy sand, 0 to 6 percent slopes A 22.4 19.5% Totals for Area of Interest 114.9 100.0% 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. USDA Natural Resources Web Soil Survey 4/4/2022 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Hoke County, North Carolina Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff.- None Specified Tie -break Rule: Higher USDA Natural Resources Web Soil Survey 4/4/2022 Conservation Service National Cooperative Soil Survey Page 4 of 4 dOOl Na?n3 : Lai If/_ SC6,B ,,BOSTfC&RD, , l Q w w 0 N Q Q fi C N c N c c C i Q .O-i m OGN Q dILL 'lb �pEQ Uyo�l �+ � c d 3 d N « �O�O0 NO co E H CNatR GNO Op O -0 .0 E> N O a w wEO R w p v .O o LL Y O d N C o O J N N N 1>6 'O R N N4y3 N �+ V WO O r 0 yNNR_6 cN 1 O 0 '6 m.2 N UNTE 4 co O ONS co N N -6 pNN+ O E OU co co .p '6 O OO ID Z C d > C NOO/ 'O Co mLL U . "O C y a O- 9N=T "M UO N> N, p O It N C -O ='OOC 2N r .O O Q O WLL U w=RyO NpLL% N 0 OQ N Q N CO :t. OEW 0 N O« OQO 'O o co u N M IL N to O O m O 'OC N «c O (O@fy6 N'p N •6Q 6 N -N y N>N N dp ol° N 'oN O0T «iV N 2NNQN O'O co ILLUJ U J U LO) GO C.) a. 2 Z O y 2 = N W e dN damNLL V z _ N FFF O C N ID 9 = y I 'I F Q f6 N w 3 N 3\ N 'O > G£ £ N _ I = as 2 m m Q f6 N@ 'O LL O N J Vmi Z O N O N E= O EL S N E Q c N d 2 N M y c = J O W fn Q W S S 2 S W Z U o E N Q O 5 m Z O f6 O L d N £ 9CL cmi N 9 T Q N C N J Q 2 Q Z H ~ d N T £ N N 0 O y 0. O F E E N 9 Q Q m Q Q C7 � CL N .. N N N N N V N E .2 £ O S 0 W a U tbOSU s Jmw Eu, :E to �vrm HM-C30: �d2r dQ WO p In 2 H LL O #y • -lop_ c3 41F a V k. 4p 0 0 0 o IC) C o 0 LO �C) LO N O am tc mfz tr x U «� n VU _ m LE V iY K � v c z L) g w 6 '� �•� rat c to U1 u •Q 3 E ri au awn fy1 .Oli Lt 0 y�ipw%es Ln Rl d 0 J 7- C m U I 1 ul SillemuJoz) w Ii V � m cu l a ol ct o V Y m Q1 6 4/4/22, 2:43 PM Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 (D Location name: Raeford, North Carolina, USA* Latitude: 34.9904*, Longitude:-79.0855* Elevation: 223.18 ft** ' source: ESRI Maps kw W. M ** 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. 95-0 482 0.46 0 569 0.544-0 664 0.601---0733 0.668-0.817 0.7117-0 877 0.761---0.936 0. 03-0 991 0.8511--1 06 0.888-1.11 0.695 0.821 0.960 1.06 1.18 1.27 1.35 1.43 1.53 1.60 10-min (0.631-0.769) (0.746-0.909) (0.871-1.06) (0.961-1.17) 1 (1.07-1.30) 11 (1.14-1.40) 1 (1.21-1.49) 1 (1.27-1.57) (1.35-1.68) (1.40-1.75) 0.869 1.03 1.21 1.34 1.50 1.61 1.71 1.80 1.92 2.00 1 5-min (0.789-0.962) (0.938-1.14) 1 (1.10-1.35) 11 (1.22-1.48) 1 (1.35-1.65) 11 (1.45-1.77) 1 (1.53-1.88) 1 (1.61-1.98) (1.70-2.11) (1.76-2.20) 1.19 1.43 1.73 1.95 2.22 2.42 2.62 2.81 3.06 3.24 30-min 1 ( .08-1.32) 1 (1.30-1.58) 1 (1.57-1.91) 11 (1.76-2.15) 1 (2.00-2.44) 11 (2.18-2.66) 1 (2.34-2.88) 1 (2.50-3.08) (2.70-3.36) (2.84-3.57) 1.49 1.79 2.21 2.53 2.95 3.28 3.61 3.94 4.39 4.74 60-min (1 .35-1.64) (1.63-1.98) (2.01-2.45) (2.29-2.80) (2.66-3.26) (2.95-3.61) (3.23-3.96) (3.51-4.33) (3.87-4.82) ( 4.15-5.20) 1.73 2.09 2.64 3.05 3.61 4.06 4.51 4.98 5.61 6.11 2-hr (1.55-1.95) 1 (1.88-2.36) 1 (2.37-2.97) 11 (2.73-3.43) 1 (3.22-4.07) 11 (3.60-4.56) 1 (3.98-5.07) 1 (4.37-5.59) (4.87-6.29) (5.27-6.86) 3-hr 1.65 2308 1. 9 2?51 2.52 3117 2. 3-3.69 3.48 4?42 3. 3 5501 4. 9 5063 4.86 6927 5.514.19 6.02-07794 6-hr 2.19 (1 .97-2.45) 2.65 (2.39-2.96) 3.35 (3.02-3.74) 3.92 (3.52-4.36) 4.71 (4.20-5.23) 5.36 (4.75-5.95) 6.05 (5.32-6.70) 6.78 (5.90-7.49) 7.81 (6.72-8.63) 8.65 ( 7.36-9.56) 12-hr 2.58 (2 .33-2.89) 3.12 1 (2.82-3.49) 3.97 1 (3.57-4.44) 11 4.67 (4.18-5.20) 5.65 1 (5.02-6.28) 11 6.47 (5.71-7.17) 7.34 1 (6.41-8.12) 8.28 1 (7.16-9.15) 9.63 (8.21-10.6) 10.7 (9.04-11.9) 3.04 3.68 4.67 5.46 6.56 7.44 8.36 9 10.6 11.7 24-hr .31 (2 .82-3.28) (3.42-3.97) (4.33-5.04) (5.05-5.89) (6.04-7.07) (6.83-8.02) (7.65-9.01) (8.49-10.0) (9.65-11.5) ( 10.6-12.6) 3.52 4.25 5.36 6.24 7.46 8.44 9.45 10.5 11.9 13.1 2iiay (3.28-3.79) 1 (3.964.58) 1 (4.98-5.76) 11 (5.79-6.70) 1 (6.89-8.01) 11 (7.77-9.06) 1 (8.66-10.2) 1 (9.59-11.3) (10.9-12.9) (11.8-14.1) 3.74 4.51 5.65 6.56 7.81 8.81 9.85 10.9 12.4 13.6 3iiay (3.50-4.01) 1 (4.224.83) 1 (5.27-6.05) 11 (6.10-7.02) 1 (7.24-8.36) 11 (8.14-9.43) 1 (9.07-10.5) 1 (10.0-11.7) (11.3-13.3) (12.3-14.6) 3.96 4.77 5.94 6.88 8.16 9.19 10.3 11.4 12.9 14.1 4iiay (3.71-4.23) (4.47-5.09) (5.55-6.34) (6.42-7.33) (7.59-8.70) (8.51-9.80) (9.47-10.9) (10.4-12.1) ( 11.8-13.8) ( 12.8-15.1) 7iiay 4.61 (4 .31-4.93) 5.51 (5.15-5.90) 6.79 (6.34-7.27) 7.80 (7.27-8.34) 9.19 (8.53-9.82) 10.3 (9.53-11.0) 11.4 (10.6-12.2) 12.6 (11.6-13.5) 14.2 ( 13.0-15.3) 15.5 ( 14.1-16.6) 5.28 6.30 7.63 8.68 10.1 11.2 12.3 13.5 15.0 16.2 10-day (4 .97-5.61) 1 (5.92-6.70) 1 (7.17-8.11) 11 (8.14-9.21) 1 (9.42-10.7) 11 (10.4-11.9) 1 (11.4-13.1) 1 (12.5-14.3) (13.8-16.0) (14.9-17.3) 7.12 8.43 10.1 11.3 13.0 14.4 15.7 17.1 19.0 20.4 20-day (6.71-7.56) (7.96-8.96) (9.47-10.7) 11 (10.6-12.0) 1 (12.2-13.8) (13.4-15.3) JI (14.7-16.7) 1 (15.9-18.2) (17.6-20.2) (18.8-21.8) 8.85 10.4 12.2 13.6 15.5 16.9 18.2 19.6 21.5 22.9 E-day]7 (8.37-9.37) (9.88-11.1) (11.6-13.0) (12.9-14.4) (14.5-16.4) (15.8-17.9) (17.1-19.4) (18.4-20.8) (20.0-22.9) (21.3-24.4) 45-day 10.6-121.8 1215-13.9 14.4- 6.0 15.8-17.6 17.6- 9.7 19?0-21.3 20.41 2.9 21?73-24.5 23 45 6.5 24?7- 8.1 13.4 15.7 17.9 19.6 21.8 23.4 25.0 26.6 28.6 30.1 60-day (12 7-14.1) (14.9-16.5) (17.0-18.9) (18.6-20.7) (20.7-22.9) (22.2-24.7) (23.6-26.4) (25.1-28.0) (26.9-30.2) (28.2-31.9) 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 hftps://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9904&Ion=-79.0855&data=depth&units=english&series=pds 1/4 4/4/22, 2:43 PM Precipitation Frequency Data Server PDS-based depth -duration -frequency (DDF) curves Latitude: 34.99041, Longitude: -79.08551 35 30 E 25 L a-+ Gl 20 c 0 15 C 10 L G C C C G L L L L L y, 7. Y. S, }• }, }• 515, { t t t L L rq -0 r0 M -0-0 rq rq -0 -0 M -U M -U M M -0 -U C �r5 O dry � O r'I N N A 4 r� o O O u' o H to 'i N rn v w Duration 35 30 c 25 s a- -(U 20 e 0 15 10 a 5 . "- .. . 0 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14, Volume 2, Version 3 Created {EMT}: Man Apr 4 18:43:45 2022 Back to Top Maps & aerials Small scale terrain Average recurrence inl erva I {years} — f 2 — 5 10 25 50 100 200 Soo 1000 Duration — "in — 2-day — 10-min — 3-day 15-min — 4-day — 30-min — 7-day — 80-min — 10-day — 2-hr — 20-day — 3fir — 30-day — 8fir — 45-day — 12fir — 50-day - 24fir https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9904&Ion=-79.0855&data=depth&units=english&series=pds 2/4 4/4/22, 2:43 PM Precipitation Frequency Data Server f Urn 2mi Large scale terrain Winston -Sal en, O * • [ t rham Greensboro Rocky nn°"l,t Raleigh uORTH CAROL INA ;Charlotte Fayettevile. Jackson, H C A R O L I N A wilmingtan + w 100k C o m 60mi Large scale map Winston-Salem Greensboro Rocky Mount n Raleigh Nort1, Greenvill Carolina ariotte QF etteville �■ Jacksonv Wilming — -/V 100km Large scale aerial https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9904&Ion=-79.0855&data=depth&units=english&series=pds 3/4 4/4/22, 2:43 PM Precipitation Frequency Data Server Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9904&Ion=-79.0855&data=depth&units=english&series=pds 4/4 Scott Cole, NCLSS 312 Copples Road Ext Asheboro, NC 27205 (336) 460-4554 Double D Engineering, PLLC Attn: Mr. Lee Humphrey 150 S. Page Street Southern Pines, NC 28387 March 21, 2022 Re: Seasonal High -Water Table Identification and Soil Infiltration Rates: Rockfish Road site, Raeford, NC; Hoke County NC parcel 494750301009. Soil conditions and infiltration rates were evaluated and measured on the above -referenced property within the proposed storm water BMP device. Work was conducted in accordance with Parts A-2 and C-1 of the North Carolina Department of Environmental Quality Stormwater Design Manual. Soil samples were evaluated with a hand auger. SEASONAL HIGH WATER TABLE IDENTIFICATION Seasonal High Water Table depth is determined by field evaluation for soil wetness conditions which are indicated by the presence of redoximorphic (rdox) features with chroma colors of 2 or less (in Munsell color notation) in mottles or the horizon matrix, and at times, saturated soil conditions and/or free water within the soil profile. Colors of chroma 2 or less due to relic minerals from parent material (underlying rock), anaerobic activity created by placement of fill material, or soil textural class transitions (perched water) are not considered as indicators for seasonal high water. Upon determination of SHWT depth, an additional 6" will be deducted from the observed depth to account for capillary fringe water movement above the SHWT. Stormwater infiltration trenches are designed to ensure the lowest point is at least two feet above the Seasonal High Water Table (SHWT). SATURATED HYDRAULIC CONDUCTIVITY Mgt) Soils evaluated on this property are typical of those within the Johnston and Blaney Soil series. These soils are moderately well drained soils with varying rates of permeability. Infiltration rates are measured to determine if soil conditions are suitable for the installation of stormwater infiltration devices. Infiltration rates are measured using a Johnson Constant Head Permeameter. Measurements are recorded at varying intervals until equilibrium was reached. The SHWT and Infiltration rates for the stormwater BMP devices are reported for each proposed location in the tables below. BMP Device Site #1 Test Location SHWT Munsell Color Ksat #1 Ksat #2 Ksat #3 (feet below Notation round surface 11' bgs 5Y 8/1 0-18" 18-50" 5011+ BMP Site 1 2.5Y 7/1 Sandy Loam Sandy Clay Exp. Elevation 205' 8" / hour Loam (heavy) Clay/Heavy 2.5" / hour Redox Not Measured Scott Cole, NCLSS 312 Copples Road Ext Asheboro, NC 27205 (336) 460-4554 BMP Device Site #2 Test Location SHWT Munsell Color Ksat #1 Ksat #2 Ksat #3 (feet below Notation round surface 10' bgs 5Y 8/1 0-24" 24-50" 5019+ BMP Site 2 2.5Y 7/1 Sandy Loam Silty Clay Exp. Elevation 189' 8" / hour 2.5" / hour Clay/Heavy Redox Not Measured BMP Device Site #3 Test Location SHWT Munsell Color Ksat #1 Ksat 92 Ksat #3 (feet below Notation round surface 9' bgs 5Y 8/1 0-36" 3659+ N/A BMP Site 3 2.5Y 7/1 Sandy Loam Exp. Elevation 184' 8" / hour Clay/Heavy Redox Not Measured BMP Device Site #4 Test Location SHWT Munsell Color Ksat #1 Ksat #2 Ksat #3 (feet below Notation round surface 9' bgs 5Y 8/1 0-24" 24-48" 4811+ BMP Site 4 2.5Y 7/1 Sandy Clay Sandy Clay Exp. Elevation 197' Loam 0.2" / hour Clay/Heavy 2.5" / hour Redox Not Measured CONCLUSION Field evaluation of hydraulic conductivity provides estimations of soil infiltration rates; however, methods used to measure these rates can influence the results. Side walls of the bore hole are "smeared" by the soil auger as the hole is prepared and loose soil in the bottom of the hole is placed in suspension when water is applied; both of these factors negatively influence water infiltration rates. To help overcome these issues, after excavation of each infiltration trench, it is recommended the trench bottom and sidewalls be raked and dusted with pulverized limestone. These are practices that have been in place within the on -site wastewater industry to help loosen the soil and aid in restoration of soil structure. I am pleased to be of service in this matter and can be contacted at questions concerning information within this report. Thank you, -� a Scott Cole North Carolina Licensed Soil Scientist should you have any rrN I_(_j' 'Ti { { '--� —Bey:____• Proposed Stormwater BMP #3 i a f' SHWT: 9' bgs SHWT Elevation: 184' Ksat 0-36" SL: 8" 1 hour _ - Ksat 36"+ SCL (heavy): Not Measured Proposed Stormwater BMP #4 SHWT: 9' bgs \• «,,.. jr �/` .�' �\::,..� SHWT Elevation: 197' �• �`° �•, Ksat 0-24" SCL: 2.5" 1 hour Ksat 24"-48" SC: .2" / hour Ksat 48"+ Expansive Clay: Not Measured , us r7,� �, `, f, ;{ tiff r ;1 � . � z l � ,_ � 1•.,� `' � i Tz .--� Proposed Stormwater BMP #2 =•-�=F:•Ea SHWT: 10' bgs SHWT Elevation: 189" �\ 1 •��'.► Ksat 0-24" SL: 8" / hour M£.. { Ksat 24"-50" SCL (heavy): 2.5" / hour (� { i:= Ksat 50"+ Expansive Clay: Not Measured k i Proposed Stormwater BMP #1 ' ,.._.,X orri _r SHWT: 11' bgs SHWT Elevation: 205' Ksat 0-18" SL: 8" / hour Ksat 18"-50" SCL (heavy): 2.5" / hour '{ Ksat 50"+ Expansive Clay: Not Measured \ 1 inch = 300 feet WATER QUANTITY -WET POND SCM 1 W C/� -q v-,i 5 s SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION _ 1 Project Name _ Project Area (ac) _ Coastal Wetland Area ac Utility Improvements to Serve Shabain Reserve - Phase 1 115.32 _ - 2 3 4 Surface Water Area ac 5 Is this ro'ect High or Low Density? High 6 Does this project use an off -site SCM? _ No COMPLIANCE WITH 02H .1003(4.) 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMS: 11 Infiltration System 1 12 Bioretention Cell 0 13 Wet Pond 3 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 1 Green Roof 0 119 Level S reader -Filter Strip (IS-FS 0 20 Disconnected Impervious Surface (DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 113ayfilter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 28 I.Name_and T .ale Organization: Street address: Carlo Pardo, PE Bowman North Carolina Ltd. 29 4006 Barrett Drive, Suite 104 30 Cit , State, Zip: Raleigh, NC 27609 31 Phone number(sj: Email: 919-553-6570 32 cpardo@bowman.com Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here ,`�``�`o��H a R��i''f�� � / J v • SEAL _ 051571 = i r %. •• •• ENG I PI�E�•'' r ,gRL o..E. !l l t! I l l l t tSeaf Signature of Designer 4 �a Date DRAINAGE AREAS 1 Is this a hi h density project? Yes 2 If so, number of drainage areas/SCMs 4 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED AREA INFORMATION Entire Site 1 2 3 4 4 T e of SCM - Wet Pond Infiltration Basin Wet Pond Wet Pond 5 Total draina a area s ft 5023339 sf 883772 394402 176822 874858 6 Onsite draina a areas ft 883772 394402 176822 874858 7 Offsite draina a area s ft 8 Total BUA in project (sq ft 980497 sf 371638 sf 171155 sf 86745 sf 350959 sf 9permitting) New BUA on subdivided lots (subject to s ft 680000 sf 272000 sf 112000 sf 64000 sf 232000 sf 10permitting) New BUA not on subdivided lots (subject to s 300497 sf 99638 sf 59155 sf 22745 sf 118959 sf 11 10ffsite BUA (sq ft 12 Breakdown of new BUA not on subdivided lots: Parking (sq ft Sidewalk (sq ft 75573 sf 27645 sf 15376 sf 5672 sf 26880 sf Roof (sq ft Roadway s ft 215004 sf 71993 sf 43779 sf 17073 sf 82159 sf Future (sq ft Other, please specify in the comment box below (sq ft 9920 sf 9920 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft 14 New infiltrating permeable pavement not on subdivided lots (sq ft 15permitting) Existing BUA that will remain (not subject to s ft 16 1 Existing BUA that is already permitted (sq ft 17 Existing BUA that will be removed (sq ft 18 Percent BUA 19.52% 42.1% 43% 49% 40% 19 Design storm inches 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM cu ft 32182 cf 62235 cf 7580 cf 31488 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method ONAL INFORMATION ease use this space to provide any additional information about the "22drainagearea(s): 12-Postal Kiosk for additional BUA WET POND 1 11 Drainage area number 1 3 4 21 Minimum required treatment volume (cu ft) 31555 cf 7243 cf 29967 cf NERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes 5 What are the side slopes of the SCM (H:V)? 3:1 3:1 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No No No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes Yes Yes 11 Does the maintenance access comply with General MDC (8)? Yes Yes Yes 12 Does the drainage easement comply with General MDC (9)? Yes Yes Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC (10)? N/A N/A N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes Yes Yes 161 Does the SCM follow the device specific MDC? Yes Yes Yes 17 Was the SCM designed b an NC licensedprofessional? Yes Yes Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA SA/DA SA/DA 19 Has a stage/storage table been provided in the calculations? Yes Yes Yes 20 Elevation of the excavated main pool depth (bottom of sediment removal) (fmsl 206.00 189.00 202.00 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 207.00 190.00 203.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 211.50 195.50 206.50 23 Elevation of the permanent pool (fmsl) 212.00 196.00 207.00 24 Elevation of the top of the vegetated shelf (fmsl) 212.50 196.50 207.50 25 Elevation of the temporary pool (fmsl) 213.90 197.50 208.70 26 Surface area of the main permanent pool (square feet) 11390 2950 13155 27 Volume of the main permanent pool (cubic feet) 43138 cf 8526 cf 42764 cf 28 Average depth of the main pool (feet) 4.22 ft 3.66 ft 3.58 ft 29 Average depth equation used Equation 3 Equation 3 Equation 3 301 If using equation 3, main pool perimeter (feet) 423.0 ft 237.0 ft 442.0 ft 31 If using equation 3, width of submerged veg. shelf (feet) 3.0 ft 3.0 ft 3.0 ft 32 Volume of the forebay (cubic feet) 6715 cf 1583 cf 7964 cf 33 Is this 15-20% of the volume in the main pool? Yes Yes Yes 34 Clean -out depth for forebay (inches) 48 in 48 in 48 in 35 Design volume of SCM (cu ft) 32182 cf 7580 cf 31488 cf 36 Is the outlet an orifice or a weir? Orifice Orifice Orifice 371 If orifice, orifice diameter (inches) 2.00 in 1.00 in 2.50 in 38 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.59 3.61 2.41 41 Are the inlet(s) and outlet located in a manner that avoids short- circuiting? Yes Yes Yes 42 Are berms or baffles provided to improve the flow path? Yes Yes Yes 431 Depth of forebay at entrance (inches) 60 in 60 in 60 in 44 Depth of forebay at exit (inches) 54 in 54 in 54 in 45 Does water flow out of the forebay in a non -erosive manner? Yes Yes Yes 46 Width of the vegetated shelf (feet) 6 ft 6 ft 6 ft 47 Slope of vegetated shelf (H:V) 6:1 6:1 6:1 48 Does the orifice drawdown from below the top surface of the permanentpool? Yes Yes Yes 49 Does the pond minimize impacts to the receiving channel from the 1- r, 24-hr storm? Yes Yes Yes 50 Are fountains proposed? (If Y, please provide documentation that MDC(9) is met. No No No 51 Is a trash rack or other device provided to protect the outlet system? Yes Yes Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes Yes Yes 53 Species of turf that will be used on the dam and embankment Hybrid Bermuda Hybrid Bermuda Hybrid Bermuda 54 Hasa planting plan been provided for the vegetated shelf? Yes Yes Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): Wet Pond 1 9:16 AM 4/12/2023 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Pre -Developed Conditions #1 Drainage Area (acres): 20.29 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A NoB Norfolk Loamy Sand 16.22 80% A WaB Wagram Loamy Sand 0.33 2% C Bad Blaney Loamy Sand 3.74 18% Existing Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Stand A 16.55 55 44.9 Wooded - Good Stand C 3.74 74 13.6 Cumulative Curve # = 58.5 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Post -Developed Conditions #1 Drainage Area (acres): 20.29 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A NoB Norfolk Loamy Sand 16.22 80% A WaB Wagram Loamy Sand 0.33 2% C Bad Blaney Loamy Sand 3.74 18% Proposed Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Condition A 9.44 55 25.6 Open Space - Good Condition C 2.32 77 8.8 Impervious Area A & C 8.53 98 41.2 Cumulative Curve # = 75.6 Proposed Wet Pond #1 Project Information Project Name: Shabain Reserve Project #: Designed by: CEP Date: 12/19/2022 Revised by: Date: Checked by: Date: Site Information Sub Area Location: Drainage To Proposed Wet Pond Drainage Area (DA) = 20.29 Acres 883,772 sf Impervious Area (IA) = 8.53 Acres 371,638 sf Percent Impervious (1) = % 42.05 % Required Surface Area Permament Pool Depth: 4.22 ft SA/DA = 1.260 Min Req'd Surface Area = 11,137 sf (at Permanent Pool) Required WQv Storage Volume Design Storm = inch Non -Coastal County Determine Rv Value = 0.05 + .009 (1) = 0.428 in/in Storage Volume Required = cf (above Permanent Pool) Elevations Top of Pond Elevation = 220.00 ft Temporary Pool Elevation = 213.90 ft Permanent Pool Elevation = 212.00 ft Shelf Begining Elevation = 212.50 ft Forebay Weir = 211.50 ft Shelf Ending Elevation = 211.50 ft Bottom Elevation = 207.00 ft Permanent Pool Area Area @ Top of Permanent Pool = 11,390 sf Volume of Temporary Storage = 32,182 cf Is Permenant Pool Surface Area Sufficient (yes/no)? Volume of Storage for Design Storm = 32,182 Y ( 11390 > 11137) sf ( 32182 > 31555) cf Incremental Drawdown Time STORMWATER POND #1 INCREMENTAL DRAWDOWN METHOD -Water Quality Volume Project Information Project NarShabain Reserve Project #: esigned by: CEP hecked by: Water Date: 12/19/2022 Date: ity Orifice Incremental Determination of Water Quality Volume Drawdown Time Zone 2 Orifice Diameter (D) = Cd = Ei = Zone 1 Range = Zone 2 Range = Zone 3 Range = Q3 = 0.0437 CD - D2 (Z-D/24-Ei)^(1/2) Qz = 0.372 CD ' D'(Z-Ei)^(3i2) Q, = 0 in 0.6 212 Orifice Inv. 0.00 to 212 212 to 212.1 212.1 to 213 Incremental Drawdown Method Countour Contour Area Incremental Volume Stage, Z Zone Q Drawdown Time sq ft cu ft ft cfs min 212.00 14,430 0 0.00 2.00 0.000 -- 212.50 16080 7,628 0.50 3.00 0.068 1,878 213.00 17120 8,300 0.50 3.00 0.100 1,378 213.90 19000 16,254 0.90 3.00 0.141 1,916 Total -- -- -- -- Drawdown Time = Incremental Volume / Q / 60sec/min Summary Total Volume= 32,182 of Total Time= 5,172 min Total Time = 3.59 days Between 2-5 12/19/2022 Prop Wet Pond- new design-#1.xls 1 of 1 Project: Pond #1 Date: 12/19/2022 Main -Pond Contours -Volumes Elevation Main -Pond Incremental Vol. Accumulated Vol. Description 212 11,390 5,385 43,138 A2 (Perm -Pool) 211.5 10,150 4,963 37,753 Al (Bottom -Shelf) 211 9,700 9,313 32,790 210 8,925 8,553 23,478 209 8,180 7,818 14,925 208 7,455 7,108 7,108 207 6,760 0 0 A3 (Bottom -Pond) Forebay Contours -Volumes Elevation FB1 FB2 FB3 Total -Areas Incremental Vol. Accumulated Vol. 212 2,805 2,805 1,333 6,715 211.5 2,525 2,525 1,193 5,383 211 2,245 2,245 1,980 4,190 210 1,715 1,715 1,460 2,210 209 1,205 1,205 750 750 208 295 295 0 0 Forebay Volume Average Depth (Option 1) Average Depth Calculation (Option 2) Vpp permeter of shelf width of shelf Al (Bottom -Shelf): 15.6% *Between 15% & 20% 3.72 *At least 3' average depth 43,138 423 3 10,150 Average Depth = 4.22 Proposed Wet Pond #1 Project Information Project Name: Shabain Reserve Project #: Designed by: CEP Date: Revised by: Date: Checked by: Date: Site Information 12/19/2022 Sub Area Location: Drainage to Proposed Pond Drainage Area (DA) = 20.29 Acres Impervious Area (IA) = 8.53 Acres Percent Impervious (I) = 42.05 % (Drainage Area) Orifice Sizing Orifice Size = 2.00 in Drawdown Time = 3.59 days 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: 208.0 cf Weight: 12979 Ibs Factor of Safety 1.20 WT Req'd of Anti -Flotation Device: 15,575 Ibs Volume of Concrete Req'd: 103.8 cf (Diameter) (Incremental Draw Down Method) (Water Displaced - Top of Pond to Bottom of Pond) (Unit WT of Concrete = 150 pcf) Volume Provided: 165.5 cf (4'x4' riser x 8' = 128sf, 5'x5' footing x 1.5'=37.5cf) 50 STORMWATER � MANAGEMENTS EASEMENT INLET PIPE WITH--,,, RIP -RAP APRON LITORAL SHELF AREA-2,485 SF DEFER TO DETAIL \ FOR PLANTINGS 11�1 SOD AREAS ABOVE NORMAL POOL EELVATION,� _ - FOREBAY AREA b'2- BOO CLASS B RIP -RAP ATE - 0 FOREBAY WEIR \� OUTLET CONTROL STRUCTURE REFER TO DETAILS ON Cl THIS SHEET - � �, \ ----" 24" OUTLET PIPE 1� REFER TO GRADING �1 _PLAN 016 sq.ft. -6 acres TOP OF EMBANKMENT FES ELEV-220.0 � ELEV-211.5 GRAPHIC SCALE 0 25 50 100 200 ( IN FEET ) 1 inch = 50 ft. PLAN VIEW STAGE/STORAGE TABLE STAGE (FT) ELEVATION (FT) CONTOUR AREA (SF) INCREMENTAL STORAGE (CF) TOTAL STORAGE (CF) 0.0 212.0 14430 0 0 0.5 212.5 16080 7628 7628 1.0 213.0 17120 8300 15928 1.9 213.9 19000 16254 32182 (WQV) 2.0 214.0 19160 1908 34090 3.0 215.0 20780 19970 54060 4.0 216.0 22455 21618 75677 5.0 217.0 24185 23320 98997 6.0 218.0 25970 25078 124075 7.0 219.0 27815 26893 150967 8.0 220.0 29720 28768 179735 4' MIN EMBANKMENT WIDTH 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION 24" HDPE WITH WATER TIGHT SEAL PIPE TO BE BEDDED PER DIRECTION OF GEOTECHNICAL ENGINEER 2 � 6° CLAY SOIL LINER ON INSIDE FACE OF EMBANKMENT 3' MIN CUTOFF TRENCH APPROXIMATE SIZE EXCAVATE AND BACKFILL WITH COMPACTED STRUCTURAL FILL AS rx�m�r" ENGINEER 42'-24" HDPE @ 1.19% TRASH RACK REFER TO DETAIL THIS SHEET TOP OF EMBANKMENT ELEVATION=220.0 6" TOPSOIL ABOVE NOTE: 1.0" STORM ELEVATION IS 212.16 AND INTERMEDIATE 6" CLAY LINER REFER TO DETAIL 100 YEAR STORM ELEVATION=219.60 WEIR IS ELEVATION 213.9. THERE IS ADDITIONAL STORAGE DESIGNED FROM THE 1.0" STORM ELEVATION TO THE I i ON LITTORAL SHELF FOR INCREMENTAL 3 WEIR INTERMEDIATE WEIR ELEVATION. 1 10 YEAR STORM ELEVATION=216.61 6 4'x4' PRECAST � 6FT LITTORAL 1 CONCRETE RISER SHELF (INSTALL STEPS 2 YEAR STORM ELEVATION=214.80 AS NECESSARY) 1 YEAR STORM ELEVATION=214.32 INV=212.0 1.0—INCH STORM ELEVATION=212.16 EXISTING GRADE=213.5f NORMAL POND ELEVATION=212.0 d a d PVC ELBOW ° SEE DETAIL a � 2 ELEV=210.0 d 2 NOTE: PUMPS SHALL BE USED TO DRAIN 1 w 1 1 1 THE POND WHEN NECESSARY. REFER TO DETAIL THIS SHEET FOR DEWATERING REQUIREMENTS. O n_ O 4' IN. ASTM C-923 SEAL BETWEEN BARREL & RISER. KEY RISER BASE TO BE FILLED WITH CONC. TO INVERT OF BOTTOM OF POND (TOP OF SEDIMENT STORAGE)=207.0 BARREL CONCRETE SHALL BE 8"X8"X1"X12" LONG ANGLE (6 TOT. REQUIRED) TO ANCHOR RISER TO PLACED IN RISER AFTER BOTTOM OF SEDIMENT STORAGE)=206.0 BASE. PROVIDE 2-3/4" A307 BOLTS FROM ANGLE TO RISER AND ANGLES ARE SECURED „ „ TO BASE AND RISER. 2—A307 J HOOKS 3/4 DIA. X 12 LONG FROM ANGLE TO BASE. — —� ANGLE TO BE FIELD COATED WITH ZINC RICH PAINT AFTER CONSTRUCTION. "J" HOOKS TO BE PLACED UNDER LOWER REINFORCING STEEL. 6" CLAY SOIL 5'x5'x1.5' CONC. BASE REINFORCE WITH #4 BARS AT 12" O.C. TOP LINER AND BOTTOM OF EACH DIRECTION PROVIDE 3" MIN. CLEARANCE MAIN POOL BETWEEN EDGE OF CONC. AND STEEL REINFORCING. PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. '941:11: TOPSOIL 6" CLAY LITTORAL LITTORAL SH ELF 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION VI\/\JJ I VI\LU/-\ I ' AT ELEV=211.5 FOREBAY WIDTH AT NOTE: PUMPS SHALL BE USED TO DRAIN THE FOREBAY WHEN NECESSARY. REFER TO SEDIMENT STORAGE THIS SHEET FOR DFWATFRING REQUIREMENTS. FOREBAY ENTRANCE SHALL BE - III 6" TOPSOIL FOR ALLAREAS ABOVE THE DEEPER THAN FOREBAY EXIT NORMAL POND ELEVATION PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. BOTTOM OF SEDIMENT STORAGE/EXIT BOTTOM OF SEDIMENT ELEV=207.5 STORAGE/ENTRANCE ELEV=207.0 FOREBAY ENTRANCE SHALL BE ' FOREBAY DEEPER THAN FOREBAY EXIT jop 0F WEIR ; 1Ai _ rno nr crgUCTURE NOT SHOWN TRASH RACK) OUTLET CONTROL STRUCTURE - INCREMENTAL WEIR PERM. POND ELEV.-212.0 4" PVC SCREW CAP FOR CLEANING ACCESS 12" f 4"x4" PVC 1 2"DIA. HOLE DRILLE1 INTO BOTTOM CAP SCALE: N.T.S. DICCD OTDI lf'\TI IDC PVC DRAIN OUTLET FOR CLARITY SCALE: N.T.S. Pond Report s Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Pond No. 1 - Wet Pond Pond Data Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 212.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 212.00 14,430 0 0 0.50 212.50 16,080 7,628 7,628 1.00 213.00 17,120 8,300 15,928 1.90 213.90 19,000 16,254 32,182 2.00 214.00 19,160 1,908 34,090 3.00 215.00 20,780 19,970 54,060 4.00 216.00 22,455 21,618 75,677 5.00 217.00 24,185 23,320 98,997 6.00 218.00 25,970 25,078 124,075 7.00 219.00 27,815 26,893 150,967 8.00 220.00 29,720 28,768 179,735 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) = 24.00 2.00 Inactive Inactive Crest Len (ft) = 1.50 15.50 Inactive Inactive Span (in) = 24.00 2.00 0.00 0.00 Crest El. (ft) = 213.90 216.70 0.00 0.00 No. Barrels = 1 1 0 0 Weir Coeff. = 3.33 2.60 3.33 3.33 Invert El. (ft) = 212.00 212.00 0.00 0.00 Weir Type = Rect Broad --- --- Length (ft) = 42.00 0.50 0.00 0.00 Multi -Stage = Yes Yes No No Slope (%) = 1.19 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) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00 Stage (ft) 8.00 4.00 RIM 0.00 ' ' 0.00 4.00 - Total Q Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Discharge 8.00 12.00 16.00 20.00 24.00 28.00 32.00 Elev (ft) 220.00 216.00 214.00 212.00 36.00 40.00 Discharge (cfs) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 2.507 2 740 22,489 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 25.13 2 724 73,237 ------ ------ ------ Post Developed to Pond 3 Reservoir 1.512 2 836 66,097 2 214.32 40,503 Post Through Pond 5 SCS Runoff 0.255 2 360 2,519 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.028 2 378 2,255 5 212.16 2,381 1.0inPost Through Pond Wet Pond#1.gpw Return Period: 1 Year Monday, 12 / 19 / 2022 Hydrograph Report 2 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Peak discharge = 2.507 cfs Storm frequency = 1 yrs Time to peak = 740 min Time interval = 2 min Hyd. volume = 22,489 cuft Drainage area = 20.290 ac Curve number = 58.5 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 32.50 min Total precip. = 3.04 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Pre -Developed -Overall Site Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs) 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 3 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.04 in Storm duration = 24 hrs Q (cfs) 28.00 24.00 20.00 16.00 12.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 1 Year Monday, 12 / 19 / 2022 = 25.13 cfs = 724 min = 73,237 cuft = 75.6 = 0 ft = 13.60 min = Type II = 484 Q (cfs) 28.00 24.00 20.00 16.00 12.00 4.00 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 1.512 cfs Storm frequency = 1 yrs Time to peak = 836 min Time interval = 2 min Hyd. volume = 66,097 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 214.32 ft Reservoir name = Wet Pond Max. Storage = 40,503 cuft Storage Indication method used. Post Through Pond Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs) 28.00 28.00 24.00 24.00 20.00 20.00 16.00 16.00 12.00 12.00 8.00 8.00 4.00 4.00 0.00 0.00 0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000 Time (min) — Hyd No. 3 Hyd No. 2 Total storage used = 40,503 cult A Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 5 1.0 Post -Developed to Pond Hydrograph type = SCS Runoff Peak discharge = 0.255 cfs Storm frequency = 1 yrs Time to peak = 360 min Time interval = 2 min Hyd. volume = 2,519 cuft Drainage area = 20.290 ac Curve number = 75.6 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 13.60 min Total precip. = 1.00 in Distribution = SCS 6-Hr Storm duration = 6.00 hrs Shape factor = 484 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 00 1.0 Post -Developed to Pond Hyd. No. 5 -- 1 Year 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 60 120 180 240 300 360 420 — Hyd No. 5 Time (min) 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 6 1.0inPost Through Pond Hydrograph type = Reservoir Peak discharge = 0.028 cfs Storm frequency = 1 yrs Time to peak = 378 min Time interval = 2 min Hyd. volume = 2,255 cuft Inflow hyd. No. = 5 - 1.0 Post -Developed to Pond/lax. Elevation = 212.16 ft Reservoir name = Wet Pond Max. Storage = 2,381 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 1.0inPost Through Pond Hyd. No. 6 -- 1 Year 1200 1800 2400 Hyd No. 5 3000 3600 4200 4800 5400 Total storage used = 2,381 cuft Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.05 0.00 6000 Time (min) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 6.221 2 736 40,743 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 37.01 2 722 105,597 ------ ------ ------ Post Developed to Pond 3 Reservoir 4.430 2 760 98,350 2 214.80 50,119 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 212.00 0.000 1.0inPost Through Pond Wet Pond#1.gpw Return Period: 2 Year Monday, 12 / 19 / 2022 Hydrograph Report 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.68 in Storm duration = 24 hrs Q (cfs) 7.00 5.00 3.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 2 Year Monday, 12 / 19 / 2022 = 6.221 cfs = 736 min = 40,743 cuft = 58.5 = 0 ft = 32.50 min = Type II = 484 Q (cfs) 7.00 . We 5.00 4.00 3.00 2.00 1.00 0.00 ' 1 1 1 1 " ' ' ' ' ' ' � ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Peak discharge = 37.01 cfs Storm frequency = 2 yrs Time to peak = 722 min Time interval = 2 min Hyd. volume = 105,597 cuft Drainage area = 20.290 ac Curve number = 75.6 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 13.60 min Total precip. = 3.68 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Post Developed to Pond 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 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) Hydrograph Report 12 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 4.430 cfs Storm frequency = 2 yrs Time to peak = 760 min Time interval = 2 min Hyd. volume = 98,350 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 214.80 ft Reservoir name = Wet Pond Max. Storage = 50,119 cuft Storage Indication method used Q (cfs) 40.00 20.00 10.00 0.00 ' --./ 0 600 — Hyd No. 3 Post Through Pond Hyd. No. 3 -- 2 Year 1200 1800 2400 3000 3600 4200 4800 5400 Hyd No. 2 Total storage used = 50,119 cuft Q (cfs) 40.00 30.00 20.00 10.00 1 0.00 6000 Time (min) Hydrograph Summary Report 15 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 22.38 2 734 109,371 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 73.84 2 722 206,981 ------ ------ ------ Post Developed to Pond 3 Reservoir 20.54 2 738 199,561 2 216.61 89,922 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 212.00 0.000 1.0inPost Through Pond Wet Pond#1.gpw Return Period: 10 Year Monday, 12 / 19 / 2022 Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.46 in Storm duration = 24 hrs Q (cfs) 24.00 20.00 16.00 12.00 m 4.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 10 Year Monday, 12 / 19 / 2022 = 22.38 cfs = 734 min = 109,371 cuft = 58.5 = Oft = 32.50 min = Type II = 484 Q (cfs) 24.00 20.00 16.00 12.00 M 4.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 17 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.46 in Storm duration = 24 hrs Q (cfs) 80.00 70.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Monday, 12 / 19 / 2022 = 73.84 cfs = 722 min = 206,981 cuft = 75.6 = 0 ft = 13.60 min = Type II = 484 Q (cfs) 80.00 70.00 50.00 40.00 30.00 20.00 10.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 20.54 cfs Storm frequency = 10 yrs Time to peak = 738 min Time interval = 2 min Hyd. volume = 199,561 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 216.61 ft Reservoir name = Wet Pond Max. Storage = 89,922 cuft Storage Indication method used. Post Through Pond Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs) 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0 00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0 00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 89,922 cult Hydrograph Summary Report 21 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 57.72 2 734 255,996 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 138.16 2 722 390,581 ------ ------ ------ Post Developed to Pond 3 Reservoir 38.71 2 738 383,021 2 219.60 168,086 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 212.00 0.000 1.0inPost Through Pond Wet Pond#1.gpw Return Period: 100 Year Monday, 12 / 19 / 2022 Hydrograph Report 22 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 60.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 100 Year Monday, 12 / 19 / 2022 = 57.72 cfs = 734 min = 255,996 cuft = 58.5 = 0 ft = 32.50 min = Type II = 484 Q (cfs) 60.00 50.00 40.00 30.00 20.00 10.00 0.00 1 1 1 1 1_ I I I I I I I_ i 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 23 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 20.290 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 140.00 120.00 100.00 40.00 20.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Monday, 12 / 19 / 2022 = 138.16 cfs = 722 min = 390,581 cuft = 75.6 = 0 ft = 13.60 min = Type II = 484 Q (cfs) 140.00 120.00 100.00 40.00 20.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) Hydrograph Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 38.71 cfs Storm frequency = 100 yrs Time to peak = 738 min Time interval = 2 min Hyd. volume = 383,021 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 219.60 ft Reservoir name = Wet Pond Max. Storage = 168,086 cuft Storage Indication method used Q (cfs) 140.00 120.00 100.00 40.00 20.00 Q (cfs) 140.00 120.00 100.00 40.00 20.00 J 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Time (min) Hyd No. 3 — Hyd No. 2 Total storage used = 168,086 cult OF CONCENTRATION ng Conditions DA1 OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007ml-y0.8)/(P2"0.5)(s"0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R21IS112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T�, T­ 1L Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area (fl-2) (fl fl fl fl/fl (fps) 10 min 0.67c hrs 1 100 229.8 228.0 0.018 3.68 0.24 13.88 1671 228.0 213 0.00898 Unpaved 1.50 18.57 32.45 32.45 0.32 1 TIME OF CONCENTRATION Proposed Conditions SCS Methodology Note: Fields in blue are manual entry OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007m`-y`0.8)/(P2A0.5)(sA0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R�S112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T,3 T,,A� Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area flA2 fl fl t t (fps) 10 min 0.67c hrs 1 100 229.8 228.4 0.014 3.68 0.018 1.93 1463 228.4 212 0.01121 Paved 2.10 11.61 13.54 13.54 0.14 1 WATER QUANTITY- INFILTRATION BASIN SCM 2 bml',\a5 A4-ec, q.oSac. SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION _ 1 Project Name _ Project Area (ac) _ Coastal Wetland Area ac Utility Improvements to Serve Shabain Reserve - Phase 1 115.32 _ - 2 3 4 Surface Water Area ac 5 Is this ro'ect High or Low Density? High 6 Does this project use an off -site SCM? _ No COMPLIANCE WITH 02H .1003(4.) 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMS: 11 Infiltration System 1 12 Bioretention Cell 0 13 Wet Pond 3 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 1 Green Roof 0 119 Level S reader -Filter Strip (IS-FS 0 20 Disconnected Impervious Surface (DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 113ayfilter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 28 I.Name_and T .ale Organization: Street address: Carlo Pardo, PE Bowman North Carolina Ltd. 29 4006 Barrett Drive, Suite 104 30 Cit , State, Zip: Raleigh, NC 27609 31 Phone number(sj: Email: 919-553-6570 32 cpardo@bowman.com Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here ,`�``�`o��H a R��i''f�� � / J v • SEAL _ 051571 = i r %. •• •• ENG I PI�E�•'' r ,gRL o..E. !l l t! I l l l t tSeaf Signature of Designer 4 �a Date DRAINAGE AREAS 1 Is this a hi h density project? Yes 2 If so, number of drainage areas/SCMs 4 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED AREA INFORMATION Entire Site 1 2 3 4 4 T e of SCM - Wet Pond Infiltration Basin Wet Pond Wet Pond 5 Total draina a area s ft 5023339 sf 883772 394402 176822 874858 6 Onsite draina a areas ft 883772 394402 176822 874858 7 Offsite draina a area s ft 8 Total BUA in project (sq ft 980497 sf 371638 sf 171155 sf 86745 sf 350959 sf 9permitting) New BUA on subdivided lots (subject to s ft 680000 sf 272000 sf 112000 sf 64000 sf 232000 sf 10permitting) New BUA not on subdivided lots (subject to s 300497 sf 99638 sf 59155 sf 22745 sf 118959 sf 11 10ffsite BUA (sq ft 12 Breakdown of new BUA not on subdivided lots: Parking (sq ft Sidewalk (sq ft 75573 sf 27645 sf 15376 sf 5672 sf 26880 sf Roof (sq ft Roadway s ft 215004 sf 71993 sf 43779 sf 17073 sf 82159 sf Future (sq ft Other, please specify in the comment box below (sq ft 9920 sf 9920 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft 14 New infiltrating permeable pavement not on subdivided lots (sq ft 15permitting) Existing BUA that will remain (not subject to s ft 16 1 Existing BUA that is already permitted (sq ft 17 Existing BUA that will be removed (sq ft 18 Percent BUA 19.52% 42.1% 43% 49% 40% 19 Design storm inches 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM cu ft 32182 cf 62235 cf 7580 cf 31488 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method ONAL INFORMATION ease use this space to provide any additional information about the "22drainagearea(s): 12-Postal Kiosk for additional BUA INFILTRATION SYSTEM 1 Drainage area number 2 1 Minimum required treatment volume (cu ft) ERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes 4 Is the SCM located away from contaminated soils? Yes 5 What are the side slopes of the SCM (H:V or enter "Vertical' for trenches)? 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes 9 lWhat is the method for dewatering the SCM for maintenance? Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC (8)? Yes 12 Does the drainage easement comply with General MDC (9)? Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC 10 ? N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes 16 Does the SCM follow the device specific MDC? Yes 17 Was the SCM designed by an NC licensedprofessional? Yes 18 1 Proposed slope of the subgrade surface (%) 0% 19 jAre terraces or baffles provided? No 20 1Tvpe of pretreatment: Forebay Data 21 Was the soil investigated in the footprint and at the elevation of the infiltrations stem? Yes 22 SHWT elevation (fmsl) 189.00 23 Depth to SHWT per soils report (in) 120 in 24 Ground elevation at boring in soils report (fmsl) 199.00 25 Is a detailed hydrogeologic study attached if the separation is between 1 and 2 feet? N/A 26 ISoil infiltration rate (in/hr) 4.00 27 1 Factor of safety (FS) (2 is recommended): 2.00 Elevations 29 113ottom elevation (fmsl) 199 ft 30 IStorage elevation (fmsl) 204.5 ft 31 1 Bypass elevation (fmsl) 204.5 ft Basins 32 113ottom surface area(ft) 7230 ft 33 Istorage elevation surface area(ft) 15675. ft For Trenches Only 34 Length (ft) 35 Width (ft) 36 Perforated pipe diameter, if applicable (inches) 37 Number of laterals 38 Total length of perforated piping 39 Stone type, if applicable 40 Stone porosity (%) 41 Is stone free of fines? 42 Is the stone wrapped in geotextile fabric? 43 Has at least one inspection port been provided? Volumes/Drawdown 44 IDesign volume of SCM (cu ft) 62235 cf 45 ITime to draw down (hours) 51.6 hrs 46 Please use this space to provide any additional information about the infiltration system(s): Line 26 - The soils report found the infiltration rate of the soil to be 8.0"/hr. A more conservative value of 4.0"/hr was used in the calculations, to account for clogging of the soils that will happen over time. Infiltration 1 9:16 AM 4/12/2023 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Pre -Developed Conditions #2 Drainage Area (acres): 9.05 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A WaB Wagram Loamy Sand 1.60 18% A NoB Norfolk Loamy Sand 1.61 18% A/D IT Johnston Loam 2.28 25% C Bad Blaney Loamy Sand 3.56 39% Existing Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Wooded - Good Stand A 3.25 54 19.4 Wooded - Good Stand C 2.51 74 20.5 Open Space - Good Stand A 2.24 55 13.6 Open Space - Good Stand C 1.05 77 8.9 Cumulative Curve # = 62.5 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Post -Developed Conditions #2 Drainage Area (acres): 9.05 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A WaB Wagram Loamy Sand 1.60 18% A NoB Norfolk Loamy Sand 1.61 18% A/D IT Johnston Loam 2.28 25% C Bad Blaney Loamy Sand 3.56 39% Proposed Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Condition A 3.33 55 20.3 Open Space - Good Condition C 1.79 77 15.2 Impervious Area A & C 3.93 98 42.5 Cumulative Curve # = 78.0 Infiltration Basin Design Site Information Sub Area Location: Drainage To Infiltration Basin Drainage Area (DA) = 9.05 Acres 394402 sf Impervious Area (IA) = 3.93 Acres 171155 sf Percent Impervious (1) = 43.4 % Required Water Quality Volume Design Storm = 1 inch Determine Rv Value = 0.05 + .009 (1) = 0.44 in/in Water Quality Volume = 0.332 ac-ft Water Quality Volume = 14,480 cf Water Quality Volume = 0.441 inches of runoff NOAA 1-year, 24-hour event = 3.09 inches Minimum Surface Area SA = (12-FS-DV)/(K-T) Factor of Safety (FS) = 2 Design Volume (DV) = 62235.0 cf Hydraulic Conductivity of Soil (K) = 4.00 in/hr Max Dewatering Time (T) = 72 hours Minimum Surface Area = 5186.3 sf Drawdown Time T = FS - (DV-12)/(K-SA) Factor of Safety (FS) = 2 Design Volume (DV) = 62235.0 cf Hydraulic Conductivity of Soil (K) = 4.00 in/hr Surface Area Provided = 7230 sf Drawdown Time = 51.6 hours 50 8JI76SF 0 T� J L Ti 1 1 6 �2 S STORMWATERr � � MANAGEMENT �r� EASEMENT / GFZAPHIC SCALE o 25 50 ,00 ( IN FEET ) 1 inch = 50 ft. more GRASS SPILL REFER TO DETAIL THIS SHEET OBSERVATION WELL (TYP.) INLET PIPE WITH RIP -RAP APRON - TOP OE EMBANKMENT I ELEV-206.0 ✓ \I/ \I/ \I/ \I/ I W � � � \4/\ \1/ / PLAN VIEW STAGE/STORAGE TABLE STAGE (FT) ELEVATION (FT) CONTOUR AREA (SF) INCREMENTAL STORAGE (CF) TOTAL STORAGE (CF) 0.0 199.0 7230 0 0 l'o 200.0 8640 7935 7935 2.0 201.0 10105 9373 17308 3.0 202.0 11625 10865 28173 4.0 203.0 13205 12415 40588 5.0 204.0 14835 14020 54608 5.5 204.5 15675 7628 62235 (WQV) 6.0 205.0 16530 8051 70286 7.0 206.0 18275 17403 87689 EXISTING GRADE = 199.0 w W 0 0 F- TOP OF EMBANKMENT = 206.0 100-YEAR STORM ELEVATION = 205.36 SPILLWAY ELEVATION = 204.5 10-YEAR STORM ELEVATION = 204.42 2-YEAR STORM ELEVATION = 202.09 1-YEAR STORM ELEVATION = 201.17 1.0" RAINFALL ELEVATION = 199.14 BOTTOM OF BASIN = 199.0 z N SEASONAL HIGH WATER TABLE = 189.0 41 FILTER MIXTURE (FRoM Top) V-0" OF CLEAN ASTM C-33 SAND (MEDIUM AGGREGATE SAND WITH A SIZE RANGE OF 0.02-INCH TO 0.04-INCH DIAMETER) LAYER OF GEOTEXTILE PERMEABLE FILTER FABRIC (MIRAFI N-SERIES OR EQUIVALENT) l'-0" MIN. UNDISTURBED IN -SITU SOIL 0 1'-O" CLEAN SAND INFILTRATION BASIN TYPICAL SECTION FILTER FABRIC AT BOTTOM AND SIDES OF CLEAN SAND RIP -RAP PRE-TREATMENT FOREBAY AT PIPE INLETS SEE DETAIL THIS SHEET n GRASS SOD 4 FILTER FABRIC FLOW LONG TOP OF EMBANKMENT SPILLWAY Q(l 00) SLOPE(%) H B W SS CHANNEL LINING ELEVATION SPILLWAY ELEVATION INFILTRATION STRAW WITH NET NAG SPILLWAY 41.44 CFS 50.0% L5' 20.0' 29.0' 3:1 SHOREMAX W/ P300 206.0 204.5 EXTEND LINING TO TOP OF SPILLWAY S\ H W EXTEND LINING TO TOP OF SPILLWAY CHANNEL LINING MATTING SHALL BE AS NOTED OR APPROVED EQUAL. B GRASS SPILLWAY DETAIL TOP OF EMBANKMENT-206.0 SPILLWAY ELEVATION-204.5 GRASS SOD ON SPILLWAY AND SIDE SLOPES Hydrograph Report 12 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through SCM Hydrograph type = Reservoir Peak discharge = 41.44 cfs Storm frequency = 100 yrs Time to peak = 12.07 hrs Time interval = 2 min Hyd. volume = 61,654 cuft Inflow hyd. No. = 2 - SCM Post-Developlibelservoir name = BMP Pond Max. Elevation = 205.36 ft Max. Storage = 76,531 cuft Storage Indication method used. Exfiltration extracted from Outflow. Hydrograph Discharge Table (Printed values -1.00% ofQp.) Time Inflow Elevation Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow (hrs) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 12.00 76.74 204.89 ----- ----- ----- ----- 12.52 ----- ----- ----- 1.513 12.52 12.03 65.78 205.22 ----- ----- ----- ----- 31.98 ----- ----- ----- 1.566 31.98 12.07 50.32 205.36 << ----- ----- ----- ----- 41.44 ----- ----- ----- 1.589 41.44 12.10 35.33 205.36 ----- ----- ----- ----- 41.36 ----- ----- ----- 1.588 41.36 12.13 23.66 205.28 ----- ----- ----- ----- 36.08 ----- ----- ----- 1.576 36.08 12.17 16.15 205.18 ----- ----- ----- ----- 29.44 ----- ----- ----- 1.560 29.44 12.20 12.51 205.09 ----- ----- ----- ----- 23.55 ----- ----- ----- 1.545 23.55 12.23 11.24 205.01 ----- ----- ----- ----- 19.15 ----- ----- ----- 1.533 19.15 12.27 10.75 204.95 ----- ----- ----- ----- 15.93 ----- ----- ----- 1.523 15.93 12.30 10.27 204.91 ----- ----- ----- ----- 13.71 ----- ----- ----- 1.516 13.71 12.33 9.786 204.88 ----- ----- ----- ----- 12.11 ----- ----- ----- 1.511 12.11 12.37 9.300 204.85 ----- ----- ----- ----- 10.88 ----- ----- ----- 1.507 10.88 12.40 8.812 204.83 ----- ----- ----- ----- 9.925 ----- ----- ----- 1.504 9.925 12.43 8.322 204.81 ----- ----- ----- ----- 9.112 ----- ----- ----- 1.501 9.112 12.47 7.830 204.80 ----- ----- ----- ----- 8.402 ----- ----- ----- 1.498 8.402 12.50 7.336 204.78 ----- ----- ----- ----- 7.790 ----- ----- ----- 1.496 7.789 12.53 6.857 204.77 ----- ----- ----- ----- 7.211 ----- ----- ----- 1.494 7.211 12.57 6.425 204.75 ----- ----- ----- ----- 6.665 ----- ----- ----- 1.492 6.665 12.60 6.073 204.74 ----- ----- ----- ----- 6.190 ----- ----- ----- 1.490 6.190 12.63 5.807 204.73 ----- ----- ----- ----- 5.768 ----- ----- ----- 1.488 5.768 Continues on next page... 13 Post Through SCM Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow (hrs) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 12.67 5.609 204.72 ----- ----- ----- ----- 5.393 ----- ----- ----- 1.486 5.394 12.70 5.459 204.71 ----- ----- ----- ----- 5.068 ----- ----- ----- 1.485 5.068 12.73 5.338 204.70 ----- ----- ----- ----- 4.788 ----- ----- ----- 1.484 4.788 12.77 5.226 204.70 ----- ----- ----- ----- 4.559 ----- ----- ----- 1.483 4.559 12.80 5.114 204.69 ----- ----- ----- ----- 4.370 ----- ----- ----- 1.482 4.371 12.83 5.002 204.69 ----- ----- ----- ----- 4.199 ----- ----- ----- 1.481 4.199 12.87 4.890 204.68 ----- ----- ----- ----- 4.040 ----- ----- ----- 1.480 4.040 12.90 4.777 204.68 ----- ----- ----- ----- 3.891 ----- ----- ----- 1.479 3.891 12.93 4.664 204.67 ----- ----- ----- ----- 3.750 ----- ----- ----- 1.479 3.750 12.97 4.551 204.67 ----- ----- ----- ----- 3.616 ----- ----- ----- 1.478 3.616 13.00 4.438 204.66 ----- ----- ----- ----- 3.486 ----- ----- ----- 1.477 3.486 13.03 4.326 204.66 ----- ----- ----- ----- 3.360 ----- ----- ----- 1.477 3.360 13.07 4.222 204.66 ----- ----- ----- ----- 3.238 ----- ----- ----- 1.476 3.238 13.10 4.128 204.65 ----- ----- ----- ----- 3.121 ----- ----- ----- 1.476 3.121 13.13 4.046 204.65 ----- ----- ----- ----- 3.012 ----- ----- ----- 1.475 3.012 13.17 3.974 204.65 ----- ----- ----- ----- 2.923 ----- ----- ----- 1.475 2.923 13.20 3.908 204.64 ----- ----- ----- ----- 2.838 ----- ----- ----- 1.474 2.838 13.23 3.845 204.64 ----- ----- ----- ----- 2.757 ----- ----- ----- 1.474 2.757 13.27 3.784 204.64 ----- ----- ----- ----- 2.680 ----- ----- ----- 1.473 2.680 13.30 3.723 204.63 ----- ----- ----- ----- 2.606 ----- ----- ----- 1.473 2.606 13.33 3.662 204.63 ----- ----- ----- ----- 2.534 ----- ----- ----- 1.472 2.534 13.37 3.601 204.63 ----- ----- ----- ----- 2.464 ----- ----- ----- 1.472 2.464 13.40 3.540 204.63 ----- ----- ----- ----- 2.396 ----- ----- ----- 1.472 2.396 13.43 3.479 204.62 ----- ----- ----- ----- 2.330 ----- ----- ----- 1.471 2.330 13.47 3.417 204.62 ----- ----- ----- ----- 2.264 ----- ----- ----- 1.471 2.264 13.50 3.356 204.62 ----- ----- ----- ----- 2.199 ----- ----- ----- 1.470 2.199 13.53 3.295 204.62 ----- ----- ----- ----- 2.135 ----- ----- ----- 1.470 2.135 13.57 3.236 204.62 ----- ----- ----- ----- 2.072 ----- ----- ----- 1.470 2.072 Continues on next page... 14 Post Through SCM Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow (hrs) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 13.60 3.182 204.61 ----- ----- ----- ----- 2.010 ----- ----- ----- 1.469 2.010 13.63 3.131 204.61 ----- ----- ----- ----- 1.950 ----- ----- ----- 1.469 1.950 13.67 3.083 204.61 ----- ----- ----- ----- 1.892 ----- ----- ----- 1.469 1.892 13.70 3.037 204.61 ----- ----- ----- ----- 1.836 ----- ----- ----- 1.468 1.836 13.73 2.993 204.61 ----- ----- ----- ----- 1.782 ----- ----- ----- 1.468 1.782 13.77 2.949 204.60 ----- ----- ----- ----- 1.730 ----- ----- ----- 1.468 1.730 13.80 2.905 204.60 ----- ----- ----- ----- 1.680 ----- ----- ----- 1.467 1.680 13.83 2.860 204.60 ----- ----- ----- ----- 1.634 ----- ----- ----- 1.467 1.633 13.87 2.816 204.60 ----- ----- ----- ----- 1.595 ----- ----- ----- 1.467 1.595 13.90 2.772 204.60 ----- ----- ----- ----- 1.556 ----- ----- ----- 1.467 1.556 13.93 2.728 204.59 ----- ----- ----- ----- 1.516 ----- ----- ----- 1.466 1.516 13.97 2.684 204.59 ----- ----- ----- ----- 1.475 ----- ----- ----- 1.466 1.475 14.00 2.640 204.59 ----- ----- ----- ----- 1.434 ----- ----- ----- 1.466 1.434 14.03 2.596 204.59 ----- ----- ----- ----- 1.393 ----- ----- ----- 1.465 1.393 14.07 2.557 204.59 ----- ----- ----- ----- 1.352 ----- ----- ----- 1.465 1.352 14.10 2.524 204.58 ----- ----- ----- ----- 1.311 ----- ----- ----- 1.465 1.311 14.13 2.497 204.58 ----- ----- ----- ----- 1.272 ----- ----- ----- 1.464 1.272 14.17 2.475 204.58 ----- ----- ----- ----- 1.235 ----- ----- ----- 1.464 1.235 14.20 2.457 204.58 ----- ----- ----- ----- 1.201 ----- ----- ----- 1.464 1.201 14.23 2.441 204.58 ----- ----- ----- ----- 1.169 ----- ----- ----- 1.464 1.169 14.27 2.426 204.58 ----- ----- ----- ----- 1.140 ----- ----- ----- 1.463 1.140 14.30 2.411 204.57 ----- ----- ----- ----- 1.113 ----- ----- ----- 1.463 1.113 14.33 2.395 204.57 ----- ----- ----- ----- 1.088 ----- ----- ----- 1.463 1.087 14.37 2.380 204.57 ----- ----- ----- ----- 1.064 ----- ----- ----- 1.463 1.063 14.40 2.365 204.57 ----- ----- ----- ----- 1.041 ----- ----- ----- 1.463 1.041 14.43 2.349 204.57 ----- ----- ----- ----- 1.019 ----- ----- ----- 1.463 1.019 14.47 2.334 204.57 ----- ----- ----- ----- 0.999 ----- ----- ----- 1.462 0.999 14.50 2.319 204.57 ----- ----- ----- ----- 0.979 ----- ----- ----- 1.462 0.979 Continues on next page... 15 Post Through SCM Hydrograph Discharge Table Time Inflow Elevation Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow (hrs) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 14.53 2.304 204.57 ----- ----- ----- ----- 0.960 ----- ----- ----- 1.462 0.960 14.57 2.288 204.57 ----- ----- ----- ----- 0.942 ----- ----- ----- 1.462 0.941 14.60 2.273 204.57 ----- ----- ----- ----- 0.923 ----- ----- ----- 1.462 0.923 14.63 2.258 204.57 ----- ----- ----- ----- 0.906 ----- ----- ----- 1.462 0.906 14.67 2.242 204.56 ----- ----- ----- ----- 0.889 ----- ----- ----- 1.462 0.889 14.70 2.227 204.56 ----- ----- ----- ----- 0.872 ----- ----- ----- 1.461 0.872 14.73 2.212 204.56 ----- ----- ----- ----- 0.855 ----- ----- ----- 1.461 0.855 14.77 2.196 204.56 ----- ----- ----- ----- 0.838 ----- ----- ----- 1.461 0.838 14.80 2.181 204.56 ----- ----- ----- ----- 0.822 ----- ----- ----- 1.461 0.822 14.83 2.165 204.56 ----- ----- ----- ----- 0.806 ----- ----- ----- 1.461 0.806 14.87 2.150 204.56 ----- ----- ----- ----- 0.790 ----- ----- ----- 1.461 0.790 14.90 2.135 204.56 ----- ----- ----- ----- 0.774 ----- ----- ----- 1.461 0.774 14.93 2.119 204.56 ----- ----- ----- ----- 0.758 ----- ----- ----- 1.461 0.758 14.97 2.104 204.56 ----- ----- ----- ----- 0.742 ----- ----- ----- 1.460 0.742 15.00 2.088 204.56 ----- ----- ----- ----- 0.727 ----- ----- ----- 1.460 0.727 15.03 2.073 204.56 ----- ----- ----- ----- 0.711 ----- ----- ----- 1.460 0.711 15.07 2.057 204.56 ----- ----- ----- ----- 0.696 ----- ----- ----- 1.460 0.695 15.10 2.042 204.55 ----- ----- ----- ----- 0.680 ----- ----- ----- 1.460 0.680 15.13 2.026 204.55 ----- ----- ----- ----- 0.664 ----- ----- ----- 1.460 0.664 15.17 2.011 204.55 ----- ----- ----- ----- 0.649 ----- ----- ----- 1.460 0.649 15.20 1.995 204.55 ----- ----- ----- ----- 0.633 ----- ----- ----- 1.460 0.633 15.23 1.980 204.55 ----- ----- ----- ----- 0.618 ----- ----- ----- 1.460 0.618 15.27 1.964 204.55 ----- ----- ----- ----- 0.603 ----- ----- ----- 1.459 0.602 15.30 1.949 204.55 ----- ----- ----- ----- 0.587 ----- ----- ----- 1.459 0.587 15.33 1.933 204.55 ----- ----- ----- ----- 0.576 ----- ----- ----- 1.459 0.576 15.37 1.918 204.55 ----- ----- ----- ----- 0.567 ----- ----- ----- 1.459 0.567 15.40 1.902 204.55 ----- ----- ----- ----- 0.557 ----- ----- ----- 1.459 0.557 15.43 1.886 204.55 ----- ----- ----- ----- 0.547 ----- ----- ----- 1.459 0.547 Continues on next page... Post Through SCM 16 Hydrograph Discharge Table Time Inflow Elevation (hrs) cfs ft 15.47 1.871 204.55 - 15.50 1.855 204.55 - 15.53 1.840 204.54 - 15.57 1.824 204.54 - 15.60 1.808 204.54 - 15.63 1.793 204.54 - 15.67 1.777 204.54 - 15.70 1.762 204.54 - 15.73 1.746 204.54 - 15.77 1.730 204.54 - End Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs ---- ----- ----- ----- 0.536 ----- ----- ----- 1.459 0.536 ---- ----- ----- ----- 0.525 ----- ----- ----- 1.459 0.525 ---- ----- ----- ----- 0.514 ----- ----- ----- 1.458 0.514 ---- ----- ----- ----- 0.502 ----- ----- ----- 1.458 0.502 ---- ----- ----- ----- 0.490 ----- ----- ----- 1.458 0.490 ---- ----- ----- ----- 0.478 ----- ----- ----- 1.458 0.478 ---- ----- ----- ----- 0.466 ----- ----- ----- 1.458 0.466 ---- ----- ----- ----- 0.453 ----- ----- ----- 1.458 0.453 ---- ----- ----- ----- 0.440 ----- ----- ----- 1.457 0.440 ---- ----- ----- ----- 0.427 ----- ----- ----- 1.457 0.427 12/19/22, 11:17 AM NORTH AMERICAN GREEN SPILLWAY ANALYSIS > > > Grass Spillway Name Grass Spillway Discharge 41.44 Peak Flow Period 4 Channel Slope 0.5 Channel Bottom Width 20 Low Flow Liner Retardence Class C 6-12 in Vegetation Type Mix (Sod and Bunch) Vegetation Density Very Good 80-95% Soil Type Sandy Loam (GM) Shoremax - Class C - Mix (Sod & Bunch) - Very Good 80-95% ECMDS 7.0 North American Green 5401 St. Wendel -Cynthia na Rd. Poseyville, Indiana 47633 Tel. 800.772.2040 > Fax 812.867.0247 www.nagreen.com ECM DS v7.0 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Mannings N Remarks Depth Shear Stress Shear Stress Factor Pattern Shoremax w/ Straight 41.44 cfs 12.52 ft/s 0.16 ft 0.025 8.5 Ibs/ft2 5.12 Ibs/ft2 1.66 STABLE F P300 Unvegetated Underlying Straight 41.44 cfs 12.52 ft/s 0.16 ft 0.025 5.68 Ibs/ft2 5.05 Ibs/ft2 1.13 STABLE F Substrate Shoremax w/ Straight 41.44 cfs 12.62 ft/s 0.16 ft 0.025 14 Ibs/ft2 5.08 Ibs/ft2 2.75 STABLE F P300 Reinforced Vegetation Underlying Straight 41.44 cfs 12.62 ft/s 0.16 ft 0.025 8.5 Ibs/ft2 5.01 Ibs/ft2 1.7 STABLE F Substrate https://ecmds.com/project/l 51829/spillway-analysis/236059/show 1 /1 Pond Report s Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Pond No. 1 - BMP Pond Pond Data Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 199.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 199.00 7,230 0 0 1.00 200.00 8,640 7,935 7,935 2.00 201.00 10,105 9,373 17,308 3.00 202.00 11,625 10,865 28,173 4.00 203.00 13,205 12,415 40,588 5.00 204.00 14,835 14,020 54,608 5.50 204.50 15,675 7,628 62,235 6.00 205.00 16,530 8,051 70,286 7.00 206.00 18,275 17,403 87,689 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) Inactive Inactive Inactive Inactive Crest Len (ft) = 20.00 0.00 0.00 0.00 Span (in) = 0.00 0.00 0.00 0.00 Crest El. (ft) = 204.50 0.00 0.00 0.00 No. Barrels = 0 0 1 0 Weir Coeff. = 2.60 3.33 3.33 3.33 Invert El. (ft) = 0.00 0.00 0.00 0.00 Weir Type = Broad --- --- --- Length (ft) = 0.00 0.00 0.00 0.00 Multi -Stage = No No No No Slope (%) = 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 4.000 (by Contour) Multi -Stage = n/a No Yes No TW Elev. (ft) = 0.00 Stage (ft) 8.00 AM 4.00 ►41I17 0.00 r 0.00 10.00 20.00 - Total Q Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Discharge 30.00 40.00 50.00 60.00 70.00 80.00 Elev (ft) 207.00 205.00 203.00 f180S91I11 199.00 90.00 100.00 Discharge (cfs) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 4.305 2 722 15,331 ------ ------ ------ SCM Pre -Developed 2 SCS Runoff 17.11 2 720 39,203 ------ ------ ------ SCM Post -Developed 3 Reservoir 0.000 2 1358 0 2 201.17 19,166 Post Through SCM 5 SCS Runoff 0.163 2 248 1,916 ------ ------ ------ 1.0 Post -Developed to SCM 6 Reservoir 0.000 2 328 0 5 199.14 1,091 1.0inPost Through SCM Infiltration#2.gpw Return Period: 1 Year Monday, 12 / 19 / 2022 Hydrograph Report 2 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 SCM Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.09 in Storm duration = 24 hrs Q (cfs) 5.00 4.00 3.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Pre -Developed Hyd. No. 1 -- 1 Year Monday, 12 / 19 / 2022 = 4.305 cfs = 722 min = 15,331 cuft = 62.5 = Oft = 11.60 min = Type II = 484 Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 3 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 SCM Post -Developed Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.09 in Storm duration = 24 hrs Q (cfs) 18.00 15.00 12.00 M M 3.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Post -Developed Hyd. No. 2 -- 1 Year Monday, 12 / 19 / 2022 = 17.11 cfs = 720 min = 39,203 cuft = 78 = 0 ft = 7.20 min = Type II = 484 Q (cfs) 18.00 15.00 12.00 M . �� 3.00 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 2 Time (min) 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through SCM Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = 1358 min Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - SCM Post -Developed Max. Elevation = 201.17 ft Reservoir name = BMP Pond Max. Storage = 19,166 cuft Storage Indication method used. Exfiltration extracted from Outflow. Q (cfs) 18.00 15.00 12.00 M M 3.00 Post Through SCM Hyd. No. 3 -- 1 Year 240 480 720 960 Hyd No. 3 — Hyd No. 2 Q (cfs) 18.00 15.00 12.00 M . �� 3.00 0.00 1200 1440 1680 1920 2160 Time (min) Total storage used = 19,166 cult A Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 5 1.0 Post -Developed to SCM Hydrograph type = SCS Runoff Peak discharge = 0.163 cfs Storm frequency = 1 yrs Time to peak = 248 min Time interval = 2 min Hyd. volume = 1,916 cuft Drainage area = 9.050 ac Curve number = 78 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 7.20 min Total precip. = 1.00 in Distribution = SCS 6-Hr Storm duration = 6.00 hrs Shape factor = 484 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 00 1.0 Post -Developed to SCM Hyd. No. 5 -- 1 Year 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 60 120 180 240 300 360 420 — Hyd No. 5 Time (min) 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 6 1.OinPost Through SCM Hydrograph type = Reservoir Peak d scharge = 0.000 cfs Storm frequency = 1 yrs Time t peak = 328 min Time interval = 2 min Hyd. v lume = 0 cuft Inflow hyd. No. = 5 - 1.0 Post -Developed to SCWax. evation = 199.14 ft Reservoir name = BMP Pond Max. orage = 1 091 cuft Storage Indication method used. Exfiltration extracted from Outflow Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 240 1.OinPost Through SCM Hyd. No. 6 -- 1 Year 360 480 600 720 840 960 Hyd No. 5 Total storage used = 1,091 cuft Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 1080 Time (min) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 8.481 2 722 25,422 ------ ------ ------ SCM Pre -Developed 2 SCS Runoff 24.02 2 720 55,003 ------ ------ ------ SCM Post -Developed 3 Reservoir 0.000 2 1612 0 2 202.09 29,303 Post Through SCM 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to SCM 6 Reservoir 0.000 2 n/a 0 5 199.00 0.000 1.0inPost Through SCM Infiltration#2.gpw Return Period: 2 Year Monday, 12 / 19 / 2022 Hydrograph Report 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 SCM Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.73 in Storm duration = 24 hrs Q (cfs) 10.00 Were . UX 4.00 r w Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Pre -Developed Hyd. No. 1 -- 2 Year Monday, 12 / 19 / 2022 = 8.481 cfs = 722 min = 25,422 cuft = 62.5 = 0 ft = 11.60 min = Type II = 484 Q (cfs) 10.00 N. We 4.00 r w 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 1 Time (min) Hydrograph Report 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 SCM Post -Developed Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.73 in Storm duration = 24 hrs Q (cfs) 28.00 24.00 20.00 16.00 12.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Post -Developed Hyd. No. 2 -- 2 Year Monday, 12 / 19 / 2022 = 24.02 cfs = 720 min = 55,003 cuft = 78 = 0 ft = 7.20 min = Type II = 484 Q (cfs) 28.00 24.00 20.00 16.00 12.00 4.00 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 12 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through SCM Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = 1612 min Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - SCM Post -Developed Max. Elevation = 202.09 ft Reservoir name = BMP Pond Max. Storage = 29,303 cuft Storage Indication method used. Exfiltration extracted from Outflow. Q (cfs) 28.00 24.00 20.00 16.00 12.00 Post Through SCM Hyd. No. 3 -- 2 Year Q (cfs) 28.00 24.00 20.00 16.00 12.00 4.00 0.00 1 1 1 1 0.00 0 240 480 720 960 1200 1440 1680 1920 2160 2400 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 29,303 cult Hydrograph Summary Report 15 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 22.51 2 722 60,146 ------ ------ ------ SCM Pre -Developed 2 SCS Runoff 44.61 2 718 102,333 ------ ------ ------ SCM Post -Developed 3 Reservoir 0.000 2 674 0 2 204.42 60,994 Post Through SCM 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to SCM 6 Reservoir 0.000 2 n/a 0 5 199.00 0.000 1.0inPost Through SCM Infiltration#2.gpw Return Period: 10 Year Monday, 12 / 19 / 2022 Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 SCM Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.47 in Storm duration = 24 hrs Q (cfs) 24.00 20.00 16.00 12.00 m 4.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Pre -Developed Hyd. No. 1 -- 10 Year Monday, 12 / 19 / 2022 = 22.51 cfs = 722 min = 60,146 cuft = 62.5 = 0 ft = 11.60 min = Type II = 484 Q (cfs) 24.00 20.00 16.00 12.00 M 4.00 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 17 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 SCM Post -Developed Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.47 in Storm duration = 24 hrs Q (cfs) 50.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Post -Developed Hyd. No. 2 -- 10 Year Monday, 12 / 19 / 2022 = 44.61 cfs = 718 min = 102,333 cuft = 78 = 0 ft = 7.20 min = Type II = 484 Q (cfs) 50.00 40.00 30.00 20.00 10.00 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) Hydrograph Report 18 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through SCM Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = 674 min Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - SCM Post -Developed Max. Elevation = 204.42 ft Reservoir name = BMP Pond Max. Storage = 60,994 cuft Storage Indication method used. Exfiltration extracted from Outflow Post Through SCM Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs) 50.00 50.00 40.00 40.00 30.00 30.00 20.00 20.00 10.00 10.00 0.00 - 0.00 0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640 2880 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 60,994 cult Hydrograph Summary Report 21 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 49.14 2 720 127,961 ------ ------ ------ SCM Pre -Developed 2 SCS Runoff 78.55 2 718 183,491 ------ ------ ------ SCM Post -Developed 3 Reservoir 41.44 2 724 61,654 2 205.36 76,531 Post Through SCM 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to SCM 6 Reservoir 0.000 2 n/a 0 5 199.00 0.000 1.0inPost Through SCM Infiltration#2.gpw Return Period: 100 Year Monday, 12 / 19 / 2022 Hydrograph Report 22 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 SCM Pre -Developed Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.21 in Storm duration = 24 hrs Q (cfs) 50.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor SCM Pre -Developed Hyd. No. 1 -- 100 Year Monday, 12 / 19 / 2022 = 49.14 cfs = 720 min = 127,961 cuft = 62.5 = 0 ft = 11.60 min = Type II = 484 Q (cfs) 50.00 40.00 30.00 20.00 10.00 0.00 - 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 23 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 SCM Post -Developed Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 9.050 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.21 in Storm duration = 24 hrs Q (cfs) 80.00 70.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Monday, 12 / 19 / 2022 = 78.55 cfs = 718 min = 183,491 cuft = 78 = Oft = 7.20 min = Type II = 484 Q (cfs) 80.00 70.00 50.00 40.00 30.00 20.00 10.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 — Hyd No. 2 Time (min) 24 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through SCM Hydrograph type = Reservoir Peak discharge = 41.44 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 61,654 cuft Inflow hyd. No. = 2 - SCM Post -Developed Max. Elevation = 205.36 ft Reservoir name = BMP Pond Max. Storage = 76,531 cuft Storage Indication method used. Exfiltration extracted from Outflow. Q (cfs) 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0 00 0 120 — Hyd No. 3 Post Through SCM Hyd. No. 3 -- 100 Year 240 360 Hyd No. 2 480 600 720 840 Total storage used = 76,531 cuft Q (cfs) 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00 960 Time (min) OF CONCENTRATION ng Conditions DA2 OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007ml-y0.8)/(P2"0.5)(s"0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R21IS112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T�, T­ IL Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area (fl-2) (fl fl fl fl/fl (fps) 10 min 0.67c hrs 2 100 225.2 221.7 0.035 3.68 0.24 10.64 269 221.7 198 0.08810 Unpaved 4.80 0.93 11.57 11.57 0.12 2 TIME OF CONCENTRATION Proposed Conditions SCS Methodology Note: Fields in blue are manual entry OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007m`-y`0.8)/(P2A0.5)(sA0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R�S112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T,3 T,,A� Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area MA 2) fl fl t t (fps) 10 min 0.67c hrs 2 100 224.8 222.0 0.028 3.68 0.018 1.46 1031 222.0 199 0.02231 Paved 3.00 5.73 7.19 10.00 0.10 2 WATER QUANTITY -WET POND SCM 3 tJe,4- %5CA -63 zrct., ,.Ale Arec. — Ll - 0 (e a C- CC.�O, SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION _ 1 Project Name _ Project Area (ac) _ Coastal Wetland Area ac Utility Improvements to Serve Shabain Reserve - Phase 1 115.32 _ - 2 3 4 Surface Water Area ac 5 Is this ro'ect High or Low Density? High 6 Does this project use an off -site SCM? _ No COMPLIANCE WITH 02H .1003(4.) 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMS: 11 Infiltration System 1 12 Bioretention Cell 0 13 Wet Pond 3 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 1 Green Roof 0 119 Level S reader -Filter Strip (IS-FS 0 20 Disconnected Impervious Surface (DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 113ayfilter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 28 I.Name_and T .ale Organization: Street address: Carlo Pardo, PE Bowman North Carolina Ltd. 29 4006 Barrett Drive, Suite 104 30 Cit , State, Zip: Raleigh, NC 27609 31 Phone number(sj: Email: 919-553-6570 32 cpardo@bowman.com Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here ,`�``�`o��H a R��i''f�� � / J v • SEAL _ 051571 = i r %. •• •• ENG I PI�E�•'' r ,gRL o..E. !l l t! I l l l t tSeaf Signature of Designer 4 �a Date DRAINAGE AREAS 1 Is this a hi h density project? Yes 2 If so, number of drainage areas/SCMs 4 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED AREA INFORMATION Entire Site 1 2 3 4 4 T e of SCM - Wet Pond Infiltration Basin Wet Pond Wet Pond 5 Total draina a area s ft 5023339 sf 883772 394402 176822 874858 6 Onsite draina a areas ft 883772 394402 176822 874858 7 Offsite draina a area s ft 8 Total BUA in project (sq ft 980497 sf 371638 sf 171155 sf 86745 sf 350959 sf 9permitting) New BUA on subdivided lots (subject to s ft 680000 sf 272000 sf 112000 sf 64000 sf 232000 sf 10permitting) New BUA not on subdivided lots (subject to s 300497 sf 99638 sf 59155 sf 22745 sf 118959 sf 11 10ffsite BUA (sq ft 12 Breakdown of new BUA not on subdivided lots: Parking (sq ft Sidewalk (sq ft 75573 sf 27645 sf 15376 sf 5672 sf 26880 sf Roof (sq ft Roadway s ft 215004 sf 71993 sf 43779 sf 17073 sf 82159 sf Future (sq ft Other, please specify in the comment box below (sq ft 9920 sf 9920 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft 14 New infiltrating permeable pavement not on subdivided lots (sq ft 15permitting) Existing BUA that will remain (not subject to s ft 16 1 Existing BUA that is already permitted (sq ft 17 Existing BUA that will be removed (sq ft 18 Percent BUA 19.52% 42.1% 43% 49% 40% 19 Design storm inches 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM cu ft 32182 cf 62235 cf 7580 cf 31488 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method ONAL INFORMATION ease use this space to provide any additional information about the "22drainagearea(s): 12-Postal Kiosk for additional BUA WET POND 1 11 Drainage area number 1 3 4 21 Minimum required treatment volume (cu ft) 31555 cf 7243 cf 29967 cf NERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes 5 What are the side slopes of the SCM (H:V)? 3:1 3:1 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No No No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes Yes Yes 11 Does the maintenance access comply with General MDC (8)? Yes Yes Yes 12 Does the drainage easement comply with General MDC (9)? Yes Yes Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC (10)? N/A N/A N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes Yes Yes 161 Does the SCM follow the device specific MDC? Yes Yes Yes 17 Was the SCM designed b an NC licensedprofessional? Yes Yes Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA SA/DA SA/DA 19 Has a stage/storage table been provided in the calculations? Yes Yes Yes 20 Elevation of the excavated main pool depth (bottom of sediment removal) (fmsl 206.00 189.00 202.00 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 207.00 190.00 203.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 211.50 195.50 206.50 23 Elevation of the permanent pool (fmsl) 212.00 196.00 207.00 24 Elevation of the top of the vegetated shelf (fmsl) 212.50 196.50 207.50 25 Elevation of the temporary pool (fmsl) 213.90 197.50 208.70 26 Surface area of the main permanent pool (square feet) 11390 2950 13155 27 Volume of the main permanent pool (cubic feet) 43138 cf 8526 cf 42764 cf 28 Average depth of the main pool (feet) 4.22 ft 3.66 ft 3.58 ft 29 Average depth equation used Equation 3 Equation 3 Equation 3 301 If using equation 3, main pool perimeter (feet) 423.0 ft 237.0 ft 442.0 ft 31 If using equation 3, width of submerged veg. shelf (feet) 3.0 ft 3.0 ft 3.0 ft 32 Volume of the forebay (cubic feet) 6715 cf 1583 cf 7964 cf 33 Is this 15-20% of the volume in the main pool? Yes Yes Yes 34 Clean -out depth for forebay (inches) 48 in 48 in 48 in 35 Design volume of SCM (cu ft) 32182 cf 7580 cf 31488 cf 36 Is the outlet an orifice or a weir? Orifice Orifice Orifice 371 If orifice, orifice diameter (inches) 2.00 in 1.00 in 2.50 in 38 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.59 3.61 2.41 41 Are the inlet(s) and outlet located in a manner that avoids short- circuiting? Yes Yes Yes 42 Are berms or baffles provided to improve the flow path? Yes Yes Yes 431 Depth of forebay at entrance (inches) 60 in 60 in 60 in 44 Depth of forebay at exit (inches) 54 in 54 in 54 in 45 Does water flow out of the forebay in a non -erosive manner? Yes Yes Yes 46 Width of the vegetated shelf (feet) 6 ft 6 ft 6 ft 47 Slope of vegetated shelf (H:V) 6:1 6:1 6:1 48 Does the orifice drawdown from below the top surface of the permanentpool? Yes Yes Yes 49 Does the pond minimize impacts to the receiving channel from the 1- r, 24-hr storm? Yes Yes Yes 50 Are fountains proposed? (If Y, please provide documentation that MDC(9) is met. No No No 51 Is a trash rack or other device provided to protect the outlet system? Yes Yes Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes Yes Yes 53 Species of turf that will be used on the dam and embankment Hybrid Bermuda Hybrid Bermuda Hybrid Bermuda 54 Hasa planting plan been provided for the vegetated shelf? Yes Yes Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): Wet Pond 1 9:16 AM 4/12/2023 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Pre -Developed Conditions #3 Drainage Area (acres): 4.06 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A WaB Wagram Loamy Sand 3.31 82% C Bad Blaney Loamy Sand 0.75 18% Existing Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Wooded - Good Stand A 3.31 54 44.0 Wooded - Good Stand C 0.75 74 13.7 Cumulative Curve # = 57.7 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Post -Developed Conditions #3 Drainage Area (acres): 4.06 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA A WaB Wagram Loamy Sand 3.31 82% C Bad Blaney Loamy Sand 0.75 18% Proposed Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Condition A 1.32 55 17.9 Open Space - Good Condition C 0.75 77 14.2 Impervious Area A & C 1.99 98 48.0 Cumulative Curve # = 80.1 Proposed Wet Pond #3 Project Information Project Name: Shahbain Reserve Project #: 048-024 Designed by: CB Date: 12/15/2022 Revised by: Date: Checked by: Date: Site Information Sub Area Location: Drainage To Proposed Wet Pond Drainage Area (DA) = 4.06 Acres 176,822 sf Impervious Area (IA) = 1.99 Acres 86,745 sf Percent Impervious (1) = % 49.06 % Required Surface Area Permament Pool Depth: 3.66 ft SA/DA = 1.579 Min Req'd Surface Area = 2,793 sf (at Permanent Pool) Required WQv Storage Volume Design Storm = inch Non -Coastal County Determine Rv Value = 0.05 + .009 (1) = 0.492 in/in Storage Volume Required = cf (above Permanent Pool) Elevations Top of Pond Elevation = 201.00 ft Temporary Pool Elevation = 197.50 ft Permanent Pool Elevation = 196.00 ft Shelf Begining Elevation = 196.50 ft Forebay Weir = 195.50 ft Shelf Ending Elevation = 195.50 ft Bottom Elevation = 190.00 ft Permanent Pool Area Area @ Top of Permanent Pool = 2,950 sf Volume of Temporary Storage = 7,580 cf Is Permenant Pool Surface Area Sufficient (yes/no)? Volume of Storage for Design Storm = ( 2950 > 2793) sf ( 7580 > 7243) cf Incremental Drawdown Time STORMWATER POND #3 INCREMENTAL DRAWDOWN METHOD -Water Quality Volume Project Information Project Name: Shahbain Reserve Project #: 048-024 Designed by: CB Date: 12/15/2022 Revised by: Date: Checked by: Date: Water ity Orifice Incremental Determination of Water Quality Volume Drawdown Time Zone 2 Orifice Diameter (D) = Cd = Ei = Zone 1 Range = Zone 2 Range = Zone 3 Range = Q3 = 0.0437 CD ' D2 (Z-D/24-Ei)^(112) Qz = 0.372 CD ' D'(Z-Ei)^(3i2) Q, = 0 in 0.6 196 Orifice Inv. 0.00 to 196 196 to 196.1 196.1 to 197 Incremental Drawdown Method Countour Contour Area Incremental Volume Stage, Z Zone Q Drawdown Time sq ft cu ft ft cfs min 196.00 3,855 0 0.00 2.00 0.000 -- 196.50 4810 2,166 0.50 3.00 0.018 2,034 197.00 5400 2,553 0.50 3.00 0.026 1,658 197.50 6045 2,861 0.50 3.00 0.032 1,506 Total -- -- -- -- Drawdown Time = Incremental Volume / Q / 60sec/min Summary Total Volume = 7,580 of Total Time = 5,197 min Total Time = 3.61 days 2 to 5 days 12/19/2022 Prop Wet Pond- new design-#3.xls 1 of 1 Project: Pond #1 Date: 12/19/2022 Main -Pond Contours -Volumes Elevation Main -Pond Incremental Vol. Accumulated Vol. Description 196 2,950 1,308 8,526 A2 (Perm —Pool) 195.5 2,280 1,089 7,219 Al (Bottom —Shelf) 195 2,075 1,883 6,130 194 1,690 1,515 4,248 193 1,340 1,185 2,733 192 1,030 898 1,548 191 765 650 650 190 535 0 0 A3 (Bottom —Pond) Forebay Contours -Volumes Elevation FB1 FB2 FB3 Total -Areas Incremental Vol. Accumulated Vol. 196 810 810 375 1,583 195.5 690 690 315 1,208 195 570 570 468 893 194 365 365 283 425 193 200 200 143 143 192 85 85 0 0 Forebay Volume Average Depth (Option 1) Average Depth Calculation (Option 2) Vpp permeter of shelf width of shelf Al (Bottom —Shelf): 18.6% *Between 15% & 20% 3.17 *At least 3' average depth 8,526 237 3 2,280 Average Depth = 3.66 Proposed Wet Pond #3 Project Information Project Name: Shahbain Reserve Project #: 048-024 Designed by: CB Date: Revised by: Date: Checked by: Date: Site Information 12/15/2022 Sub Area Location: Drainage to Proposed Pond Drainage Area (DA) = 4.06 Acres Impervious Area (IA) = 1.99 Acres Percent Impervious (I) = 49.06 % (Drainage Area) Orifice Sizing Orifice Size = 1.00 in Drawdown Time = 3.61 days 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: 176.0 cf Weight: 10982 Ibs Factor of Safety 1.20 WT Req'd of Anti -Flotation Device: 13,179 Ibs Volume of Concrete Req'd: 87.9 cf (Diameter) (Incremental Draw Down Method) (Water Displaced - Top of Pond to Bottom of Pond) (Unit WT of Concrete = 150 pcf) Volume Provided: 117.5 cf (4'x4' riser x 5.0' = 80sf, 5'x5' footing x 1.5'=37.5cf) 09 TOP of � EMBANKMENT � ELEV-201.0 ....... STORMWATER � MANAGEMENT � EASEMENT INLET PIPE WITH � RIP -RAP APRON i ["'I 501013mmolul FOREBAY AREA CLASS B RIP RAP � AT FOREBAY WEIR \� ITORAL SHELF AREA=1,410 SP- 24 OUTLET PIPE � REFER TO DETAIL REFER TO GRADING FOR PLANTINGS PLAN Z, �/ / �� ELEV_ 194.5 0 z 14-Tswilml �Ov OO ` OO /. �O- OUTLET CONTROL \ � \ STRUCTURE REFER � \ �\\ TO DETAILS ON � \ � THIS SHEET \ \ \ MAIN POND AREA SOD AREAS ABOVE NORMAL POOL EELVATION � 1 0 15 30 60 120 ( IN FEET ) 1 inch = 30 ft. PLAN VIEW STAGE/STORAGE TABLE STAGE (FT) ELEVATION (FT) CONTOUR AREA (SF) INCREMENTAL STORAGE (CF) TOTAL STORAGE (CF) 0.0 196.0 3855 0 0 0,5 196.5 4810 2166 2166 1.0 197.0 5400 2553 4719 1.5 197.5 6045 2861 7580 (WQV) 2,0 198.0 6605 3163 10743 3.0 199.0 7775 7190 17933 4.0 200.0 9000 8388 26320 5,0 201.0 10280 9640 35960 4' MIN EMBANKMENT WIDTH 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION 24" HDPE WITH WATER TIGHT SEAL PIPE TO BE BEDDED PER DIRECTION OF GEOTECHNICAL ENGINEER 2 � 6" CLAY SOIL LINER ON INSIDE FACE OF EMBANKMENT 3' MIN CUTOFF TRENCH APPROXIMATE SIZE EXCAVATE AND BACKFILL WITH COMPACTED STRUCTURAL FILL AS DIRECTED BY GEOTECHNICAL ENGINEER 33'-24" HDPE @ 4.55% IN KEY TRASH RACK REFER TO DETAIL THIS SHEET 6" TOPSOIL ABOVE 6" CLAY LINER REFER TO DETAIL ON LITTORAL SHELF FOR INCREMENTAL 3 WEI R 1 6 6 4'x4' PRECAST 6FT LITTORAL _ 1 CONCRETE RISER SHELF (INSTALL STEPS AS NECESSARY) II NV=196.0 1 ELEV=194.0 ASTM C-923 SEAL BETWEEN BARREL & RISER. RISER BASE TO BE FILLED WITH CONC. TO INVERT OF BARREL 8"X8"X1 "X12" LONG ANGLE (6 TOT. REQUIRED) TO ANCHOR RISER TO BASE. PROVIDE 2-3/4" A307 BOLTS FROM ANGLE TO RISER AND 2—A307 "J" HOOKS 3/4" DIA. X 12" LONG FROM ANGLE TO BASE. ANGLE TO BE FIELD COATED WITH ZINC RICH PAINT AFTER CONSTRUCTION. "J" HOOKS TO BE PLACED UNDER LOWER REINFORCING STEEL. 0 TOP OF EMBANKMENT ELEVATION=201.0 100 YEAR STORM ELEVATION=200.36 10 YEAR STORM ELEVATION=199.43 2 YEAR STORM ELEVATION=198.22 1 YEAR STORM ELEVATION=197.87 NOTE: 1.0" STORM ELEVATION IS 196.25 AND INTERMEDIATE WEIR IS ELEVATION 197.5. THERE IS ADDITIONAL STORAGE DESIGNED FROM THE 1.0" STORM ELEVATION TO THE INTERMEDIATE WEIR ELEVATION. 1.0—INCH STORM ELEVATION=196.25 NORMAL POND ELEVATION=196.0 _ a _a a a a a PVC ELBOW a SEE DETAIL °a °a a a ILL =2 NOTE: PUMPS SHALL BE USED TO DRAIN 1 THE POND WHEN NECESSARY. REFER TO DETAIL THIS SHEET FOR DEWATERING REQUIREMENTS. O d O a 1 CONCRETE SHALL BE PLACED IN RISER AFTER ANGLES ARE SECURED TO BASE AND RISER. 5'x5'x1.5' CONC. BASE REINFORCE WITH #4 BARS AT 12" O.C. TOP AND BOTTOM OF EACH DIRECTION PROVIDE 3" MIN. CLEARANCE BETWEEN EDGE OF CONC. AND STEEL REINFORCING. PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. BOTTOM OF POND (TOP OF SEDIMENT STORAGE)=190.0 (BOTTOM OF SEDIMENT STORAGE)=189.0 6" CLAY SOIL LINER MAIN POOL EXISTING GRADE=202.Of lt� 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION FOREBAY BERM 6" TOPSOIL ABOVE 6" CLAY LINER 3:1 ON LITTORAL SHELF 1111, 6FT LITTORAL SHELF Cm CLASS B RIP -RAP OVER FILTER FABRIC MIN. 4' GRASS FOREBAY WEIR AT ELEV=195.5 FOREBAY TOP ELEV= 197.0 WIDTH AT TOP = 2.0 FT 3/ FOREBAY ENTRANCE SHALL BE DEEPER THAN FOREBAY EXIT PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. NOTE: PUMPS SHALL BE USED TO DRAIN THE FOREBAY WHEN NECESSARY. REFER TO DETAIL SEDIMENT STORAGE THIS SHEET FOR DEWATERING REQUIREMENTS. TOP FOREBAY BOTTOM ELEV=192.0 BOTTOM OF SEDIMENT STORAGE/EXIT ELEV=191.5 FOREBAY ENTRANCE SHALL BE DEEPER THAN FOREBAY EXIT fNG]: LM,a go] MINaM,n go]1 BOTTOM LITTORAL SHELF ELEV. Z_ 'KI]OLINDOYMIM 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION BOTTOM OF SEDIMENT STORAGE/ENTRANCE ELEV=191.0 jOp 0F 99,5 IAIi -,, _ rno nr cTgUCTURE NOT SHOWN FOR CLARITY TRASH RACK) OUTLET CONTROL STRUCTURE - INCREMENTAL WEIR PERM. POND ELEV.-196.0 4" PVC SCREW CAP FOR CLEANING ACCESS 12" 4"x4" PVC I 1"DIA. HOLE DRILLE[ INTO BOTTOM CAP SCALE: N.T.S. DICCD OTDI lr\TI IDC PVC DRAIN OUTLET SCALE: N.T.S. Pond Report s Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Pond No. 1 - Wet Pond Pond Data Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 196.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 196.00 3,855 0 0 0.50 196.50 4,810 2,166 2,166 1.00 197.00 5,400 2,553 4,719 1.50 197.50 6,045 2,861 7,580 2.00 198.00 6,605 3,163 10,743 3.00 199.00 7,775 7,190 17,933 4.00 200.00 9,000 8,388 26,320 5.00 201.00 10,280 9,640 35,960 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) = 24.00 1.00 Inactive Inactive Crest Len (ft) = 0.50 15.50 Inactive Inactive Span (in) = 24.00 1.00 0.00 0.00 Crest El. (ft) = 197.50 199.50 0.00 0.00 No. Barrels = 1 1 0 0 Weir Coeff. = 3.33 2.60 3.33 3.33 Invert El. (ft) = 196.00 196.00 0.00 0.00 Weir Type = Rect Broad --- --- Length (ft) = 33.00 0.50 0.00 0.00 Multi -Stage = Yes Yes No No Slope (%) = 4.55 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) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00 Stage (ft) 5.00 !91I11 c m RIM M Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 3.00 6.00 9.00 Total Q Stage / Discharge Elev (ft) 201.00 f180I1l<1I11 198.00 197.00 196.00 12.00 15.00 18.00 21.00 24.00 27.00 30.00 Discharge (cfs) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 0.668 2 726 3,994 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 8.863 2 718 17,774 ------ ------ ------ Post Developed to Pond 3 Reservoir 0.408 2 804 16,029 2 197.87 9,916 Post Through Pond 5 SCS Runoff 0.129 2 152 1,170 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.012 2 366 1,087 5 196.25 1,075 1.0inPost Through Pond Wet Pond#3.gpw Return Period: 1 Year Monday, 12 / 19 / 2022 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Peak discharge = 0.668 cfs Storm frequency = 1 yrs Time to peak = 726 min Time interval = 2 min Hyd. volume = 3,994 cuft Drainage area = 4.060 ac Curve number = 57.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 16.00 min Total precip. = 3.04 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 Pre -Developed -Overall Site Hyd. No. 1 -- 1 Year Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.10 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hydrograph Report 3 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.04 in Storm duration = 24 hrs Q (cfs) 10.00 Were . OX 4.00 r w Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 1 Year Monday, 12 / 19 / 2022 = 8.863 cfs = 718 min = 17,774 cuft = 80.1 = 0 ft = 5.40 min = Type II = 484 Q (cfs) 10.00 N. We 4.00 r w 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 2 Time (min) 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 0.408 cfs Storm frequency = 1 yrs Time to peak = 804 min Time interval = 2 min Hyd. volume = 16,029 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 197.87 ft Reservoir name = Wet Pond Max. Storage = 9,916 cuft Storage Indication method used. Q (cfs) 10.00 UR . UX 4.00 r W Post Through Pond Hyd. No. 3 -- 1 Year 600 1200 1800 2400 3000 3600 4200 4800 5400 Hyd No. 3 — Hyd No. 2 Total storage used = 9,916 cuft Q (cfs) 10.00 N. We . UX 4.00 2.00 0.00 6000 Time (min) A Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 5 1.0 Post -Developed to Pond Hydrograph type = SCS Runoff Peak discharge = 0.129 cfs Storm frequency = 1 yrs Time to peak = 152 min Time interval = 2 min Hyd. volume = 1,170 cuft Drainage area = 4.060 ac Curve number = 80.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.40 min Total precip. = 1.00 in Distribution = SCS 6-Hr Storm duration = 6.00 hrs Shape factor = 484 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 00 1.0 Post -Developed to Pond Hyd. No. 5 -- 1 Year 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 60 120 180 240 300 360 420 — Hyd No. 5 Time (min) 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 6 1.0inPost Through Pond Hydrograph type = Reservoir Peak discharge = 0.012 cfs Storm frequency = 1 yrs Time to peak = 366 min Time interval = 2 min Hyd. volume = 1,087 cuft Inflow hyd. No. = 5 - 1.0 Post -Developed to Pond/lax. Elevation = 196.25 ft Reservoir name = Wet Pond Max. Storage = 1,075 cuft Storage Indication method used. 1.0inPost Through Pond •. 1 •1 1 1:1 ��1 :11 •1 1 ::1 �1 •11 •.1 Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 1.803 2 726 7,378 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 12.23 2 716 24,701 ------ ------ ------ Post Developed to Pond 3 Reservoir 1.058 2 750 22,930 2 198.22 12,337 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 196.00 0.000 1.0inPost Through Pond Wet Pond#3.gpw Return Period: 2 Year Monday, 12 / 19 / 2022 Hydrograph Report 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.68 in Storm duration = 24 hrs Q (cfs) 2.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 2 Year 120 240 360 480 600 720 840 960 Hyd No. 1 Monday, 12 / 19 / 2022 = 1.803 cfs = 726 min = 7,378 cuft = 57.7 = 0 ft = 16.00 min = Type II = 484 Q (cfs) 2.00 1.00 0.00 1080 1200 1320 1440 1560 Time (min) Hydrograph Report 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.68 in Storm duration = 24 hrs Q (cfs) 14.00 12.00 10.00 01 M 4.00 ItX Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 2 Year Monday, 12 / 19 / 2022 = 12.23 cfs = 716 min = 24,701 cuft = 80.1 = 0 ft = 5.40 min = Type II = 484 Q (cfs) 14.00 12.00 10.00 . �� 4.00 of 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 2 Time (min) 12 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 1.058 cfs Storm frequency = 2 yrs Time to peak = 750 min Time interval = 2 min Hyd. volume = 22,930 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 198.22 ft Reservoir name = Wet Pond Max. Storage = 12,337 cuft Storage Indication method used. Q (cfs) 14.00 12.00 10.00 01 M 4.00 ItX Post Through Pond Hyd. No. 3 -- 2 Year Q (cfs) 14.00 12.00 10.00 0@ 4.00 2.00 0.00 600 1200 1800 2400 3000 3600 4200 4800 5400 6000 Time (min) Hyd No. 3 — Hyd No. 2 Total storage used = 12,337 cult Hydrograph Summary Report 15 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 6.620 2 724 20,238 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 22.37 2 716 45,699 ------ ------ ------ Post Developed to Pond 3 Reservoir 4.524 2 726 43,884 2 199.43 21,581 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 196.00 0.000 1.0inPost Through Pond Wet Pond#3.gpw Return Period: 10 Year Monday, 12 / 19 / 2022 Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.46 in Storm duration = 24 hrs Q (cfs) 7.00 5.00 3.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 10 Year Monday, 12 / 19 / 2022 = 6.620 cfs = 724 min = 20,238 cuft = 57.7 = 0 ft = 16.00 min = Type II = 484 Q (cfs) 7.00 . We 5.00 4.00 3.00 2.00 1.00 0.00 ' 1 1 1 1' ' ' ' ' ' ' '� ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Peak discharge = 22.37 cfs Storm frequency = 10 yrs Time to peak = 716 min Time interval = 2 min Hyd. volume = 45,699 cuft Drainage area = 4.060 ac Curve number = 80.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.40 min Total precip. = 5.46 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (cfs) 24.00 20.00 16.00 12.00 :1M 4.00 Post Developed to Pond Hyd. No. 2 -- 10 Year Q (cfs) 24.00 20.00 16.00 12.00 m 4.00 0.00 ' —' ' ' ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 — Hyd No. 2 Time (min) Hydrograph Report 18 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 4.524 cfs Storm frequency = 10 yrs Time to peak = 726 min Time interval = 2 min Hyd. volume = 43,884 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 199.43 ft Reservoir name = Wet Pond Max. Storage = 21,581 cuft Storage Indication method used Post Through Pond Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs) 24.00 24.00 20.00 20.00 16.00 16.00 12.00 12.00 8.00 8.00 4.00 4.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 21,581 cult Hydrograph Summary Report 21 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 16.83 2 722 48,007 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 39.34 2 716 82,558 ------ ------ ------ Post Developed to Pond 3 Reservoir 26.59 2 720 80,707 2 200.36 29,754 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 196.00 0.000 1.0inPost Through Pond Wet Pond#3.gpw Return Period: 100 Year Monday, 12 / 19 / 2022 Hydrograph Report 22 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 18.00 15.00 12.00 M M 3.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 100 Year Monday, 12 / 19 / 2022 = 16.83 cfs = 722 min = 48,007 cuft = 57.7 = 0 ft = 16.00 min = Type II = 484 Q (cfs) 18.00 15.00 12.00 M . �� 3.00 0.00 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Hyd No. 1 Time (min) Hydrograph Report 23 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 4.060 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 40.00 20.00 10.00 0.00 0 120 240 — Hyd No. 2 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 100 Year 360 480 600 720 840 960 Monday, 12 / 19 / 2022 = 39.34 cfs = 716 min = 82,558 cuft = 80.1 = 0 ft = 5.40 min = Type II = 484 Q (cfs) 40.00 30.00 20.00 10.00 0.00 1080 1200 1320 Time (min) Hydrograph Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 26.59 cfs Storm frequency = 100 yrs Time to peak = 720 min Time interval = 2 min Hyd. volume = 80,707 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 200.36 ft Reservoir name = Wet Pond Max. Storage = 29,754 cuft Storage Indication method used Post Through Pond Q (cfs) Hyd. No. 3 -- 100 Year Q (cfs) 40.00 40.00 30.00 30.00 20.00 20.00 10.00 10.00 0.00 — 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 29,754 cult OF CONCENTRATION ng Conditions DA4 OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007ml-y0.8)/(P2"0.5)(s"0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R21IS112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T�, T­ 1L Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area (fl-2) (fl fl fl fl/fl (fps) 10 min 0.67c hrs 3 100 222.0 220.5 0.015 3.68 0.24 14.93 290 220.5 197 0.08103 Unpaved 4.60 1.05 15.98 15.98 0.16 3 TIME OF CONCENTRATION Proposed Conditions SCS Methodology Note: Fields in blue are manual entry OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007m`-y`0.8)/(P2A0.5)(sA0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R�S112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T,3 T,,A� Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area flA2 fl fl t t (fps) 10 min 0.67c hrs 3 100 215.6 213.0 0.026 3.68 0.018 1.51 557 213.0 205 0.01436 Paved 2.40 3.87 5.38 10.00 0.10 3 WATER QUANTITY -WET POND SCM 4 oa,- jc Arec, a L .- A 5} 1 O e SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION _ 1 Project Name _ Project Area (ac) _ Coastal Wetland Area ac Utility Improvements to Serve Shabain Reserve - Phase 1 115.32 _ - 2 3 4 Surface Water Area ac 5 Is this ro'ect High or Low Density? High 6 Does this project use an off -site SCM? _ No COMPLIANCE WITH 02H .1003(4.) 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMS: 11 Infiltration System 1 12 Bioretention Cell 0 13 Wet Pond 3 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 1 Green Roof 0 119 Level S reader -Filter Strip (IS-FS 0 20 Disconnected Impervious Surface (DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 113ayfilter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 28 I.Name_and T .ale Organization: Street address: Carlo Pardo, PE Bowman North Carolina Ltd. 29 4006 Barrett Drive, Suite 104 30 Cit , State, Zip: Raleigh, NC 27609 31 Phone number(sj: Email: 919-553-6570 32 cpardo@bowman.com Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here ,`�``�`o��H a R��i''f�� � / J v • SEAL _ 051571 = i r %. •• •• ENG I PI�E�•'' r ,gRL o..E. !l l t! I l l l t tSeaf Signature of Designer 4 �a Date DRAINAGE AREAS 1 Is this a hi h density project? Yes 2 If so, number of drainage areas/SCMs 4 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED AREA INFORMATION Entire Site 1 2 3 4 4 T e of SCM - Wet Pond Infiltration Basin Wet Pond Wet Pond 5 Total draina a area s ft 5023339 sf 883772 394402 176822 874858 6 Onsite draina a areas ft 883772 394402 176822 874858 7 Offsite draina a area s ft 8 Total BUA in project (sq ft 980497 sf 371638 sf 171155 sf 86745 sf 350959 sf 9permitting) New BUA on subdivided lots (subject to s ft 680000 sf 272000 sf 112000 sf 64000 sf 232000 sf 10permitting) New BUA not on subdivided lots (subject to s 300497 sf 99638 sf 59155 sf 22745 sf 118959 sf 11 10ffsite BUA (sq ft 12 Breakdown of new BUA not on subdivided lots: Parking (sq ft Sidewalk (sq ft 75573 sf 27645 sf 15376 sf 5672 sf 26880 sf Roof (sq ft Roadway s ft 215004 sf 71993 sf 43779 sf 17073 sf 82159 sf Future (sq ft Other, please specify in the comment box below (sq ft 9920 sf 9920 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft 14 New infiltrating permeable pavement not on subdivided lots (sq ft 15permitting) Existing BUA that will remain (not subject to s ft 16 1 Existing BUA that is already permitted (sq ft 17 Existing BUA that will be removed (sq ft 18 Percent BUA 19.52% 42.1% 43% 49% 40% 19 Design storm inches 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM cu ft 32182 cf 62235 cf 7580 cf 31488 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method ONAL INFORMATION ease use this space to provide any additional information about the "22drainagearea(s): 12-Postal Kiosk for additional BUA WET POND 1 11 Drainage area number 1 3 4 21 Minimum required treatment volume (cu ft) 31555 cf 7243 cf 29967 cf NERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes 5 What are the side slopes of the SCM (H:V)? 3:1 3:1 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No No No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes Yes Yes 11 Does the maintenance access comply with General MDC (8)? Yes Yes Yes 12 Does the drainage easement comply with General MDC (9)? Yes Yes Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC (10)? N/A N/A N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes Yes Yes 161 Does the SCM follow the device specific MDC? Yes Yes Yes 17 Was the SCM designed b an NC licensedprofessional? Yes Yes Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA SA/DA SA/DA 19 Has a stage/storage table been provided in the calculations? Yes Yes Yes 20 Elevation of the excavated main pool depth (bottom of sediment removal) (fmsl 206.00 189.00 202.00 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 207.00 190.00 203.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 211.50 195.50 206.50 23 Elevation of the permanent pool (fmsl) 212.00 196.00 207.00 24 Elevation of the top of the vegetated shelf (fmsl) 212.50 196.50 207.50 25 Elevation of the temporary pool (fmsl) 213.90 197.50 208.70 26 Surface area of the main permanent pool (square feet) 11390 2950 13155 27 Volume of the main permanent pool (cubic feet) 43138 cf 8526 cf 42764 cf 28 Average depth of the main pool (feet) 4.22 ft 3.66 ft 3.58 ft 29 Average depth equation used Equation 3 Equation 3 Equation 3 301 If using equation 3, main pool perimeter (feet) 423.0 ft 237.0 ft 442.0 ft 31 If using equation 3, width of submerged veg. shelf (feet) 3.0 ft 3.0 ft 3.0 ft 32 Volume of the forebay (cubic feet) 6715 cf 1583 cf 7964 cf 33 Is this 15-20% of the volume in the main pool? Yes Yes Yes 34 Clean -out depth for forebay (inches) 48 in 48 in 48 in 35 Design volume of SCM (cu ft) 32182 cf 7580 cf 31488 cf 36 Is the outlet an orifice or a weir? Orifice Orifice Orifice 371 If orifice, orifice diameter (inches) 2.00 in 1.00 in 2.50 in 38 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.59 3.61 2.41 41 Are the inlet(s) and outlet located in a manner that avoids short- circuiting? Yes Yes Yes 42 Are berms or baffles provided to improve the flow path? Yes Yes Yes 431 Depth of forebay at entrance (inches) 60 in 60 in 60 in 44 Depth of forebay at exit (inches) 54 in 54 in 54 in 45 Does water flow out of the forebay in a non -erosive manner? Yes Yes Yes 46 Width of the vegetated shelf (feet) 6 ft 6 ft 6 ft 47 Slope of vegetated shelf (H:V) 6:1 6:1 6:1 48 Does the orifice drawdown from below the top surface of the permanentpool? Yes Yes Yes 49 Does the pond minimize impacts to the receiving channel from the 1- r, 24-hr storm? Yes Yes Yes 50 Are fountains proposed? (If Y, please provide documentation that MDC(9) is met. No No No 51 Is a trash rack or other device provided to protect the outlet system? Yes Yes Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes Yes Yes 53 Species of turf that will be used on the dam and embankment Hybrid Bermuda Hybrid Bermuda Hybrid Bermuda 54 Hasa planting plan been provided for the vegetated shelf? Yes Yes Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): Wet Pond 1 9:16 AM 4/12/2023 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Pre -Developed Conditions #4 Drainage Area (acres): 20.08 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA C BaD Blaney Loamy Sand 1.28 6% A NoB Norfolk Loamy Sand 15.77 79% A WaB Wagram Loamy Sand 3.03 15% Existing Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Wooded - Good Stand C 1.28 74 4.7 Wooded - Good Stand A 4.49 54 12.1 Open Space - Fair Stand A 14.31 55 39.2 Cumulative Curve # = 56.0 Bowman North Carolina, Ltd. Shahbain Reserve, Hoke County, NC Curve Number Calculation (CN) Post -Developed Conditions #4 Drainage Area (acres): 20.08 Existing Soil Groups Soil Group Map Symbol Soil Description Acres Percent of DA C BaD Blaney Loamy Sand 1.28 6% A NoB Norfolk Loamy Sand 15.77 79% A WaB Wagram Loamy Sand 3.03 15% Proposed Land Uses Land Use Description Existing Soil Group Acres Curve # Weighted CN Open Space - Good Condition C 0.60 77 2.3 Open Space - Good Condition A 11.42 55 31.3 Impervious Area A & C 8.06 98 39.3 Cumulative Curve # = 72.9 Proposed Wet Pond #4 Project Information Project Name: Shahbain Reserve Project #: 048-024 Designed by: CB Date: 12/15/2022 Revised by: Date: Checked by: Date: Site Information Sub Area Location: Drainage To Proposed Wet Pond Drainage Area (DA) = 20.08 Acres 874,858 sf Impervious Area (IA) = 8.06 Acres 350,959 sf Percent Impervious (1) = % 40.12 % Required Surface Area Permament Pool Depth: 3.58 ft SA/DA = 1.357 Min Req'd Surface Area = 11,868 sf (at Permanent Pool) Required WQv Storage Volume Design Storm = 1 inch Non -Coastal County Determine Rv Value = 0.05 + .009 (1) = 0.411 in/in Storage Volume Required = 29,967 cf (above Permanent Pool) Elevations Top of Pond Elevation = 215.00 ft Temporary Pool Elevation = 208.70 ft Permanent Pool Elevation = 207.00 ft Shelf Begining Elevation = 207.50 ft Forebay Weir = 206.00 ft Shelf Ending Elevation = 206.50 ft Bottom Elevation = 203.00 ft Permanent Pool Area Area @ Top of Permanent Pool = 13,155 sf Volume of Temporary Storage = 31,488 cf Is Permenant Pool Surface Area Sufficient (yes/no)? Volume of Storage for Design Storm = 31,488 Y ( 13155 > 11868) sf ( 31488 > 29967) cf Incremental Drawdown Time STORMWATER POND #4 INCREMENTAL DRAWDOWN METHOD -Water Quality Volume Project Information Project NarShahbain Reserve Project #: 048-024 esigned by: CB Date: 12/15/2022 hecked by: Date: Water Quality Orifice Incremental Determination of Water Quality Volume Drawdown Time Zone 2 Q3 = 0.0437 CD - D2 (Z-D/24-Ei)^(1/2) Qz = 0.372 CD ' D'(Z-Ei)^(3i2) m • Orifice Diameter (D) = 2.5 in Cd = 0.6 Ei = 207 Orifice Inv. Zone 1 Range = 0.00 to 207 Zone 2 Range = 207 to 207.1 Zone 3 Range = 207.1 to 208 Incremental Drawdown Method Countour Contour Area Incremental Volume Stage, Z Zone Q Drawdown Time sq ft cu ft ft cfs min 207.00 16,200 0 0.00 2.00 0.000 -- 207.50 17850 8,513 0.50 3.00 0.103 1,376 208.00 18860 9,178 0.50 3.00 0.155 986 208.70 20560 13,797 0.70 3.00 0.207 1,111 Total -- -- -- -- Drawdown Time = Incremental Volume / Q / 60sec/min Summary Total Volume = 31,488 of Total Time = 3,473 min Total Time = 2.41 days 2 to 5 days 12/19/2022 Prop Wet Pond- new design-#4.xls 1 of 1 Project: Pond #1 Date: 12/19/2022 Main -Pond Contours -Volumes Elevation Main -Pond Incremental Vol. Accumulated Vol. Description 207 13,155 6,254 42,764 A2 (Perm -Pool) 206.5 11,860 5,825 36,510 Al (Bottom -Shelf) 206 11,440 11,030 30,685 205 10,620 10,220 19,655 204 9,820 9,435 9,435 A3 (Bottom -Pond) 203 9,050 0 0 Forebay Contours -Volumes Elevation FB1 FB2 FB3 Total -Areas Incremental Vol. Accumulated Vol. 207 2,860 2,860 1,373 7,964 206.5 2,630 2,630 1,259 6,591 206 2,405 2,405 2,188 5,333 205 1,970 1,970 1,768 3,145 204 1,565 1,565 1,378 1,378 203 1,190 1,190 0 0 Forebay Volume Average Depth (Option 1) Average Depth Calculation (Option 2) Vpp permeter of shelf width of shelf Al (Bottom -Shelf): 18.6% *Between 15% & 20% 3.08 *At least 3' average depth 42,764 442 3 11,860 Average Depth = 3.58 Proposed Wet Pond #4 Project Information Project Name: Shahbain Reserve Project #: 048-024 Designed by: CB Date: Revised by: Date: Checked by: Date: Site Information 12/15/2022 Sub Area Location: Drainage to Proposed Pond Drainage Area (DA) = 20.08 Acres Impervious Area (IA) = 8.06 Acres Percent Impervious (I) = 40.12 % (Drainage Area) Orifice Sizing Orifice Size = 2.50 in Drawdown Time = 2.41 days 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: 192.0 cf Weight: 11981 Ibs Factor of Safety 1.20 WT Req'd of Anti -Flotation Device: 14,377 Ibs Volume of Concrete Req'd: 95.8 cf (Diameter) (Incremental Draw Down Method) (Water Displaced - Top of Pond to Bottom of Pond) (Unit WT of Concrete = 150 pcf) Volume Provided: 165.5 cf (4'x4' riser x 8.0' = 128sf, 5'x5' footing x 1.5'=37.5cf) 50 STORMWATER� � \ MANAGEMENT,, - \ � EASEMENel 0 BOO INLET PIPE WITH; -� RIP -RAP APRON GRAPHIC o 25 50 K ( IN FEET ) 1 inch = 50 ft. yv/ FES � ELEV 205.0 LOT 147 z+89 SF 24" OUTLET PIPE REFER TO GRADING 146 � \ PLAN v g SF \ ` � OUTLET CONTROL � STRUCTURE REFER - --� TO DETAILS ON � THIS SHEET _ � MAIN POND AREA �✓/ LITORAL SHELF AREA-2,595 SF REFER TO DETAIL /7 FOR PLANTINGS F OREBAY AREA � Kir-KNr N i FOREBAY WEIR _ � S TO R M WA TE R MANAGEMENT EASEMENT 20 PLAN VIEW STAGE/STORAGE TABLE STAGE (FT) ELEVATION (FT) CONTOUR AREA (SF) INCREMENTAL STORAGE (CF) TOTAL STORAGE (CF) 0.0 207.0 16200 0 0 0.5 207.5 17850 8513 8513 1.0 208.0 18860 9178 17690 1.7 208.7 20560 13797 31487 (WQV) 2.0 209.0 21025 6238 37725 3.0 210.0 22635 21830 59555 4.0 211.0 24300 23468 83022 5.0 212.0 26020 25160 108182 6.0 213.0 27800 26910 135092 7.0 214.0 29635 28718 163810 8.0 215.0 31525 30580 194390 4' MIN EMBANKMENT WIDTH 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION 24" HDPE WITH WATER TIGHT SEAL PIPE TO BE BEDDED PER DIRECTION OF GEOTECHNICAL ENGINEER 2 � 6" CLAY SOIL LINER ON INSIDE FACE OF EMBANKMENT 3' MIN CUTOFF TRENCH APPROXIMATE SIZE EXCAVATE AND BACKFI LL WITH COMPACTED STRUCTURAL FILL AS DIRECTED BY GEOTECHNICAL ENGINEER 37'-24" HDPE @ 5.71 8 6FT LITTORAL SHELF 6" TOPSOIL ABOVE 6" CLAY LINER ON LITTORAL SHELF 3 TRASH RACK REFER TO DETAIL THIS SHEET 6 11 REFER TO DETAIL FOR INCREMENTAL WEIR 4'x4' PRECAST CONCRETE RISER (INSTALL STEPS AS NECESSARY) LL- 0 oj TOP OF EMBANKMENT ELEVATION=215.00 100 YEAR STORM ELEVATION=213.84 10 YEAR STORM ELEVATION=211.17 2 YEAR STORM ELEVATION=209.47 1 YEAR STORM ELEVATION=209.05 NOTE: 1.0" STORM ELEVATION IS 207.07 AND INTERMEDIATE WEIR IS ELEVATION 208.7. THERE IS ADDITIONAL STORAGE DESIGNED FROM THE 1.0" STORM ELEVATION TO THE INTERMEDIATE WEIR ELEVATION. INV=207.0 1.0—INCH STORM ELEVATION=207.07 EXISTING GRADE=209.0f a NORMAL POND ELEVATION=207.00 a PVC ELBOW SEE DETAIL °a 2 1 ELEV=205.0 a 2 NOTE: PUMPS SHALL BE USED TO DRAIN 1 1 THE POND WHEN NECESSARY. REFER TO DETAIL 1u u THIS SHEET FOR DEWATERING REQUIREMENTS. 0 0 0 0 4' IN. ASTM C-923 SEAL KEY BETWEEN BARREL & RISER. RISER BASE TO BE FILLED WITH CONC. TO INVERT OF BOTTOM OF POND (TOP OF SEDIMENT STORAGE)=203.0 BARREL CONCRETE SHALL BE —_ 8"X8"X1"X12" LONG ANGLE (6 TOT. REQUIRED) TO ANCHOR RISER TO PLACED IN RISER AFTER — (BOTTOM OF SEDIMENT STORAGE)=202.0 BASE. PROVIDE 2-3/4" A307 BOLTS FROM ANGLE TO RISER AND ANGLES ARE SECURED 2—A307 "J" HOOKS 3/4" DIA. X 12" LONG FROM ANGLE TO BASE. TO BASE AND RISER. ANGLE TO BE FIELD COATED WITH ZINC RICH PAINT AFTER CONSTRUCTION. "J" HOOKS TO BE PLACED UNDER LOWER REINFORCING STEEL. 6" CLAY SOIL 5'x5'x1.5' CONC. BASE REINFORCE WITH #4 BARS AT 12" O.C. TOP LINER AND BOTTOM OF EACH DIRECTION PROVIDE 3" MIN. CLEARANCE MAIN POOL BETWEEN EDGE OF CONC. AND STEEL REINFORCING. PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. 6" TOPSOIL ABOVE 6" CLAY LINER ON LITTORAL SHELF 6FT LITTORAL SH ELF 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION 3:1 CLASS B RIP -RAP OVER FILTER FABRIC MIN. 4' GRASS FOREBAY WEIR AT ELEV= 206.5 FOREBAY TOP ELEV= 208.0 WIDTH AT TOP = 2.0 FT FOREBAY ENTRANCE SHALL BE DEEPER THAN FOREBAY EXIT PROFILE OF WET POND DETENTION SYSTEM SCALE: N.T.S. SEDIMENT STORAGE TOP FOREBAY BOTTOM ELEV= 203.0 BOTTOM OF SEDIMENT STORAGE/EXIT ELEV=202.5 FOREBAY ENTRANCE SHALL BE DEEPER THAN FOREBAY EXIT NOTE: PUMPS SHALL BE USED TO DRAIN THE FOREBAY WHEN NECESSARY. REFER TO THIS SHEET FOR DEWATERING REQUIREMENTS. NORMAL POND ELEVATION BOTTOM LITTORAL SHELF ELEV. 960495MEM C�� DETAIL 6" TOPSOIL FOR ALL AREAS ABOVE THE NORMAL POND ELEVATION BOTTOM OF SEDIMENT STORAGE/ENTRANCE ELEV=202.0 Tip OF �✓E/R \ 27 J 20 1Ai -)-,, �� nr crRUCTURE NOT SHOWN TRASH RACK) OUTLET CONTROL STRUCTURE - INCREMENTAL WEIR PERM. POND ELEV.-207.0 4" PVC SCREW CAP FOR CLEANING ACCESS 12" P 4"x4" PVC 1 2.5"DIA. HOLE DRILLE1 INTO BOTTOM CAP SCALE: N.T.S. DICE-D OTDI I(-`TI IDC PVC DRAIN OUTLET SCALE: N.T.S. FOR CLARITY Pond Report s Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Pond No. 1 - Wet Pond Pond Data Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 207.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 207.00 16,200 0 0 0.50 207.50 17,850 8,513 8,513 1.00 208.00 18,860 9,178 17,690 1.70 208.70 20,560 13,797 31,487 2.00 209.00 21,025 6,238 37,725 3.00 210.00 22,635 21,830 59,555 4.00 211.00 24,300 23,468 83,022 5.00 212.00 26,020 25,160 108,182 6.00 213.00 27,800 26,910 135,092 7.00 214.00 29,635 28,718 163,810 8.00 215.00 31,525 30,580 194,390 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) = 24.00 2.50 Inactive Inactive Crest Len (ft) = 1.00 15.00 Inactive Inactive Span (in) = 24.00 2.50 0.00 0.00 Crest El. (ft) = 208.70 211.20 0.00 0.00 No. Barrels = 1 1 0 0 Weir Coeff. = 3.33 2.60 3.33 3.33 Invert El. (ft) = 207.00 207.00 0.00 0.00 Weir Type = Rect Broad --- --- Length (ft) = 37.00 0.50 0.00 0.00 Multi -Stage = Yes Yes No No Slope (%) = 5.71 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) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00 Stage (ft) 8.00 4.00 RIM Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Discharge 4.00 8.00 12.00 16.00 20.00 24.00 28.00 32.00 Total Q Elev (ft) 215.00 WA19111I11 211.00 209.00 207.00 36.00 40.00 Discharge (cfs) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 1.483 2 746 17,067 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 18.98 2 726 63,922 ------ ------ ------ Post Developed to Pond 3 Reservoir 0.913 2 944 61,601 2 209.05 38,865 Post Through Pond 5 SCS Runoff 0.168 2 360 1,207 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.010 2 386 1,027 5 207.07 1,170 1.0inPost Through Pond Wet Pond#4.gpw Return Period: 1 Year Monday, 12 / 19 / 2022 Hydrograph Report 2 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.04 in Storm duration = 24 hrs Q (cfs) 2.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 1 Year 120 240 360 480 600 720 840 960 Hyd No. 1 Monday, 12 / 19 / 2022 = 1.483 cfs = 746 min = 17,067 cuft = 56 = 0 ft = 33.50 min = Type II = 484 Q (cfs) 2.00 1.00 0.00 1080 1200 1320 1440 1560 Time (min) Hydrograph Report 3 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.04 in Storm duration = 24 hrs Q (cfs) 21.00 18.00 15.00 12.00 3.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 1 Year Monday, 12 / 19 / 2022 = 18.98 cfs = 726 min = 63,922 cuft = 72.9 = 0 ft = 18.10 min = Type II = 484 Q (cfs) 21.00 18.00 15.00 12.00 3.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 0.913 cfs Storm frequency = 1 yrs Time to peak = 944 min Time interval = 2 min Hyd. volume = 61,601 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 209.05 ft Reservoir name = Wet Pond Max. Storage = 38,865 cuft Storage Indication method used. Post Through Pond Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs) 21.00 21.00 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 3.00 3.00 0.00 0.00 0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000 Time (min) — Hyd No. 3 Hyd No. 2 Total storage used = 38,865 cult A Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 5 1.0 Post -Developed to Pond Hydrograph type = SCS Runoff Peak discharge = 0.168 cfs Storm frequency = 1 yrs Time to peak = 360 min Time interval = 2 min Hyd. volume = 1,207 cuft Drainage area = 20.080 ac Curve number = 72.9 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 18.10 min Total precip. = 1.00 in Distribution = SCS 6-Hr Storm duration = 6.00 hrs Shape factor = 484 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 00 1.0 Post -Developed to Pond Hyd. No. 5 -- 1 Year 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 60 120 180 240 300 360 420 — Hyd No. 5 Time (min) 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 6 1.0inPost Through Pond Hydrograph type = Reservoir Peak discharge = 0.010 cfs Storm frequency = 1 yrs Time to peak = 386 min Time interval = 2 min Hyd. volume = 1,027 cuft Inflow hyd. No. = 5 - 1.0 Post -Developed to Pond/lax. Elevation = 207.07 ft Reservoir name = Wet Pond Max. Storage = 1,170 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 1.0inPost Through Pond Hyd. No. 6 -- 1 Year 1200 1800 2400 Hyd No. 5 3000 3600 4200 4800 5400 Total storage used = 1,170 cuft Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.05 0.00 6000 Time (min) Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v2022 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 4.348 2 738 32,924 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 29.07 2 726 94,462 ------ ------ ------ Post Developed to Pond 3 Reservoir 2.480 2 804 92,063 2 209.47 48,013 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 207.00 0.000 1.0inPost Through Pond Wet Pond#4.gpw Return Period: 2 Year Monday, 12 / 19 / 2022 Hydrograph Report 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.68 in Storm duration = 24 hrs Q (cfs) 5.00 4.00 3.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 2 Year Monday, 12 / 19 / 2022 = 4.348 cfs = 738 min = 32,924 cuft = 56 = 0 ft = 33.50 min = Type II = 484 Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.68 in Storm duration = 24 hrs Q (cfs) 30.00 25.00 20.00 15.00 10.00 5.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 2 Year Monday, 12 / 19 / 2022 = 29.07 cfs = 726 min = 94,462 cuft = 72.9 = 0 ft = 18.10 min = Type II = 484 Q (cfs) 30.00 25.00 20.00 15.00 10.00 5.00 0.00 ' 1 1 1' --.- ' ' ' ' ' ' " ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 12 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 2.480 cfs Storm frequency = 2 yrs Time to peak = 804 min Time interval = 2 min Hyd. volume = 92,063 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 209.47 ft Reservoir name = Wet Pond Max. Storage = 48,013 cuft Storage Indication method used. Q (cfs) 30.00 25.00 20.00 15.00 10.00 5.00 0.00 ' 1" 0 600 — Hyd No. 3 Post Through Pond Hyd. No. 3 -- 2 Year Q (cfs) 30.00 25.00 20.00 15.00 10.00 5.00 0.00 1200 1800 2400 3000 3600 4200 4800 5400 6000 Time (min) Hyd No. 2 Total storage used = 48,013 cult Hydrograph Summary Report 15 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 18.48 2 734 95,009 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 61.18 2 724 192,257 ------ ------ ------ Post Developed to Pond 3 Reservoir 13.13 2 746 189,729 2 211.17 87,177 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 207.00 0.000 1.0inPost Through Pond Wet Pond#4.gpw Return Period: 10 Year Monday, 12 / 19 / 2022 Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.46 in Storm duration = 24 hrs Q (cfs) 21.00 18.00 15.00 12.00 3.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 10 Year Monday, 12 / 19 / 2022 = 18.48 cfs = 734 min = 95,009 cuft = 56 = 0 ft = 33.50 min = Type II = 484 Q (cfs) 21.00 18.00 15.00 12.00 3.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 17 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.46 in Storm duration = 24 hrs Q (cfs) 70.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 10 Year Monday, 12 / 19 / 2022 = 61.18 cfs = 724 min = 192,257 cuft = 72.9 = 0 ft = 18.10 min = Type II = 484 Q (cfs) 70.00 50.00 40.00 30.00 20.00 10.00 0.00 ' ' ' ' ' ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 13.13 cfs Storm frequency = 10 yrs Time to peak = 746 min Time interval = 2 min Hyd. volume = 189,729 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 211.17 ft Reservoir name = Wet Pond Max. Storage = 87,177 cuft Storage Indication method used. Q (cfs) 70.00 40.00 20.00 10.00 0.00 ' 0 360 — Hyd No. 3 Post Through Pond Hyd. No. 3 -- 10 Year Q (cfs) 70.00 50.00 40.00 30.00 20.00 10.00 0.00 720 1080 1440 1800 2160 2520 2880 3240 3600 Time (min) — Hyd No. 2 Total storage used = 87,177 cult Hydrograph Summary Report 21 Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2022 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 51.67 2 734 232,226 ------ ------ ------ Pre -Developed -Overall Site 2 SCS Runoff 119.13 2 724 373,080 ------ ------ ------ Post Developed to Pond 3 Reservoir 36.42 2 742 370,441 2 213.84 159,087 Post Through Pond 5 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ 1.0 Post -Developed to Pond 6 Reservoir 0.000 2 n/a 0 5 207.00 0.000 1.0inPost Through Pond Wet Pond#4.gpw Return Period: 100 Year Monday, 12 / 19 / 2022 Hydrograph Report 22 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 1 Pre -Developed -Overall Site Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 60.00 40.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Pre -Developed -Overall Site Hyd. No. 1 -- 100 Year Monday, 12 / 19 / 2022 = 51.67 cfs = 734 min = 232,226 cuft = 56 = 0 ft = 33.50 min = Type II = 484 Q (cfs) 60.00 50.00 40.00 30.00 20.00 10.00 0.00 ' 1 1 1' -..- ' ' ' ' ' ' ' � ' 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 1 Time (min) Hydrograph Report 23 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hyd. No. 2 Post Developed to Pond Hydrograph type = SCS Runoff Storm frequency = 100 yrs Time interval = 2 min Drainage area = 20.080 ac Basin Slope = 0.0 % Tc method = User Total precip. = 8.36 in Storm duration = 24 hrs Q (cfs) 120.00 100.00 40.00 20.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Post Developed to Pond Hyd. No. 2 -- 100 Year Monday, 12 / 19 / 2022 = 119.13 cfs = 724 min = 373,080 cuft = 72.9 = 0 ft = 18.10 min = Type II = 484 Q (cfs) 120.00 100.00 40.00 20.00 0.00 1 1 1 1 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 — Hyd No. 2 Time (min) Hydrograph Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Monday, 12 / 19 / 2022 Hyd. No. 3 Post Through Pond Hydrograph type = Reservoir Peak discharge = 36.42 cfs Storm frequency = 100 yrs Time to peak = 742 min Time interval = 2 min Hyd. volume = 370,441 cuft Inflow hyd. No. = 2 - Post Developed to Pond Max. Elevation = 213.84 ft Reservoir name = Wet Pond Max. Storage = 159,087 cuft Storage Indication method used Q (cfs) 120.00 100.00 40.00 20.00 Post Through Pond Hyd. No. 3 -- 100 Year Q (cfs) 120.00 100.00 40.00 20.00 0.00 '1 1 1 L�-' ' ' ' ' -T--- ry 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Time (min) — Hyd No. 3 — Hyd No. 2 Total storage used = 159,087 cult OF CONCENTRATION ng Conditions DA3 OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007ml-y0.8)/(P2"0.5)(s"0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R21IS112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T�, T­ IL Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area (fl-2) (fl fl fl fl/fl (fps) 10 min 0.67c hrs 4 100 228.2 227.2 0.010 3.68 0.24 17.56 1725 227.2 206 0.01229 Unpaved 1.80 15.97 33.53 33.53 0.34 4 TIME OF CONCENTRATION Proposed Conditions SCS Methodology Note: Fields in blue are manual entry OPEN CHANNEL SHALLOW CONIC FLOW: FLOW: TOTAL SHEET FLOW: SEGMENT1 Manning's Equation: Tc = (0.007m`-y`0.8)/(P2A0.5)(sA0.4) 2-year24-hr �SEGMENTI Tc = L / 60'V V = 1.49R�S112/ n Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's T' Length Elev2 Elev3 Slope Condition Vavg T12 Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V T,3 T,,A� Tc(minimum) Tlag Basin fl fl/fl TP-40 in fl flAt TR-55 Fig. 3-1 fl/sec Flow Area flA2 fl fl t t (fps) 10 min 0.67c hrs 4 100 228.2 227.2 0.010 3.68 0.018 2.21 1905 227.2 207 0.01060 Paved 2.00 15.86 18.09 18.09 0.18 4