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SW3231101_Stormwater Report_20240514
SCM CALCULATIONS AURORA AT PRICE MILL CREEK Prepared for: Shea Homes 8800 N. Gainey Center Drive, Suite 350 Scottsdale, AZ 85258 Prepared by: ESP Associates, Inc. 20484 Chartwell Center Drive, Suite D Cornelius, NC 28031 (704) 990-9428 Project Number: KT37.400 ���������►►►,,, Original: August 30, 2023 �' 9.:g Revised: May 10, 2024 _ �25775 : ,„„,.11110`' 2024.05.13 12:59:14-04'00' aESP .. License No. F-1407 PROJECT NARATIVE The proposed project, "Aurora at Price Mill Creek" is a residential subdivision that is located in Wesley Chapel, Union County, North Carolina. The site is located on the east and west side of Weddington Road (NC Hwy. 84). The proposed main entrance will be located approximately 1,600 feet East from the intersection of Underwood Road and Weddington Road. There will be one stream crossing to access the rear of the property. The project site is located in Zone X and Zone AE per FIRM Map for Union County, North Carolina— Map Number 3710449600J, Effective Date: October 16, 2008. The existing site consists of woods and open fields. Price Mill Creek bisects the property from north to south and runs along the western boundary. The existing storm water runoff flows towards Price Mill Creek and has a 100-year floodplain associated with it. There are no known flooding problems located either downstream or immediately adjacent to the site. The proposed site will be a single family residential subdivision consisting of 35 lots. There will be four(4) paved streets and four (4) cul-de-sacs, valley curb, and concrete sidewalks. There will be a total of two (2) Stormwater Control Measures; (1) dry detention with sand filter and (1)wet detention basin installed to detain and treat storm water runoff from the proposed development as necessary. All runoff from every house will be detained and treated within the SCM. The project will disturb approximately 40 acres. On site erosion control measures will be provided throughout the construction phases. The erosion control plan will have two (2) phases and two (2) stages. These erosion control measures include five (5) skimmer type sediment basins that have been designed to meet the North Carolina Erosion and Sediment Control Planning and Design Manual. Conclusion The proposed SCM's and associated control structures (risers) and outfall pipes have been designed to meet the water quality requirements for: • Treat the first 1 inch of rainfall to remove 85% TSS removal. • Detention requirements for the 1-year, 24-hour storm event. • Detention requirements for the 2-year, 24-hour storm event. • Detention requirements for the 10-year, 24-hour storm event. • Detention requirement for the 25-year, 24 hour storm event. In conclusion, due to existing site conditions and proposed runoff control measures, the proposed project is not anticipated to have negative impacts on downstream or adjacent properties. SUMMARY Aurora at Price Mill Creek SCM Summary Pre-Development Flows 2-yr, 24-hr 10-yr, 24-hr 25-yr, 24-hr SCM 1 6.78 29.48 47.55 SCM 2 3.40 14.89 24.06 Routed Post-Development Flows 2-yr, 24-hr 10-yr, 24-hr 25-yr, 24-hr SCM 1 1.82 18.33 38.48 SCM 2 0.72 7.33 22.37 *All flows in CFS Rainfall & Soil Report NOAA Atlas 14,Volume 2,Version 3 ° Location name:Monroe,North Carolina,USA* '" t E Latitude:35.0065°,Longitude:-80.6834° p tigi Tfri Elevation:590 ft** a df *source:ESRI Maps ll, **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 0.418 0.494 0.573 0.632 0.698 0.744 0.786 0.823 0.865 0.896 (0.386-0.454) (0.455-0.538) (0.527-0.624) (0.579-0.686) (0.637-0.757) (0.676-0.806) (0.710-0.851) (0.740-0.892) (0.772-0.941) (0.792-0.975) 10-min 0.668 0.790 0.918 1.01 1.11 1.18 1.25 1.30 1.37 1.41 (0.616-0.726) (0.727-0.861) (0.843-1.00) (0.926-1.10) (1.02-1.21) (1.08-1.28) (1.13-1.35) (1.17-1.42) (1.22-1.49) (1.25-1.54) 15-min 0.835 0.994 1.16 1.28 1.41 1.50 1.58 1.65 1.72 1.77 (0.770-0.907) (0.914-1.08) (1.07-1.26) (1.17-1.39) (1.29-1.53) (1.36-1.62) (1.43-1.71) (1.48-1.78) (1.54-1.87) (1.57-1.93) 30-min 1.14 1.37 1.65 1.85 2.09 2.26 2.42 2.56 2.74 2.87 (1.06-1.24) (1.26-1.49) (1.52-1.80) (1.70-2.01) (1.91-2.26) (2.05-2.45) (2.18-2.62) (2.30-2.78) (2.44-2.98) (2.54-3.12) 60-min 1.43 1.72 2.12 2.41 2.78 3.06 3.33 3.59 3.93 4.18 (1.32-1.55) (1.58-1.88) (1.94-2.30) (2.21-2.62) (2.54-3.01) (2.78-3.32) (3.01-3.61) (3.23-3.90) (3.51-4.28) (3.70-4.56) 2-hr 1.65 2.00 2.48 2.84 3.31 3.67 4.03 4.38 4.85 5.21 (1.51-1.80) (1.83-2.19) (2.26-2.71) (2.59-3.10) (3.00-3.61) (3.32-4.00) (3.62-4.39) (3.91-4.78) (4.29-5.29) (4.56-5.69) 3-hr 1.75 2.12 2.64 3.05 3.60 4.03 4.47 4.92 5.54 6.02 (1.60-1.93) (1.94-2.33) (2.41-2.90) (2.77-3.34) (3.26-3.93) (3.63-4.40) (4.00-4.87) (4.36-5.36) (4.85-6.04) (5.22-6.58) 6-hr 2.11 2.54 3.17 3.67 4.34 4.88 5.43 6.00 6.80 7.42 (1.93-2.31) (2.33-2.79) i (2.90-3.48) (3.35-4.01) (3.94-4.74) (4.40-5.32) (4.86-5.91) (5.32-6.53) (5.94-7.38) (6.41-8.07) 12-hr 2.49 3.01 3.77 4.38 5.23 5.91 6.62 7.37 8.42 9.28 (2.29-2.73) (2.76-3.31) (3.45-4.13) (4.00-4.80) (4.74-5.71) (5.32-6.44) (5.90-7.21) (6.49-8.02) (7.30-9.15) (7.93-10.1) 24-hr 2.95 3.55 4.47 5.19 6.20 7.00 7.85 8.73 9.96 11.0 (2.72-3.19) (3.29-3.86) (4.12-4.84) (4.79-5.63) (5.69-6.71) (6.41-7.59) (7.16-8.51) (7.92-9.47) (8.99-10.8) (9.83-11.9) 2-day 3.47 4.18 5.21 6.04 7.17 8.09 9.04 10.0 11.4 12.5 (3.21-3.76) (3.87-4.54) (4.82-5.66) (5.56-6.54) (6.59-7.77) (7.41-8.77) (8.24-9.81) (9.11-10.9)_ (10.3-12.4) (11.2-13.7_ 3-day 3.68 4.42 5.48 6.33 7.51 8.45 9.43 10.4 11.9 13.0 (3.41-3.98) (4.10-4.78) (5.08-5.94) (5.85-6.85) (6.91-8.12) (7.76-9.15) (8.62-10.2) (9.52-11.3) (10.8-12.9) (11.7-14.2 _ 4-day 3.89 4.66 5.76 6.63 7.84 8.82 9.82 10.9 12.3 13.5 (3.61-4.19) (4.33-5.03) (5.34-6.22) (6.13-7.16) (7.23-8.47) (8.10-9.53)_ (9.00-10.6) (9.92-11.8)_ (11.2-13.4) (12.2-14.7) 7-day 4.50 5.36 6.54 7.48 8.78 9.82 10.9 12.0 13.6 14.9 (4.20-4.82) (5.02-5.76) (6.11-7.02) (6.98-8.02) (8.16-9.42) (9.10-10.5)_ (10.1-11.7) (11.1-12.9)_ (12.4-14.7) (13.5-16.1) 10-day 5.15 6.13 7.38 8.36 9.70 10.8 11.8 12.9 14.4 15.7 (4.83-5.51) (5.74-6.55) (6.90-7.89) (7.81-8.94) (9.03-10.4) (9.99-11.5) (11.0-12.7) (11.9-13.9) (13.3-15.5) _(14.4-16.9)_ 20-day 6.89 8.13 9.61 . . . 1 . 6. . (6.49-7.34) (7.66-8.66) (9.03-10.2) (10.1-10181.5) (11.6-12143.2) (12.7-13164.5) (13.9-4195.8) (15.01.-117.2) (16.5-17199.1) (17.7-219.20.6) 30-day 8.45 9.94 11.6 12.8 14.5 15.8 17.1 18.3 20.0 21.3 (7.98-8.96) (9.39-10.5) (10.9-12.3) (12.1-13.6) (13.7-15.4) (14.8-16.8) (16.0-18.1) (17.1-19.5) (18.7-21.4) (19.8-22.8) 45-day 10.6 12.5 14.3 15.6 17.5 18.8 20.2 21.5 23.2 24.5 (10.1-11.2) (11.8-13.1) (13.5-15.0) (14.8-16.4) (16.5-18.3) (17.8-19.8) (19.0-21.2) (20.2-22.6) (21.8-24.5) (22.9-25.9) 60-day 12.7 14.8 16.7 18.2 20.2 21.6 23.0 24.4 26.2 27.5 (12.1-13.3) (14.1-15.5) (15.9-17.5) (17.4-19.1) (19.2-21.1) (20.5-22.7) (21.8-24.2) (23.1-25.6) (24.7-27.5) (25.9-29.0) 1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAAAtlas 14 document for more information. Back to Top PF graphical PDS-based depth-duration-frequency(DDF)curves Latitude:35.0065°,Longitude:-80.6834° Average recurrence interval 25 (years) c — 1 ,= 20- 2 L a — N 15 - — 10 O — 25 ro — 50 a10 - — 100 v v — 200 a 5- — 500 — 1000 J-- 0 -- L L L L L f0 r0 rls 40 N o f0 fo E E E c Air01 vb rL y 13 13-o -0 7 7 U 77 rl N p min ko Duration N r O� N M v au. 25- — -._ C - 20- --=— Duration i —�' — 5-min — 2-day c 15 ' Willi — 10-min — 3-day 0 15-min — 4-day ' ': - — -- 2-hr_— — 2fir��— — — 3-hr — 30-day ���— — 6a1r — 45-day 0 --- — 12-hr — 60-day 24-hr 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval(years) NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Fri Jul 28 20:20:33 2023 Back to Top Maps&aerials Small scale terrain Me RC -' Vie rid i_r) Rd % _ 3km 2mi Large scale terrain • 'onc_ity 0 0 �• Winston-Sal em • • Parham Greensboro • r it r:liicildi Ral •Asheville NORTH CAROLINA 0 (tad otte Fayetteville• Greenville F, X -I- SOUTH CAROLINA w P 'lumbi 60mi IlL__ Large scale map /— ...."Ti fnstonS gem o Greensboro D man Re Asheville- North � ® Carolina • arlotte I F ett -\•,- o `Greenvire L 1181 1III�, mb is 100km o • \oath / 60mi Carolina Lar•a scale aerial • Winston-Salmi Durtiiani, Fn Asheville • North Carolina C harlotte • er t Greenville 1 \111 Cctumbia 11 100km • 60mi South Carolina 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 NOAA Atlas 14,Volume 2,Version 3 ° Location name:Monroe,North Carolina,USA* IN t Latitude:35.0065°,Longitude:-80.6834° ffiffi Elevation:590 ft** d *source:ESRI Maps E"ej f **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/hour)1 Average recurrence interval(years) Duration 1 2 5 10 25 50 100 200 500 1 1000 1 5-min 5.02 5.93 6.88 7.58 8.38 8.93 9.43 9.88 10.4 10.8 (4.63-5.45) (5.46-6.46) (6.32-7.49) (6.95-8.23) (7.64-9.08) (8.11-9.67) (8.52-10.2) (8.88-10.7) (9.26-11.3) (9.50-11.7) 10-min 4.01 4.74 5.51 6.06 6.67 7.10 7.49 7.83 8.21 8.46 (3.70-4.36) (4.36-5.17) (5.06-6.00) (5.56-6.58) (6.09-7.24) (6.46-7.70) (6.77-8.11) (7.04-8.49) (7.32-8.93) (7.49-9.22) 15-min 3.34 3.98 4.65 5.11 5.64 6.00 6.31 6.58 6.89 7.08 (3.08-3.63) (3.66-4.33) (4.27-5.06) (4.68-5.55) (5.15-6.11) (5.45-6.50) (5.70-6.84) (5.92-7.14) (6.14-7.49) (6.26-7.71) 30-min 2.29 2.74 3.30 3.70 4.18 4.52 4.83 5.13 5.48 5.73 (2.11-2.49) (2.52-2.99) (3.03-3.59) (3.39-4.02) (3.81-4.53) (4.10-4.89) (4.37-5.24) (4.61-5.56) (4.89-5.96) (5.07-6.24) 60-min 1.43 1.72 2.12 2.41 2.78 3.06 3.33 3.59 3.93 4.18 (1.32-1.55) (1.58-1.88) (1.94-2.30) (2.21-2.62) (2.54-3.01) (2.78-3.32) (3.01-3.61) (3.23-3.90) (3.51-4.28) (3.70-4.56) 2-hr 0.825 0.998 1.24 1.42 1.66 1.83 2.01 2.19 2.42 2.60 (0.756-0.902) (0.914-1.09) (1.13-1.35) (1.29-1.55) (1.50-1.80) (1.66-2.00) (1.81-2.19) (1.96-2.39) (2.14-2.64) (2.28-2.84) 3-hr 0.584 0.704 0.879 1.01 1.20 1.34 1.49 1.64 1.84 2.00 (0.534-0.642) (0.645-0.775) (0.803-0.966) (0.923-1.11) (1.08-1.31) (1.21-1.46) (1.33-1.62) (1.45-1.78) (1.61-2.01) (1.74-2.19) 6-hr 0.351 0.424 0.529 0.612 0.725 0.815 0.907 1.00 1.13 1.24 (0.322-0.386) (0.388-0.465) (0.484-0.580)(0.558-0.670) (0.657-0.790) (0.734-0.887) (0.811-0.987) (0.888-1.09) (0.991-1.23) (1.07-1.35) 12-hr 0.206 0.249 0.312 0.363 0.433 0.490 0.549 0.612 0.699 0.769 (0.189-0.226) (0.229-0.274) (0.286-0.343) (0.331-0.398) (0.393-0.473) (0.441-0.534) (0.489-0.598) (0.538-0.665) (0.605-0.759) (0.658-0.836) 24-hr 0.122 0.148 0.186 0.216 0.258 0.291 0.327 0.363 0.415 0.456 (0.113-0.132) (0.137-0.160) (0.171-0.201) (0.199-0.234) (0.236-0.279) (0.267-0.316) (0.298-0.354) (0.330-0.394) (0.374-0.450) (0.409-0.497) 2-day 0.072 0.086 0.108 0.125 0.149 0.168 0.188 0.208 0.237 0.260 (0.066-0.078) (0.080-0.094) (0.100-0.117) (0.115-0.136) (0.137-0.161) (0.154-0.182) (0.171-0.204) (0.189-0.227) (0.214-0.259) (0.233-0.285) 3-day 0.051 0.061 0.076 0.087 0.104 0.117 0.130 0.145 0.164 0.180 (0.047-0.055) (0.056-0.066) (0.070-0.082)(0.081-0.095) (0.095-0.112) (0.107-0.127) (0.119-0.141) (0.132-0.157) (0.149-0.179) (0.162-0.197) 4-day 0.040 0.048 0.059 0.069 0.081 0.091 0.102 0.113 0.128 0.140 (0.037-0.043) (0.045-0.052) (0.055-0.064)(0.063-0.074) (0.075-0.088) (0.084-0.099) (0.093-0.110) (0.103-0.122) (0.116-0.139) (0.127-0.153). 7-day 0.026 0.031 0.038 0.044 0.052 0.058 0.064 0.071 0.080 0.088 (0.025-0.028) (0.029-0.034) (0.036-0.041)(0.041-0.047) (0.048-0.056) (0.054-0.062) (0.059-0.069) (0.065-0.076) (0.074-0.087) (0.080-0.095). 10-day 0.021 0.025 0.030 0.034 0.040 0.044 0.049 0.053 0.060 0.065 (0.020-0.022) (0.023-0.027) (0.028-0.032)(0.032-0.037) (0.037-0.043) (0.041-0.047) (0.045-0.052) (0.049-0.057) (0.055-0.064) (0.059-0.070) 20-day 0.014 0.016 0.020 0.022 0.025 0.028 0.030 0.033 0.037 0.040 (0.013-0.015) (0.015-0.018) (0.018-0.021)(0.021-0.023) (0.024-0.027) (0.026-0.030) (0.028-0.033) (0.031-0.035) (0.034-0.039) (0.036-0.042) 30-day 0.011 0.013 0.016 0.017 0.020 0.021 0.023 0.025 0.027 0.029 (0.011-0.012) (0.013-0.014) (0.015-0.017)(0.016-0.018) (0.018-0.021) (0.020-0.023) (0.022-0.025) (0.023-0.027) (0.025-0.029) (0.027-0.031) 45-day 0.009 0.011 0.013 0.014 0.016 0.017 0.018 0.019 0.021 0.022 (0.009-0.010) (0.010-0.012) (0.012-0.013)(0.013-0.015) (0.015-0.016) (0.016-0.018) (0.017-0.019) (0.018-0.020) (0.020-0.022) (0.021-0.023) 60 day 0.008 0.010 0.011 0.012 0.014 0.015 0.015 0.016 0.018 0.019 (0.008-0.009) (0.009-0.010) (0.011-0.012) (0.012-0.013) (0.013-0.014) (0.014-0.015) (0.015-0.016) (0.016-0.017) (0.017-0.019) (0.017-0.020) 1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAAAtlas 14 document for more information. Back to Top PF graphical PDS-based intensity-duration-frequency(IDF)curves Latitude:35.0065°,Longitude:-80.6834° 101 Average recurrence __ interval :_ (years) C — 1 u \` — 5 d \ — 10 c \- — 25 o \._ — 50 y 10-1 �. — 100 a \\ — 200 V �\ A — 500 r1 \ --... — 1000 10-2- r i i r r i i i c c c c c >. >,>, >, >, >, >. >,>. •E E •E •E L t L r t ro ro ro ro ro oo ro ro ro N fit 6 N y' -0 -0U -0 7 7 7 U7p V1 O .A r6 $ Duration N N e 4 r` O N M u S 101- _. TZ -c c Duration Z' 10° _ c — 5-rnrn — 2-day v c — 10-11rn — 3-day c 15-mm — 4-day 0 roo 10-1 — 30 rrnn — 7-day a — 60-mm — 10-day .0 — 2-hr — 20-day o_ — 3-hr — 30-day — 6-hr — 45-day 10-2 — 12-hr — 60-day t t , 24-hr 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval(years) NOAA Atlas 14,Volume 2,Version 3 Created(GMT)Fri Jul 28 20:21:33 2023 Back to Top Maps&aerials Small scale terrain Me RC —' _ _g vieddigton Rd � 3km 2mi Large scale terrain • 'onc_ity 0 0 �• Winston-Sal em • • Parham Greensboro • r it r:liicildi Ral •Asheville NORTH CAROLINA 0 (tad otte Fayetteville• Greenville F, X -I- SOUTH CAROLINA w P 'lumbi 60mi IlL__ Large scale map /— ...."Ti fnstonS gem o Greensboro D man Re Asheville- North � ® Carolina • arlotte I F ett -\•,- o `Greenvire L 1181 1III�, mb is 100km o • \oath / 60mi Carolina Lar•a scale aerial • Winston-Salmi Durtiiani, Fn Asheville • North Carolina C harlotte • er t Greenville 1 \111 Cctumbia 11 100km • 60mi South Carolina 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 USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for \ RCS States Department of Agriculture and other Union County Federal agencies, State Natural agencies including the Resources Agricultural Experiment North Carolina Conservation Stations, and local Service participants • v Ate,,. �'f :. .-.) ,. . i'l' . ->\-- , -,,, . N _ .„.., ., __ . . ,, ....._, „.... 0. , . .,_.. „ - i ,,It i .,.. __ (T) ^ .. -. , F u r..44: '• 0,,„iiiii*.,,,..1.1,,„•, ., -,,,...,-, . -,i+. tvN• * ). , ,444 Soiolore-7''_....I VI I cif t i • 4,..,, ', 4:N1 ,c, , vi \ (.(44. $a - 0....■..■..1,000 ft . July 27, 2023 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs)or your NRCS State Soil Scientist(http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice)or(202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Map 5 Soil Map 6 Legend 7 Map Unit Legend 8 Map Unit Descriptions 8 Union County, North Carolina 10 BaC—Badin channery silt loam, 8 to 15 percent slopes 10 BdB2—Badin channery silty clay loam, 2 to 8 percent slopes, moderately eroded 11 BdC2—Badin channery silty clay loam, 8 to 15 percent slopes, moderately eroded 12 ChA—Chewacla silt loam, 0 to 2 percent slopes, frequently flooded 13 TbB2—Tarrus gravelly silty clay loam, 2 to 8 percent slopes, moderately eroded 14 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 Custom Soil Resource Report Soil Map 4 R 528500 528600 528700 528800 528900 529000 529100 529200 35°0'44"N - , 35°0'44"N L . \ r pI .�� 4 A-.. 0 •. n/ \ fir'" �3 �f,,BdC2 '''/ i II .. i . , IL. . 2..r. .t g • l� � 8 BdC2 , "` 8 A 4:>'.,4 Vi S ' A ChA TbB2 �' ls� . y BdB2 M \ <w S'�a�eN`Ny 8 1 � BdC2 A• ' ,5.. ' \ -4.„,...._ BdC2 TbB2 ;, ChA A 1*. \tr* N 404:0' BaC 1 L%i s. co Nr©U B tR EG a7 o o ea0od ate RM-0 oc�a0.;° r 35°0'7"N 35°0'7"N 528500 528600 528700 528800 528900 529000 529100 529200 3 3 Map Scale:1:5,640 if printed on A portrait(8.5"x 11")sheet. Meters N 0 50 100 200 300 : Feet 0 250 500 1000 1500 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 17N WGS84 A 6 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(AOI) 14 Spoil Area The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 1:24,000. Q Stony Spot Soilsit Very Stony Spot Soil Map Unit Polygons Warning:Soil Map may not be valid at this scale. Wet Spot ,..,. Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause p Other misunderstandingof the detail of mapping and accuracyof soil p Soil Map Unit Points pp 9 .• Special Line Features line placement.The maps do not show the small areas of Special Point Features contrasting soils that could have been shown at a more detailed Blowout Water Features scale. Streams and Canals kg Borrow Pit Transportation Please rely on the bar scale on each map sheet for map * clay Spot 1.44 Rails measurements. 0 Closed Depression o,/ Interstate Highways Gravel Pit Source of Map: Natural Resources Conservation Service .r US Routes Web Soil Survey URL: Gravelly Spot Major Roads Coordinate System: Web Mercator(EPSG:3857) ® Landfill Local Roads Maps from the Web Soil Survey are based on the Web Mercator • Lava Flow Background projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the 46 Marsh or swamp Aerial Photography Albers equal-area conic projection,should be used if more It Mine or Quarry accurate calculations of distance or area are required. 4 Miscellaneous Water This product is generated from the USDA-NRCS certified data as O Perennial Water of the version date(s)listed below. v Rock Outcrop Soil Survey Area: Union County, North Carolina + Saline Spot Survey Area Data: Version 23,Sep 12,2022 Sandy Spot Soil map units are labeled(as space allows)for map scales Severely Eroded Spot 1:50,000 or larger. • Sinkhole Date(s)aerial images were photographed: Mar 13,2022—May 31 Slide or Slip 9,2022 oa Sodic Spot 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. 7 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI BaC Badin channery silt loam,8 to 3.2 4.1% 15 percent slopes BdB2 Badin channery silty clay loam, 19.1 25.0% 2 to 8 percent slopes, moderately eroded BdC2 Badin channery silty clay loam, 16.7 21.9% 8 to 15 percent slopes, moderately eroded ChA Chewacla silt loam,0 to 2 21.0 27.4% percent slopes,frequently flooded TbB2 Tarrus gravelly silty clay loam,2 16.5 21.5% to 8 percent slopes, moderately eroded Totals for Area of Interest 76.4 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor 8 Custom Soil Resource Report components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 9 Custom Soil Resource Report Union County, North Carolina BaC—Badin channery silt loam, 8 to 15 percent slopes Map Unit Setting National map unit symbol: 3w0g Elevation: 200 to 650 feet Mean annual precipitation: 37 to 60 inches Mean annual air temperature: 59 to 66 degrees F Frost-free period: 200 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Badin and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Badin Setting Landform: Hillslopes on ridges Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Linear Across-slope shape: Convex Parent material: Residuum weathered from metavolcanics and/or argillite Typical profile Ap- 0 to 6 inches: channery silt loam Bt- 6 to 35 inches: silty clay Cr-35 to 43 inches: weathered bedrock R-43 to 80 inches: unweathered bedrock Properties and qualities Slope: 8 to 15 percent Depth to restrictive feature: 20 to 40 inches to paralithic bedrock; 40 to 80 inches to lithic bedrock Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat):Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches: Low(about 6.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: F136XY830NC -Acidic upland forest, dry-moist Hydric soil rating: No 10 Custom Soil Resource Report BdB2—Badin channery silty clay loam, 2 to 8 percent slopes, moderately eroded Map Unit Setting National map unit symbol: 2mx85 Elevation: 200 to 650 feet Mean annual precipitation: 37 to 60 inches Mean annual air temperature: 59 to 66 degrees F Frost-free period: 200 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Badin, moderately eroded, and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Badin, Moderately Eroded Setting Landform: Interfluves Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from metavolcanics and/or argillite Typical profile Ap- 0 to 6 inches: silty clay loam Bt- 6 to 20 inches: silty clay BC-20 to 28 inches: channery silty clay loam Cr-28 to 42 inches: weathered bedrock R-42 to 80 inches: unweathered bedrock Properties and qualities Slope: 2 to 8 percent Depth to restrictive feature: 20 to 40 inches to paralithic bedrock; 40 to 80 inches to lithic bedrock Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat):Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches: Low(about 4.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: C Ecological site: F136XY830NC -Acidic upland forest, dry-moist Hydric soil rating: No 11 Custom Soil Resource Report BdC2—Badin channery silty clay loam, 8 to 15 percent slopes, moderately eroded Map Unit Setting National map unit symbol: 2mx86 Elevation: 200 to 650 feet Mean annual precipitation: 37 to 60 inches Mean annual air temperature: 59 to 66 degrees F Frost-free period: 200 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Badin, moderately eroded, and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Badin, Moderately Eroded Setting Landform: Hillslopes on ridges Landform position (two-dimensional): Shoulder, backslope Landform position (three-dimensional): Side slope Down-slope shape: Linear Across-slope shape: Convex Parent material: Residuum weathered from metavolcanics and/or argillite Typical profile Ap- 0 to 6 inches: silty clay loam Bt- 6 to 20 inches: silty clay BC-20 to 28 inches: channery silty clay loam Cr-28 to 42 inches: weathered bedrock R-42 to 80 inches: unweathered bedrock Properties and qualities Slope: 8 to 15 percent Depth to restrictive feature: 20 to 40 inches to paralithic bedrock; 40 to 80 inches to lithic bedrock Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat):Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches: Low(about 4.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: F136XY830NC -Acidic upland forest, dry-moist Hydric soil rating: No 12 Custom Soil Resource Report ChA—Chewacla silt loam, 0 to 2 percent slopes, frequently flooded Map Unit Setting National map unit symbol: 3w0p Elevation: 200 to 1,400 feet Mean annual precipitation: 37 to 60 inches Mean annual air temperature: 59 to 66 degrees F Frost-free period: 200 to 240 days Farmland classification: Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Map Unit Composition Chewacla and similar soils: 87 percent Minor components: 5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Chewacla Setting Landform: Flood plains Down-slope shape: Concave Across-slope shape: Linear Parent material: Loamy alluvium derived from igneous and metamorphic rock Typical profile A -0 to 4 inches: silt loam Bw1 -4 to 26 inches: silty clay loam Bw2-26 to 38 inches: loam Bw3-38 to 60 inches: clay loam C- 60 to 80 inches: loam Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Drainage class: Somewhat poorly drained Runoff class: Low Capacity of the most limiting layer to transmit water(Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table:About 6 to 24 inches Frequency of flooding: NoneFrequent Frequency of ponding: None Available water supply, 0 to 60 inches: High (about 11.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4w Hydrologic Soil Group: B/D Ecological site: F136XY610GA- Flood plain forest, wet Hydric soil rating: No 13 Custom Soil Resource Report Minor Components Wehadkee, undrained Percent of map unit: 5 percent Landform: Depressions on flood plains Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: Yes TbB2—Tarrus gravelly silty clay loam, 2 to 8 percent slopes, moderately eroded Map Unit Setting National map unit symbol: 2mx8q Elevation: 200 to 1,400 feet Mean annual precipitation: 37 to 60 inches Mean annual air temperature: 59 to 66 degrees F Frost-free period: 200 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Tarrus, moderately eroded, and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Tarrus, Moderately Eroded Setting Landform: Interfluves Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from schist and/or other metamorphic rock Typical profile Ap- 0 to 6 inches: gravelly silty clay loam Bt- 6 to 45 inches: silty clay Cr-45 to 80 inches: weathered bedrock Properties and qualities Slope: 2 to 8 percent Depth to restrictive feature:40 to 60 inches to paralithic bedrock Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat):Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches: Low(about 4.5 inches) 14 Custom Soil Resource Report Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Ecological site: F136XY820GA-Acidic upland forest, moist Hydric soil rating: No 15 SCM #1 Time of Concentrations & Curve Numbers ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Time of Concentration (Tc) or Travel Time (Tt) Project Aurora at Price Mill Creek By JWF 7/28/2023 Location Wesley Chapel, NC Checked Date: Circle One:C-Present) Developed SCM 1 Pre-Development 1. SHEET FLOW SEGMENT ID A 1. Surface description (table.3-1). Woods-Light 2. Manning's roughness coefficient, n (table 3-1) 0.4 3. Flow length, L(total L<_3Q0.ft) ft 100 4. Two-year 24-hour rainfall, P in 5.93 5. Land slope, s ft/ft 0.025 6. Tt=0.007(nL)^0.8 Compute Tt hr 0.240 P2^0.5 s"0.4 Total Sheet Flow Tt(hr) 0.24 2. SHALLOW CONCENTRATED FLOW SEGMENT ID B 7. Surface description (paved or unpaved) Unpaved 8. Flow length,.L ft 152 9. Watercourse slope,.s ft/ft 0.033 10. Average velocity,V(figure.3-.1) _ 2.931 11. Tt= L Compute Tt hr 0.014 3600 V Total Shallow Concentrated Flow Tt(hr) 0.01 3. CHANNEL FLOW SEGMENT ID C 12. Channel type(Pipe or Open 0.26 Open Channel 13. Cross sectional flow area,.a ft2 630.00 14. Wetted perimeter,.pw ft 160.70 15. Hydraulic radius r=a/pw Compute r ft 3.92 16. Channel slope,.s ft/ft 0.020 17. Manning's roughness coefficient,.n 0.030 18. V=[1.49 r^(2/3)s^(1/2)]/n Compute V ft/s 17.46 19. Flow length.,.L ft 479 20. Tt= L Compute Tt hr 0.008 Total Channel Flow Tt(hr) 0.01 3600 V 21. Watershed or subarea Tc or Tt(add Tt in steps 6, 11, and 19) Total Tt (hr) = 0.26 Total Tt (min) = 15.6 Reference: Urban Hydrology for Small Watersheds Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Associates',PA SCM 1 Pre Po Box 7030 TOC Calcs.xlsx Charlotte NC 28241 8/30/2023 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Time of Concentration (Tc) or Travel Time (Tt) Project Aurora at Price Mill Creek By JWF 7/28/2023 Location Wesley Chapel, NC Checked Date: Circle One: Present (Develope-iDI SCM 1 Post-Development 1. SHEET FLOW SEGMENT ID A 1. Surface description (table.3-1). Grass-Bermuda 2. Manning's roughness coefficient, n (table 3-1) 0.41 3. Flow length, L(total L<_3Q0.ft) ft 100 4. Two-year 24-hour rainfall, P in 5.44 5. Land slope, s ft/ft 0.055 6. Tt=0.007(nL)^0.8 Compute Tt hr 0.187 P2^0.5 s"0.4 Total Sheet Flow Tt(hr) 0.19 2. SHALLOW CONCENTRATED FLOW SEGMENT ID B 7. Surface description (paved or unpaved) Unpaved 8. Flow length,.L ft 27 9. Watercourse slope,.s ft/ft 0.055 10. Average velocity,V(figure.3,1.) _ 3.784 11. Tt= L Compute Tt hr 0.002 3600 V Total Shallow Concentrated Flow Tt(hr) 0.00 3. CHANNEL FLOW SEGMENT ID C D E 12. Channel type(Pipe or Open 0.26 Pipe Pipe Pipe 13. Cross sectional flow area,.a ft' 1.77 3.14 4.91 14. Wetted perimeter,.pw ft 4.71 6.28 7.85 15. Hydraulic radius r=a/pw Compute r ft 0.38 0.50 0.63 16. Channel slope,.s ft/ft 0.005 0.005 0.005 17. Manning's roughness coefficient,.n 0.012 0.012 0.012 18. V=[1.49 r^(2/3)s^(1/2)]/n Compute.V ft/s 4.57 5.53 6.42 19. Flow length.,.L ft 439 498 342 20. Tt= L Compute Tt hr 0.027 0.025 0.015 Total Channel Flow Tt(hr) 0.07 3600 V 21. Watershed or subarea Tc or Tt(add Tt in steps 6, 11, and 19) Total Tt (hr) = 0.26 Total Tt (min) = 15.6 Reference: Urban Hydrology for Small Watersheds Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Associates',PA SCM 1 Post Po Box 7030 TOC Calcs.xlsx Charlotte NC 28241 8/30/2023 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Runoff Curve Number and Runoff Project Aurora at Price Mill Creek By JWF Date 5/9/2024 Location Wesley Chapel, NC Checked Date Circle One: Present Developed SCM 1 Pre-Development 1. Runoff Curve Number Soil Cover Description CN* Area Product Hydrologic (cover type,treatment Tbl. Fig. Fig. of Group and hydrologic condition) 2-2 2-3 2-4 Acres L CN x area B Brush—brush-weed-grass mixture with brush, Fair condition 56 18.59 1041.04 (BdC2,BdB2,TbB2) B Woods, Good condition (BdC2,BdB2,TbB2) 55 2.49 136.95 * Use only one CN source per line Totals= 21.08 1177.99 CN(weighted) total product = 1177.99 = 55.9 Use CN= 56 total area 21.08 2. Runoff III Storm#1 Storm#2 Storm#3 Frequency yr 2 10 100 Rainfall , P(24-hour) in 5.93 7.58 9.43 Runoff,Q in 1.56 2.60 3.93 (Use P and CN with table 3-11,fig.2-1, and equation 3-14) Reference: Urban Hydrology for Small Watersheds Rainfall,P,taken from: Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Assocates,PA SCM 1 PRE PoBox 7030 CN Calcs.xlsx Charlotte NC 28241 5/9/2024 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Runoff Curve Number and Runoff Project Aurora at Price Mill Creek By JWF Date 5/9/2024 Location Wesley Chapel, NC Checked Date Circle One: Present cDeveloped SCM 1 Post-Development 1. Runoff Curve Number Soil Cover Description CN* Area Product Hydrologic (cover type,treatment Tbl. Fig. Fig. of Group and hydrologic condition) 2-2 2-3 2-4 Acres L CN x area B Paved areas,streets, roofs,driveways,etc(excl.ROW) 98 5.30 519.40 (BdC2,BdB2,TbB2) B Open space, Good condition(grass cover>75%) (BdC2,BdB2,TbB2) 61 15.78 962.58 * Use only one CN source per line Totals= 21.08 1481.98 CN(weighted) total product = 1481.98 = 70.3 Use CN= 70 total area 21.08 2. Runoff III Storm#1 Storm#2 Storm#3 Frequency yr 2 10 100 Rainfall , P(24-hour) in 5.93 7.58 9.43 Runoff,Q in 2.75 4.11 5.72 (Use P and CN with table 3-11,fig.2-1, and equation 3-14) Reference: Urban Hydrology for Small Watersheds Rainfall,P,taken from: Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Assocates,PA SCM 1 POST PoBox 7030 CN Calcs.xlsx Charlotte NC 28241 5/9/2024 Wet Pond Design Wet Detention Basin Worksheet Basin ID: Wet Pond#1 Project Name: Aurora at Price Mill Creek Project#: KT37.400 Designer: JWF Date: 07/12/23 Rev: 05/09/24 This wet detention basin has been designed in accordance with Part C of the NC Stormwater Design Manual revised January 1,2017. Basin Drainage Area Summary Pre-Development Impervious Area: 0.00 ac Pre-Development Pervious Area: 21.08 ac Post-Development Impervious Area: 5.30 ac Design Rainfall: 1.00 Inch Post-Development Pervious Area: 18.36 ac Off-Site Impervious Area: 0.00 ac Off-Site Pervious Area: 0.00 ac Future Impervious Area: 0.00 ac Total Area(Pre): 21.08 ac Total Area(Post): 23.66 ac Pre-Percent Impervious 0.00% Post-Percent Impervious: 22.40% Calculate the Avg Depth and Design Volume of Basin from Proposed Contours Elev.Of Permanent Pool: 573.50 Basin Permanent Pool Stage/Storage Elev. Forebay Area Main Bay Area Total Area Avg.Total Main Bay Accumul.Vol. Forebay Total Accumul. Area Accumul.Vol. Vol. 569 1,160.00 sf 10,865.00 sf 12,025.00 sf 0.00 sf 0.00 cf 0.00 cf 0.00 cf 570 1,730.00 sf 12,095.00 sf 13,825.00 sf 12,925.00 sf 11,480.00 cf 1,445.00 cf 12,925.00 cf 571 2,400.00 sf 13,350.00 sf 15,750.00 sf 14,787.50 sf 24,202.50 cf 3,510.00 cf 27,712.50 cf 572 3,175.00 sf 14,625.00 sf 17,800.00 sf 16,775.00 sf 38,190.00 cf 6,297.50 cf 44,487.50 cf 573 4,040.00 sf_ 15,860.00 sf_ 19,900.00 sf 18,850.00 sf 53,432.50 cf 9,905.00 cf 63,337.50 cf 573.5 5,260.00 sf 18,270.00 sf 23,530.00 sf 21,715.00 sf 61,965.00 cf 12,230.00 cf 74,195.00 cf Basin Detention Stage/Storage Above Permanent Pool Elevation Elev. Contour Area Incr.Vol. Accumul.Vol. 573.50 23,530.00 sf 0.00 cf 0.00 cf 574 27,314.00 sf 12,711.00 cf 12,711.00 cf 575 29,660.00 sf 28,487.00 cf 41,198.00 cf 576 32,068.00 sf 30,864.00 cf 72,062.00 cf 577 34,522.00 sf 33,295.00 cf 105,357.00 cf 578 37,037.00 sf 35,779.50 cf 141,136.50 cf 579 39,609.00 sf 38,323.00 cf 179,459.50 cf Calculate the Minimum Required Volume Surface Area for the Permanent Pool Option 1: Main Pool Volume by Hydraulic Retention Time(HRT) Method 0.87= Factor to adjust for the volume in the forebay VMP=0.87* HRT * DV VMP= Main pool volume,not including forebay Ts HRT= Volume of permanent Pool(ft3) = 14-days TS= Area of permanent Pool(ft2) = 5-days DV= Area of permanent Pool(ft2) = 18,270-sf Actual Volume of Permanent Pool: 61,965.00 cf Req'd Volume of Permanent Pool: 44,505.72 cf Actual Greater Than Req'd-Acceptable Main Pool Depth: Average Depth of Permanent Pool(Excluding forebay): 3.39' Avg.Depth is Acceptable and is Greater Than The Assumed Depth Davg= Average Depth in feet = 3.39-ft _ VPP Vpp= Volume of permanent Pool(ft3) = 61,965-cf Davg App APP= Area of permanent Pool(ft2) = 18,270-sf NOTE:Min.Avg. Depth Allowed is 3',Max.Avg.Depth is 9' Compute Forebay Ratio Forebay Volume: 12,230.00-cf Permanent Pool Volume: 61,965.00-cf Forebay Ratio: 19.7% NOTE:Recommended Volume in Forebay is Between 15%and 20%of Total Volume Determine The Volume & Elevation of The Temporary Water Quality Pool Determine the Runoff Coefficient(Rv)for the 1.00 Inch Rainfall. V=3630*RD*Rv*A Rv-Post=0.05+0.9 x(I) I= 22.40% Rv_post= 0.25 Determine the Water Quality Volume(WQv) WQv=VPOST V=3630 x Design Rainfall x Rv x Drainage Area Design Rainfall is 1 Inch VPOST= 21,609.39 cf Rv-post is 0.25 WQv= 21,609.39 cf Drainage Area is 23.66 Acres Vpost=1 x 0.25 x 23.66 Determine the Elevation of the WQv Elev. Vol.Above Perm.Pool Highest Elev.Below WQv 574.00 12,711.00 cf X 21,609.39 cf Estimated WQv Elev. 575.00 41,198.00 cf Provided WQv Min.WQv Elev.: 574.31 WQv Elev. Used: 574.40 24,106-cf Temporary WQv Pool Depth: 0.90 ft Determine The Release Rate for the Water Quality Pool Compute Water Quality Volume Release Rate Estimated Orifice Dia.: 3.00 in Orifice Eq. Q=ca(2gh)^'/2 c= 0.62 Draw-down Time=WQv Vol./Q a= 0.0491 sf Note:Head(h)is taken as 1/3 actual g= 32.17 ft/s Orifice Invert Assumed at Perm.Pool Elev. h= 0.26' Q= 0.12 cfs Draw-down Time: 48.37 hrs Draw-down Time should be 2 to 5 days Acceptable Wet Extended Detention Basin Summary 10'Littoral Shelf WQv ELEV.574.4 ::::::::::: OUTFLOW PIPE Add'I 0.5'of Sediment Storage Elevation= 568.50 Riser Anti-Flotation Calculations AURORA at PRICE MILL CREEK CONCRETE ANCHOR BUOYANCY CALCULATIONS SCM #1 Unit wt. of concrete (pcf) = 150 lb/ft3 Unit wt. of H2O = 62.4 lb/ft3 TOP OF RISER ELEV. = 576.00 ft INV. OUT OF RISER ELEV. = 569.00 ft INT. WIDTH OF RISER = 48 in INT. LENGTH OF RISER= 48 in WALL THICK. OF RISER = 6 in BASE THICK. OF RISER= 6 in VOL. OF RISER = 187.5 ft3 BUOYANT FORCE = 11700.0 lbs Vol. of Riser x Unit wt. of H2O VOL. CONC. IN RISER= 75.5 ft3 SINKING FORCE OF RISER= 11325 lbs Vol. of Conc. x(Unit wt. of Conc) CONC. PAD THICKNESS = 12 in CONC. PAD WIDTH/LENGTH = 5 ft VOL. OF CONC. PAD = 25.00 ft3 L x W x H/ Pad Thickness SINKING FORCE OF PAD = 2190 lbs Vol. of Pad x(Unit wt. of Conc. - Unit wt. of H2O) TOTAL SINKING FORCE = 13515.0 lbs Factor of safety= SINKING FORCE BUOYANT FORCE F.S. = 1.16 OK F.S. MUST BE GREATER THAN 1.10 HydroCAD Detention 1 year, 24 hour 2 year, 24 hour 10 year, 24 hour 25 year, 24 hour (100 year, 24 hour — shown for spillway) 1A) (11 B SCM 1 Pre S M 1 Post 1 P SCM 1 (Subca Reach 'on• It Routing Diagram for KT37-SCM Calculations Prepared by ESP Associates Inc, Printed 5/9/2024 HydroCAD®10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 2 Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 1-yr Type II 24-hr Default 24.00 1 2.95 2 2 2-yr Type II 24-hr Default 24.00 1 3.55 2 3 10-yr Type II 24-hr Default 24.00 1 5.19 2 4 25-yr Type II 24-hr Default 24.00 1 6.20 2 5 100-yr Type II 24-hr Default 24.00 1 7.85 2 KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 3 Area Listing (selected nodes) Area CN Description (sq-ft) (subcatchment-numbers) 687,377 61.0 >75% Grass cover, Good, HSG B (1B) 809,780 56.0 Brush, Fair, HSG B (1A) 230,868 98.0 Paved parking, HSG B (1B) 108,464 55.0 Woods, Good, HSG B (1A) KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 4 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlA: SCM 1 Pre Runoff Area=21.080 ac 0.00% Impervious Runoff Depth=0.20" Tc=15.6 min CN=55.9 Runoff=1.73 cfs 15,523 cf SubcatchmentlB: SCM 1 Post Runoff Area=21.080 ac 25.14% Impervious Runoff Depth=0.70" Tc=15.6 min CN=70.3 Runoff=16.69 cfs 53,578 cf Pond 1P: SCM 1 Peak Elev=575.02' Storage=41,726 cf Inflow=16.69 cfs 53,578 cf Primary=0.35 cfs 52,626 cf Secondary=0.00 cfs 0 cf Outflow=0.35 cfs 52,626 cf KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 1A: SCM 1 Pre Runoff = 1.73 cfs @ 12.17 hrs, Volume= 15,523 cf, Depth= 0.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 1-yr Rainfall=2.95" Area (ac) CN Description 18.590 56.0 Brush, Fair, HSG B 2.490 55.0 Woods, Good, HSG B 21.080 55.9 Weighted Average 21.080 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Pre Subcatchment 1A: SCM 1 Pre Hydrograph I I I I I I I I I ❑Runoff` 11.73 cfs I ' 1 I I I I 1 1 1 1 Type II 24-h r I Runoff Area=21.080 ac Muingff; vPIWIle= �5i5431 c#11 y / " Ruiroff Dep'th`C20'� - 1 O 1 1 I I I I ITc=15.6 m i n LL tN=55.9 I 1 I 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 6 Hydrograph for Subcatchment 1A: SCM 1 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 2.95 0.20 0.00 2.00 0.06 0.00 0.00 106.00 2.95 0.20 0.00 4.00 0.14 0.00 0.00 108.00 2.95 0.20 0.00 6.00 0.24 0.00 0.00 110.00 2.95 0.20 0.00 8.00 0.35 0.00 0.00 112.00 2.95 0.20 0.00 10.00 0.53 0.00 0.00 114.00 2.95 0.20 0.00 12.00 1.96 0.02 0.27 116.00 2.95 0.20 0.00 14.00 2.42 0.08 0.47 118.00 2.95 0.20 0.00 16.00 2.60 0.12 0.33 120.00 2.95 0.20 0.00 18.00 2.72 0.14 0.27 122.00 2.95 0.20 0.00 20.00 2.81 0.17 0.21 124.00 2.95 0.20 0.00 22.00 2.88 0.18 0.20 126.00 2.95 0.20 0.00 24.00 2.95 0.20 0.19 128.00 2.95 0.20 0.00 26.00 2.95 0.20 0.00 130.00 2.95 0.20 0.00 28.00 2.95 0.20 0.00 132.00 2.95 0.20 0.00 30.00 2.95 0.20 0.00 134.00 2.95 0.20 0.00 32.00 2.95 0.20 0.00 136.00 2.95 0.20 0.00 34.00 2.95 0.20 0.00 138.00 2.95 0.20 0.00 36.00 2.95 0.20 0.00 140.00 2.95 0.20 0.00 38.00 2.95 0.20 0.00 142.00 2.95 0.20 0.00 40.00 2.95 0.20 0.00 144.00 2.95 0.20 0.00 42.00 2.95 0.20 0.00 44.00 2.95 0.20 0.00 46.00 2.95 0.20 0.00 48.00 2.95 0.20 0.00 50.00 2.95 0.20 0.00 52.00 2.95 0.20 0.00 54.00 2.95 0.20 0.00 56.00 2.95 0.20 0.00 58.00 2.95 0.20 0.00 60.00 2.95 0.20 0.00 62.00 2.95 0.20 0.00 64.00 2.95 0.20 0.00 66.00 2.95 0.20 0.00 68.00 2.95 0.20 0.00 70.00 2.95 0.20 0.00 72.00 2.95 0.20 0.00 74.00 2.95 0.20 0.00 76.00 2.95 0.20 0.00 78.00 2.95 0.20 0.00 80.00 2.95 0.20 0.00 82.00 2.95 0.20 0.00 84.00 2.95 0.20 0.00 86.00 2.95 0.20 0.00 88.00 2.95 0.20 0.00 90.00 2.95 0.20 0.00 92.00 2.95 0.20 0.00 94.00 2.95 0.20 0.00 96.00 2.95 0.20 0.00 98.00 2.95 0.20 0.00 100.00 2.95 0.20 0.00 102.00 2.95 0.20 0.00 KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1 B: SCM 1 Post Runoff = 16.69 cfs @ 12.10 hrs, Volume= 53,578 cf, Depth= 0.70" Routed to Pond 1 P : SCM 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 1-yr Rainfall=2.95" Area (ac) CN Description 5.300 98.0 Paved parking, HSG B 15.780 61.0 >75% Grass cover, Good, HSG B 21.080 70.3 Weighted Average 15.780 74.86% Pervious Area 5.300 25.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Post Subcatchment 1 B: SCM 1 Post Hydrograph 1 1 I I 1 I I 1 1 I I I I I I I I I I I I I I I I I I 18y I I I I I I I 1 1 I I I I I I I I I I I I I I I I I I ■Runoff 17_ 116.69 cfs I I I I I I I I I I I I I I I 16 1 I 1 I I 1 1 I I I I I I I I I I I I'jype IC24TIIC 15 / — 14 137' 7 I RunoffArea 21.080 ac 12y 1 / 1 1 1 1 1 1 1 1 1 I j 1 1 11� -I 1 -1- T 1 I KulnOir 1/1101 irne1-4-j-jib Q CI - 10� 7 1 7 7 7 1 1 7 7 7 1 7 fi -r 1 1' 1- -rl-r Cp1L11'I�0 � - 0 9= fi % 1 -I- 1 fi t -I -1- 1- rt -1 -I- 1- 1 t -I -1- I- fi -rT-C=1I-JV411111 1 -k 4 -I I- 4 4 -1 -1- 4 4 4 -I -I- 1- # -I -1- I # + — 5; # •I -1- # # 4 -I -I- I- 4 4 -1 -1- 4 4 4 -1 -I- 1- 4 4 -I -1- I- 4 4 4 — 4; 7 I -I- 4 4 4 -I -I- I- 4 4 -I -I- I- 4 4 -I -I- I- 4 4 -I -I- I- 4 74 - 3 -1- 4 4 7 -I -I- 4 4 7 -1 -I- 1- 4 7 -I -I- I- 4 7 7 -I- I- 4 7 7 - 1- iiiiiiiiii�iiiiiiiiiii�l/��l/��/��l/l/��//%������1/����1%�/1��/�%���/��/l/ 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 8 Hydrograph for Subcatchment 1 B: SCM 1 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 2.95 0.70 0.00 2.00 0.06 0.00 0.00 106.00 2.95 0.70 0.00 4.00 0.14 0.00 0.00 108.00 2.95 0.70 0.00 6.00 0.24 0.00 0.00 110.00 2.95 0.70 0.00 8.00 0.35 0.00 0.00 112.00 2.95 0.70 0.00 10.00 0.53 0.00 0.00 114.00 2.95 0.70 0.00 12.00 1.96 0.23 11.17 116.00 2.95 0.70 0.00 14.00 2.42 0.43 1.22 118.00 2.95 0.70 0.00 16.00 2.60 0.51 0.77 120.00 2.95 0.70 0.00 18.00 2.72 0.57 0.60 122.00 2.95 0.70 0.00 20.00 2.81 0.62 0.45 124.00 2.95 0.70 0.00 22.00 2.88 0.66 0.41 126.00 2.95 0.70 0.00 24.00 2.95 0.70 0.39 128.00 2.95 0.70 0.00 26.00 2.95 0.70 0.00 130.00 2.95 0.70 0.00 28.00 2.95 0.70 0.00 132.00 2.95 0.70 0.00 30.00 2.95 0.70 0.00 134.00 2.95 0.70 0.00 32.00 2.95 0.70 0.00 136.00 2.95 0.70 0.00 34.00 2.95 0.70 0.00 138.00 2.95 0.70 0.00 36.00 2.95 0.70 0.00 140.00 2.95 0.70 0.00 38.00 2.95 0.70 0.00 142.00 2.95 0.70 0.00 40.00 2.95 0.70 0.00 144.00 2.95 0.70 0.00 42.00 2.95 0.70 0.00 44.00 2.95 0.70 0.00 46.00 2.95 0.70 0.00 48.00 2.95 0.70 0.00 50.00 2.95 0.70 0.00 52.00 2.95 0.70 0.00 54.00 2.95 0.70 0.00 56.00 2.95 0.70 0.00 58.00 2.95 0.70 0.00 60.00 2.95 0.70 0.00 62.00 2.95 0.70 0.00 64.00 2.95 0.70 0.00 66.00 2.95 0.70 0.00 68.00 2.95 0.70 0.00 70.00 2.95 0.70 0.00 72.00 2.95 0.70 0.00 74.00 2.95 0.70 0.00 76.00 2.95 0.70 0.00 78.00 2.95 0.70 0.00 80.00 2.95 0.70 0.00 82.00 2.95 0.70 0.00 84.00 2.95 0.70 0.00 86.00 2.95 0.70 0.00 88.00 2.95 0.70 0.00 90.00 2.95 0.70 0.00 92.00 2.95 0.70 0.00 94.00 2.95 0.70 0.00 96.00 2.95 0.70 0.00 98.00 2.95 0.70 0.00 100.00 2.95 0.70 0.00 102.00 2.95 0.70 0.00 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 9 Summary for Pond 1 P: SCM 1 Inflow Area = 918,245 sf, 25.14% Impervious, Inflow Depth = 0.70" for 1-yr event Inflow = 16.69 cfs @ 12.10 hrs, Volume= 53,578 cf Outflow = 0.35 cfs @ 24.11 hrs, Volume= 52,626 cf, Atten= 98%, Lag= 720.7 min Primary = 0.35 cfs @ 24.11 hrs, Volume= 52,626 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 575.02'@ 24.11 hrs Surf.Area= 29,703 sf Storage= 41,726 cf Plug-Flow detention time= 1,809.6 min calculated for 52,626 cf(98% of inflow) Center-of-Mass det. time= 1,799.7 min ( 2,686.5 - 886.9 ) Volume Invert Avail.Storage Storage Description #1 573.50' 179,460 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.50 23,530 0 0 574.00 27,314 12,711 12,711 575.00 29,660 28,487 41,198 576.00 32,068 30,864 72,062 577.00 34,522 33,295 105,357 578.00 37,037 35,780 141,137 579.00 39,609 38,323 179,460 Device Routing Invert Outlet Devices #1 Primary 569.00' 24.0" Round Outlet Pipe L= 67.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 569.00'/ 568.00' S= 0.0149 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 3.14 sf #2 Device 1 573.50' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 574.40' 0.5" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 1 575.00' 6.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 576.00' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 577.00' 20.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.33 cfs @ 24.11 hrs HW=575.02' (Free Discharge) 4 -1=Outlet Pipe (Passes 0.33 cfs of 33.88 cfs potential flow) -2=Orifice (Orifice Controls 0.28 cfs @ 5.68 fps) -3=Orifice/Grate (Orifice Controls 0.01 cfs @ 3.72 fps) -4=Rect Notch (Weir Controls 0.05 cfs @ 0.44 fps) -5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.50' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 10 Pond 1 P: SCM 1 Hydrograph I I I I I I I I /I I I I I I I I I I I I I ■Inflow / / 116.69 cfs 1 •Outflow J 4 J I I I L 1 , / /I - — -L — -4 — —I I I -n ro�nr�► ea7 1- — 1 — •Primary ■Secondary 1$ / / ;H / I - 4 - - l - I I— — I— - I— — Pea'kftev:575.0r - 16 / / 1 — — — 1 1 1 t 11 -1 1 15 -r -r 1 1 Storage=41,726-c-f — 14 / / / / / T T 7 1 1 L T 7 7 J I 13 / / / /I / I I I I I I I I I I 12 / / / /I / I I I I I I I I I I w 11 / / /I °- 10 / / /I_ / 1 I I I I I I I I I I 0 9 / / / /L _ _ 1 — J J I I L L 1 J J I u. 8 / / / /1 — _ _ — 7 7 1 1 H -L 7 7 —I I 7 / / /7 + 4 - 1 1 I— T 4 4 4 I 6 / / 5 / / /H — + — + — + — — -I — I— — I — H — t — + — + — + — 1 — 4 7 7 I I 3 / / •�� 0.35 cfs , / 000ds rZ/ iii 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 11 Hydrograph for Pond 1 P: SCM 1 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.50 0.00 0.00 0.00 4.00 0.00 0 573.50 0.00 0.00 0.00 8.00 0.00 0 573.50 0.00 0.00 0.00 12.00 11.17 3,422 573.64 0.04 0.04 0.00 16.00 0.77 35,337 574.80 0.26 0.26 0.00 20.00 0.45 40,111 574.96 0.28 0.28 0.00 24.00 0.39 41,717 575.02 0.35 0.35 0.00 28.00 0.00 37,938 574.89 0.27 0.27 0.00 32.00 0.00 34,151 574.76 0.26 0.26 0.00 36.00 0.00 30,577 574.64 0.24 0.24 0.00 40.00 0.00 27,219 574.52 0.23 0.23 0.00 44.00 0.00 24,085 574.41 0.21 0.21 0.00 48.00 0.00 21,174 574.31 0.19 0.19 0.00 52.00 0.00 18,470 574.21 0.18 0.18 0.00 56.00 0.00 15,974 574.12 0.17 0.17 0.00 60.00 0.00 13,688 574.04 0.15 0.15 0.00 64.00 0.00 11,614 573.96 0.14 0.14 0.00 68.00 0.00 9,754 573.89 0.12 0.12 0.00 72.00 0.00 8,114 573.83 0.11 0.11 0.00 76.00 0.00 6,697 573.77 0.09 0.09 0.00 80.00 0.00 5,507 573.73 0.08 0.08 0.00 84.00 0.00 4,550 573.69 0.06 0.06 0.00 88.00 0.00 3,817 573.66 0.04 0.04 0.00 92.00 0.00 3,251 573.64 0.03 0.03 0.00 96.00 0.00 2,813 573.62 0.03 0.03 0.00 100.00 0.00 2,471 573.60 0.02 0.02 0.00 104.00 0.00 2,190 573.59 0.02 0.02 0.00 108.00 0.00 1,957 573.58 0.01 0.01 0.00 112.00 0.00 1,762 573.57 0.01 0.01 0.00 116.00 0.00 1,601 573.57 0.01 0.01 0.00 120.00 0.00 1,467 573.56 0.01 0.01 0.00 124.00 0.00 1,356 573.56 0.01 0.01 0.00 128.00 0.00 1,262 573.55 0.01 0.01 0.00 132.00 0.00 1,176 573.55 0.01 0.01 0.00 136.00 0.00 1,096 573.55 0.01 0.01 0.00 140.00 0.00 1,021 573.54 0.01 0.01 0.00 144.00 0.00 952 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 12 Stage-Discharge for Pond 1 P: SCM 1 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) ' (feet) (cfs) (cfs) (cfs) 573.50 0.00 0.00 0.00 578.70 161.65 44.62 117.03 573.60 0.02 0.02 0.00 578.80 172.38 44.87 127.51 573.70 0.06 0.06 0.00 578.90 183.41 45.13 138.28 573.80 0.10 0.10 0.00 579.00 194.72 45.38 149.34 573.90 0.12 0.12 0.00 574.00 0.14 0.14 0.00 574.10 0.16 0.16 0.00 574.20 0.18 0.18 0.00 574.30 0.19 0.19 0.00 574.40 0.21 0.21 0.00 574.50 0.22 0.22 0.00 574.60 0.24 0.24 0.00 574.70 0.25 0.25 0.00 574.80 0.26 0.26 0.00 574.90 0.27 0.27 0.00 575.00 0.28 0.28 0.00 575.10 0.91 0.91 0.00 575.20 2.05 2.05 0.00 575.30 3.50 3.50 0.00 575.40 5.22 5.22 0.00 575.50 7.15 7.15 0.00 575.60 9.28 9.28 0.00 575.70 11.57 11.57 0.00 575.80 14.02 14.02 0.00 575.90 16.61 16.61 0.00 576.00 19.34 19.34 0.00 576.10 23.32 23.32 0.00 576.20 28.30 28.30 0.00 576.30 33.99 33.99 0.00 576.40 38.27 38.27 0.00 576.50 38.57 38.57 0.00 576.60 38.86 38.86 0.00 576.70 39.15 39.15 0.00 576.80 39.45 39.45 0.00 576.90 39.73 39.73 0.00 577.00 40.02 40.02 0.00 577.10 41.88 40.31 1.57 577.20 45.04 40.59 4.45 577.30 49.17 40.87 8.30 577.40 54.10 41.15 12.95 577.50 60.02 41.43 18.60 577.60 66.80 41.70 25.10 577.70 73.54 41.97 31.57 577.80 80.74 42.25 38.50 577.90 88.37 42.52 45.85 578.00 96.38 42.78 53.60 578.10 105.00 43.05 61.95 578.20 114.04 43.32 70.72 578.30 123.03 43.58 79.45 578.40 132.30 43.84 88.46 578.50 141.65 44.10 97.55 578.60 151.22 44.36 106.86 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 13 Stage-Area-Storage for Pond 1 P: SCM 1 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.50 23,530 0 578.70 38,837 167,693 573.60 24,287 2,391 578.80 39,095 171,589 573.70 25,044 4,857 578.90 39,352 175,511 573.80 25,800 7,400 579.00 39,609 179,460 573.90 26,557 10,017 574.00 27,314 12,711 574.10 27,549 15,454 574.20 27,783 18,221 574.30 28,018 21,011 574.40 28,252 23,824 574.50 28,487 26,661 574.60 28,722 29,522 574.70 28,956 32,406 574.80 29,191 35,313 574.90 29,425 38,244 575.00 29,660 41,198 575.10 29,901 44,176 575.20 30,142 47,178 575.30 30,382 50,204 575.40 30,623 53,255 575.50 30,864 56,329 575.60 31,105 59,427 575.70 31,346 62,550 575.80 31,586 65,697 575.90 31,827 68,867 576.00 32,068 72,062 576.10 32,313 75,281 576.20 32,559 78,525 576.30 32,804 81,793 576.40 33,050 85,086 576.50 33,295 88,403 576.60 33,540 91,745 576.70 33,786 95,111 576.80 34,031 98,502 576.90 34,277 101,917 577.00 34,522 105,357 577.10 34,774 108,822 577.20 35,025 112,312 577.30 35,276 115,827 577.40 35,528 119,367 577.50 35,780 122,932 577.60 36,031 126,523 577.70 36,283 130,139 577.80 36,534 133,779 577.90 36,785 137,445 578.00 37,037 141,137 578.10 37,294 144,853 578.20 37,551 148,595 578.30 37,809 152,363 578.40 38,066 156,157 578.50 38,323 159,977 578.60 38,580 163,822 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 14 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlA: SCM 1 Pre Runoff Area=21.080 ac 0.00% Impervious Runoff Depth=0.39" Tc=15.6 min CN=55.9 Runoff=6.05 cfs 30,132 cf SubcatchmentlB: SCM 1 Post Runoff Area=21.080 ac 25.14% Impervious Runoff Depth=1.06" Tc=15.6 min CN=70.3 Runoff=26.71 cfs 80,811 cf Pond 1P: SCM 1 Peak Elev=575.16' Storage=45,926 cf Inflow=26.71 cfs 80,811 cf Primary=1.54 cfs 79,848 cf Secondary=0.00 cfs 0 cf Outflow=1.54 cfs 79,848 cf KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 1A: SCM 1 Pre Runoff = 6.05 cfs @ 12.13 hrs, Volume= 30,132 cf, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 2-yr Rainfall=3.55" Area (ac) CN Description 18.590 56.0 Brush, Fair, HSG B 2.490 55.0 Woods, Good, HSG B 21.080 55.9 Weighted Average 21.080 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Pre Subcatchment 1A: SCM 1 Pre Hydrograph I - I I I I I I I I ❑Runoff' I6.05 cfs I-1 I I— tHH I 1 I H —1 I I Ht 6- 1 1 I 1 I 1 I I I I I I I I Type II 24-h r - 1 / I I I I II I I 1 , I I I I I I"�'I 'T. - — / -I I rt - 1 r -r1 1 1 1 T -r 1-' �L -r - 5. 1 / 1 1 1 I Runoff Area=21.0901ac _ 1 / i 1 1 1 1 1 / 1 1 T77 -1- - 777 - - 11 � N/plprlEl 011 2ci y 4_ / I I I I 1 1 1 1 Runoff 'Depth=0 39" / 1 1 II II 11 1 1 1' i 1 2 3_ I I I 1 I I I I I I 1 c=1 1 m i n 11 1 1 1 1 1 1 1 1 1IcN 155.9 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2-' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 16 Hydrograph for Subcatchment 1A: SCM 1 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 3.55 0.39 0.00 2.00 0.08 0.00 0.00 106.00 3.55 0.39 0.00 4.00 0.17 0.00 0.00 108.00 3.55 0.39 0.00 6.00 0.28 0.00 0.00 110.00 3.55 0.39 0.00 8.00 0.43 0.00 0.00 112.00 3.55 0.39 0.00 10.00 0.64 0.00 0.00 114.00 3.55 0.39 0.00 12.00 2.35 0.07 2.18 116.00 3.55 0.39 0.00 14.00 2.91 0.19 0.83 118.00 3.55 0.39 0.00 16.00 3.12 0.25 0.55 120.00 3.55 0.39 0.00 18.00 3.27 0.30 0.45 122.00 3.55 0.39 0.00 20.00 3.38 0.33 0.34 124.00 3.55 0.39 0.00 22.00 3.47 0.36 0.32 126.00 3.55 0.39 0.00 24.00 3.55 0.39 0.30 128.00 3.55 0.39 0.00 26.00 3.55 0.39 0.00 130.00 3.55 0.39 0.00 28.00 3.55 0.39 0.00 132.00 3.55 0.39 0.00 30.00 3.55 0.39 0.00 134.00 3.55 0.39 0.00 32.00 3.55 0.39 0.00 136.00 3.55 0.39 0.00 34.00 3.55 0.39 0.00 138.00 3.55 0.39 0.00 36.00 3.55 0.39 0.00 140.00 3.55 0.39 0.00 38.00 3.55 0.39 0.00 142.00 3.55 0.39 0.00 40.00 3.55 0.39 0.00 144.00 3.55 0.39 0.00 42.00 3.55 0.39 0.00 44.00 3.55 0.39 0.00 46.00 3.55 0.39 0.00 48.00 3.55 0.39 0.00 50.00 3.55 0.39 0.00 52.00 3.55 0.39 0.00 54.00 3.55 0.39 0.00 56.00 3.55 0.39 0.00 58.00 3.55 0.39 0.00 60.00 3.55 0.39 0.00 62.00 3.55 0.39 0.00 64.00 3.55 0.39 0.00 66.00 3.55 0.39 0.00 68.00 3.55 0.39 0.00 70.00 3.55 0.39 0.00 72.00 3.55 0.39 0.00 74.00 3.55 0.39 0.00 76.00 3.55 0.39 0.00 78.00 3.55 0.39 0.00 80.00 3.55 0.39 0.00 82.00 3.55 0.39 0.00 84.00 3.55 0.39 0.00 86.00 3.55 0.39 0.00 88.00 3.55 0.39 0.00 90.00 3.55 0.39 0.00 92.00 3.55 0.39 0.00 94.00 3.55 0.39 0.00 96.00 3.55 0.39 0.00 98.00 3.55 0.39 0.00 100.00 3.55 0.39 0.00 102.00 3.55 0.39 0.00 KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 1 B: SCM 1 Post Runoff = 26.71 cfs @ 12.09 hrs, Volume= 80,811 cf, Depth= 1.06" Routed to Pond 1 P : SCM 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 2-yr Rainfall=3.55" Area (ac) CN Description 5.300 98.0 Paved parking, HSG B 15.780 61.0 >75% Grass cover, Good, HSG B 21.080 70.3 Weighted Average 15.780 74.86% Pervious Area 5.300 25.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Post Subcatchment 1 B: SCM 1 Post Hydrograph I I 1 I I 1 1 I I I I I I I I I I I I I I I I I I I 1 1 1 4 -1 -1- 1- 4 1 1 1- 4 -1 -1- 1 4 - 1 1 + - - ■Runoff 28� 126.7l cfs l 1 I 1 I I 1 1 1 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 26 17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 �Type I1 124+h r 24 4- t /- I 11 I rt -11 -11- fi rt 1 1 11- fi rt 11 11�71 ''.."f" I11= H - 22� L /-I 1 L L A -I _1_ L L L 1 1 L L -Rtlno Areaa21-.O8O-aG - 20i/ 1 / 1 1 1 1 1 I I I I 1 � 1 1 1 18� 1 1 1 1 1 1 I I I I rulnQ111 V1o1i11l Ae=tWiOT1 'CT " 167- c 14� 1 / 1 1 1 1 1 1 1 1 I I I I 1 1 1 1 1TC=l5.61 rain 1 % 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1� 1'1' ' T' 10_ �- 1 1 4 -1 -1- 1- 4HI 1- 4 -I -1- 1H -1 1 H + -1 1 1 1 1 1I I 111 11 1 11I1 1 1 1 11 1 1 1 I 1 1 1 1 I I I I 1 4i I I I I 1 1 1 I I I I 1 1 1 1 I I I I I I I r t 1 t rt -1 -1- 1 t rt 1 1 1 t rt -1 -1- 1 t rt H 1 1 t rt - - 2 iiiiiiii � I %0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 18 Hydrograph for Subcatchment 1 B: SCM 1 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 3.55 1.06 0.00 2.00 0.08 0.00 0.00 106.00 3.55 1.06 0.00 4.00 0.17 0.00 0.00 108.00 3.55 1.06 0.00 6.00 0.28 0.00 0.00 110.00 3.55 1.06 0.00 8.00 0.43 0.00 0.00 112.00 3.55 1.06 0.00 10.00 0.64 0.00 0.00 114.00 3.55 1.06 0.00 12.00 2.35 0.40 19.26 116.00 3.55 1.06 0.00 14.00 2.91 0.68 1.72 118.00 3.55 1.06 0.00 16.00 3.12 0.80 1.07 120.00 3.55 1.06 0.00 18.00 3.27 0.88 0.83 122.00 3.55 1.06 0.00 20.00 3.38 0.95 0.62 124.00 3.55 1.06 0.00 22.00 3.47 1.01 0.57 126.00 3.55 1.06 0.00 24.00 3.55 1.06 0.53 128.00 3.55 1.06 0.00 26.00 3.55 1.06 0.00 130.00 3.55 1.06 0.00 28.00 3.55 1.06 0.00 132.00 3.55 1.06 0.00 30.00 3.55 1.06 0.00 134.00 3.55 1.06 0.00 32.00 3.55 1.06 0.00 136.00 3.55 1.06 0.00 34.00 3.55 1.06 0.00 138.00 3.55 1.06 0.00 36.00 3.55 1.06 0.00 140.00 3.55 1.06 0.00 38.00 3.55 1.06 0.00 142.00 3.55 1.06 0.00 40.00 3.55 1.06 0.00 144.00 3.55 1.06 0.00 42.00 3.55 1.06 0.00 44.00 3.55 1.06 0.00 46.00 3.55 1.06 0.00 48.00 3.55 1.06 0.00 50.00 3.55 1.06 0.00 52.00 3.55 1.06 0.00 54.00 3.55 1.06 0.00 56.00 3.55 1.06 0.00 58.00 3.55 1.06 0.00 60.00 3.55 1.06 0.00 62.00 3.55 1.06 0.00 64.00 3.55 1.06 0.00 66.00 3.55 1.06 0.00 68.00 3.55 1.06 0.00 70.00 3.55 1.06 0.00 72.00 3.55 1.06 0.00 74.00 3.55 1.06 0.00 76.00 3.55 1.06 0.00 78.00 3.55 1.06 0.00 80.00 3.55 1.06 0.00 82.00 3.55 1.06 0.00 84.00 3.55 1.06 0.00 86.00 3.55 1.06 0.00 88.00 3.55 1.06 0.00 90.00 3.55 1.06 0.00 92.00 3.55 1.06 0.00 94.00 3.55 1.06 0.00 96.00 3.55 1.06 0.00 98.00 3.55 1.06 0.00 100.00 3.55 1.06 0.00 102.00 3.55 1.06 0.00 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 19 Summary for Pond 1 P: SCM 1 Inflow Area = 918,245 sf, 25.14% Impervious, Inflow Depth = 1.06" for 2-yr event Inflow = 26.71 cfs @ 12.09 hrs, Volume= 80,811 cf Outflow = 1.54 cfs @ 14.29 hrs, Volume= 79,848 cf, Atten= 94%, Lag= 132.1 min Primary = 1.54 cfs @ 14.29 hrs, Volume= 79,848 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 575.16'@ 14.29 hrs Surf.Area= 30,041 sf Storage= 45,926 cf Plug-Flow detention time= 1,278.8 min calculated for 79,848 cf(99% of inflow) Center-of-Mass det. time= 1,271.9 min ( 2,144.9 - 872.9 ) Volume Invert Avail.Storage Storage Description _ #1 573.50' 179,460 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.50 23,530 0 0 574.00 27,314 12,711 12,711 575.00 29,660 28,487 41,198 576.00 32,068 30,864 72,062 577.00 34,522 33,295 105,357 578.00 37,037 35,780 141,137 579.00 39,609 38,323 179,460 Device Routing Invert Outlet Devices #1 Primary 569.00' 24.0" Round Outlet Pipe L= 67.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 569.00'/ 568.00' S= 0.0149 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 3.14 sf #2 Device 1 573.50' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 574.40' 0.5" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 1 575.00' 6.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 576.00' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 577.00' 20.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=1.53 cfs @ 14.29 hrs HW=575.16' (Free Discharge) 4 -1=Outlet Pipe (Passes 1.53 cfs of 34.36 cfs potential flow) -2=Orifice (Orifice Controls 0.29 cfs @ 5.96 fps) -3=Orifice/Grate (Orifice Controls 0.01 cfs @ 4.14 fps) -4=Rect Notch (Weir Controls 1.23 cfs @ 1.30 fps) -5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.50' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 20 Pond 1 P: SCM 1 Hydrograph /r r r r 1 I— r r r rt 1 —I ■Inflow 26.71 cfs •OUtfloW — — _1 Inflo i�11/ Aea913,245 s _ •Secondary 28� / / / / / 1 - L - -I I I Peak-E ev:5-75.16-- - 26 / / /1 / 1 1 1 1 1 1 1 24 , / , /1 0 I I 1 1 Sforage45,1326cf 22� / / /1 I I I I I I I I I I / it I I I I I I I I I I I I I 20� - r 7 7 1 1 r r i I 1 1 w 18_ / / / fr. ± -t - H t t -[ -II - 16� / / 4 4 4 1 1 4 4 - 1 c 14� , / / / 1 _ L L L L 1 _l _I " 12� 1 1 1 1 1 1 1 1 10 // / / �1 1% 1 1 1 1 1 1 1 1 8y / / /I 6: / / 1.54 cfs / / .7 / Aliklow''y 1000cfs , 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 21 Hydrograph for Pond 1 P: SCM 1 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.50 0.00 0.00 0.00 4.00 0.00 0 573.50 0.00 0.00 0.00 8.00 0.00 0 573.50 0.00 0.00 0.00 12.00 19.26 7,577 573.81 0.10 0.10 0.00 16.00 1.07 45,179 575.13 1.26 1.26 0.00 20.00 0.62 43,512 575.08 0.73 0.73 0.00 24.00 0.53 42,804 575.05 0.55 0.55 0.00 28.00 0.00 38,598 574.91 0.27 0.27 0.00 32.00 0.00 34,776 574.78 0.26 0.26 0.00 36.00 0.00 31,165 574.66 0.24 0.24 0.00 40.00 0.00 27,770 574.54 0.23 0.23 0.00 44.00 0.00 24,598 574.43 0.21 0.21 0.00 48.00 0.00 21,651 574.32 0.20 0.20 0.00 52.00 0.00 18,912 574.22 0.18 0.18 0.00 56.00 0.00 16,380 574.13 0.17 0.17 0.00 60.00 0.00 14,059 574.05 0.15 0.15 0.00 64.00 0.00 11,949 573.97 0.14 0.14 0.00 68.00 0.00 10,053 573.90 0.12 0.12 0.00 72.00 0.00 8,376 573.84 0.11 0.11 0.00 76.00 0.00 6,921 573.78 0.09 0.09 0.00 80.00 0.00 5,692 573.73 0.08 0.08 0.00 84.00 0.00 4,694 573.69 0.06 0.06 0.00 88.00 0.00 3,927 573.66 0.05 0.05 0.00 92.00 0.00 3,337 573.64 0.04 0.04 0.00 96.00 0.00 2,879 573.62 0.03 0.03 0.00 100.00 0.00 2,524 573.61 0.02 0.02 0.00 104.00 0.00 2,234 573.59 0.02 0.02 0.00 108.00 0.00 1,993 573.58 0.02 0.02 0.00 112.00 0.00 1,793 573.58 0.01 0.01 0.00 116.00 0.00 1,626 573.57 0.01 0.01 0.00 120.00 0.00 1,488 573.56 0.01 0.01 0.00 124.00 0.00 1,373 573.56 0.01 0.01 0.00 128.00 0.00 1,277 573.55 0.01 0.01 0.00 132.00 0.00 1,190 573.55 0.01 0.01 0.00 136.00 0.00 1,109 573.55 0.01 0.01 0.00 140.00 0.00 1,034 573.54 0.01 0.01 0.00 144.00 0.00 963 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 22 Stage-Discharge for Pond 1 P: SCM 1 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) ' (feet) (cfs) (cfs) (cfs) 573.50 0.00 0.00 0.00 578.70 161.65 44.62 117.03 573.60 0.02 0.02 0.00 578.80 172.38 44.87 127.51 573.70 0.06 0.06 0.00 578.90 183.41 45.13 138.28 573.80 0.10 0.10 0.00 579.00 194.72 45.38 149.34 573.90 0.12 0.12 0.00 574.00 0.14 0.14 0.00 574.10 0.16 0.16 0.00 574.20 0.18 0.18 0.00 574.30 0.19 0.19 0.00 574.40 0.21 0.21 0.00 574.50 0.22 0.22 0.00 574.60 0.24 0.24 0.00 574.70 0.25 0.25 0.00 574.80 0.26 0.26 0.00 574.90 0.27 0.27 0.00 575.00 0.28 0.28 0.00 575.10 0.91 0.91 0.00 575.20 2.05 2.05 0.00 575.30 3.50 3.50 0.00 575.40 5.22 5.22 0.00 575.50 7.15 7.15 0.00 575.60 9.28 9.28 0.00 575.70 11.57 11.57 0.00 575.80 14.02 14.02 0.00 575.90 16.61 16.61 0.00 576.00 19.34 19.34 0.00 576.10 23.32 23.32 0.00 576.20 28.30 28.30 0.00 576.30 33.99 33.99 0.00 576.40 38.27 38.27 0.00 576.50 38.57 38.57 0.00 576.60 38.86 38.86 0.00 576.70 39.15 39.15 0.00 576.80 39.45 39.45 0.00 576.90 39.73 39.73 0.00 577.00 40.02 40.02 0.00 577.10 41.88 40.31 1.57 577.20 45.04 40.59 4.45 577.30 49.17 40.87 8.30 577.40 54.10 41.15 12.95 577.50 60.02 41.43 18.60 577.60 66.80 41.70 25.10 577.70 73.54 41.97 31.57 577.80 80.74 42.25 38.50 577.90 88.37 42.52 45.85 578.00 96.38 42.78 53.60 578.10 105.00 43.05 61.95 578.20 114.04 43.32 70.72 578.30 123.03 43.58 79.45 578.40 132.30 43.84 88.46 578.50 141.65 44.10 97.55 578.60 151.22 44.36 106.86 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 23 Stage-Area-Storage for Pond 1 P: SCM 1 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.50 23,530 0 578.70 38,837 167,693 573.60 24,287 2,391 578.80 39,095 171,589 573.70 25,044 4,857 578.90 39,352 175,511 573.80 25,800 7,400 579.00 39,609 179,460 573.90 26,557 10,017 574.00 27,314 12,711 574.10 27,549 15,454 574.20 27,783 18,221 574.30 28,018 21,011 574.40 28,252 23,824 574.50 28,487 26,661 574.60 28,722 29,522 574.70 28,956 32,406 574.80 29,191 35,313 574.90 29,425 38,244 575.00 29,660 41,198 575.10 29,901 44,176 575.20 30,142 47,178 575.30 30,382 50,204 575.40 30,623 53,255 575.50 30,864 56,329 575.60 31,105 59,427 575.70 31,346 62,550 575.80 31,586 65,697 575.90 31,827 68,867 576.00 32,068 72,062 576.10 32,313 75,281 576.20 32,559 78,525 576.30 32,804 81,793 576.40 33,050 85,086 576.50 33,295 88,403 576.60 33,540 91,745 576.70 33,786 95,111 576.80 34,031 98,502 576.90 34,277 101,917 577.00 34,522 105,357 577.10 34,774 108,822 577.20 35,025 112,312 577.30 35,276 115,827 577.40 35,528 119,367 577.50 35,780 122,932 577.60 36,031 126,523 577.70 36,283 130,139 577.80 36,534 133,779 577.90 36,785 137,445 578.00 37,037 141,137 578.10 37,294 144,853 578.20 37,551 148,595 578.30 37,809 152,363 578.40 38,066 156,157 578.50 38,323 159,977 578.60 38,580 163,822 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 24 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlA: SCM 1 Pre Runoff Area=21.080 ac 0.00% Impervious Runoff Depth=1.13" Tc=15.6 min CN=55.9 Runoff=26.27 cfs 86,719 cf SubcatchmentlB: SCM 1 Post Runoff Area=21.080 ac 25.14% Impervious Runoff Depth=2.20" Tc=15.6 min CN=70.3 Runoff=58.53 cfs 168,593 cf Pond 1P: SCM 1 Peak Elev=575.88' Storage=68,123 cf Inflow=58.53 cfs 168,593 cf Primary=16.00 cfs 167,620 cf Secondary=0.00 cfs 0 cf Outflow=16.00 cfs 167,620 cf KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 25 Summary for Subcatchment 1A: SCM 1 Pre Runoff = 26.27 cfs @ 12.10 hrs, Volume= 86,719 cf, Depth= 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 10-yr Rainfall=5.19" Area (ac) CN Description 18.590 56.0 Brush, Fair, HSG B 2.490 55.0 Woods, Good, HSG B 21.080 55.9 Weighted Average 21.080 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Pre Subcatchment 1A: SCM 1 Pre Hydrograph 1 1 1 1 1 1 I 1 1 1 1 I I I I I I I I I I I I I 1 I I 1 1 I I I I I I I 1 I 1 1 I I 1 I I 1 ■Runoff 28-- 6.27crs I -I- 1 4 4 -1 -I- I- 4 4 -I -I- 1- 4 4 -I -I- I- 4 4 - -I- 1- 4 4 - - 261/ - / I 1 1 1 I 1 1 I I I I I 1 1 1 1 1 Type_IIL24thr- 24 -- 1 / 1 I 1 I I 1 1 1 1 1 1 1 I I AIn rl 1 II= iico, / I 1 I I 1 1 I 1 1 I I I 1 i IV-' '- 1 I -1 22_ 4- t -1 -1- H t 4 -1 -1- I- t H- -1 -1- I- 1- -J n ioif Area=2 4.080-act - 20� H / _I -I- L L 1 _I -1- L L 1 _I -1- I- 1 -1 L 1 J I 18� I I I I I I I I I I I I rgu1n0Tf1 V1yol�.1117e=06'7 97cc 016� / Runoff'Dep'th'=1.113" 4fi /-1 1 LL -[ 1 t 1 1- -4 1 1 t H 1 1- LtH - 0 14t" L /-1 I L L I 1 1 L L L 1 L L 1 1 1 L LTc= 6Lmi n u 121 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Ii. - 5 S� 101 1 / I I 1 I I 1 I 1 1 I I I I 1 I 1 1 I I 1 I ' 4- H /-1 I LLH 1 1 I H H I LLH 1 1 I H H H 1 1 LHH - 8� ,_ L _I I L L I 1 1 L L L I L L 1 1 I I L L H I I L 1 L 63-/ 1 I I I I I 1 1 1 1 1 1 1 1 I I I I I I I I I 41/ I I I I I 1 I 1 1 I I I I I I I I I I I I I I t —1— 1 -r rt —1 —I— 1 -r rt —1 —1— I— -r rt —1 —I— 1— -r rt - —1— 1— fi -r - 2 0 / �������� ��i/���������������������i������� ������ ������ 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105'110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 26 Hydrograph for Subcatchment 1A: SCM 1 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 5.19 1.13 0.00 2.00 0.11 0.00 0.00 106.00 5.19 1.13 0.00 4.00 0.25 0.00 0.00 108.00 5.19 1.13 0.00 6.00 0.42 0.00 0.00 110.00 5.19 1.13 0.00 8.00 0.62 0.00 0.00 112.00 5.19 1.13 0.00 10.00 0.94 0.00 0.00 114.00 5.19 1.13 0.00 12.00 3.44 0.36 16.95 116.00 5.19 1.13 0.00 14.00 4.26 0.68 2.02 118.00 5.19 1.13 0.00 16.00 4.57 0.82 1.28 120.00 5.19 1.13 0.00 18.00 4.78 0.92 1.01 122.00 5.19 1.13 0.00 20.00 4.94 1.00 0.76 124.00 5.19 1.13 0.00 22.00 5.07 1.07 0.69 126.00 5.19 1.13 0.00 24.00 5.19 1.13 0.65 128.00 5.19 1.13 0.00 26.00 5.19 1.13 0.00 130.00 5.19 1.13 0.00 28.00 5.19 1.13 0.00 132.00 5.19 1.13 0.00 30.00 5.19 1.13 0.00 134.00 5.19 1.13 0.00 32.00 5.19 1.13 0.00 136.00 5.19 1.13 0.00 34.00 5.19 1.13 0.00 138.00 5.19 1.13 0.00 36.00 5.19 1.13 0.00 140.00 5.19 1.13 0.00 38.00 5.19 1.13 0.00 142.00 5.19 1.13 0.00 40.00 5.19 1.13 0.00 144.00 5.19 1.13 0.00 42.00 5.19 1.13 0.00 44.00 5.19 1.13 0.00 46.00 5.19 1.13 0.00 48.00 5.19 1.13 0.00 50.00 5.19 1.13 0.00 52.00 5.19 1.13 0.00 54.00 5.19 1.13 0.00 56.00 5.19 1.13 0.00 58.00 5.19 1.13 0.00 60.00 5.19 1.13 0.00 62.00 5.19 1.13 0.00 64.00 5.19 1.13 0.00 66.00 5.19 1.13 0.00 68.00 5.19 1.13 0.00 70.00 5.19 1.13 0.00 72.00 5.19 1.13 0.00 74.00 5.19 1.13 0.00 76.00 5.19 1.13 0.00 78.00 5.19 1.13 0.00 80.00 5.19 1.13 0.00 82.00 5.19 1.13 0.00 84.00 5.19 1.13 0.00 86.00 5.19 1.13 0.00 88.00 5.19 1.13 0.00 90.00 5.19 1.13 0.00 92.00 5.19 1.13 0.00 94.00 5.19 1.13 0.00 96.00 5.19 1.13 0.00 98.00 5.19 1.13 0.00 100.00 5.19 1.13 0.00 102.00 5.19 1.13 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 1 B: SCM 1 Post Runoff = 58.53 cfs @ 12.08 hrs, Volume= 168,593 cf, Depth= 2.20" Routed to Pond 1 P : SCM 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 10-yr Rainfall=5.19" Area (ac) CN Description 5.300 98.0 Paved parking, HSG B 15.780 61.0 >75% Grass cover, Good, HSG B 21.080 70.3 Weighted Average 15.780 74.86% Pervious Area 5.300 25.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Post Subcatchment 1 B: SCM 1 Post Hydrograph 1- -II L t 1- I I I- 1- fi I I L 1- t I I I fit -I I I t t -I - 65� ■Runoff 60 ' r 158.53 GIs I I I 1 I I 1 I 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 4- - �/ -I -1- 1 t rt -I -1- 1- t t - -1- 1- t t -1 -1- 1- t rtTypa II24# it - 55� / _I Q� _ i _ 50� / 1 1 1 1 1 1 1 1 1 1 1 1 -1 7 I ` 1 7 11 1 - t -I -1- I r rt -1 -1- r r rt -1 -1- 1- 1- -r Runoff Area= 1O80-a¢ - 45:-/ / 1 1 1 1 1 1 1 1 .k11�ncff1 V1 1 1 __1e,t 5 30- 40� / 1 1 1 1 1 1 1 1 1p.�" ir4 1 1,� qI-A�� 4 = - r /-1 1 Lr7 -1 -1- 1- rrt 1 1 1- r -r RulloffDep = .2 - 3 35:-/ / 1 1 1 1 1 1 1 1 1 1 1 1 1 _,._(� 1 . 11 0 30% / 1 1 1 1 1 1 1 1 1 1 1 1 1 11C7IP'q mill ill T / 1 -I- 7 T 7 -I 717 1 T 7 -I -I- 7 T 7 -I -1- 1- T 7 T -ICN 7-0.3 - 25 / L / -1- L L i -I -1- L L L -I -1- I- L 1 -I -1- 1- L L _I -1- 1- L 1 L - 20� / 1 1 1 1 1 1 1 1 1 1 1 I I I I I I I I I 153' "- T 1 1 7T7 1 1T7 1 1 7T7 777 T T 7 L -I I L L A _I _I_ L L 1 I I L t 1 _I _1_ I L L J I I L t L - 10 -' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 — r 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 0- 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 28 Hydrograph for Subcatchment 1 B: SCM 1 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 5.19 2.20 0.00 2.00 0.11 0.00 0.00 106.00 5.19 2.20 0.00 4.00 0.25 0.00 0.00 108.00 5.19 2.20 0.00 6.00 0.42 0.00 0.00 110.00 5.19 2.20 0.00 8.00 0.62 0.00 0.00 112.00 5.19 2.20 0.00 10.00 0.94 0.00 0.09 114.00 5.19 2.20 0.00 12.00 3.44 0.99 45.57 116.00 5.19 2.20 0.00 14.00 4.26 1.52 3.18 118.00 5.19 2.20 0.00 16.00 4.57 1.74 1.95 120.00 5.19 2.20 0.00 18.00 4.78 1.90 1.50 122.00 5.19 2.20 0.00 20.00 4.94 2.02 1.11 124.00 5.19 2.20 0.00 22.00 5.07 2.11 1.00 126.00 5.19 2.20 0.00 24.00 5.19 2.20 0.93 128.00 5.19 2.20 0.00 26.00 5.19 2.20 0.00 130.00 5.19 2.20 0.00 28.00 5.19 2.20 0.00 132.00 5.19 2.20 0.00 30.00 5.19 2.20 0.00 134.00 5.19 2.20 0.00 32.00 5.19 2.20 0.00 136.00 5.19 2.20 0.00 34.00 5.19 2.20 0.00 138.00 5.19 2.20 0.00 36.00 5.19 2.20 0.00 140.00 5.19 2.20 0.00 38.00 5.19 2.20 0.00 142.00 5.19 2.20 0.00 40.00 5.19 2.20 0.00 144.00 5.19 2.20 0.00 42.00 5.19 2.20 0.00 44.00 5.19 2.20 0.00 46.00 5.19 2.20 0.00 48.00 5.19 2.20 0.00 50.00 5.19 2.20 0.00 52.00 5.19 2.20 0.00 54.00 5.19 2.20 0.00 56.00 5.19 2.20 0.00 58.00 5.19 2.20 0.00 60.00 5.19 2.20 0.00 62.00 5.19 2.20 0.00 64.00 5.19 2.20 0.00 66.00 5.19 2.20 0.00 68.00 5.19 2.20 0.00 70.00 5.19 2.20 0.00 72.00 5.19 2.20 0.00 74.00 5.19 2.20 0.00 76.00 5.19 2.20 0.00 78.00 5.19 2.20 0.00 80.00 5.19 2.20 0.00 82.00 5.19 2.20 0.00 84.00 5.19 2.20 0.00 86.00 5.19 2.20 0.00 88.00 5.19 2.20 0.00 90.00 5.19 2.20 0.00 92.00 5.19 2.20 0.00 94.00 5.19 2.20 0.00 96.00 5.19 2.20 0.00 98.00 5.19 2.20 0.00 100.00 5.19 2.20 0.00 102.00 5.19 2.20 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 29 Summary for Pond 1 P: SCM 1 Inflow Area = 918,245 sf, 25.14% Impervious, Inflow Depth = 2.20" for 10-yr event Inflow = 58.53 cfs @ 12.08 hrs, Volume= 168,593 cf Outflow = 16.00 cfs @ 12.39 hrs, Volume= 167,620 cf, Atten= 73%, Lag= 18.3 min Primary = 16.00 cfs @ 12.39 hrs, Volume= 167,620 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 575.88'@ 12.39 hrs Surf.Area= 31,771 sf Storage= 68,123 cf Plug-Flow detention time=640.3 min calculated for 167,597 cf(99% of inflow) Center-of-Mass det. time=637.7 min ( 1,488.2 - 850.5 ) Volume Invert Avail.Storage Storage Description _ #1 573.50' 179,460 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.50 23,530 0 0 574.00 27,314 12,711 12,711 575.00 29,660 28,487 41,198 576.00 32,068 30,864 72,062 577.00 34,522 33,295 105,357 578.00 37,037 35,780 141,137 579.00 39,609 38,323 179,460 Device Routing Invert Outlet Devices #1 Primary 569.00' 24.0" Round Outlet Pipe L= 67.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 569.00'/ 568.00' S= 0.0149 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 3.14 sf #2 Device 1 573.50' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 574.40' 0.5" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 1 575.00' 6.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 576.00' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 577.00' 20.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=15.99 cfs @ 12.39 hrs HW=575.88' (Free Discharge) 4 -1=Outlet Pipe (Passes 15.99 cfs of 36.67 cfs potential flow) -2=Orifice (Orifice Controls 0.35 cfs @ 7.22 fps) -3=Orifice/Grate (Orifice Controls 0.01 cfs @ 5.81 fps) -4=Rect Notch (Weir Controls 15.62 cfs @ 3.06 fps) -5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.50' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 30 Pond 1 P: SCM 1 Hydrograph / — — t — t — t — t — 1 1 t — — —I — —I — / I I — —I — — L — L — 4 — _t — _I — _I _ ■Inflow / / 158 53 cfs I I I •Outflow / / / / / I I iriflo A ea 91 245s ■Prima 65_ T I ■Secondary 7 — 7 — II60� , / , /I I I Pea�c�Tev�575.88'I - 55� / / / I I Storage=68,1213 cf 50 -/ / /I / I I I I I I I I 45 / /I / I I I I I I I I — — I— — I— — H — t — —F — —t — H — —I — w 40� , / / /I_ / I I I I I I I I 13 351,/ / /1 / I I I I I I I I 0 301/ / /I 7 I I I I I I I 25-- / 16 00 cfs / I— L L 4 1 4 —I 6.00 cfs 15- ; I 10 - 0j ////////////////////////////////////////////////////////% 0.00 cfs / AND/7 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 31 Hydrograph for Pond 1 P: SCM 1 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.50 0.00 0.00 0.00 4.00 0.00 0 573.50 0.00 0.00 0.00 8.00 0.00 0 573.50 0.00 0.00 0.00 12.00 45.57 25,761 574.47 0.22 0.22 0.00 16.00 1.95 47,693 575.22 2.28 2.28 0.00 20.00 1.11 45,183 575.13 1.26 1.26 0.00 24.00 0.93 44,300 575.10 0.96 0.96 0.00 28.00 0.00 39,166 574.93 0.27 0.27 0.00 32.00 0.00 35,313 574.80 0.26 0.26 0.00 36.00 0.00 31,672 574.67 0.25 0.25 0.00 40.00 0.00 28,246 574.56 0.23 0.23 0.00 44.00 0.00 25,040 574.44 0.21 0.21 0.00 48.00 0.00 22,062 574.34 0.20 0.20 0.00 52.00 0.00 19,293 574.24 0.19 0.19 0.00 56.00 0.00 16,732 574.15 0.17 0.17 0.00 60.00 0.00 14,380 574.06 0.16 0.16 0.00 64.00 0.00 12,239 573.98 0.14 0.14 0.00 68.00 0.00 10,313 573.91 0.13 0.13 0.00 72.00 0.00 8,604 573.85 0.11 0.11 0.00 76.00 0.00 7,117 573.79 0.10 0.10 0.00 80.00 0.00 5,855 573.74 0.08 0.08 0.00 84.00 0.00 4,823 573.70 0.06 0.06 0.00 88.00 0.00 4,026 573.67 0.05 0.05 0.00 92.00 0.00 3,413 573.64 0.04 0.04 0.00 96.00 0.00 2,938 573.62 0.03 0.03 0.00 100.00 0.00 2,571 573.61 0.02 0.02 0.00 104.00 0.00 2,273 573.60 0.02 0.02 0.00 108.00 0.00 2,025 573.58 0.02 0.02 0.00 112.00 0.00 1,819 573.58 0.01 0.01 0.00 116.00 0.00 1,648 573.57 0.01 0.01 0.00 120.00 0.00 1,506 573.56 0.01 0.01 0.00 124.00 0.00 1,388 573.56 0.01 0.01 0.00 128.00 0.00 1,290 573.55 0.01 0.01 0.00 132.00 0.00 1,202 573.55 0.01 0.01 0.00 136.00 0.00 1,120 573.55 0.01 0.01 0.00 140.00 0.00 1,044 573.54 0.01 0.01 0.00 144.00 0.00 973 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 32 Stage-Discharge for Pond 1 P: SCM 1 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) ' (feet) (cfs) (cfs) (cfs) 573.50 0.00 0.00 0.00 578.70 161.65 44.62 117.03 573.60 0.02 0.02 0.00 578.80 172.38 44.87 127.51 573.70 0.06 0.06 0.00 578.90 183.41 45.13 138.28 573.80 0.10 0.10 0.00 579.00 194.72 45.38 149.34 573.90 0.12 0.12 0.00 574.00 0.14 0.14 0.00 574.10 0.16 0.16 0.00 574.20 0.18 0.18 0.00 574.30 0.19 0.19 0.00 574.40 0.21 0.21 0.00 574.50 0.22 0.22 0.00 574.60 0.24 0.24 0.00 574.70 0.25 0.25 0.00 574.80 0.26 0.26 0.00 574.90 0.27 0.27 0.00 575.00 0.28 0.28 0.00 575.10 0.91 0.91 0.00 575.20 2.05 2.05 0.00 575.30 3.50 3.50 0.00 575.40 5.22 5.22 0.00 575.50 7.15 7.15 0.00 575.60 9.28 9.28 0.00 575.70 11.57 11.57 0.00 575.80 14.02 14.02 0.00 575.90 16.61 16.61 0.00 576.00 19.34 19.34 0.00 576.10 23.32 23.32 0.00 576.20 28.30 28.30 0.00 576.30 33.99 33.99 0.00 576.40 38.27 38.27 0.00 576.50 38.57 38.57 0.00 576.60 38.86 38.86 0.00 576.70 39.15 39.15 0.00 576.80 39.45 39.45 0.00 576.90 39.73 39.73 0.00 577.00 40.02 40.02 0.00 577.10 41.88 40.31 1.57 577.20 45.04 40.59 4.45 577.30 49.17 40.87 8.30 577.40 54.10 41.15 12.95 577.50 60.02 41.43 18.60 577.60 66.80 41.70 25.10 577.70 73.54 41.97 31.57 577.80 80.74 42.25 38.50 577.90 88.37 42.52 45.85 578.00 96.38 42.78 53.60 578.10 105.00 43.05 61.95 578.20 114.04 43.32 70.72 578.30 123.03 43.58 79.45 578.40 132.30 43.84 88.46 578.50 141.65 44.10 97.55 578.60 151.22 44.36 106.86 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 33 Stage-Area-Storage for Pond 1 P: SCM 1 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.50 23,530 0 578.70 38,837 167,693 573.60 24,287 2,391 578.80 39,095 171,589 573.70 25,044 4,857 578.90 39,352 175,511 573.80 25,800 7,400 579.00 39,609 179,460 573.90 26,557 10,017 574.00 27,314 12,711 574.10 27,549 15,454 574.20 27,783 18,221 574.30 28,018 21,011 574.40 28,252 23,824 574.50 28,487 26,661 574.60 28,722 29,522 574.70 28,956 32,406 574.80 29,191 35,313 574.90 29,425 38,244 575.00 29,660 41,198 575.10 29,901 44,176 575.20 30,142 47,178 575.30 30,382 50,204 575.40 30,623 53,255 575.50 30,864 56,329 575.60 31,105 59,427 575.70 31,346 62,550 575.80 31,586 65,697 575.90 31,827 68,867 576.00 32,068 72,062 576.10 32,313 75,281 576.20 32,559 78,525 576.30 32,804 81,793 576.40 33,050 85,086 576.50 33,295 88,403 576.60 33,540 91,745 576.70 33,786 95,111 576.80 34,031 98,502 576.90 34,277 101,917 577.00 34,522 105,357 577.10 34,774 108,822 577.20 35,025 112,312 577.30 35,276 115,827 577.40 35,528 119,367 577.50 35,780 122,932 577.60 36,031 126,523 577.70 36,283 130,139 577.80 36,534 133,779 577.90 36,785 137,445 578.00 37,037 141,137 578.10 37,294 144,853 578.20 37,551 148,595 578.30 37,809 152,363 578.40 38,066 156,157 578.50 38,323 159,977 578.60 38,580 163,822 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 34 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlA: SCM 1 Pre Runoff Area=21.080 ac 0.00% Impervious Runoff Depth=1.71" Tc=15.6 min CN=55.9 Runoff=42.37 cfs 130,554 cf SubcatchmentlB: SCM 1 Post Runoff Area=21.080 ac 25.14% Impervious Runoff Depth=2.99" Tc=15.6 min CN=70.3 Runoff=80.11 cfs 229,079 cf Pond 1P: SCM 1 Peak Elev=576.35' Storage=83,359 cf Inflow=80.11 cfs 229,079 cf Primary=36.92 cfs 228,102 cf Secondary=0.00 cfs 0 cf Outflow=36.92 cfs 228,102 cf KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment 1A: SCM 1 Pre Runoff = 42.37 cfs @ 12.09 hrs, Volume= 130,554 cf, Depth= 1.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 25-yr Rainfall=6.20" Area (ac) CN Description 18.590 56.0 Brush, Fair, HSG B 2.490 55.0 Woods, Good, HSG B 21.080 55.9 Weighted Average 21.080 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Pre Subcatchment 1A: SCM 1 Pre Hydrograph I III II III II II I I III III II III 464 I I _I -I- H L H -I -I- H L H -1 -I- I- L 4 -I -I- I- H H H -I- I- L H H - ■Runoff 444/ -142.37crsI-I Ht t H t H I H H H I- 1 H t H - 42 — r / -I -1- 7r7 -1- rr7 1 -1- 7r4 1 1 r7TypeH24Ar- 381 L / .I -I- L I -I -I- L L L -I -I- I- L 1 _I -, ,I-y L"j _I 1Q�' _ 34 H /-I -I- H � 4 -I -I- I- H 4 -I -I- I- T Runoff Area=211080-a$ - 32+/ — -r -1- fi -r -I -1- fi rt -I -1- 1- 1rtfiu 7 T 7 1 7 7 I 7 "I"T#I��I T p-14 laPgdr 28� I 1 I I 1 1 I 1 1 I I 1 I I 26; Ru nQf Qept*h=1.mZ1nt - 244/ — L �-I I H H H I I H L 4 1 I H H T I I H H��14- -L.'T - 0 -I- H t H -I -I- H t H -I -I- I- t t -I -I- I- t u 20 r % - - 1- r rt -I -1- r rt -I -1- 1- r rt —I —1— I— r rt -1Cp=55J.9 -_ 16� I I I I I I I I I I I I I I I I I I I I I I I I I 14 1 I I I I I I I I I I I I I I I I I I I I I I I I I 12 H I -I- H H 4 -I -I- H H 4 -I -I- I- H 4 -I -I- I- H 4 -I -I- 1- H 4 - - 10 t % -1- H t H -1 -1- H t t -I -I- 1- fi t -1 -1- 1- t t H -1- I- t t t - 6 T / I I P T H I I I- T 7 I I P r T I I I T T 7 I 1 r T H 4 I I I I I I I I I I I I I I I I I I I I I I I I I o. ����/0 5 10 15 20 25 30 35 40 45 50 55 60 65 70��75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 36 Hydrograph for Subcatchment 1A: SCM 1 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 6.20 1.71 0.00 2.00 0.14 0.00 0.00 106.00 6.20 1.71 0.00 4.00 0.30 0.00 0.00 108.00 6.20 1.71 0.00 6.00 0.50 0.00 0.00 110.00 6.20 1.71 0.00 8.00 0.74 0.00 0.00 112.00 6.20 1.71 0.00 10.00 1.12 0.00 0.00 114.00 6.20 1.71 0.00 12.00 4.11 0.61 29.90 116.00 6.20 1.71 0.00 14.00 5.08 1.08 2.84 118.00 6.20 1.71 0.00 16.00 5.46 1.28 1.78 120.00 6.20 1.71 0.00 18.00 5.71 1.42 1.39 122.00 6.20 1.71 0.00 20.00 5.90 1.53 1.04 124.00 6.20 1.71 0.00 22.00 6.06 1.62 0.95 126.00 6.20 1.71 0.00 24.00 6.20 1.71 0.88 128.00 6.20 1.71 0.00 26.00 6.20 1.71 0.00 130.00 6.20 1.71 0.00 28.00 6.20 1.71 0.00 132.00 6.20 1.71 0.00 30.00 6.20 1.71 0.00 134.00 6.20 1.71 0.00 32.00 6.20 1.71 0.00 136.00 6.20 1.71 0.00 34.00 6.20 1.71 0.00 138.00 6.20 1.71 0.00 36.00 6.20 1.71 0.00 140.00 6.20 1.71 0.00 38.00 6.20 1.71 0.00 142.00 6.20 1.71 0.00 40.00 6.20 1.71 0.00 144.00 6.20 1.71 0.00 42.00 6.20 1.71 0.00 44.00 6.20 1.71 0.00 46.00 6.20 1.71 0.00 48.00 6.20 1.71 0.00 50.00 6.20 1.71 0.00 52.00 6.20 1.71 0.00 54.00 6.20 1.71 0.00 56.00 6.20 1.71 0.00 58.00 6.20 1.71 0.00 60.00 6.20 1.71 0.00 62.00 6.20 1.71 0.00 64.00 6.20 1.71 0.00 66.00 6.20 1.71 0.00 68.00 6.20 1.71 0.00 70.00 6.20 1.71 0.00 72.00 6.20 1.71 0.00 74.00 6.20 1.71 0.00 76.00 6.20 1.71 0.00 78.00 6.20 1.71 0.00 80.00 6.20 1.71 0.00 82.00 6.20 1.71 0.00 84.00 6.20 1.71 0.00 86.00 6.20 1.71 0.00 88.00 6.20 1.71 0.00 90.00 6.20 1.71 0.00 92.00 6.20 1.71 0.00 94.00 6.20 1.71 0.00 96.00 6.20 1.71 0.00 98.00 6.20 1.71 0.00 100.00 6.20 1.71 0.00 102.00 6.20 1.71 0.00 KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment 1 B: SCM 1 Post Runoff = 80.11 cfs @ 12.08 hrs, Volume= 229,079 cf, Depth= 2.99" Routed to Pond 1 P : SCM 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 25-yr Rainfall=6.20" Area (ac) CN Description 5.300 98.0 Paved parking, HSG B 15.780 61.0 >75% Grass cover, Good, HSG B 21.080 70.3 Weighted Average 15.780 74.86% Pervious Area 5.300 25.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.6 Direct Entry, SCM 1 Post Subcatchment 1 B: SCM 1 Post Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I I T 7 I I T I -I- T 7 I I T T I -I- I T 7 -I I I T T 7 - ■Runoff 85 " 80.11 cfs rl firt rfirt firt firth firth 80 -" fi j-1 1 1- t -[ -1 -1- 1- t -F 1 1 1- t t -1 1 1 t -Type 11- th- 75 /-1 I 1- 4 -1 -1- 4 I I 7 4 1 � 1- Fla n al - .. 65 /-I 1 L -I -I- L L 1 I I L 1 Runoff Area=2110811at - 60 / 1 1 1 1 I I I I ikldn ff1 v1T I 2I _n4at 55� , 1 / 1 I 1 1 I I I I I � 1 .1) 50 1 / 1 I 1 1 1 1 1 1 I I I I 1 1 I 1 R_unoff Depth=2.99't - 45� 1 1 1 1 1 1 1 C-T I pp y 'T 40 35 / 1 I 1 1 I 1 1 I I I I I 1 1 1 1 1 1 1 1 CN70.3 307' / 1 7 T -1 -1- T 7 1 1 T T -1 -1- 1 T 7 -I 1 T T - 25= t / firt rfirt firt firth firth 20? 1- ± fi Ott ± tt � 15� -I 1 + 4 -1 -I- I- 4 1 1 7 4 -1 -I- 1 4 -I 1 1 4 - 104-/ 1 7 F 4 -1 -1- 4 4 4 1 1 7 4 4 -1 -1- 1 4 4 -I 1 1 4 4 - 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 38 Hydrograph for Subcatchment 1 B: SCM 1 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 6.20 2.99 0.00 2.00 0.14 0.00 0.00 106.00 6.20 2.99 0.00 4.00 0.30 0.00 0.00 108.00 6.20 2.99 0.00 6.00 0.50 0.00 0.00 110.00 6.20 2.99 0.00 8.00 0.74 0.00 0.00 112.00 6.20 2.99 0.00 10.00 1.12 0.02 0.46 114.00 6.20 2.99 0.00 12.00 4.11 1.42 63.71 116.00 6.20 2.99 0.00 14.00 5.08 2.12 4.12 118.00 6.20 2.99 0.00 16.00 5.46 2.41 2.50 120.00 6.20 2.99 0.00 18.00 5.71 2.60 1.92 122.00 6.20 2.99 0.00 20.00 5.90 2.76 1.42 124.00 6.20 2.99 0.00 22.00 6.06 2.88 1.28 126.00 6.20 2.99 0.00 24.00 6.20 2.99 1.18 128.00 6.20 2.99 0.00 26.00 6.20 2.99 0.00 130.00 6.20 2.99 0.00 28.00 6.20 2.99 0.00 132.00 6.20 2.99 0.00 30.00 6.20 2.99 0.00 134.00 6.20 2.99 0.00 32.00 6.20 2.99 0.00 136.00 6.20 2.99 0.00 34.00 6.20 2.99 0.00 138.00 6.20 2.99 0.00 36.00 6.20 2.99 0.00 140.00 6.20 2.99 0.00 38.00 6.20 2.99 0.00 142.00 6.20 2.99 0.00 40.00 6.20 2.99 0.00 144.00 6.20 2.99 0.00 42.00 6.20 2.99 0.00 44.00 6.20 2.99 0.00 46.00 6.20 2.99 0.00 48.00 6.20 2.99 0.00 50.00 6.20 2.99 0.00 52.00 6.20 2.99 0.00 54.00 6.20 2.99 0.00 56.00 6.20 2.99 0.00 58.00 6.20 2.99 0.00 60.00 6.20 2.99 0.00 62.00 6.20 2.99 0.00 64.00 6.20 2.99 0.00 66.00 6.20 2.99 0.00 68.00 6.20 2.99 0.00 70.00 6.20 2.99 0.00 72.00 6.20 2.99 0.00 74.00 6.20 2.99 0.00 76.00 6.20 2.99 0.00 78.00 6.20 2.99 0.00 80.00 6.20 2.99 0.00 82.00 6.20 2.99 0.00 84.00 6.20 2.99 0.00 86.00 6.20 2.99 0.00 88.00 6.20 2.99 0.00 90.00 6.20 2.99 0.00 92.00 6.20 2.99 0.00 94.00 6.20 2.99 0.00 96.00 6.20 2.99 0.00 98.00 6.20 2.99 0.00 100.00 6.20 2.99 0.00 102.00 6.20 2.99 0.00 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 39 Summary for Pond 1 P: SCM 1 Inflow Area = 918,245 sf, 25.14% Impervious, Inflow Depth = 2.99" for 25-yr event Inflow = 80.11 cfs @ 12.08 hrs, Volume= 229,079 cf Outflow = 36.92 cfs @ 12.26 hrs, Volume= 228,102 cf, Atten= 54%, Lag= 11.0 min Primary = 36.92 cfs @ 12.26 hrs, Volume= 228,102 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 576.35'@ 12.26 hrs Surf.Area= 32,921 sf Storage= 83,359 cf Plug-Flow detention time=480.8 min calculated for 228,071 cf(100% of inflow) Center-of-Mass det. time=479.2 min ( 1,320.8 - 841.6 ) Volume Invert Avail.Storage Storage Description #1 573.50' 179,460 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.50 23,530 0 0 574.00 27,314 12,711 12,711 575.00 29,660 28,487 41,198 576.00 32,068 30,864 72,062 577.00 34,522 33,295 105,357 578.00 37,037 35,780 141,137 579.00 39,609 38,323 179,460 Device Routing Invert Outlet Devices #1 Primary 569.00' 24.0" Round Outlet Pipe L= 67.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 569.00'/ 568.00' S= 0.0149 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 3.14 sf #2 Device 1 573.50' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 574.40' 0.5" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Device 1 575.00' 6.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 576.00' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 577.00' 20.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=36.86 cfs @ 12.26 hrs HW=576.35' (Free Discharge) 4 -1=Outlet Pipe (Passes 36.86 cfs of 38.11 cfs potential flow) -2=Orifice (Orifice Controls 0.39 cfs @ 7.94 fps) -3=Orifice/Grate (Orifice Controls 0.01 cfs @ 6.68 fps) -4=Rect Notch (Orifice Controls 25.77 cfs @ 4.44 fps) -5=Top of Riser (Weir Controls 10.69 cfs @ 1.93 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.50' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 40 Pond 1 P: SCM 1 Hydrograph I I I I I I i I I I I I I I ■Inflow i /11 80.11 cfs I I� •Outflow •Prima - i z /l it loW-A �T -0,245- I •Se ondary 85 / / ' /1 - I I Peak-Be - 75 / / zI_ I I I I I I I Sforage 3,359c 70 / /i /I _L J _1I I I _ I I I _II 654" i ' i I L J J I I L L J J J I 60" i z J J J —I I I L L J J J I 55 z 4 4 -1 I I I— 4 4 —II v50� / 36.92 cfs 45� / ' 136.92 cfs 4 + 1 35=' - + - + -1 L L + -[ H 1 - 30 - , z + + —1 L t + —r - 1 25 i , " 0 I — I I - — — 1 — —I - 1 - —1 1 15 - % Z 1A����������������������������� I 0.00 cfs / Z / 333)7 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 41 Hydrograph for Pond 1 P: SCM 1 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.50 0.00 0.00 0.00 4.00 0.00 0 573.50 0.00 0.00 0.00 8.00 0.00 0 573.50 0.00 0.00 0.00 12.00 63.71 40,726 574.98 0.28 0.28 0.00 16.00 2.50 49,000 575.26 2.89 2.89 0.00 20.00 1.42 46,058 575.16 1.59 1.59 0.00 24.00 1.18 45,058 575.13 1.22 1.22 0.00 28.00 0.00 39,359 574.94 0.28 0.28 0.00 32.00 0.00 35,496 574.81 0.26 0.26 0.00 36.00 0.00 31,845 574.68 0.25 0.25 0.00 40.00 0.00 28,408 574.56 0.23 0.23 0.00 44.00 0.00 25,191 574.45 0.22 0.22 0.00 48.00 0.00 22,202 574.34 0.20 0.20 0.00 52.00 0.00 19,423 574.24 0.19 0.19 0.00 56.00 0.00 16,852 574.15 0.17 0.17 0.00 60.00 0.00 14,490 574.06 0.16 0.16 0.00 64.00 0.00 12,339 573.99 0.14 0.14 0.00 68.00 0.00 10,401 573.91 0.13 0.13 0.00 72.00 0.00 8,682 573.85 0.11 0.11 0.00 76.00 0.00 7,184 573.79 0.10 0.10 0.00 80.00 0.00 5,911 573.74 0.08 0.08 0.00 84.00 0.00 4,867 573.70 0.06 0.06 0.00 88.00 0.00 4,060 573.67 0.05 0.05 0.00 92.00 0.00 3,439 573.64 0.04 0.04 0.00 96.00 0.00 2,959 573.62 0.03 0.03 0.00 100.00 0.00 2,587 573.61 0.02 0.02 0.00 104.00 0.00 2,286 573.60 0.02 0.02 0.00 108.00 0.00 2,036 573.59 0.02 0.02 0.00 112.00 0.00 1,828 573.58 0.01 0.01 0.00 116.00 0.00 1,656 573.57 0.01 0.01 0.00 120.00 0.00 1,513 573.56 0.01 0.01 0.00 124.00 0.00 1,394 573.56 0.01 0.01 0.00 128.00 0.00 1,295 573.55 0.01 0.01 0.00 132.00 0.00 1,206 573.55 0.01 0.01 0.00 136.00 0.00 1,124 573.55 0.01 0.01 0.00 140.00 0.00 1,048 573.54 0.01 0.01 0.00 144.00 0.00 976 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 42 Stage-Discharge for Pond 1 P: SCM 1 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) ' (feet) (cfs) (cfs) (cfs) 573.50 0.00 0.00 0.00 578.70 161.65 44.62 117.03 573.60 0.02 0.02 0.00 578.80 172.38 44.87 127.51 573.70 0.06 0.06 0.00 578.90 183.41 45.13 138.28 573.80 0.10 0.10 0.00 579.00 194.72 45.38 149.34 573.90 0.12 0.12 0.00 574.00 0.14 0.14 0.00 574.10 0.16 0.16 0.00 574.20 0.18 0.18 0.00 574.30 0.19 0.19 0.00 574.40 0.21 0.21 0.00 574.50 0.22 0.22 0.00 574.60 0.24 0.24 0.00 574.70 0.25 0.25 0.00 574.80 0.26 0.26 0.00 574.90 0.27 0.27 0.00 575.00 0.28 0.28 0.00 575.10 0.91 0.91 0.00 575.20 2.05 2.05 0.00 575.30 3.50 3.50 0.00 575.40 5.22 5.22 0.00 575.50 7.15 7.15 0.00 575.60 9.28 9.28 0.00 575.70 11.57 11.57 0.00 575.80 14.02 14.02 0.00 575.90 16.61 16.61 0.00 576.00 19.34 19.34 0.00 576.10 23.32 23.32 0.00 576.20 28.30 28.30 0.00 576.30 33.99 33.99 0.00 576.40 38.27 38.27 0.00 576.50 38.57 38.57 0.00 576.60 38.86 38.86 0.00 576.70 39.15 39.15 0.00 576.80 39.45 39.45 0.00 576.90 39.73 39.73 0.00 577.00 40.02 40.02 0.00 577.10 41.88 40.31 1.57 577.20 45.04 40.59 4.45 577.30 49.17 40.87 8.30 577.40 54.10 41.15 12.95 577.50 60.02 41.43 18.60 577.60 66.80 41.70 25.10 577.70 73.54 41.97 31.57 577.80 80.74 42.25 38.50 577.90 88.37 42.52 45.85 578.00 96.38 42.78 53.60 578.10 105.00 43.05 61.95 578.20 114.04 43.32 70.72 578.30 123.03 43.58 79.45 578.40 132.30 43.84 88.46 578.50 141.65 44.10 97.55 578.60 151.22 44.36 106.86 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 43 Stage-Area-Storage for Pond 1 P: SCM 1 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.50 23,530 0 578.70 38,837 167,693 573.60 24,287 2,391 578.80 39,095 171,589 573.70 25,044 4,857 578.90 39,352 175,511 573.80 25,800 7,400 579.00 39,609 179,460 573.90 26,557 10,017 574.00 27,314 12,711 574.10 27,549 15,454 574.20 27,783 18,221 574.30 28,018 21,011 574.40 28,252 23,824 574.50 28,487 26,661 574.60 28,722 29,522 574.70 28,956 32,406 574.80 29,191 35,313 574.90 29,425 38,244 575.00 29,660 41,198 575.10 29,901 44,176 575.20 30,142 47,178 575.30 30,382 50,204 575.40 30,623 53,255 575.50 30,864 56,329 575.60 31,105 59,427 575.70 31,346 62,550 575.80 31,586 65,697 575.90 31,827 68,867 576.00 32,068 72,062 576.10 32,313 75,281 576.20 32,559 78,525 576.30 32,804 81,793 576.40 33,050 85,086 576.50 33,295 88,403 576.60 33,540 91,745 576.70 33,786 95,111 576.80 34,031 98,502 576.90 34,277 101,917 577.00 34,522 105,357 577.10 34,774 108,822 577.20 35,025 112,312 577.30 35,276 115,827 577.40 35,528 119,367 577.50 35,780 122,932 577.60 36,031 126,523 577.70 36,283 130,139 577.80 36,534 133,779 577.90 36,785 137,445 578.00 37,037 141,137 578.10 37,294 144,853 578.20 37,551 148,595 578.30 37,809 152,363 578.40 38,066 156,157 578.50 38,323 159,977 578.60 38,580 163,822 KT37 - SCM Calculations Type II 24-hr 100-yr Rainfall=7.85" Prepared by ESP Associates Inc Printed 5/9/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 50 Pond 1 P: SCM 1 Hydrograph ❑Inflow r/1117.06 cfs ❑Outflow 1307 % Inflow Area=918,245 sf o se ondary 120 j Peak Elev=577.38' 110- / Storage=118,580 cf 100- 90- 80- / • = • 79-' 52 97 cfs I / • 60- 50- I41.o cfs 40-" 307 O 20-- .4 11.89 cfs 107 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) SCM #2 Time of Concentrations & Curve Numbers ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Time of Concentration (Tc) or Travel Time (Tt) Project Aurora at Price Mill Creek By JWF 7/28/2023 Location Wesley Chapel, NC Checked Date: Circle One:C-Present) Developed SCM 2 Pre-Development 1. SHEET FLOW SEGMENT ID A 1. Surface description (table.3-1). Woods-Light 2. Manning's roughness coefficient, n (table 3-1) 0.4 3. Flow length, L(total L<_3Q0.ft) ft 100 4. Two-year 24-hour rainfall, P in 5.44 5. Land slope, s ft/ft 0.025 6. Tt=0.007(nL)^0.8 Compute Tt hr 0.251 P2^0.5 s"0.4 Total Sheet Flow Tt(hr) 0.25 2. SHALLOW CONCENTRATED FLOW SEGMENT ID B 7. Surface description (paved or unpaved) Unpaved 8. Flow length,.L ft 369 9. Watercourse slope,.s ft/ft 0.060 10. Average velocity,V(figure.3-.1) _ 3.952 11. Tt= L Compute Tt hr 0.026 3600 V Total Shallow Concentrated Flow Tt(hr) 0.03 3. CHANNEL FLOW SEGMENT ID C 12. Channel type(Pipe or Open 0.28 Open Channel 13. Cross sectional flow area,.a ft2 483.00 14. Wetted perimeter,.pw ft 118.99 15. Hydraulic radius r=a/pw Compute r ft 4.06 16. Channel slope,.s ft/ft 0.040 17. Manning's roughness coefficient,.n 0.030 18. V=[1.49 r^(2/3)s^(1/2)]/n Compute V ft/s 25.28 19. Flow length.,.L ft 358 20. Tt= L Compute Tt hr 0.004 Total Channel Flow Tt(hr) 0.00 3600 V 21. Watershed or subarea Tc or Tt(add Tt in steps 6, 11, and 19) Total Tt (hr) =L 0.28 Total Tt (min) = 16.8 Reference: Urban Hydrology for Small Watersheds Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Associates',PA SCM 2 Pre Po Box 7030 TOC Calcs.xlsx Charlotte NC 28241 8/30/2023 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Time of Concentration (Tc) or Travel Time (Tt) Project Aurora at Price Mill Creek By JWF 7/28/2023 Location Wesley Chapel, NC Checked Date: Circle One: Present (Develope-iDI SCM 2 Post-Development 1. SHEET FLOW SEGMENT ID A 1. Surface description (table.3-1). Grass-Bermuda 2. Manning's roughness coefficient, n (table 3-1) 0.41 3. Flow length, L(total L<_3Q0.ft) ft 100 4. Two-year 24-hour rainfall, P in 5.44 5. Land slope, s ft/ft 0.055 6. Tt=0.007(nL)^0.8 Compute Tt hr 0.187 P2^0.5 s"0.4 Total Sheet Flow Tt(hr) 0.19 2. SHALLOW CONCENTRATED FLOW SEGMENT ID B 7. Surface description (paved or unpaved) Unpaved 8. Flow length,.L ft 61 9. Watercourse slope,.s ft/ft 0.020 10. Average velocity,V(figure.3,1.) _ 2.282 11. Tt= L Compute Tt hr 0.007 3600 V Total Shallow Concentrated Flow Tt(hr) 0.01 3. CHANNEL FLOW SEGMENT ID C D 12. Channel type(Pipe or Open 0.23 Pipe Pipe 13. Cross sectional flow area,.a ft' 1.77 3.14 14. Wetted perimeter,.pw ft 4.71 6.28 15. Hydraulic radius r=a/pw Compute r ft 0.38 0.50 16. Channel slope,.s ft/ft 0.005 0.010 17. Manning's roughness coefficient,.n 0.012 0.012 18. V=[1.49 r^(2/3)s^(1/2)]/n Compute.V ft/s 4.57 7.82 19. Flow length.,.L ft 344 362 20. Tt= L Compute Tt hr 0.021 0.013 Total Channel Flow Tt(hr) 0.03 3600 V 21. Watershed or subarea Tc or Tt(add Tt in steps 6, 11, and 19) Total Tt (hr) =L 0.23 Total Tt (min) = 13.8 Reference: Urban Hydrology for Small Watersheds Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Associates',PA SCM 2 Post Po Box 7030 TOC Calcs.xlsx Charlotte NC 28241 8/30/2023 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Runoff Curve Number and Runoff Project Aurora at Price Mill Creek By JWF Date 5/9/2024 Location Wesley Chapel, NC Checked Date Circle One:(Present Developed SCM 2 Pre-Development 1. Runoff Curve Number Soil Cover Description CN* Area Product Hydrologic (cover type,treatment Tbl. Fig. Fig. of Group and hydrologic condition) 2-2 2-3 2-4 Acres CN x area B Brush—brush-weed-grass mixture with brush, Fair condition 56 10.74 601.44 (BdC2,BdB2,TbB2) B Woods,Good condition 55 1.00 55.00 (BdC2,BdB2,TbB2) * Use only one CN source per line Totals= 11.74 656.44 CN(weighted)total product = 656.44 = 55.9 Use CN= 56 total area 11.74 2. Runoff Storm#1 Storm#2 Storm#3 Frequency yr 2 10 100 Rainfall, P(24-hour) in 5.93 7.58 9.43 Runoff,Q in 1.56 2.60 3.93 (Use P and CN with table 3-11,fig.2-1, and equation 3-14) Reference: Urban Hydrology for Small Watersheds Rainfall,P,taken from: Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Assocates,PA SCM 2 PRE PoBox 7030 CN Calcs.xlsx Charlotte NC 28241 5/9/2024 ESP Associates, Inc. 20484 Chartwell Center Drive,Suite D Cornelius,NC 28031 Phone 704-990-9438 Runoff Curve Number and Runoff Project Aurora at Price Mill Creek By JWF Date 5/9/2024 Location Wesley Chapel, NC Checked Date Circle One: Present Cevelopee SCM 2 Post-Development 1. Runoff Curve Number Soil Cover Description CN* Area Product Hydrologic (cover type,treatment Tbl. Fig. Fig. of Group and hydrologic condition) 2-2 2-3 2-4 Acres CN x area B Paved areas,streets,roofs,driveways,etc(excl.ROW) 98 3.45 338.10 (BdC2,BdB2,TbB2) B Open space,Good condition(grass cover>75%) 61 8.29 505.69 (BdC2,BdB2,TbB2) * Use only one CN source per line Totals= 11.74 843.79 CN(weighted)total product = 843.79 = 71.9 Use CN= 72 total area 11.74 2. Runoff Storm#1 Storm#2 Storm#3 Frequency yr 2 10 100 Rainfall, P(24-hour) in 5.93 7.58 9.43 Runoff,Q in 2.94 4.33 5.97 (Use P and CN with table 3-11,fig.2-1, and equation 3-14) Reference: Urban Hydrology for Small Watersheds Rainfall,P,taken from: Technical Release 55,Soil Conservation Service NCDENR BMP Design Manual,July 2007 U.S.Department of Agriculture,June 1986 ESP Assocates,PA SCM 2 POST PoBox 7030 CN Calcs.xlsx Charlotte NC 28241 5/9/2024 Sand Filter Design SAND FILTER CALCULATIONS PROJECT NAME: Aurora at Price Mill Creek SCM ID: 2 Dry Pond PROJECT NUMBER: KT37.400 DESIGNER: JWF CHECKED BY: DATE: 07/14/23 DATE: REV.: 05/09/24 DATE: Drainage Area Characteristics: Total Drainage Area: 11.74 ac 0.00 ac Exist./Prop. Impervious 3.45 ac Future Impervious Area: 0.00 ac WATER QUALITY VOLUME CALCULATION SCM ID Pervious Area Impervious Total Imperv. Runoff Coeff. Rainfall Depth Drainage Area Water Quality Area Fraction IA Rv P (A) Volume(WQv) 2 I 8.29 ac I 3.45 ac I 11.74 ac I 0.29 I 0.31 I 1.00 in' 11.74 ac I 13,402.01 cf Simple Method Water Quality Volume: Calculate the Adjusted Water Quality Volume(WQadjv): Rv=0.05+0.9 x IA WQv=(P x Rv x A)/12 WQadjv= 13,402.01 cf WQadjv=0.75 x WQv 10,051.51 cf Calculate the Water Quality Peak Flow(Qp): Calculate CNm CNm= 1,000410+5P+ 10WQv- 10(WQv2+ 1.25WQv P)°5] P=Rainfall in inches P: 1.00 in WQv(Inches) =P*Rv WQv: 0.31 in 0.308 acre-ft CNm: 89.84 Qp: 4.75 cfs Taken from Pond Modeling Software-See attached routing for more info. SAND FILTER SURFACE AREA SCM ID Water Quality Filter Bed Coeff.of Avg. Ht of Design Drain Req'd Area of Surface Area Volume Depth(df) Permeability Water Above Time(tf) BMP(Af) Provided (WQv) (k) Filter Bed(hf) 2 10,051.51 cf 1.50-ft 3.50-ft/day 1.00-ft 2.13 days 810.88-sf 900.00-sf ACCEPTABLE Darcy's Law Surface Area Calculation Af=(WQ)(df)/((k) (hf+dr)(till Sediment Forebay Volume Calculation Fv=0.20*WQv Fv: 2,680.40 cf Minimum Req'd Volume Forebay Elev.: 574.00 WQv Elev.: 576.00 Forebay Vol. Provided: 5,265.00 cf 0.121 acre-ft WQv Provided: 23,000.00 cf Forebay Vol.Required: 2,680.40 cf WQv Req'd: 10,051.51 cf ACCEPTABLE ACCEPTABLE Page 1 Calculate the Stage-Discharge for the Sand Filter WQv/tt=Qo=Ar(k)(hf+df)/(df) Af: 900.00-sf Ar: 900.00-sf (Provided Surface Area of Filter Bed) k: 3.5 ft/day (Coeff.Of Permeability) df: 1.5 ft (Filter Bed Depth) Depth above sand filter(hf) Elevation(ft) (ft) Discharge(cfs) Q 573.00 0 0.000 574.00 1.00 0.061 E E 575.00 2.00 0.085 E 576.00 3.00 0.109 0 co 577.00 4.00 0.134 E 578.00 5.00 0.158 578.50 5.50 0.170 Calculate the Underdrain Outflow and Minimum Drawdown Calculate Minimum Drawdown(Qmin) Qmin=(WQv/tf)/86,400 sec/day Qmin: 0.05 cfs Size Underdrain System for SCM Calculate Perforation Capacity Perforations: 8/If holes/row Linear Ft of Pipe 52.00 (2 row @ 26') Total Perforations: 416 50% Perforations: 208 Dia.of Area of Perforation: 0.375-in Perforation: 0.001 sq-ft. c= 0.62 Q=ca(2gh)os Total Head Above Drain: 2.00-ft Capacity Per Perforation 0.01-cfs Total Capacity: 1.12-cfs ACCEPTABLE Page 2 Basin Stage/Storage Elev. Forebay Area Main Bay Total Area Avg.Total Main Bay Forebay Total Area Area Accumul.Vol. Accumul.Vol. Accumul.Vol. 574 1,850.00 sf 8,150.00 sf 10,000.00 sf 0.00 sf 0.00 cf 0.00 cf 0.00 cf 575 2,605.00 sf 8,895.00 sf 11,500.00 sf 10,750.00 sf 8,522.50 cf 2,227.50 cf 10,750.00 cf 576 3,470.00 sf 9,530.00 sf 13,000.00 sf 12,250.00 sf 17,735.00 cf 5,265.00 cf 23,000.00 cf Page 3 Riser Anti-Flotation Calculations AURORA at PRICE MILL CREEK CONCRETE ANCHOR BUOYANCY CALCULATIONS SCM #2 Unit wt. of concrete (pcf) = 150 lb/ft3 Unit wt. of H2O = 62.4 lb/ft3 TOP OF RISER ELEV. = 576.00 ft INV. OUT OF RISER ELEV. = 569.00 ft INT. WIDTH OF RISER = 48 in INT. LENGTH OF RISER= 48 in WALL THICK. OF RISER = 6 in BASE THICK. OF RISER= 6 in VOL. OF RISER = 187.5 ft3 BUOYANT FORCE = 11700.0 lbs Vol. of Riser x Unit wt. of H2O VOL. CONC. IN RISER= 75.5 ft3 SINKING FORCE OF RISER= 11325 lbs Vol. of Conc. x(Unit wt. of Conc) CONC. PAD THICKNESS = 12 in CONC. PAD WIDTH/LENGTH = 5 ft VOL. OF CONC. PAD = 25.00 ft3 L x W x H/ Pad Thickness SINKING FORCE OF PAD = 2190 lbs Vol. of Pad x(Unit wt. of Conc. - Unit wt. of H2O) TOTAL SINKING FORCE = 13515.0 lbs Factor of safety= SINKING FORCE BUOYANT FORCE F.S. = 1.16 OK F.S. MUST BE GREATER THAN 1.10 HydroCAD Detention 1 year, 24 hour 2 year, 24 hour 10 year, 24 hour 25 year, 24 hour (100 year, 24 hour — shown for spillway) < 2A > < 4S > SCM 2 Pre S M 2 Post 2P SCM 2 SubCat Reach 'On. til _ _ _ Routing Diagram for KT37-SCM Calculations Prepared by ESP Associates Inc, Printed 5/10/2024 HydroCAD®10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 2 Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 1-yr Type II 24-hr Default 24.00 1 2.95 2 2 2-yr Type II 24-hr Default 24.00 1 3.55 2 3 10-yr Type II 24-hr Default 24.00 1 5.19 2 4 25-yr Type II 24-hr Default 24.00 1 6.20 2 5 100-yr Type II 24-hr Default 24.00 1 7.85 2 KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 3 Area Listing (selected nodes) Area CN Description (sq-ft) (subcatchment-numbers) 361,112 61.0 >75% Grass cover, Good, HSG B (4S) 467,834 56.0 Brush, Fair, HSG B (2A) 150,282 98.0 Paved parking, HSG B (4S) 43,560 55.0 Woods, Good, HSG B (2A) KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 4 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment2A: SCM 2 Pre Runoff Area=11.740 ac 0.00% Impervious Runoff Depth=0.20" Tc=16.8 min CN=55.9 Runoff=0.93 cfs 8,680 cf Subcatchment4S: SCM 2 Post Runoff Area=11.740 ac 29.39% Impervious Runoff Depth=0.77" Tc=13.8 min CN=71.9 Runoff=11.30 cfs 32,920 cf Pond 2P: SCM 2 Peak Elev=575.71' Storage=24,935 cf Inflow=11.30 cfs 32,920 cf Primary=0.25 cfs 30,961 cf Secondary=0.00 cfs 0 cf Outflow=0.25 cfs 30,961 cf KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 2A: SCM 2 Pre Runoff = 0.93 cfs @ 12.19 hrs, Volume= 8,680 cf, Depth= 0.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 1-yr Rainfall=2.95" Area (ac) CN Description 10.740 56.0 Brush, Fair, HSG B 1.000 55.0 Woods, Good, HSG B 11.740 55.9 Weighted Average 11.740 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) _ 16.8 Direct Entry, SCM 2 Pre Subcatchment 2A: SCM 2 Pre Hydrograph A 1 1 1 1 1 1 I I I I I I I I I I I I ❑Runoff` 10.93 cfs l I I I I II 1 1 1 1 1 1 j 1 1 1 1 Type II 24-hrr II II 1�-yr aiafall= .9;5", 1 Ruhdff 1Ai-e'a=11.740 ad I Runoff Volume 8,6801cf N 1I II � p n1^ff a th 01II".21 1i I I I I I I I I 0 1 I I Tc 16181mlirh II II I I I I I CN=55.9 II II II II II II II 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 6 Hydrograph for Subcatchment 2A: SCM 2 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 2.95 0.20 0.00 2.00 0.06 0.00 0.00 106.00 2.95 0.20 0.00 4.00 0.14 0.00 0.00 108.00 2.95 0.20 0.00 6.00 0.24 0.00 0.00 110.00 2.95 0.20 0.00 8.00 0.35 0.00 0.00 112.00 2.95 0.20 0.00 10.00 0.53 0.00 0.00 114.00 2.95 0.20 0.00 12.00 1.96 0.02 0.13 116.00 2.95 0.20 0.00 14.00 2.42 0.08 0.26 118.00 2.95 0.20 0.00 16.00 2.60 0.12 0.18 120.00 2.95 0.20 0.00 18.00 2.72 0.14 0.15 122.00 2.95 0.20 0.00 20.00 2.81 0.17 0.12 124.00 2.95 0.20 0.00 22.00 2.88 0.19 0.11 126.00 2.95 0.20 0.00 24.00 2.95 0.20 0.11 128.00 2.95 0.20 0.00 26.00 2.95 0.20 0.00 130.00 2.95 0.20 0.00 28.00 2.95 0.20 0.00 132.00 2.95 0.20 0.00 30.00 2.95 0.20 0.00 134.00 2.95 0.20 0.00 32.00 2.95 0.20 0.00 136.00 2.95 0.20 0.00 34.00 2.95 0.20 0.00 138.00 2.95 0.20 0.00 36.00 2.95 0.20 0.00 140.00 2.95 0.20 0.00 38.00 2.95 0.20 0.00 142.00 2.95 0.20 0.00 40.00 2.95 0.20 0.00 144.00 2.95 0.20 0.00 42.00 2.95 0.20 0.00 44.00 2.95 0.20 0.00 46.00 2.95 0.20 0.00 48.00 2.95 0.20 0.00 50.00 2.95 0.20 0.00 52.00 2.95 0.20 0.00 54.00 2.95 0.20 0.00 56.00 2.95 0.20 0.00 58.00 2.95 0.20 0.00 60.00 2.95 0.20 0.00 62.00 2.95 0.20 0.00 64.00 2.95 0.20 0.00 66.00 2.95 0.20 0.00 68.00 2.95 0.20 0.00 70.00 2.95 0.20 0.00 72.00 2.95 0.20 0.00 74.00 2.95 0.20 0.00 76.00 2.95 0.20 0.00 78.00 2.95 0.20 0.00 80.00 2.95 0.20 0.00 82.00 2.95 0.20 0.00 84.00 2.95 0.20 0.00 86.00 2.95 0.20 0.00 88.00 2.95 0.20 0.00 90.00 2.95 0.20 0.00 92.00 2.95 0.20 0.00 94.00 2.95 0.20 0.00 96.00 2.95 0.20 0.00 98.00 2.95 0.20 0.00 100.00 2.95 0.20 0.00 102.00 2.95 0.20 0.00 KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 4S: SCM 2 Post Runoff = 11.30 cfs @ 12.07 hrs, Volume= 32,920 cf, Depth= 0.77" Routed to Pond 2P : SCM 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 1-yr Rainfall=2.95" Area (ac) CN Description 3.450 98.0 Paved parking, HSG B 8.290 61.0 >75% Grass cover, Good, HSG B 11.740 71.9 Weighted Average 8.290 70.61% Pervious Area 3.450 29.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 Direct Entry, SCM 1 Post Subcatchment 4S: SCM 2 Post Hydrograph I I 1 I I 1 1 I I I I I I I I I I I I I I I I I I I - 1- T 7 -I -1- 7 T 7 -I -1- I- T 7 -I -I- I- T 7 -I -I- 1 T 7 - 1- I- T T T - ■Runoff 12: I li.30cf.LI 1 1 1 1 1 1 1 1 1 I I I I I I I I I I I I I I I 11� 1 I- I I 1 I I 1 1 11 1 I 1 I I 1 1 I 1 Type I1I 24.hr 10� T / 1 1 1 1 1 1 1 1 1 1 11-�r1 R,a1PfP11�= .�5� 9 -' 11 1 1 1 1 1 1 1 1 1 I Runoff Area=111.740 lac - r t 1 t t rt -I -1- t t rt 1 -r -I - t rt - - 1 rt 8� / 1 I 1 I 1 1 1 I FgulnOff;VyO1�.111ney,- 2i9 01c 7� / 1 1 1 1 1 1 1 1 1 1 1 1 1 Runoff off'DC 'th'=0.77" - 4- t -1- t t 4F -I -I- H t -I -I- t t t -I -1- I- t t H pI- I- t t H 6i' / 1 I 1 I I 1 1 1 1 1 I I I 1 I 1 ITc=13.81 min _ `� - / I I 1 I I 1 I 1 1 I I I I 1 I 1 1 5: 4 / -1- I- 4 -I -I- I- 4 -I -1- I- 4 -I -I- 1- 4 -I -I111—1 - 4- 1 / I 1 I I 1 1 1 1 1 I I I 11 1 1 1 11 11 3_ 1 I 1 I I 1 1 11 1 I I I 11 1 1 1 11 11 ,1- -I- I- -[ -I -1- I- 4 -I -I- I- 4 -I -1- I- 4 -I -I- 1- -L 4 - - 2_ 1 1 1 1 11 1 1 1 1 I I I I 1 1 I 1 1 1� - 1 1 1 1 1 1 1 1 1 I I I I 1 iiiiiiiii � i, 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 8 Hydrograph for Subcatchment 4S: SCM 2 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 2.95 0.77 0.00 2.00 0.06 0.00 0.00 106.00 2.95 0.77 0.00 4.00 0.14 0.00 0.00 108.00 2.95 0.77 0.00 6.00 0.24 0.00 0.00 110.00 2.95 0.77 0.00 8.00 0.35 0.00 0.00 112.00 2.95 0.77 0.00 10.00 0.53 0.00 0.00 114.00 2.95 0.77 0.00 12.00 1.96 0.27 8.76 116.00 2.95 0.77 0.00 14.00 2.42 0.48 0.72 118.00 2.95 0.77 0.00 16.00 2.60 0.57 0.45 120.00 2.95 0.77 0.00 18.00 2.72 0.64 0.36 122.00 2.95 0.77 0.00 20.00 2.81 0.69 0.27 124.00 2.95 0.77 0.00 22.00 2.88 0.73 0.24 126.00 2.95 0.77 0.00 24.00 2.95 0.77 0.23 128.00 2.95 0.77 0.00 26.00 2.95 0.77 0.00 130.00 2.95 0.77 0.00 28.00 2.95 0.77 0.00 132.00 2.95 0.77 0.00 30.00 2.95 0.77 0.00 134.00 2.95 0.77 0.00 32.00 2.95 0.77 0.00 136.00 2.95 0.77 0.00 34.00 2.95 0.77 0.00 138.00 2.95 0.77 0.00 36.00 2.95 0.77 0.00 140.00 2.95 0.77 0.00 38.00 2.95 0.77 0.00 142.00 2.95 0.77 0.00 40.00 2.95 0.77 0.00 144.00 2.95 0.77 0.00 42.00 2.95 0.77 0.00 44.00 2.95 0.77 0.00 46.00 2.95 0.77 0.00 48.00 2.95 0.77 0.00 50.00 2.95 0.77 0.00 52.00 2.95 0.77 0.00 54.00 2.95 0.77 0.00 56.00 2.95 0.77 0.00 58.00 2.95 0.77 0.00 60.00 2.95 0.77 0.00 62.00 2.95 0.77 0.00 64.00 2.95 0.77 0.00 66.00 2.95 0.77 0.00 68.00 2.95 0.77 0.00 70.00 2.95 0.77 0.00 72.00 2.95 0.77 0.00 74.00 2.95 0.77 0.00 76.00 2.95 0.77 0.00 78.00 2.95 0.77 0.00 80.00 2.95 0.77 0.00 82.00 2.95 0.77 0.00 84.00 2.95 0.77 0.00 86.00 2.95 0.77 0.00 88.00 2.95 0.77 0.00 90.00 2.95 0.77 0.00 92.00 2.95 0.77 0.00 94.00 2.95 0.77 0.00 96.00 2.95 0.77 0.00 98.00 2.95 0.77 0.00 100.00 2.95 0.77 0.00 102.00 2.95 0.77 0.00 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 9 Summary for Pond 2P: SCM 2 Inflow Area = 511,394 sf, 29.39% Impervious, Inflow Depth = 0.77" for 1-yr event Inflow = 11.30 cfs @ 12.07 hrs, Volume= 32,920 cf Outflow = 0.25 cfs @ 21.07 hrs, Volume= 30,961 cf, Atten= 98%, Lag= 540.1 min Primary = 0.25 cfs @ 21.07 hrs, Volume= 30,961 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 575.71'@ 21.07 hrs Surf.Area= 12,567 sf Storage= 24,935 cf Plug-Flow detention time=2,002.3 min calculated for 30,957 cf(94% of inflow) Center-of-Mass det. time= 1,971.2 min ( 2,850.3 - 879.1 ) Volume Invert Avail.Storage_ Storage Description #1 573.00' 93,825 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.00 1,250 0 0 574.00 10,000 5,625 5,625 575.00 11,500 10,750 16,375 576.00 13,000 12,250 28,625 577.00 14,600 13,800 42,425 578.00 16,250 15,425 57,850 579.00 17,975 17,113 74,963 580.00 19,750 18,863 93,825 Device Routing _ Invert Outlet Devices #1 Primary 566.46' 18.0" Round Outlet Pipe L= 79.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 566.46'/ 564.00' S= 0.0311 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 573.50' Sand Filter Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50 Disch. (cfs) 0.000 0.084 0.118 0.152 0.186 0.219 0.236 #3 Device 1 575.50' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 576.50' 3.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 577.50' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 578.50' 15.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 KT37 - SCM Calculations Type II 24-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 10 Primary OutFlow Max=0.25 cfs @ 21.07 hrs HW=575.71' (Free Discharge) —1=Outlet Pipe (Passes 0.25 cfs of 24.81 cfs potential flow) —2=Sand Filter (Custom Controls 0.13 cfs) —3=Orifice (Orifice Controls 0.12 cfs @ 1.57 fps) —4=Rect Notch ( Controls 0.00 cfs) —5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.00' (Free Discharge) 4-6=Spillway ( Controls 0.00 cfs) Pond 2P: SCM 2 Hydrograph I I I I I I I I I /1 I I I I I I I I I I I ■Inflow / I 11.30 cfs I— + - H - - - 1 - H + _ •�UtfIOW Infloyv Area7511,3 ,4 st, •Primary e ondary 12 / / I I I PeakF_.lev 575.7'Lt _ 11 / / /1 I I Imo+ I I AI A I ,, I - T H H 1 I Stora-ge�4,-935-4f - 10 / / / / 1 1 1 I I I I I I I I 9 / /1 I I I I I I I I I I / / 8 / /1 1 1 I I I I I I I I / / - 4 4 1 I I I- 4 4 - I /4- 7 / / /1 1 1 I I I I I I I I 8 / /1 I I I I I I I I I ° / / LL 5 / / T 7 7 1 I I I- 7 7 - I / / T -1 - 1 I I H - I 4 / / / /1 1 1 3 / /1 It I I 2 r A 0.25 cfs , // 0.25cfs i ///////////////////////�i///////////////////////////////////////////////// 1 % i� Z 000 ors �� ��0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 11 Hydrograph for Pond 2P: SCM 2 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.00 0.00 0.00 0.00 4.00 0.00 0 573.00 0.00 0.00 0.00 8.00 0.00 0 573.00 0.00 0.00 0.00 12.00 8.76 3,079 573.71 0.02 0.02 0.00 16.00 0.45 22,611 575.52 0.12 0.12 0.00 20.00 0.27 24,914 575.71 0.25 0.25 0.00 24.00 0.23 24,842 575.70 0.24 0.24 0.00 28.00 0.00 22,615 575.52 0.12 0.12 0.00 32.00 0.00 20,935 575.39 0.11 0.11 0.00 36.00 0.00 19,325 575.25 0.11 0.11 0.00 40.00 0.00 17,779 575.12 0.11 0.11 0.00 44.00 0.00 16,297 574.99 0.10 0.10 0.00 48.00 0.00 14,876 574.87 0.10 0.10 0.00 52.00 0.00 13,516 574.75 0.09 0.09 0.00 56.00 0.00 12,215 574.63 0.09 0.09 0.00 60.00 0.00 10,970 574.51 0.08 0.08 0.00 64.00 0.00 9,810 574.41 0.08 0.08 0.00 68.00 0.00 8,774 574.31 0.07 0.07 0.00 72.00 0.00 7,852 574.22 0.06 0.06 0.00 76.00 0.00 7,031 574.14 0.05 0.05 0.00 80.00 0.00 6,303 574.07 0.05 0.05 0.00 84.00 0.00 5,656 574.00 0.04 0.04 0.00 88.00 0.00 5,083 573.94 0.04 0.04 0.00 92.00 0.00 4,580 573.89 0.03 0.03 0.00 96.00 0.00 4,139 573.84 0.03 0.03 0.00 100.00 0.00 3,756 573.79 0.02 0.02 0.00 104.00 0.00 3,425 573.75 0.02 0.02 0.00 108.00 0.00 3,142 573.72 0.02 0.02 0.00 112.00 0.00 2,901 573.68 0.02 0.02 0.00 116.00 0.00 2,697 573.65 0.01 0.01 0.00 120.00 0.00 2,525 573.63 0.01 0.01 0.00 124.00 0.00 2,382 573.61 0.01 0.01 0.00 128.00 0.00 2,263 573.59 0.01 0.01 0.00 132.00 0.00 2,164 573.57 0.01 0.01 0.00 136.00 0.00 2,082 573.56 0.01 0.01 0.00 140.00 0.00 2,014 573.55 0.00 0.00 0.00 144.00 0.00 1,960 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 12 Stage-Discharge for Pond 2P: SCM 2 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs) 573.00 0.00 0.00 0.00 578.20 28.21 28.21 0.00 573.10 0.00 0.00 0.00 578.30 28.34 28.34 0.00 573.20 0.00 0.00 0.00 578.40 28.46 28.46 0.00 573.30 0.00 0.00 0.00 578.50 28.59 28.59 0.00 573.40 0.00 0.00 0.00 578.60 29.90 28.72 1.18 573.50 0.00 0.00 0.00 578.70 32.18 28.84 3.34 573.60 0.01 0.01 0.00 578.80 35.19 28.97 6.22 573.70 0.02 0.02 0.00 578.90 38.81 29.09 9.71 573.80 0.03 0.03 0.00 579.00 43.16 29.22 13.95 573.90 0.03 0.03 0.00 579.10 48.16 29.34 18.82 574.00 0.04 0.04 0.00 579.20 53.14 29.46 23.68 574.10 0.05 0.05 0.00 579.30 58.46 29.59 28.87 574.20 0.06 0.06 0.00 579.40 64.10 29.71 34.39 574.30 0.07 0.07 0.00 579.50 70.03 29.83 40.20 574.40 0.08 0.08 0.00 579.60 76.42 29.95 46.46 574.50 0.08 0.08 0.00 579.70 83.11 30.07 53.04 574.60 0.09 0.09 0.00 579.80 89.78 30.19 59.59 574.70 0.09 0.09 0.00 579.90 96.65 30.31 66.34 574.80 0.09 0.09 0.00 580.00 103.59 30.43 73.16 574.90 0.10 0.10 0.00 575.00 0.10 0.10 0.00 575.10 0.10 0.10 0.00 575.20 0.11 0.11 0.00 575.30 0.11 0.11 0.00 575.40 0.11 0.11 0.00 575.50 0.12 0.12 0.00 575.60 0.15 0.15 0.00 575.70 0.24 0.24 0.00 575.80 0.36 0.36 0.00 575.90 0.49 0.49 0.00 576.00 0.61 0.61 0.00 576.10 0.70 0.70 0.00 576.20 0.78 0.78 0.00 576.30 0.85 0.85 0.00 576.40 0.91 0.91 0.00 576.50 0.97 0.97 0.00 576.60 1.34 1.34 0.00 576.70 1.95 1.95 0.00 576.80 2.71 2.71 0.00 576.90 3.60 3.60 0.00 577.00 4.58 4.58 0.00 577.10 5.65 5.65 0.00 577.20 6.79 6.79 0.00 577.30 8.00 8.00 0.00 577.40 9.27 9.27 0.00 577.50 10.59 10.59 0.00 577.60 13.40 13.40 0.00 577.70 17.41 17.41 0.00 577.80 22.21 22.21 0.00 577.90 27.67 27.67 0.00 578.00 27.95 27.95 0.00 578.10 28.08 28.08 0.00 KT37 - SCM Calculations Type 1124-hr 1-yr Rainfall=2.95" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 13 Stage-Area-Storage for Pond 2P: SCM 2 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.00 1,250 0 578.20 16,595 61,135 573.10 2,125 169 578.30 16,767 62,803 573.20 3,000 425 578.40 16,940 64,488 573.30 3,875 769 578.50 17,113 66,191 573.40 4,750 1,200 578.60 17,285 67,911 573.50 5,625 1,719 578.70 17,458 69,648 573.60 6,500 2,325 578.80 17,630 71,402 573.70 7,375 3,019 I 578.90 17,802 73,174 573.80 8,250 3,800 579.00 17,975 74,963 573.90 9,125 4,669 579.10 18,153 76,769 574.00 10,000 5,625 579.20 18,330 78,593 574.10 10,150 6,633 579.30 18,507 80,435 574.20 10,300 7,655 579.40 18,685 82,294 574.30 10,450 8,692 579.50 18,863 84,172 574.40 10,600 9,745 579.60 19,040 86,067 574.50 10,750 10,813 579.70 19,218 87,980 574.60 10,900 11,895 579.80 19,395 89,910 574.70 11,050 12,993 579.90 19,572 91,859 574.80 11,200 14,105 580.00 19,750 93,825 574.90 11,350 15,232 575.00 11,500 16,375 575.10 11,650 17,533 575.20 11,800 18,705 575.30 11,950 19,892 575.40 12,100 21,095 575.50 12,250 22,313 575.60 12,400 23,545 575.70 12,550 24,793 575.80 12,700 26,055 575.90 12,850 27,332 576.00 13,000 28,625 576.10 13,160 29,933 576.20 13,320 31,257 576.30 13,480 32,597 576.40 13,640 33,953 576.50 13,800 35,325 576.60 13,960 36,713 576.70 14,120 38,117 576.80 14,280 39,537 576.90 14,440 40,973 577.00 14,600 42,425 577.10 14,765 43,893 577.20 14,930 45,378 577.30 15,095 46,879 577.40 15,260 48,397 577.50 15,425 49,931 577.60 15,590 51,482 577.70 15,755 53,049 577.80 15,920 54,633 577.90 16,085 56,233 578.00 16,250 57,850 578.10 16,423 59,484 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 14 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment2A: SCM 2 Pre Runoff Area=11.740 ac 0.00% Impervious Runoff Depth=0.39" Tc=16.8 min CN=55.9 Runoff=3.21 cfs 16,831 cf Subcatchment4S: SCM 2 Post Runoff Area=11.740 ac 29.39% Impervious Runoff Depth=1.15" Tc=13.8 min CN=71.9 Runoff=17.49 cfs 48,850 cf Pond 2P: SCM 2 Peak Elev=576.08' Storage=29,665 cf Inflow=17.49 cfs 48,850 cf Primary=0.68 cfs 46,876 cf Secondary=0.00 cfs 0 cf Outflow=0.68 cfs 46,876 cf KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 2A: SCM 2 Pre Runoff = 3.21 cfs @ 12.15 hrs, Volume= 16,831 cf, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 2-yr Rainfall=3.55" Area (ac) CN Description 10.740 56.0 Brush, Fair, HSG B 1.000 55.0 Woods, Good, HSG B 11.740 55.9 Weighted Average 11.740 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 Direct Entry, SCM 2 Pre Subcatchment 2A: SCM 2 Pre Hydrograph I 1 1 I I I I ❑Runoff` 3.21 cfs l 1 1 1 1 1 1 1 r --1 —1 - 1— H -i --+ —I —I— H Type-III-24-h r 3 / 1 1 1 1 1 1 1 1 I I I Runoff Area=111.740 ac I F4uingff;Vplur q='�6�8 1 c 2 ✓ I I 11 Runoff IDep'th=0.339" II II o 1 1 1 1 I I ITc=1 6.8 m i n u I I I I I II I I CN=55.9 11 11 11 11 I 11 11 11 11 1 11 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 16 Hydrograph for Subcatchment 2A: SCM 2 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 3.55 0.39 0.00 2.00 0.08 0.00 0.00 106.00 3.55 0.39 0.00 4.00 0.17 0.00 0.00 108.00 3.55 0.39 0.00 6.00 0.28 0.00 0.00 110.00 3.55 0.39 0.00 8.00 0.43 0.00 0.00 112.00 3.55 0.39 0.00 10.00 0.64 0.00 0.00 114.00 3.55 0.39 0.00 12.00 2.35 0.07 1.00 116.00 3.55 0.39 0.00 14.00 2.91 0.19 0.47 118.00 3.55 0.39 0.00 16.00 3.12 0.25 0.31 120.00 3.55 0.39 0.00 18.00 3.27 0.30 0.25 122.00 3.55 0.39 0.00 20.00 3.38 0.34 0.19 124.00 3.55 0.39 0.00 22.00 3.47 0.37 0.18 126.00 3.55 0.39 0.00 24.00 3.55 0.39 0.17 128.00 3.55 0.39 0.00 26.00 3.55 0.39 0.00 130.00 3.55 0.39 0.00 28.00 3.55 0.39 0.00 132.00 3.55 0.39 0.00 30.00 3.55 0.39 0.00 134.00 3.55 0.39 0.00 32.00 3.55 0.39 0.00 136.00 3.55 0.39 0.00 34.00 3.55 0.39 0.00 138.00 3.55 0.39 0.00 36.00 3.55 0.39 0.00 140.00 3.55 0.39 0.00 38.00 3.55 0.39 0.00 142.00 3.55 0.39 0.00 40.00 3.55 0.39 0.00 144.00 3.55 0.39 0.00 42.00 3.55 0.39 0.00 44.00 3.55 0.39 0.00 46.00 3.55 0.39 0.00 48.00 3.55 0.39 0.00 50.00 3.55 0.39 0.00 52.00 3.55 0.39 0.00 54.00 3.55 0.39 0.00 56.00 3.55 0.39 0.00 58.00 3.55 0.39 0.00 60.00 3.55 0.39 0.00 62.00 3.55 0.39 0.00 64.00 3.55 0.39 0.00 66.00 3.55 0.39 0.00 68.00 3.55 0.39 0.00 70.00 3.55 0.39 0.00 72.00 3.55 0.39 0.00 74.00 3.55 0.39 0.00 76.00 3.55 0.39 0.00 78.00 3.55 0.39 0.00 80.00 3.55 0.39 0.00 82.00 3.55 0.39 0.00 84.00 3.55 0.39 0.00 86.00 3.55 0.39 0.00 88.00 3.55 0.39 0.00 90.00 3.55 0.39 0.00 92.00 3.55 0.39 0.00 94.00 3.55 0.39 0.00 96.00 3.55 0.39 0.00 98.00 3.55 0.39 0.00 100.00 3.55 0.39 0.00 102.00 3.55 0.39 0.00 KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 4S: SCM 2 Post Runoff = 17.49 cfs @ 12.07 hrs, Volume= 48,850 cf, Depth= 1.15" Routed to Pond 2P : SCM 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 2-yr Rainfall=3.55" Area (ac) CN Description 3.450 98.0 Paved parking, HSG B 8.290 61.0 >75% Grass cover, Good, HSG B 11.740 71.9 Weighted Average 8.290 70.61% Pervious Area 3.450 29.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 Direct Entry, SCM 1 Post Subcatchment 4S: SCM 2 Post Hydrograph 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 191-/ _ 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 ■Runoff 181-/ ,_117.49;fs1 1 I 1 I I 1 1 I 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I�,1 17 _ J .1 I 1 I I 1 1 I 1 1 I 1 1 I 1 1 1 1 11 �1�T�ypf e_11L 2_4_�jJ�j11 _ 164/ _ 1J 1 1 1 1 1 I I 1 1 1 1 1 �.IY 1 1 ""ill""Fi II �I"" 15= 14/ .1 1 1 1 1 1 1 1 I I 1 1 1 -RunoffArea 111-.740-ac 12 -/ _ L 1 1 1 1 1 1 1 1 1 Runoff, olIunle=48i85V I C w 11� L 1 1 1 1 1 1 1 1 1 1 1 1 1 1 R u iroff pth= - 15- . 1o� _ J .1 _1_ L L J _I _I_ L I 1 _I _I_ L L 1 _I _I_ 1_ I 1 J —1_ I_ L 1 J _ c 4/ ,_ J .1 _I_ L L J _I _I_ L L 1 J —I_ L L 1 _I _I_ I_ L 1T_C-rL38LmIn _ LL 8- L _I I L L A I 1 L L L I I L 1 1 I 1 1 1 J L 7� ,_ J .1 _I_ L L J _I _I_ L L 1 _I _I_ L L 1 _I _I_ I_ L 1 J _1"1= L� 'F 6 / ,- I _ 1 L L J _I _1 L L 1 J LI L L 1 _I _1 IL L 1 J 1 I L 1 J _ 5 ,_ 1 / J— L L J —I —I— L I 1 _I J— L L 1 J —I— I_ L 1 J J— I— L 1 J _ 44/ ,_ L _ 1 L L J 11 L L L LI1 L L L 1L L 1 L IL L 1 J 1 1 L 1 J _ 34/ _ 1 I _1_ L L J —I —I_ L I 1 _I J— L L 1 J —I— I_ I 1 J _I_ I— L 1 J _ 2 -/ _ J I_ L J —I —I_ L 1 —I —II— L L 1 1 II —I —I— I— L 1 _' I_ I— L 1 J _ oiiii �iii�il iiiii�iiiiii�ii� 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 18 Hydrograph for Subcatchment 4S: SCM 2 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 3.55 1.15 0.00 2.00 0.08 0.00 0.00 106.00 3.55 1.15 0.00 4.00 0.17 0.00 0.00 108.00 3.55 1.15 0.00 6.00 0.28 0.00 0.00 110.00 3.55 1.15 0.00 8.00 0.43 0.00 0.00 112.00 3.55 1.15 0.00 10.00 0.64 0.00 0.00 114.00 3.55 1.15 0.00 12.00 2.35 0.45 14.18 116.00 3.55 1.15 0.00 14.00 2.91 0.75 1.00 118.00 3.55 1.15 0.00 16.00 3.12 0.88 0.62 120.00 3.55 1.15 0.00 18.00 3.27 0.97 0.49 122.00 3.55 1.15 0.00 20.00 3.38 1.04 0.36 124.00 3.55 1.15 0.00 22.00 3.47 1.09 0.33 126.00 3.55 1.15 0.00 24.00 3.55 1.15 0.31 128.00 3.55 1.15 0.00 26.00 3.55 1.15 0.00 130.00 3.55 1.15 0.00 28.00 3.55 1.15 0.00 132.00 3.55 1.15 0.00 30.00 3.55 1.15 0.00 134.00 3.55 1.15 0.00 32.00 3.55 1.15 0.00 136.00 3.55 1.15 0.00 34.00 3.55 1.15 0.00 138.00 3.55 1.15 0.00 36.00 3.55 1.15 0.00 140.00 3.55 1.15 0.00 38.00 3.55 1.15 0.00 142.00 3.55 1.15 0.00 40.00 3.55 1.15 0.00 144.00 3.55 1.15 0.00 42.00 3.55 1.15 0.00 44.00 3.55 1.15 0.00 46.00 3.55 1.15 0.00 48.00 3.55 1.15 0.00 50.00 3.55 1.15 0.00 52.00 3.55 1.15 0.00 54.00 3.55 1.15 0.00 56.00 3.55 1.15 0.00 58.00 3.55 1.15 0.00 60.00 3.55 1.15 0.00 62.00 3.55 1.15 0.00 64.00 3.55 1.15 0.00 66.00 3.55 1.15 0.00 68.00 3.55 1.15 0.00 70.00 3.55 1.15 0.00 72.00 3.55 1.15 0.00 74.00 3.55 1.15 0.00 76.00 3.55 1.15 0.00 78.00 3.55 1.15 0.00 80.00 3.55 1.15 0.00 82.00 3.55 1.15 0.00 84.00 3.55 1.15 0.00 86.00 3.55 1.15 0.00 88.00 3.55 1.15 0.00 90.00 3.55 1.15 0.00 92.00 3.55 1.15 0.00 94.00 3.55 1.15 0.00 96.00 3.55 1.15 0.00 98.00 3.55 1.15 0.00 100.00 3.55 1.15 0.00 102.00 3.55 1.15 0.00 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 19 Summary for Pond 2P: SCM 2 Inflow Area = 511,394 sf, 29.39% Impervious, Inflow Depth = 1.15" for 2-yr event Inflow = 17.49 cfs @ 12.07 hrs, Volume= 48,850 cf Outflow = 0.68 cfs @ 15.66 hrs, Volume= 46,876 cf, Atten= 96%, Lag= 215.4 min Primary = 0.68 cfs @ 15.66 hrs, Volume= 46,876 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 576.08'@ 15.66 hrs Surf.Area= 13,127 sf Storage= 29,665 cf Plug-Flow detention time= 1,436.0 min calculated for 46,876 cf(96% of inflow) Center-of-Mass det. time= 1,413.5 min ( 2,279.7 - 866.2 ) Volume Invert Avail.Storage Storage Description _ #1 573.00' 93,825 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.00 1,250 0 0 574.00 10,000 5,625 5,625 575.00 11,500 10,750 16,375 576.00 13,000 12,250 28,625 577.00 14,600 13,800 42,425 578.00 16,250 15,425 57,850 579.00 17,975 17,113 74,963 580.00 19,750 18,863 93,825 Device Routing _ Invert Outlet Devices #1 Primary 566.46' 18.0" Round Outlet Pipe L= 79.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 566.46'/ 564.00' S= 0.0311 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 573.50' Sand Filter Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50 Disch. (cfs) 0.000 0.084 0.118 0.152 0.186 0.219 0.236 #3 Device 1 575.50' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 576.50' 3.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 577.50' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 578.50' 15.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 KT37 - SCM Calculations Type II 24-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 20 Primary OutFlow Max=0.68 cfs @ 15.66 hrs HW=576.08' (Free Discharge) —1=Outlet Pipe (Passes 0.68 cfs of 25.34 cfs potential flow) —2=Sand Filter (Custom Controls 0.14 cfs) —3=Orifice (Orifice Controls 0.54 cfs @ 2.76 fps) —4=Rect Notch ( Controls 0.00 cfs) —5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.00' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) Pond 2P: SCM 2 Hydrograph - 1- 7 - - I I L- L -f - I ■Inflow 17.49 cfs _ _ _ _ •Outflow i , zI .. - + - 4 - � I ,I,-�'wI- - 4 - - • Primary fi - rt 11111low ea751 �3�4- 19 �1 7�oiII - ■Secondary 18� i T 7 7 QealC�@)/ �/�.S�R 17� , z z it I I I I I Imo+ I I I I I 165 / , / /1_ _ I I I I Storage ,665 cli 15 / / L L _ I I L L 1 L J I 14 -/ ii , /- 4 - - I I I- -k 4 4 -II 13 / iH 4 - -4 - -I - -I- - I- - I- - H - -h - 4 - 4 - H - -I - 124/ i 1 rt H I I 1- fi -r rt - I w 114-' i c 19 / , /, / /1 I I I I I I I I I I `L 84/ i , / /1- I I I I I I I I 7 z , I_ 1/ _L _4 I I I_ L 1 _L J I 64ji - I - 4 - -4I- - I- - - 4 - 4 - -I - -I/ / � I - H - -4I I- - H - t - t - H - H - -I - 3 �/ a66 Cfs 2�, 0.68 cfs ~��������/���������������������������������������������������������������������� 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 21 Hydrograph for Pond 2P: SCM 2 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.00 0.00 0.00 0.00 4.00 0.00 0 573.00 0.00 0.00 0.00 8.00 0.00 0 573.00 0.00 0.00 0.00 12.00 14.18 6,163 574.05 0.05 0.05 0.00 16.00 0.62 29,632 576.08 0.68 0.68 0.00 20.00 0.36 27,721 575.93 0.53 0.53 0.00 24.00 0.31 26,164 575.81 0.37 0.37 0.00 28.00 0.00 23,179 575.57 0.14 0.14 0.00 32.00 0.00 21,434 575.43 0.12 0.12 0.00 36.00 0.00 19,804 575.29 0.11 0.11 0.00 40.00 0.00 18,239 575.16 0.11 0.11 0.00 44.00 0.00 16,737 575.03 0.10 0.10 0.00 48.00 0.00 15,298 574.91 0.10 0.10 0.00 52.00 0.00 13,920 574.78 0.09 0.09 0.00 56.00 0.00 12,601 574.66 0.09 0.09 0.00 60.00 0.00 11,340 574.55 0.09 0.09 0.00 64.00 0.00 10,146 574.44 0.08 0.08 0.00 68.00 0.00 9,074 574.34 0.07 0.07 0.00 72.00 0.00 8,119 574.24 0.06 0.06 0.00 76.00 0.00 7,269 574.16 0.06 0.06 0.00 80.00 0.00 6,513 574.09 0.05 0.05 0.00 84.00 0.00 5,843 574.02 0.04 0.04 0.00 88.00 0.00 5,249 573.96 0.04 0.04 0.00 92.00 0.00 4,725 573.91 0.03 0.03 0.00 96.00 0.00 4,265 573.85 0.03 0.03 0.00 100.00 0.00 3,866 573.81 0.03 0.03 0.00 104.00 0.00 3,520 573.77 0.02 0.02 0.00 108.00 0.00 3,223 573.73 0.02 0.02 0.00 112.00 0.00 2,969 573.69 0.02 0.02 0.00 116.00 0.00 2,755 573.66 0.01 0.01 0.00 120.00 0.00 2,574 573.64 0.01 0.01 0.00 124.00 0.00 2,422 573.61 0.01 0.01 0.00 128.00 0.00 2,296 573.59 0.01 0.01 0.00 132.00 0.00 2,192 573.58 0.01 0.01 0.00 136.00 0.00 2,105 573.57 0.01 0.01 0.00 140.00 0.00 2,033 573.55 0.00 0.00 0.00 144.00 0.00 1,975 573.54 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 22 Stage-Discharge for Pond 2P: SCM 2 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs) 573.00 0.00 0.00 0.00 578.20 28.21 28.21 0.00 573.10 0.00 0.00 0.00 578.30 28.34 28.34 0.00 573.20 0.00 0.00 0.00 578.40 28.46 28.46 0.00 573.30 0.00 0.00 0.00 578.50 28.59 28.59 0.00 573.40 0.00 0.00 0.00 578.60 29.90 28.72 1.18 573.50 0.00 0.00 0.00 578.70 32.18 28.84 3.34 573.60 0.01 0.01 0.00 578.80 35.19 28.97 6.22 573.70 0.02 0.02 0.00 578.90 38.81 29.09 9.71 573.80 0.03 0.03 0.00 579.00 43.16 29.22 13.95 573.90 0.03 0.03 0.00 579.10 48.16 29.34 18.82 574.00 0.04 0.04 0.00 579.20 53.14 29.46 23.68 574.10 0.05 0.05 0.00 579.30 58.46 29.59 28.87 574.20 0.06 0.06 0.00 579.40 64.10 29.71 34.39 574.30 0.07 0.07 0.00 579.50 70.03 29.83 40.20 574.40 0.08 0.08 0.00 579.60 76.42 29.95 46.46 574.50 0.08 0.08 0.00 579.70 83.11 30.07 53.04 574.60 0.09 0.09 0.00 579.80 89.78 30.19 59.59 574.70 0.09 0.09 0.00 579.90 96.65 30.31 66.34 574.80 0.09 0.09 0.00 580.00 103.59 30.43 73.16 574.90 0.10 0.10 0.00 575.00 0.10 0.10 0.00 575.10 0.10 0.10 0.00 575.20 0.11 0.11 0.00 575.30 0.11 0.11 0.00 575.40 0.11 0.11 0.00 575.50 0.12 0.12 0.00 575.60 0.15 0.15 0.00 575.70 0.24 0.24 0.00 575.80 0.36 0.36 0.00 575.90 0.49 0.49 0.00 576.00 0.61 0.61 0.00 576.10 0.70 0.70 0.00 576.20 0.78 0.78 0.00 576.30 0.85 0.85 0.00 576.40 0.91 0.91 0.00 576.50 0.97 0.97 0.00 576.60 1.34 1.34 0.00 576.70 1.95 1.95 0.00 576.80 2.71 2.71 0.00 576.90 3.60 3.60 0.00 577.00 4.58 4.58 0.00 577.10 5.65 5.65 0.00 577.20 6.79 6.79 0.00 577.30 8.00 8.00 0.00 577.40 9.27 9.27 0.00 577.50 10.59 10.59 0.00 577.60 13.40 13.40 0.00 577.70 17.41 17.41 0.00 577.80 22.21 22.21 0.00 577.90 27.67 27.67 0.00 578.00 27.95 27.95 0.00 578.10 28.08 28.08 0.00 KT37 - SCM Calculations Type 1124-hr 2-yr Rainfall=3.55" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 23 Stage-Area-Storage for Pond 2P: SCM 2 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.00 1,250 0 578.20 16,595 61,135 573.10 2,125 169 578.30 16,767 62,803 573.20 3,000 425 578.40 16,940 64,488 573.30 3,875 769 578.50 17,113 66,191 573.40 4,750 1,200 578.60 17,285 67,911 573.50 5,625 1,719 578.70 17,458 69,648 573.60 6,500 2,325 578.80 17,630 71,402 573.70 7,375 3,019 I 578.90 17,802 73,174 573.80 8,250 3,800 579.00 17,975 74,963 573.90 9,125 4,669 579.10 18,153 76,769 574.00 10,000 5,625 579.20 18,330 78,593 574.10 10,150 6,633 579.30 18,507 80,435 574.20 10,300 7,655 579.40 18,685 82,294 574.30 10,450 8,692 579.50 18,863 84,172 574.40 10,600 9,745 579.60 19,040 86,067 574.50 10,750 10,813 579.70 19,218 87,980 574.60 10,900 11,895 579.80 19,395 89,910 574.70 11,050 12,993 579.90 19,572 91,859 574.80 11,200 14,105 580.00 19,750 93,825 574.90 11,350 15,232 575.00 11,500 16,375 575.10 11,650 17,533 575.20 11,800 18,705 575.30 11,950 19,892 575.40 12,100 21,095 575.50 12,250 22,313 575.60 12,400 23,545 575.70 12,550 24,793 575.80 12,700 26,055 575.90 12,850 27,332 576.00 13,000 28,625 576.10 13,160 29,933 576.20 13,320 31,257 576.30 13,480 32,597 576.40 13,640 33,953 576.50 13,800 35,325 576.60 13,960 36,713 576.70 14,120 38,117 576.80 14,280 39,537 576.90 14,440 40,973 577.00 14,600 42,425 577.10 14,765 43,893 577.20 14,930 45,378 577.30 15,095 46,879 577.40 15,260 48,397 577.50 15,425 49,931 577.60 15,590 51,482 577.70 15,755 53,049 577.80 15,920 54,633 577.90 16,085 56,233 578.00 16,250 57,850 578.10 16,423 59,484 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 24 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment2A: SCM 2 Pre Runoff Area=11.740 ac 0.00% Impervious Runoff Depth=1.14" Tc=16.8 min CN=55.9 Runoff=14.03 cfs 48,388 cf Subcatchment4S: SCM 2 Post Runoff Area=11.740 ac 29.39% Impervious Runoff Depth=2.33" Tc=13.8 min CN=71.9 Runoff=36.84 cfs 99,486 cf Pond 2P: SCM 2 Peak Elev=577.20' Storage=45,364 cf Inflow=36.84 cfs 99,486 cf Primary=6.78 cfs 97,481 cf Secondary=0.00 cfs 0 cf Outflow=6.78 cfs 97,481 cf KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 25 Summary for Subcatchment 2A: SCM 2 Pre Runoff = 14.03 cfs @ 12.11 hrs, Volume= 48,388 cf, Depth= 1.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 10-yr Rainfall=5.19" Area (ac) CN Description 10.740 56.0 Brush, Fair, HSG B 1.000 55.0 Woods, Good, HSG B 11.740 55.9 Weighted Average 11.740 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 Direct Entry, SCM 2 Pre Subcatchment 2A: SCM 2 Pre Hydrograph 1 1 1 1 1 1 I 1 1 1 1 i 1 1 I 1 1 I I 1 I I 1 15� I I I I 1 I I 1 1 I I I I I I I I I I I I I I I I I I ■Runoff 1 14.03 ors r1 — — if if rt -I —1— if if rt -I —I— if fi rt -I —1— I— fi rt nif if if - -I- 1- - 4 -I -1- I- -4 -I -I- 1- - - -I -1- - -Type-i1-24.h III 1111 I 1213� / l I 1 I 1 1 I I I I I I 11IV-17' I'�""T"7I `7' irj - 11� I 1 1 1 1 1 -I- I RunbfArea=11t 4r0 act 7 / 'I -I- r -1 -1- I- 7 7 -1 -1- - 7 -1 -�-J- 7 rt -1 - - I- Qrt 10t7 /-I -1- -k 4 1 1 -k 4 I I 4RQII1 u -V1101-P r e=-410 r M,+I, w 9=✓ , J / .I _I_ J J J _I _1_ J J J _1 _1_ I_ J J _I Ri u IM 1 iDenth='r'f4F! - 8� I / 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 II 1 11 I I 0 7y T I % I T7 1 1 I- T7 I I T7 1 1 I- T7J irtN_F5 - 4 3y 1 I I I I I I I I I I I I I I I I I I I I I I I I I � T I P T 7 I P T 7 1 1 7 T T 1 T 7 J 1 T T 2� = k - -I -I- H t fi -I -I- I- t t -I -I- I- t t H -I- I- t t H 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 26 Hydrograph for Subcatchment 2A: SCM 2 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 5.19 1.14 0.00 2.00 0.11 0.00 0.00 106.00 5.19 1.14 0.00 4.00 0.25 0.00 0.00 108.00 5.19 1.14 0.00 6.00 0.42 0.00 0.00 110.00 5.19 1.14 0.00 8.00 0.62 0.00 0.00 112.00 5.19 1.14 0.00 10.00 0.94 0.00 0.00 114.00 5.19 1.14 0.00 12.00 3.44 0.36 8.29 116.00 5.19 1.14 0.00 14.00 4.26 0.68 1.13 118.00 5.19 1.14 0.00 16.00 4.57 0.82 0.72 120.00 5.19 1.14 0.00 18.00 4.78 0.93 0.56 122.00 5.19 1.14 0.00 20.00 4.94 1.01 0.43 124.00 5.19 1.14 0.00 22.00 5.07 1.07 0.39 126.00 5.19 1.14 0.00 24.00 5.19 1.14 0.36 128.00 5.19 1.14 0.00 26.00 5.19 1.14 0.00 130.00 5.19 1.14 0.00 28.00 5.19 1.14 0.00 132.00 5.19 1.14 0.00 30.00 5.19 1.14 0.00 134.00 5.19 1.14 0.00 32.00 5.19 1.14 0.00 136.00 5.19 1.14 0.00 34.00 5.19 1.14 0.00 138.00 5.19 1.14 0.00 36.00 5.19 1.14 0.00 140.00 5.19 1.14 0.00 38.00 5.19 1.14 0.00 142.00 5.19 1.14 0.00 40.00 5.19 1.14 0.00 144.00 5.19 1.14 0.00 42.00 5.19 1.14 0.00 44.00 5.19 1.14 0.00 46.00 5.19 1.14 0.00 48.00 5.19 1.14 0.00 50.00 5.19 1.14 0.00 52.00 5.19 1.14 0.00 54.00 5.19 1.14 0.00 56.00 5.19 1.14 0.00 58.00 5.19 1.14 0.00 60.00 5.19 1.14 0.00 62.00 5.19 1.14 0.00 64.00 5.19 1.14 0.00 66.00 5.19 1.14 0.00 68.00 5.19 1.14 0.00 70.00 5.19 1.14 0.00 72.00 5.19 1.14 0.00 74.00 5.19 1.14 0.00 76.00 5.19 1.14 0.00 78.00 5.19 1.14 0.00 80.00 5.19 1.14 0.00 82.00 5.19 1.14 0.00 84.00 5.19 1.14 0.00 86.00 5.19 1.14 0.00 88.00 5.19 1.14 0.00 90.00 5.19 1.14 0.00 92.00 5.19 1.14 0.00 94.00 5.19 1.14 0.00 96.00 5.19 1.14 0.00 98.00 5.19 1.14 0.00 100.00 5.19 1.14 0.00 102.00 5.19 1.14 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 4S: SCM 2 Post Runoff = 36.84 cfs @ 12.06 hrs, Volume= 99,486 cf, Depth= 2.33" Routed to Pond 2P : SCM 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 10-yr Rainfall=5.19" Area (ac) CN Description 3.450 98.0 Paved parking, HSG B 8.290 61.0 >75% Grass cover, Good, HSG B 11.740 71.9 Weighted Average 8.290 70.61% Pervious Area 3.450 29.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 Direct Entry, SCM 1 Post Subcatchment 4S: SCM 2 Post Hydrograph 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 40 -/ _ I 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 ■Runoff 38 ,_ 136.84ors1_I -I- L L J -I -I- L L L -I -I- L L L -I -I- I- L L J -I- I- L 1 J - 36 l/' L -1 I LL4 I I LLL I I LL4 11 I LLTypeIt244hr 34 _ -1 -I- I- 1- -V -1 -1- I- 1- 4 -I -I- 1- 1- 4 -I j -1 ita 32 - - / -1 -1- I- 14 -1 -1- I- 14 -1 -1- I- 14 -I -'I�`rr +ate. T117• • J-1 - 30� - t /-1 -1- I- t 4 1 1 H 14 1 1 1- R�:1no11 Area111-.74O-ae - 28 t -I -1- t t -t -1 -I- 1 t t -1 -1- - t -1 - `- - t t - - - I- ± 26 / _ t /-1 I I- t -V -1 -I I- t b -I -I- I Kufn-Q �/Iyol-ume- 9 4 jj - 24 R`u�loff'��p'fFl3r3 H -r /-1 1 1 -rrt -1 -1 rt 1 1 rt - 22 3 20� � T / _I -I- 7 T 7 -I -I- I- T 7 -I -I- I- T T -I -I- I- T 7 -1 1- I-�r�,T� 7 — 0 1 / I 1 1 1 I 1 1 I I I I I 1 1 1 1 IT �3.0C= 1Illin a 18 -/ ✓ 16; _ 1 / 1 I 1 I I 1 1 I I I I I 1 I1 I eil4=44 14/ 1 / 1 I 1 I I 1 1 I I I I I I I 1 I 1 I I‘-1 10 -/ _ / 11 I I 1 1 I I I I I I I 1 I I I I I I I I 8 / 1 I 1 I 1 1 1 1 I I I I 1 I 1 LLLH 11 11 1 1I I I I111 1 I L -I- LLJ -I -1- L 1 1 -I -1- LL1 -I -1- I- 1 1 - 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 28 Hydrograph for Subcatchment 4S: SCM 2 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 5.19 2.33 0.00 2.00 0.11 0.00 0.00 106.00 5.19 2.33 0.00 4.00 0.25 0.00 0.00 108.00 5.19 2.33 0.00 6.00 0.42 0.00 0.00 110.00 5.19 2.33 0.00 8.00 0.62 0.00 0.00 112.00 5.19 2.33 0.00 10.00 0.94 0.01 0.13 114.00 5.19 2.33 0.00 12.00 3.44 1.08 31.39 116.00 5.19 2.33 0.00 14.00 4.26 1.63 1.82 118.00 5.19 2.33 0.00 16.00 4.57 1.86 1.11 120.00 5.19 2.33 0.00 18.00 4.78 2.02 0.86 122.00 5.19 2.33 0.00 20.00 4.94 2.14 0.64 124.00 5.19 2.33 0.00 22.00 5.07 2.24 0.57 126.00 5.19 2.33 0.00 24.00 5.19 2.33 0.53 128.00 5.19 2.33 0.00 26.00 5.19 2.33 0.00 130.00 5.19 2.33 0.00 28.00 5.19 2.33 0.00 132.00 5.19 2.33 0.00 30.00 5.19 2.33 0.00 134.00 5.19 2.33 0.00 32.00 5.19 2.33 0.00 136.00 5.19 2.33 0.00 34.00 5.19 2.33 0.00 138.00 5.19 2.33 0.00 36.00 5.19 2.33 0.00 140.00 5.19 2.33 0.00 38.00 5.19 2.33 0.00 142.00 5.19 2.33 0.00 40.00 5.19 2.33 0.00 144.00 5.19 2.33 0.00 42.00 5.19 2.33 0.00 44.00 5.19 2.33 0.00 46.00 5.19 2.33 0.00 48.00 5.19 2.33 0.00 50.00 5.19 2.33 0.00 52.00 5.19 2.33 0.00 54.00 5.19 2.33 0.00 56.00 5.19 2.33 0.00 58.00 5.19 2.33 0.00 60.00 5.19 2.33 0.00 62.00 5.19 2.33 0.00 64.00 5.19 2.33 0.00 66.00 5.19 2.33 0.00 68.00 5.19 2.33 0.00 70.00 5.19 2.33 0.00 72.00 5.19 2.33 0.00 74.00 5.19 2.33 0.00 76.00 5.19 2.33 0.00 78.00 5.19 2.33 0.00 80.00 5.19 2.33 0.00 82.00 5.19 2.33 0.00 84.00 5.19 2.33 0.00 86.00 5.19 2.33 0.00 88.00 5.19 2.33 0.00 90.00 5.19 2.33 0.00 92.00 5.19 2.33 0.00 94.00 5.19 2.33 0.00 96.00 5.19 2.33 0.00 98.00 5.19 2.33 0.00 100.00 5.19 2.33 0.00 102.00 5.19 2.33 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 29 Summary for Pond 2P: SCM 2 Inflow Area = 511,394 sf, 29.39% Impervious, Inflow Depth = 2.33" for 10-yr event Inflow = 36.84 cfs @ 12.06 hrs, Volume= 99,486 cf Outflow = 6.78 cfs @ 12.45 hrs, Volume= 97,481 cf, Atten= 82%, Lag= 23.6 min Primary = 6.78 cfs @ 12.45 hrs, Volume= 97,481 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 577.20'@ 12.45 hrs Surf.Area= 14,928 sf Storage= 45,364 cf Plug-Flow detention time=785.6 min calculated for 97,468 cf(98% of inflow) Center-of-Mass det. time= 774.6 min ( 1,619.5 - 844.9 ) Volume Invert Avail.Storage Storage Description _ #1 573.00' 93,825 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.00 1,250 0 0 574.00 10,000 5,625 5,625 575.00 11,500 10,750 16,375 576.00 13,000 12,250 28,625 577.00 14,600 13,800 42,425 578.00 16,250 15,425 57,850 579.00 17,975 17,113 74,963 580.00 19,750 18,863 93,825 Device Routing _ Invert Outlet Devices #1 Primary 566.46' 18.0" Round Outlet Pipe L= 79.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 566.46'/ 564.00' S= 0.0311 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 573.50' Sand Filter Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50 Disch. (cfs) 0.000 0.084 0.118 0.152 0.186 0.219 0.236 #3 Device 1 575.50' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 576.50' 3.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 577.50' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 578.50' 15.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 30 Primary OutFlow Max=6.78 cfs © 12.45 hrs HW=577.20' (Free Discharge) —1=Outlet Pipe (Passes 6.78 cfs of 26.89 cfs potential flow) —2=Sand Filter (Custom Controls 0.18 cfs) —3=Orifice (Orifice Controls 1.14 cfs © 5.80 fps) —4=Rect Notch (Weir Controls 5.46 cfs @ 2.73 fps) —5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs © 0.00 hrs HW=573.00' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) Pond 2P: SCM 2 Hydrograph L + _t I I I I I I H L 4- A A I ■Inflow 36.84 cfs I ❑Outflow + I ,I I- fi fi_C Q- //I— T 7 I11flO�A/ �T1 7��1 "'I ❑Secondary 404/ / / - - - 38� i / / /1_ _ I I I I Peak-E1/:577.20-' 364-/ i , L L 4 _ I I L L 1 A A I 34 / , / /1 + 7 7 I I Storage=45,364_cf- 324/ / / /_ _ I 4 -4 I I r fi rt rt 1 I 304/ / , z I 7 7 I I 1 T 7 7 7 I 284/ i , - - 26i , //4 /1_ _ I I I 1 I I I I I -7,-) 244/ i , L + 4 _41 I I I_ L 1 1 A I 2. 224./ / , / + 4 -4 I I I- L + 4 4 I c 204/ ' / / ,- -r 7 4 4 I I r T 7 rt - 1 • 18 z ' , i1 I I I 1 1 1 1 1 I 16= i i �I 14= / / 12=' / , 'I 6.78 + 4- _ 1 1 H L 7 4 4 1 10= i �s.7acfs + — + — + — 1 — —1 — I— — I — H — T — + - 4 - H - 1 - 81/ / / z' I 0.00 cfs ��lllllllll�� 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 31 Hydrograph for Pond 2P: SCM 2 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.00 0.00 0.00 0.00 4.00 0.00 0 573.00 0.00 0.00 0.00 8.00 0.00 0 573.00 0.00 0.00 0.00 12.00 31.39 18,614 575.19 0.11 0.11 0.00 16.00 1.11 36,690 576.60 1.34 1.34 0.00 20.00 0.64 34,003 576.40 0.91 0.91 0.00 24.00 0.53 30,468 576.14 0.73 0.73 0.00 28.00 0.00 24,479 575.67 0.21 0.21 0.00 32.00 0.00 22,338 575.50 0.12 0.12 0.00 36.00 0.00 20,672 575.36 0.11 0.11 0.00 40.00 0.00 19,072 575.23 0.11 0.11 0.00 44.00 0.00 17,536 575.10 0.10 0.10 0.00 48.00 0.00 16,064 574.97 0.10 0.10 0.00 52.00 0.00 14,653 574.85 0.10 0.10 0.00 56.00 0.00 13,303 574.73 0.09 0.09 0.00 60.00 0.00 12,010 574.61 0.09 0.09 0.00 64.00 0.00 10,775 574.50 0.08 0.08 0.00 68.00 0.00 9,635 574.39 0.07 0.07 0.00 72.00 0.00 8,619 574.29 0.07 0.07 0.00 76.00 0.00 7,713 574.21 0.06 0.06 0.00 80.00 0.00 6,908 574.13 0.05 0.05 0.00 84.00 0.00 6,193 574.06 0.05 0.05 0.00 88.00 0.00 5,559 573.99 0.04 0.04 0.00 92.00 0.00 4,998 573.93 0.04 0.04 0.00 96.00 0.00 4,504 573.88 0.03 0.03 0.00 100.00 0.00 4,073 573.83 0.03 0.03 0.00 104.00 0.00 3,699 573.79 0.02 0.02 0.00 108.00 0.00 3,377 573.75 0.02 0.02 0.00 112.00 0.00 3,101 573.71 0.02 0.02 0.00 116.00 0.00 2,866 573.68 0.01 0.01 0.00 120.00 0.00 2,667 573.65 0.01 0.01 0.00 124.00 0.00 2,500 573.63 0.01 0.01 0.00 128.00 0.00 2,361 573.60 0.01 0.01 0.00 132.00 0.00 2,245 573.59 0.01 0.01 0.00 136.00 0.00 2,150 573.57 0.01 0.01 0.00 140.00 0.00 2,070 573.56 0.01 0.01 0.00 144.00 0.00 2,005 573.55 0.00 0.00 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 32 Stage-Discharge for Pond 2P: SCM 2 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs) 573.00 0.00 0.00 0.00 578.20 28.21 28.21 0.00 573.10 0.00 0.00 0.00 578.30 28.34 28.34 0.00 573.20 0.00 0.00 0.00 578.40 28.46 28.46 0.00 573.30 0.00 0.00 0.00 578.50 28.59 28.59 0.00 573.40 0.00 0.00 0.00 578.60 29.90 28.72 1.18 573.50 0.00 0.00 0.00 578.70 32.18 28.84 3.34 573.60 0.01 0.01 0.00 578.80 35.19 28.97 6.22 573.70 0.02 0.02 0.00 578.90 38.81 29.09 9.71 573.80 0.03 0.03 0.00 579.00 43.16 29.22 13.95 573.90 0.03 0.03 0.00 579.10 48.16 29.34 18.82 574.00 0.04 0.04 0.00 579.20 53.14 29.46 23.68 574.10 0.05 0.05 0.00 579.30 58.46 29.59 28.87 574.20 0.06 0.06 0.00 579.40 64.10 29.71 34.39 574.30 0.07 0.07 0.00 579.50 70.03 29.83 40.20 574.40 0.08 0.08 0.00 579.60 76.42 29.95 46.46 574.50 0.08 0.08 0.00 579.70 83.11 30.07 53.04 574.60 0.09 0.09 0.00 579.80 89.78 30.19 59.59 574.70 0.09 0.09 0.00 579.90 96.65 30.31 66.34 574.80 0.09 0.09 0.00 580.00 103.59 30.43 73.16 574.90 0.10 0.10 0.00 575.00 0.10 0.10 0.00 575.10 0.10 0.10 0.00 575.20 0.11 0.11 0.00 575.30 0.11 0.11 0.00 575.40 0.11 0.11 0.00 575.50 0.12 0.12 0.00 575.60 0.15 0.15 0.00 575.70 0.24 0.24 0.00 575.80 0.36 0.36 0.00 575.90 0.49 0.49 0.00 576.00 0.61 0.61 0.00 576.10 0.70 0.70 0.00 576.20 0.78 0.78 0.00 576.30 0.85 0.85 0.00 576.40 0.91 0.91 0.00 576.50 0.97 0.97 0.00 576.60 1.34 1.34 0.00 576.70 1.95 1.95 0.00 576.80 2.71 2.71 0.00 576.90 3.60 3.60 0.00 577.00 4.58 4.58 0.00 577.10 5.65 5.65 0.00 577.20 6.79 6.79 0.00 577.30 8.00 8.00 0.00 577.40 9.27 9.27 0.00 577.50 10.59 10.59 0.00 577.60 13.40 13.40 0.00 577.70 17.41 17.41 0.00 577.80 22.21 22.21 0.00 577.90 27.67 27.67 0.00 578.00 27.95 27.95 0.00 578.10 28.08 28.08 0.00 KT37 - SCM Calculations Type II 24-hr 10-yr Rainfall=5.19" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 33 Stage-Area-Storage for Pond 2P: SCM 2 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.00 1,250 0 578.20 16,595 61,135 573.10 2,125 169 578.30 16,767 62,803 573.20 3,000 425 578.40 16,940 64,488 573.30 3,875 769 578.50 17,113 66,191 573.40 4,750 1,200 578.60 17,285 67,911 573.50 5,625 1,719 578.70 17,458 69,648 573.60 6,500 2,325 578.80 17,630 71,402 573.70 7,375 3,019 I 578.90 17,802 73,174 573.80 8,250 3,800 579.00 17,975 74,963 573.90 9,125 4,669 579.10 18,153 76,769 574.00 10,000 5,625 579.20 18,330 78,593 574.10 10,150 6,633 579.30 18,507 80,435 574.20 10,300 7,655 579.40 18,685 82,294 574.30 10,450 8,692 579.50 18,863 84,172 574.40 10,600 9,745 579.60 19,040 86,067 574.50 10,750 10,813 579.70 19,218 87,980 574.60 10,900 11,895 579.80 19,395 89,910 574.70 11,050 12,993 579.90 19,572 91,859 574.80 11,200 14,105 580.00 19,750 93,825 574.90 11,350 15,232 575.00 11,500 16,375 575.10 11,650 17,533 575.20 11,800 18,705 575.30 11,950 19,892 575.40 12,100 21,095 575.50 12,250 22,313 575.60 12,400 23,545 575.70 12,550 24,793 575.80 12,700 26,055 575.90 12,850 27,332 576.00 13,000 28,625 576.10 13,160 29,933 576.20 13,320 31,257 576.30 13,480 32,597 576.40 13,640 33,953 576.50 13,800 35,325 576.60 13,960 36,713 576.70 14,120 38,117 576.80 14,280 39,537 576.90 14,440 40,973 577.00 14,600 42,425 577.10 14,765 43,893 577.20 14,930 45,378 577.30 15,095 46,879 577.40 15,260 48,397 577.50 15,425 49,931 577.60 15,590 51,482 577.70 15,755 53,049 577.80 15,920 54,633 577.90 16,085 56,233 578.00 16,250 57,850 578.10 16,423 59,484 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 34 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment2A: SCM 2 Pre Runoff Area=11.740 ac 0.00% Impervious Runoff Depth=1.71" Tc=16.8 min CN=55.9 Runoff=22.66 cfs 72,824 cf Subcatchment4S: SCM 2 Post Runoff Area=11.740 ac 29.39% Impervious Runoff Depth=3.15" Tc=13.8 min CN=71.9 Runoff=49.79 cfs 134,038 cf Pond 2P: SCM 2 Peak Elev=577.77' Storage=54,077 cf Inflow=49.79 cfs 134,038 cf Primary=20.46 cfs 132,021 cf Secondary=0.00 cfs 0 cf Outflow=20.46 cfs 132,021 cf KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment 2A: SCM 2 Pre Runoff = 22.66 cfs @ 12.11 hrs, Volume= 72,824 cf, Depth= 1.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 25-yr Rainfall=6.20" Area (ac) CN Description 10.740 56.0 Brush, Fair, HSG B 1.000 55.0 Woods, Good, HSG B 11.740 55.9 Weighted Average 11.740 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 Direct Entry, SCM 2 Pre Subcatchment 2A: SCM 2 Pre Hydrograph 25i -I -1- r rt -I -1- r rt -I -1- - r rt -I -1- 1- r rt -1- I- r -r - ■Runoff 23 122ss ccts i1 I 1 I I 1 1 I 1 1 I I I I 1 1 I 1 1 I I 1 I 1 ,,_ 22 - - ' -1 -1- 1 T 4 -1 -1- T 4 -1 -1- I- T 4 -1 -1- 1- T -Type II 24-I4.H - 21 / -1- t -r -I -1- rtrt -I -1- - trt -I -1C- - firth f � 20 � / 1 1 1 1 1 1 1 1 1 1 1 �I`� rl'-""T"alli'f•,_ 19- 184-/ _- / -1 -1- _L _L - -1 L1 -1 -1- L -ttlnie_Area=_111-.740-ac - 17 t /-1 -1- StS 1 1 Stfi 1 1 I t 1 J tfi - 1 I ± 16 I 1 1 1 1 1 1 1 1 1 1 1 rg Q„{�I Y18Iurne=�1j2 8 41 - 15_ — 13� -I -I- I- t 4 I -I 1 4 4 -I -I- I- + 4 1 -I- 1- S 4 JC p�1,,1��11 +1� - 0 124 � T 1 1 7 T j I T 7 I I 7 T 7 -I -I- I- r 7TC=1 11 I VA3T171i n - LL 11 104 L I -1- L L I -1 -1- L L 1 -1 -1- L L 1 -1 -1- 1- L 1 J _h.4J54 _ �g 4 •i —I— I- T 4 —I —I— 5 T 4 —I —I— I— T 4 —I —I— I— T 4 - —I—►III— r - 8 1 -1- r rt -1 -1- t s -I -1- 1- r s -1 -1- 1- t rt -1- 1- r -r - 6 54-/ S -I -1- 4 t 4 1 -1 1 4 4 1 -1- 4 t 4 1 1 1- 4 4 -I -I- 1 t 4 - - 44 -1- 5t5 I -I- 5tfi 1 -1- 5tfi 1 -I- 1- tfiH 1 tfiH - - 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 36 Hydrograph for Subcatchment 2A: SCM 2 Pre Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 6.20 1.71 0.00 2.00 0.14 0.00 0.00 106.00 6.20 1.71 0.00 4.00 0.30 0.00 0.00 108.00 6.20 1.71 0.00 6.00 0.50 0.00 0.00 110.00 6.20 1.71 0.00 8.00 0.74 0.00 0.00 112.00 6.20 1.71 0.00 10.00 1.12 0.00 0.00 114.00 6.20 1.71 0.00 12.00 4.11 0.62 14.89 116.00 6.20 1.71 0.00 14.00 5.08 1.08 1.60 118.00 6.20 1.71 0.00 16.00 5.46 1.28 1.00 120.00 6.20 1.71 0.00 18.00 5.71 1.42 0.78 122.00 6.20 1.71 0.00 20.00 5.90 1.53 0.58 124.00 6.20 1.71 0.00 22.00 6.06 1.62 0.53 126.00 6.20 1.71 0.00 24.00 6.20 1.71 0.49 128.00 6.20 1.71 0.00 26.00 6.20 1.71 0.00 130.00 6.20 1.71 0.00 28.00 6.20 1.71 0.00 132.00 6.20 1.71 0.00 30.00 6.20 1.71 0.00 134.00 6.20 1.71 0.00 32.00 6.20 1.71 0.00 136.00 6.20 1.71 0.00 34.00 6.20 1.71 0.00 138.00 6.20 1.71 0.00 36.00 6.20 1.71 0.00 140.00 6.20 1.71 0.00 38.00 6.20 1.71 0.00 142.00 6.20 1.71 0.00 40.00 6.20 1.71 0.00 144.00 6.20 1.71 0.00 42.00 6.20 1.71 0.00 44.00 6.20 1.71 0.00 46.00 6.20 1.71 0.00 48.00 6.20 1.71 0.00 50.00 6.20 1.71 0.00 52.00 6.20 1.71 0.00 54.00 6.20 1.71 0.00 56.00 6.20 1.71 0.00 58.00 6.20 1.71 0.00 60.00 6.20 1.71 0.00 62.00 6.20 1.71 0.00 64.00 6.20 1.71 0.00 66.00 6.20 1.71 0.00 68.00 6.20 1.71 0.00 70.00 6.20 1.71 0.00 72.00 6.20 1.71 0.00 74.00 6.20 1.71 0.00 76.00 6.20 1.71 0.00 78.00 6.20 1.71 0.00 80.00 6.20 1.71 0.00 82.00 6.20 1.71 0.00 84.00 6.20 1.71 0.00 86.00 6.20 1.71 0.00 88.00 6.20 1.71 0.00 90.00 6.20 1.71 0.00 92.00 6.20 1.71 0.00 94.00 6.20 1.71 0.00 96.00 6.20 1.71 0.00 98.00 6.20 1.71 0.00 100.00 6.20 1.71 0.00 102.00 6.20 1.71 0.00 KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment 4S: SCM 2 Post Runoff = 49.79 cfs @ 12.06 hrs, Volume= 134,038 cf, Depth= 3.15" Routed to Pond 2P : SCM 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 25-yr Rainfall=6.20" Area (ac) CN Description 3.450 98.0 Paved parking, HSG B 8.290 61.0 >75% Grass cover, Good, HSG B 11.740 71.9 Weighted Average 8.290 70.61% Pervious Area 3.450 29.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 Direct Entry, SCM 1 Post Subcatchment 4S: SCM 2 Post Hydrograph 4 -I -I- I- 4 4 -1 -I- 1 # 4 -1 -1- 1- T + -I -I- 1- T 4 - -1- I- T + - - 55-/ I II I 1 I I 1 I 1 1 I I 1 I I 1 1 I 1 1 I I 1 I I 1 ■Runoff cfs7 T 7 1 1 I T 7 7 71717 T T 7 - 50--_ T 1 % I I I I I I I I 1 I I 1 1 I 1 1 Type II 24+h r 45� 1 / I -I- L L -I -I- L L 1 -I -I- L L 1 J - 51-yt Rai nta 1�= . 0� 407-- 1 / I I I I 1 1 Runoff Area=1117401a¢ 4- T i -I- H + 4 -I -I- H T 4 -I -I- I- � - I I T 35� I / 1 II 1 1 1 '1`u1n(�ff1VQIlIfT1e � #44,08�,1�Cs� u 30� — T /-I 1 7 T -F 717 7 T 7 1 7 T 7 1 -R-unoffDe:0=3. 1'v - I I I I I I I I I LL � T / C I . 25 % I7 n1i r1 L -I 1 L L A -I -I- 1 L 1 1 I_ L 1 -I -I- 1 L 1 J ICN 7a.9 - 20L/ I / III I 1 I 1 1 I 1 1 1 1 1 1 1 1 1 1 1 4- t / 1 -I- H t -F -1 -1- H t -F -1 -1- 1- t t -I -1- 1- t t H -1- I- T t H - 15 II % I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 103/ 5:../ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 38 Hydrograph for Subcatchment 4S: SCM 2 Post Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 6.20 3.15 0.00 2.00 0.14 0.00 0.00 106.00 6.20 3.15 0.00 4.00 0.30 0.00 0.00 108.00 6.20 3.15 0.00 6.00 0.50 0.00 0.00 110.00 6.20 3.15 0.00 8.00 0.74 0.00 0.00 112.00 6.20 3.15 0.00 10.00 1.12 0.03 0.36 114.00 6.20 3.15 0.00 12.00 4.11 1.53 43.05 116.00 6.20 3.15 0.00 14.00 5.08 2.25 2.33 118.00 6.20 3.15 0.00 16.00 5.46 2.54 1.42 120.00 6.20 3.15 0.00 18.00 5.71 2.75 1.09 122.00 6.20 3.15 0.00 20.00 5.90 2.90 0.81 124.00 6.20 3.15 0.00 22.00 6.06 3.03 0.73 126.00 6.20 3.15 0.00 24.00 6.20 3.15 0.67 128.00 6.20 3.15 0.00 26.00 6.20 3.15 0.00 130.00 6.20 3.15 0.00 28.00 6.20 3.15 0.00 132.00 6.20 3.15 0.00 30.00 6.20 3.15 0.00 134.00 6.20 3.15 0.00 32.00 6.20 3.15 0.00 136.00 6.20 3.15 0.00 34.00 6.20 3.15 0.00 138.00 6.20 3.15 0.00 36.00 6.20 3.15 0.00 140.00 6.20 3.15 0.00 38.00 6.20 3.15 0.00 142.00 6.20 3.15 0.00 40.00 6.20 3.15 0.00 144.00 6.20 3.15 0.00 42.00 6.20 3.15 0.00 44.00 6.20 3.15 0.00 46.00 6.20 3.15 0.00 48.00 6.20 3.15 0.00 50.00 6.20 3.15 0.00 52.00 6.20 3.15 0.00 54.00 6.20 3.15 0.00 56.00 6.20 3.15 0.00 58.00 6.20 3.15 0.00 60.00 6.20 3.15 0.00 62.00 6.20 3.15 0.00 64.00 6.20 3.15 0.00 66.00 6.20 3.15 0.00 68.00 6.20 3.15 0.00 70.00 6.20 3.15 0.00 72.00 6.20 3.15 0.00 74.00 6.20 3.15 0.00 76.00 6.20 3.15 0.00 78.00 6.20 3.15 0.00 80.00 6.20 3.15 0.00 82.00 6.20 3.15 0.00 84.00 6.20 3.15 0.00 86.00 6.20 3.15 0.00 88.00 6.20 3.15 0.00 90.00 6.20 3.15 0.00 92.00 6.20 3.15 0.00 94.00 6.20 3.15 0.00 96.00 6.20 3.15 0.00 98.00 6.20 3.15 0.00 100.00 6.20 3.15 0.00 102.00 6.20 3.15 0.00 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 39 Summary for Pond 2P: SCM 2 Inflow Area = 511,394 sf, 29.39% Impervious, Inflow Depth = 3.15" for 25-yr event Inflow = 49.79 cfs @ 12.06 hrs, Volume= 134,038 cf Outflow = 20.46 cfs @ 12.24 hrs, Volume= 132,021 cf, Atten= 59%, Lag= 11.0 min Primary = 20.46 cfs @ 12.24 hrs, Volume= 132,021 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 577.77'@ 12.24 hrs Surf.Area= 15,862 sf Storage= 54,077 cf Plug-Flow detention time=602.1 min calculated for 132,003 cf(98% of inflow) Center-of-Mass det. time= 593.9 min ( 1,430.3 - 836.3 ) Volume Invert Avail.Storage Storage Description _ #1 573.00' 93,825 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.00 1,250 0 0 574.00 10,000 5,625 5,625 575.00 11,500 10,750 16,375 576.00 13,000 12,250 28,625 577.00 14,600 13,800 42,425 578.00 16,250 15,425 57,850 579.00 17,975 17,113 74,963 580.00 19,750 18,863 93,825 Device Routing _ Invert Outlet Devices #1 Primary 566.46' 18.0" Round Outlet Pipe L= 79.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 566.46'/ 564.00' S= 0.0311 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 573.50' Sand Filter Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50 Disch. (cfs) 0.000 0.084 0.118 0.152 0.186 0.219 0.236 #3 Device 1 575.50' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 576.50' 3.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 577.50' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 578.50' 15.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 40 Primary OutFlow Max=20.42 cfs @ 12.24 hrs HW=577.76' (Free Discharge) —1=Outlet Pipe (Passes 20.42 cfs of 27.64 cfs potential flow) —2=Sand Filter (Custom Controls 0.19 cfs) —3=Orifice (Orifice Controls 1.34 cfs © 6.83 fps) —4=Rect Notch (Orifice Controls 11.77 cfs @ 4.20 fps) —5=Top of Riser (Weir Controls 7.11 cfs © 1.68 fps) Secondary OutFlow Max=0.00 cfs © 0.00 hrs HW=573.00' (Free Discharge) 4-6=Spillway ( Controls 0.00 cfs) Pond 2P: SCM 2 Hydrograph , + + + + III Ht + -[ HI - / I I I I I I I I I I I I •Inflow 49.79 cfs I •Outflow 55� / I Prima Infhli�ll/ ATea$51 v304 - •Se ondary / / I I I I Peak_lev 577.7T _ 50:--/ 1 i I I Imo+ I I — I I ,, I 1 45- / / / /I- � + 4 - I I I 1Stora-ge=CA,0717 W - - / / 1 1 I I I I I I I I 40- / „,1 I I I I I I I I - / 35 / / / � I- p _- 1 1 1 L 4 _L _I 1 w = / / 1 1 1 1 1 1 1 307 / ' - 1 I I I I I 20 46 cfs l0 25� / 20.46 cfs 1 - - - - - 1 _ 1 - - - - - / 20 -/ / -I - -1 - 15 -/ _I - -1 _ - i% I I 10 , o.00 cfs ��� p �Z 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 41 Hydrograph for Pond 2P: SCM 2 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.00 0.00 0.00 0.00 4.00 0.00 0 573.00 0.00 0.00 0.00 8.00 0.00 0 573.00 0.00 0.00 0.00 12.00 43.05 28,428 575.98 0.59 0.59 0.00 16.00 1.42 37,496 576.66 1.66 1.66 0.00 20.00 0.81 35,315 576.50 0.97 0.97 0.00 24.00 0.67 32,669 576.31 0.85 0.85 0.00 28.00 0.00 25,158 575.73 0.27 0.27 0.00 32.00 0.00 22,678 575.53 0.12 0.12 0.00 36.00 0.00 20,994 575.39 0.11 0.11 0.00 40.00 0.00 19,381 575.26 0.11 0.11 0.00 44.00 0.00 17,833 575.13 0.11 0.11 0.00 48.00 0.00 16,349 575.00 0.10 0.10 0.00 52.00 0.00 14,926 574.87 0.10 0.10 0.00 56.00 0.00 13,564 574.75 0.09 0.09 0.00 60.00 0.00 12,260 574.63 0.09 0.09 0.00 64.00 0.00 11,013 574.52 0.08 0.08 0.00 68.00 0.00 9,849 574.41 0.08 0.08 0.00 72.00 0.00 8,809 574.31 0.07 0.07 0.00 76.00 0.00 7,883 574.22 0.06 0.06 0.00 80.00 0.00 7,059 574.14 0.05 0.05 0.00 84.00 0.00 6,327 574.07 0.05 0.05 0.00 88.00 0.00 5,678 574.01 0.04 0.04 0.00 92.00 0.00 5,103 573.95 0.04 0.04 0.00 96.00 0.00 4,596 573.89 0.03 0.03 0.00 100.00 0.00 4,153 573.84 0.03 0.03 0.00 104.00 0.00 3,769 573.80 0.02 0.02 0.00 108.00 0.00 3,436 573.75 0.02 0.02 0.00 112.00 0.00 3,151 573.72 0.02 0.02 0.00 116.00 0.00 2,909 573.68 0.02 0.02 0.00 120.00 0.00 2,704 573.66 0.01 0.01 0.00 124.00 0.00 2,531 573.63 0.01 0.01 0.00 128.00 0.00 2,386 573.61 0.01 0.01 0.00 132.00 0.00 2,266 573.59 0.01 0.01 0.00 136.00 0.00 2,167 573.57 0.01 0.01 0.00 140.00 0.00 2,085 573.56 0.01 0.01 0.00 144.00 0.00 2,017 573.55 0.00 0.00 0.00 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 42 Stage-Discharge for Pond 2P: SCM 2 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs) 573.00 0.00 0.00 0.00 578.20 28.21 28.21 0.00 573.10 0.00 0.00 0.00 578.30 28.34 28.34 0.00 573.20 0.00 0.00 0.00 578.40 28.46 28.46 0.00 573.30 0.00 0.00 0.00 578.50 28.59 28.59 0.00 573.40 0.00 0.00 0.00 578.60 29.90 28.72 1.18 573.50 0.00 0.00 0.00 578.70 32.18 28.84 3.34 573.60 0.01 0.01 0.00 578.80 35.19 28.97 6.22 573.70 0.02 0.02 0.00 578.90 38.81 29.09 9.71 573.80 0.03 0.03 0.00 579.00 43.16 29.22 13.95 573.90 0.03 0.03 0.00 579.10 48.16 29.34 18.82 574.00 0.04 0.04 0.00 579.20 53.14 29.46 23.68 574.10 0.05 0.05 0.00 579.30 58.46 29.59 28.87 574.20 0.06 0.06 0.00 579.40 64.10 29.71 34.39 574.30 0.07 0.07 0.00 579.50 70.03 29.83 40.20 574.40 0.08 0.08 0.00 579.60 76.42 29.95 46.46 574.50 0.08 0.08 0.00 579.70 83.11 30.07 53.04 574.60 0.09 0.09 0.00 579.80 89.78 30.19 59.59 574.70 0.09 0.09 0.00 579.90 96.65 30.31 66.34 574.80 0.09 0.09 0.00 580.00 103.59 30.43 73.16 574.90 0.10 0.10 0.00 575.00 0.10 0.10 0.00 575.10 0.10 0.10 0.00 575.20 0.11 0.11 0.00 575.30 0.11 0.11 0.00 575.40 0.11 0.11 0.00 575.50 0.12 0.12 0.00 575.60 0.15 0.15 0.00 575.70 0.24 0.24 0.00 575.80 0.36 0.36 0.00 575.90 0.49 0.49 0.00 576.00 0.61 0.61 0.00 576.10 0.70 0.70 0.00 576.20 0.78 0.78 0.00 576.30 0.85 0.85 0.00 576.40 0.91 0.91 0.00 576.50 0.97 0.97 0.00 576.60 1.34 1.34 0.00 576.70 1.95 1.95 0.00 576.80 2.71 2.71 0.00 576.90 3.60 3.60 0.00 577.00 4.58 4.58 0.00 577.10 5.65 5.65 0.00 577.20 6.79 6.79 0.00 577.30 8.00 8.00 0.00 577.40 9.27 9.27 0.00 577.50 10.59 10.59 0.00 577.60 13.40 13.40 0.00 577.70 17.41 17.41 0.00 577.80 22.21 22.21 0.00 577.90 27.67 27.67 0.00 578.00 27.95 27.95 0.00 578.10 28.08 28.08 0.00 KT37 - SCM Calculations Type 1124-hr 25-yr Rainfall=6.20" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 43 Stage-Area-Storage for Pond 2P: SCM 2 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.00 1,250 0 578.20 16,595 61,135 573.10 2,125 169 578.30 16,767 62,803 573.20 3,000 425 578.40 16,940 64,488 573.30 3,875 769 578.50 17,113 66,191 573.40 4,750 1,200 578.60 17,285 67,911 573.50 5,625 1,719 578.70 17,458 69,648 573.60 6,500 2,325 578.80 17,630 71,402 573.70 7,375 3,019 I 578.90 17,802 73,174 573.80 8,250 3,800 579.00 17,975 74,963 573.90 9,125 4,669 579.10 18,153 76,769 574.00 10,000 5,625 579.20 18,330 78,593 574.10 10,150 6,633 579.30 18,507 80,435 574.20 10,300 7,655 579.40 18,685 82,294 574.30 10,450 8,692 579.50 18,863 84,172 574.40 10,600 9,745 579.60 19,040 86,067 574.50 10,750 10,813 579.70 19,218 87,980 574.60 10,900 11,895 579.80 19,395 89,910 574.70 11,050 12,993 579.90 19,572 91,859 574.80 11,200 14,105 580.00 19,750 93,825 574.90 11,350 15,232 575.00 11,500 16,375 575.10 11,650 17,533 575.20 11,800 18,705 575.30 11,950 19,892 575.40 12,100 21,095 575.50 12,250 22,313 575.60 12,400 23,545 575.70 12,550 24,793 575.80 12,700 26,055 575.90 12,850 27,332 576.00 13,000 28,625 576.10 13,160 29,933 576.20 13,320 31,257 576.30 13,480 32,597 576.40 13,640 33,953 576.50 13,800 35,325 576.60 13,960 36,713 576.70 14,120 38,117 576.80 14,280 39,537 576.90 14,440 40,973 577.00 14,600 42,425 577.10 14,765 43,893 577.20 14,930 45,378 577.30 15,095 46,879 577.40 15,260 48,397 577.50 15,425 49,931 577.60 15,590 51,482 577.70 15,755 53,049 577.80 15,920 54,633 577.90 16,085 56,233 578.00 16,250 57,850 578.10 16,423 59,484 KT37 - SCM Calculations Type 1124-hr 100-yr Rainfall=7.85" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 50 Primary OutFlow Max=28.94 cfs @ 12.21 hrs HW=578.78' (Free Discharge) —1=Outlet Pipe (Inlet Controls 28.94 cfs @ 16.38 fps) —2=Sand Filter (Passes < 0.23 cfs potential flow) —3=Orifice (Passes < 1.65 cfs potential flow) —4=Rect Notch (Passes < 18.27 cfs potential flow) —5=Top of Riser (Passes < 75.89 cfs potential flow) Secondary OutFlow Max=5.64 cfs @ 12.21 hrs HW=578.78' (Free Discharge) L6=Spillway (Weir Controls 5.64 cfs @ 1.34 fps) Pond 2P: SCM 2 Hydrograph z 1- t H I - fi - rt - rt - � - -I - H -f H I I f- t fi H H I ■Inflow 71.81 cfs 1 + II,�'w L C Q� •_ ■Outflow 80_ / /• / + H I I -JIIL IoW AFeaTu-i `4 S - ■Secon• dary 757 i• / H 4 - I I Pealkftev578.7811 65� ' i• / 1 _ I I (Storage 11,107_cf _ 55� / z 504-/ ' i I Z. 45� / 'z i /• 34.68 cfs � v40 2 35 / (28 95 cfs I I I I I I 30 -/ I I I I I 25 20- T T T 10- 1 5 73 cfs 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) 3S SCM 2 Post Mod 2P SCM 2 SubCat Reach 'on• MI Routing Diagram for KT37-SCM Calculations Prepared by ESP Associates Inc, Printed 5/10/2024 HydroCAD®10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 2 Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 1 inch Type II 24-hr Default 24.00 1 1.00 2 KT37 - SCM Calculations Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 3 Area Listing (selected nodes) Area CN Description (sq-ft) (subcatchment-numbers) 511,394 89.8 Modified CN (3S) KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 4 Time span=0.00-144.00 hrs, dt=0.02 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment3S: SCM 2 Post Mod Runoff Area=11.740 ac 0.00% Impervious Runoff Depth=0.31" Tc=13.8 min CN=89.8 Runoff=4.75 cfs 13,335 cf Pond 2P: SCM 2 Peak Elev=574.44' Storage=10,212 cf Inflow=4.75 cfs 13,335 cf Primary=0.08 cfs 11,583 cf Secondary=0.00 cfs 0 cf Outflow=0.08 cfs 11,583 cf KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 3S: SCM 2 Post Mod Runoff = 4.75 cfs @ 12.07 hrs, Volume= 13,335 cf, Depth= 0.31" Routed to Pond 2P : SCM 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Type II 24-hr 1 inch Rainfall=1.00" Area (ac) CN Description * 11.740 89.8 Modified CN 11.740 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 Direct Entry, SCM 1 Post Subcatchment 3S: SCM 2 Post Mod Hydrograph 11 1 I I 1 I I I I I I I I I I I 1 - 1- -f —1 —1— I— I I I I I - •Runoff 5—/ 14.7s cfs I I I I I I I I I I I I 1 1 1 1 1 1 I I I I I I I I I Type 1124n-I/h�r / i ; �1 100fl01 mil _ 4� zr I / I I I 1 1 1 1 1 1 I - 1 1 1 1 1 1 I Runoff Area=111.740 act 1 / 1 1 I I I / I I Il I11 4I 1 uunoff;Voumg3,35L Ct _ en 3 1 I I I I IRllofDepth�0.31' ✓ _ ./ 1 1 1 1 1 1 1 1 ITC=13.81 min - 1 1 1 1 1 1 1 1 I I I I I I 1 1 1 1 1 1 1 1 1 I I I I I I 1 I 1 i ' ��������� ��������������i/ 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110115120125130135140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 6 Hydrograph for Subcatchment 3S: SCM 2 Post Mod Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 104.00 1.00 0.31 0.00 2.00 0.02 0.00 0.00 106.00 1.00 0.31 0.00 4.00 0.05 0.00 0.00 108.00 1.00 0.31 0.00 6.00 0.08 0.00 0.00 110.00 1.00 0.31 0.00 8.00 0.12 0.00 0.00 112.00 1.00 0.31 0.00 10.00 0.18 0.00 0.00 114.00 1.00 0.31 0.00 12.00 0.66 0.12 3.83 116.00 1.00 0.31 0.00 14.00 0.82 0.20 0.28 118.00 1.00 0.31 0.00 16.00 0.88 0.24 0.17 120.00 1.00 0.31 0.00 18.00 0.92 0.26 0.13 122.00 1.00 0.31 0.00 20.00 0.95 0.28 0.10 124.00 1.00 0.31 0.00 22.00 0.98 0.30 0.09 126.00 1.00 0.31 0.00 24.00 1.00 0.31 0.08 128.00 1.00 0.31 0.00 26.00 1.00 0.31 0.00 130.00 1.00 0.31 0.00 28.00 1.00 0.31 0.00 132.00 1.00 0.31 0.00 30.00 1.00 0.31 0.00 134.00 1.00 0.31 0.00 32.00 1.00 0.31 0.00 136.00 1.00 0.31 0.00 34.00 1.00 0.31 0.00 138.00 1.00 0.31 0.00 36.00 1.00 0.31 0.00 140.00 1.00 0.31 0.00 38.00 1.00 0.31 0.00 142.00 1.00 0.31 0.00 40.00 1.00 0.31 0.00 144.00 1.00 0.31 0.00 42.00 1.00 0.31 0.00 44.00 1.00 0.31 0.00 46.00 1.00 0.31 0.00 48.00 1.00 0.31 0.00 50.00 1.00 0.31 0.00 52.00 1.00 0.31 0.00 54.00 1.00 0.31 0.00 56.00 1.00 0.31 0.00 58.00 1.00 0.31 0.00 60.00 1.00 0.31 0.00 62.00 1.00 0.31 0.00 64.00 1.00 0.31 0.00 66.00 1.00 0.31 0.00 68.00 1.00 0.31 0.00 70.00 1.00 0.31 0.00 72.00 1.00 0.31 0.00 74.00 1.00 0.31 0.00 76.00 1.00 0.31 0.00 78.00 1.00 0.31 0.00 80.00 1.00 0.31 0.00 82.00 1.00 0.31 0.00 84.00 1.00 0.31 0.00 86.00 1.00 0.31 0.00 88.00 1.00 0.31 0.00 90.00 1.00 0.31 0.00 92.00 1.00 0.31 0.00 94.00 1.00 0.31 0.00 96.00 1.00 0.31 0.00 98.00 1.00 0.31 0.00 100.00 1.00 0.31 0.00 102.00 1.00 0.31 0.00 KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 7 Summary for Pond 2P: SCM 2 Inflow Area = 511,394 sf, 0.00% Impervious, Inflow Depth = 0.31" for 1 inch event Inflow = 4.75 cfs @ 12.07 hrs, Volume= 13,335 cf Outflow = 0.08 cfs @ 24.09 hrs, Volume= 11,583 cf, Atten= 98%, Lag= 721.1 min Primary = 0.08 cfs @ 24.09 hrs, Volume= 11,583 cf Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-144.00 hrs, dt= 0.02 hrs Peak Elev= 574.44'@ 24.09 hrs Surf.Area= 10,666 sf Storage= 10,212 cf Plug-Flow detention time= 1,658.8 min calculated for 11,581 cf(87% of inflow) Center-of-Mass det. time= 1,595.7 min ( 2,463.9 - 868.2 ) Volume Invert Avail.Storage_ Storage Description #1 573.00' 93,825 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) _(cubic-feet) 573.00 1,250 0 0 574.00 10,000 5,625 5,625 575.00 11,500 10,750 16,375 576.00 13,000 12,250 28,625 577.00 14,600 13,800 42,425 578.00 16,250 15,425 57,850 579.00 17,975 17,113 74,963 580.00 19,750 18,863 93,825 Device Routing _ Invert Outlet Devices #1 Primary 566.46' 18.0" Round Outlet Pipe L= 79.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 566.46'/ 564.00' S= 0.0311 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 573.50' Sand Filter Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50 Disch. (cfs) 0.000 0.084 0.118 0.152 0.186 0.219 0.236 #3 Device 1 575.50' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 576.50' 3.0' long x 1.00' rise Rect Notch 2 End Contraction(s) #5 Device 1 577.50' 48.0" x 48.0" Horiz. Top of Riser C= 0.600 Limited to weir flow at low heads #6 Secondary 578.50' 15.0' long x 10.0' breadth Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 8 Primary OutFlow Max=0.08 cfs @ 24.09 hrs HW=574.44' (Free Discharge) 4-1=Outlet Pipe (Passes 0.08 cfs of 22.89 cfs potential flow) 44 2=Sand Filter (Custom Controls 0.08 cfs) 3=Orifice ( Controls 0.00 cfs) =Rect Notch ( Controls 0.00 cfs) 5=Top of Riser ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=573.00' (Free Discharge) L6=Spillway ( Controls 0.00 cfs) Pond 2P: SCM 2 Hydrograph iI ❑Inflow 14.75 cfs I ❑Outflow Inflow Area=511,394 sf ose ondary 5 / Peak Elev=574.44' / Storage=10,212 cf 4 I / I / w 3- / - I / 3 / o - LL 2_ I 1- 0.08 cfs zvagmvx,,,77,7: /''' cfs ./.77 z L//I 0 0 cfs 7 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Time (hours) KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 9 Hydrograph for Pond 2P: SCM 2 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 573.00 0.00 0.00 0.00 4.00 0.00 0 573.00 0.00 0.00 0.00 8.00 0.00 0 573.00 0.00 0.00 0.00 12.00 3.83 1,616 573.48 0.00 0.00 0.00 16.00 0.17 9,182 574.35 0.07 0.07 0.00 20.00 0.10 10,032 574.43 0.08 0.08 0.00 24.00 0.08 10,212 574.44 0.08 0.08 0.00 28.00 0.00 9,191 574.35 0.07 0.07 0.00 32.00 0.00 8,223 574.25 0.06 0.06 0.00 36.00 0.00 7,361 574.17 0.06 0.06 0.00 40.00 0.00 6,595 574.10 0.05 0.05 0.00 44.00 0.00 5,916 574.03 0.04 0.04 0.00 48.00 0.00 5,313 573.97 0.04 0.04 0.00 52.00 0.00 4,781 573.91 0.03 0.03 0.00 56.00 0.00 4,315 573.86 0.03 0.03 0.00 60.00 0.00 3,908 573.81 0.03 0.03 0.00 64.00 0.00 3,557 573.77 0.02 0.02 0.00 68.00 0.00 3,255 573.73 0.02 0.02 0.00 72.00 0.00 2,996 573.70 0.02 0.02 0.00 76.00 0.00 2,778 573.67 0.01 0.01 0.00 80.00 0.00 2,593 573.64 0.01 0.01 0.00 84.00 0.00 2,438 573.62 0.01 0.01 0.00 88.00 0.00 2,309 573.60 0.01 0.01 0.00 92.00 0.00 2,203 573.58 0.01 0.01 0.00 96.00 0.00 2,114 573.57 0.01 0.01 0.00 100.00 0.00 2,041 573.55 0.00 0.00 0.00 104.00 0.00 1,981 573.54 0.00 0.00 0.00 108.00 0.00 1,932 573.54 0.00 0.00 0.00 112.00 0.00 1,893 573.53 0.00 0.00 0.00 116.00 0.00 1,860 573.52 0.00 0.00 0.00 120.00 0.00 1,834 573.52 0.00 0.00 0.00 124.00 0.00 1,813 573.52 0.00 0.00 0.00 128.00 0.00 1,795 573.51 0.00 0.00 0.00 132.00 0.00 1,781 573.51 0.00 0.00 0.00 136.00 0.00 1,769 573.51 0.00 0.00 0.00 140.00 0.00 1,760 573.51 0.00 0.00 0.00 144.00 0.00 1,752 573.51 0.00 0.00 0.00 KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 10 Stage-Discharge for Pond 2P: SCM 2 Elevation Discharge Primary Secondary Elevation Discharge Primary Secondary (feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs) 573.00 0.00 0.00 0.00 578.20 28.21 28.21 0.00 573.10 0.00 0.00 0.00 578.30 28.34 28.34 0.00 573.20 0.00 0.00 0.00 578.40 28.46 28.46 0.00 573.30 0.00 0.00 0.00 578.50 28.59 28.59 0.00 573.40 0.00 0.00 0.00 578.60 29.90 28.72 1.18 573.50 0.00 0.00 0.00 578.70 32.18 28.84 3.34 573.60 0.01 0.01 0.00 578.80 35.19 28.97 6.22 573.70 0.02 0.02 0.00 578.90 38.81 29.09 9.71 573.80 0.03 0.03 0.00 579.00 43.16 29.22 13.95 573.90 0.03 0.03 0.00 579.10 48.16 29.34 18.82 574.00 0.04 0.04 0.00 579.20 53.14 29.46 23.68 574.10 0.05 0.05 0.00 579.30 58.46 29.59 28.87 574.20 0.06 0.06 0.00 579.40 64.10 29.71 34.39 574.30 0.07 0.07 0.00 579.50 70.03 29.83 40.20 574.40 0.08 0.08 0.00 579.60 76.42 29.95 46.46 574.50 0.08 0.08 0.00 579.70 83.11 30.07 53.04 574.60 0.09 0.09 0.00 579.80 89.78 30.19 59.59 574.70 0.09 0.09 0.00 579.90 96.65 30.31 66.34 574.80 0.09 0.09 0.00 580.00 103.59 30.43 73.16 574.90 0.10 0.10 0.00 575.00 0.10 0.10 0.00 575.10 0.10 0.10 0.00 575.20 0.11 0.11 0.00 575.30 0.11 0.11 0.00 575.40 0.11 0.11 0.00 575.50 0.12 0.12 0.00 575.60 0.15 0.15 0.00 575.70 0.24 0.24 0.00 575.80 0.36 0.36 0.00 575.90 0.49 0.49 0.00 576.00 0.61 0.61 0.00 576.10 0.70 0.70 0.00 576.20 0.78 0.78 0.00 576.30 0.85 0.85 0.00 576.40 0.91 0.91 0.00 576.50 0.97 0.97 0.00 576.60 1.34 1.34 0.00 576.70 1.95 1.95 0.00 576.80 2.71 2.71 0.00 576.90 3.60 3.60 0.00 577.00 4.58 4.58 0.00 577.10 5.65 5.65 0.00 577.20 6.79 6.79 0.00 577.30 8.00 8.00 0.00 577.40 9.27 9.27 0.00 577.50 10.59 10.59 0.00 577.60 13.40 13.40 0.00 577.70 17.41 17.41 0.00 577.80 22.21 22.21 0.00 577.90 27.67 27.67 0.00 578.00 27.95 27.95 0.00 578.10 28.08 28.08 0.00 KT37 - SCM Calculations Type II 24-hr 1 inch Rainfall=1.00" Prepared by ESP Associates Inc Printed 5/10/2024 HydroCAD® 10.20-2g s/n 02779 ©2022 HydroCAD Software Solutions LLC Page 11 Stage-Area-Storage for Pond 2P: SCM 2 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 573.00 1,250 0 578.20 16,595 61,135 573.10 2,125 169 578.30 16,767 62,803 573.20 3,000 425 578.40 16,940 64,488 573.30 3,875 769 578.50 17,113 66,191 573.40 4,750 1,200 578.60 17,285 67,911 573.50 5,625 1,719 578.70 17,458 69,648 573.60 6,500 2,325 578.80 17,630 71,402 573.70 7,375 3,019 I 578.90 17,802 73,174 573.80 8,250 3,800 579.00 17,975 74,963 573.90 9,125 4,669 579.10 18,153 76,769 574.00 10,000 5,625 579.20 18,330 78,593 574.10 10,150 6,633 579.30 18,507 80,435 574.20 10,300 7,655 579.40 18,685 82,294 574.30 10,450 8,692 579.50 18,863 84,172 574.40 10,600 9,745 579.60 19,040 86,067 574.50 10,750 10,813 579.70 19,218 87,980 574.60 10,900 11,895 579.80 19,395 89,910 574.70 11,050 12,993 579.90 19,572 91,859 574.80 11,200 14,105 580.00 19,750 93,825 574.90 11,350 15,232 575.00 11,500 16,375 575.10 11,650 17,533 575.20 11,800 18,705 575.30 11,950 19,892 575.40 12,100 21,095 575.50 12,250 22,313 575.60 12,400 23,545 575.70 12,550 24,793 575.80 12,700 26,055 575.90 12,850 27,332 576.00 13,000 28,625 576.10 13,160 29,933 576.20 13,320 31,257 576.30 13,480 32,597 576.40 13,640 33,953 576.50 13,800 35,325 576.60 13,960 36,713 576.70 14,120 38,117 576.80 14,280 39,537 576.90 14,440 40,973 577.00 14,600 42,425 577.10 14,765 43,893 577.20 14,930 45,378 577.30 15,095 46,879 577.40 15,260 48,397 577.50 15,425 49,931 577.60 15,590 51,482 577.70 15,755 53,049 577.80 15,920 54,633 577.90 16,085 56,233 578.00 16,250 57,850 578.10 16,423 59,484