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Home My WebLink AboutWPO200700078 Calculations 2023-01-09I, Wkstal HYDROLOGIC/HYDRAULIC CALCULATIONS I191A Luxor & North Pantops Commercial December 14, 2022 Location: Tax Map 78 Parcel 12B Albemarle County, Virginia Developer: EALTii CEVA Contractors, INC FO� 195 Riverbend Dr Charlottesville, VA 22911 0 C G R ENE Z ,o Lic. No. 55833 Prepared By: 1A Roudabush, Gale & Associates, INC L <4v P s� 999 2nd St SE Charlottesville, VA 22902 PIn1 AL "p C5 "o P: 434.977.0205 F: 434.979.1681 Contents: 1. Cover Sheet — ------------- i. 2. Project SWM Summary 3. Design Calculations -------------- — ---------------- 1-14 4. Post -Development Inflow ----- 15-17 S. Amendment Post -Development Routed ----- 18-20 6. Amendment Pond Report -------- 21 Project SWM Summary The purpose of this amendment is to adjust the SWM #3 outfall structure. SWM #3 was constructed based on the design of "Amendment to SWM Plans for Luxor & North Pantops Commercial" by Dominion Development Resources, LLC, dated February 11t^, 2008 by Timothy Ray Miller, P.E. Based on an as -built survey by Roudabush, Gale & Associates (RGA). The as -built data shows that SWM #3 was built to 85% capacity of the total design volume, however, the required 4x WQV permanent pool volume exceeds the design value. The as -built post - developed 2-yr (18.56 cfs) and 10-yr (29.09 cfs) storm peak discharge values were above the design levels by 9.07 cfs (design = 9.49 cfs) and 12.22 cfs (design = 16.87 cfs), respectively. The original design used a time of peak in order to model the modified rational routed hydrographs. The amended calculations use the Hydraflow Hydrograph Extension for Autodesk Civil 3D. The software uses a storm duration factor (SDF) for the modified rational method which was determined by dividing the time to peak storm by the time of concentration. The storm duration factors for the 2-yr, 10-yr, and 100-yr storms are as follows: 2-yr = 35/15 = 2.3 10-yr = 34/15 = 2.3 100-yr = 32/15 = 2.1 This amendment proposes to cover half of one of the two 1' orifices at elevation 489.43' on the riser with a steel plate, raise the existing 2.5' weir at elevation 491.40' to elevation 492.70', and raise the riser from 493.03' to 493.53'. These changes will bring the peak flow down to 9.24 cfs and 16.19 cfs for the 2-yr and 10-yr storms, respectively. This will satisfy the design requirements for peak flow without excessively disrupting the mature and stabilized SWM facility. Additionally, the plantings specified in the approved plan were never installed. Landscape Architect, Ammy George, performed a survey on November 4, 2022 and the conclusion of her analysis of the existing plantings on the aquatic bench was that the removal of the existing plant community would be overly disruptive and that it would take years for the replacement plantings to be a comparable size and density of the plant community that is there now. If the intent of replanting the aquatic bench is to follow the original plan, two species from the original planting plan are already in existence on the aquatic bench: iris virginica (virginia blue flag) and spirpus validus (soft -stem bulrush). Additionally, the iris pseudacorus from the approved plan would not and could not be planted today as it is considered a highly invasive species according to the virginia dcr. For these reasons, no changes to the aquatic bench or the plantings therein are proposed. AMENDMENT TO HYDROLOGIC/HYDRAULIC CALCULATIONS FOR Luxor Subdivision & Road Networks November 20, 2007 LOCATION: Tax Map 78 Parcels 12B Albemarle County, Virginia PREPARED BY: Dominion Development Resources, LLC 172 S. Pantops Drive Charlottesville, VA 22911 P: 434.979.8121 F: 434.979.1681 Run—off Summary Point of Pre-Dev Pre-Dev Pre-Dev Post - Post-Dev Post-D�v Analysis DA 2-Year 10-Year Dev Rtd. 2- Rid. 1:'- DA Year Yedr Outfall 3 3 26.71 37.38 3 Post 9.49 1(.d7 Outfall 2 2 77.46 111.13 2 Post & 61.11 6t).70 SWM#3 Outfall 1 1 122.88 175.25 Fontana 107.94 14L.1�' Pond, 1, & SWM2 0 Luxor Subdivision Index Index: Summary: Stormwater Management Pond #3 Pre -Development: Flood Hydrographs: - Post -Development: Flood Hydrographs: Outlet Structures: 10-11 Reservoir: 12 Routed Hydrographs: 13-14 Westminster Canterbury Pond, SWM #2 Pre -Development: Flood Hydrographs: 15-17 Post -Development: Flood Hydrographs: 18-22 Outlet Structures: 23-2`, Reservoir: 26-2' _ Routed Hydrographs: 28-29 Stormwater Management Pond #1 Pre -Development: Flood Hydrographs: 30-34 Post -Development: Flood Hydrographs: 35-42 Outlet Structures: 43-44 Reservoir: 45 Routed Hydrographs: 46-47 _ Uncontained Hydrographs: 48-50 Combined Hydrographs: 51-52 NOTE: DA Maps are part of the Luxor Stormwater Management Plans. Dominion Development Resources, LLC (434)984-1599 Page 2 Luxor Subdivision Summary Stormwater Management Facility #3 wil: ocov.de water quaii=y and volume - measures for portions of exis=ing 'Westminster Canterbury and Ashcrof, Subdi,.-___. currently handled by Stormwater Management Facility #2 and fu_ure residen'. ia: ,... commercial areas. The BMP measures for this rac_:iry wiLI consist ,f an 3:1-1 bench, forebays, and extended detention. Stormwater Manealement Facility 42 was originally designed to prr_vtde w.= and volume control measures for Westminster Canterbury and Fontana. Po': constructim, F3.ili-y #2 will or...i a.a ."—r - _r- ___ore -- _ for Luxor Phase -i2 and parts of '- . • '—- ... the routed flow from Facility 43 .._ -1 )�._r >i will be removed and a new emergency be Coanst-- .. 'or overland relief in a CatastrophicVevenr ..__._...; I-Mpa=tin, and proposed residential areas. The BMP measures for this facility forebays and extended detention. Stormwater Management Facility #1 will provide water quality and volume control measures for the North Pantops Commercial area, the Fontana Subdivision, and P....ees 2 s 3 of the Luxor Subdivision. The construction of Facility #1 and the road network for Luxor Subdivison will consist of the removal of the existing Fonta-r..- Pond currently serving portions of the Fontana Subdivison. The area current:•, flowing to the Fontana Pond will be redirected to Facility #1. The BMP measur for this facility will consist of forebays, an aquatic bench, and extended detention. Dominion Development Resources, LLC Page 3 (434)984-1599 Luxor Subdivision Stormwater Management Facility #3 Pre -Development Hydrograph Report Name: DA-3, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (9p) Time to Peak (Tp) Time of Base (Tb) Volume Time Step Flow Multiplier RATIONAL HYDROGRAPH INFORMATION Flow Multiplier Receding Limb Factor WEIGHTED WATERSHED AREA ---------------------------- Description Westminster (Undeveloped) Ashcroft Luxor Woods/Brush ---------------------------- Overall Approximation TIME CONCENTRATION -- User Defined Time of Concentration (Tc) RAINFALL DESCRIPTION Distribution Type Total Precipitation Return Period Storm Duration 26.71 (cfs) 11.00 (MIO 42.50 = 0.7R (ac-tci 1.00 ',min: 1.0c = 1.00 = 1.50 -------------------------------------- Area Runoff Coef --------------------------------------- 9 10 0.30 3.30 0.40 14.30 0.30 .-------------------------------------- 26.70 0.31 17.00 (min) Synthetic 0.90 (in) 2 (yr) = 0.28 (hr) Dominion Development Resources, LLC Page 4 (434) 984-1599 Luxor Subdivision Stormwater Management Facility #3 Pre -Development Hydrograph Report Name: DA-3, 10yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) - 37.38 (cfs) Time to Peak (To) _ _'. OJ 'm-n, Time of Base (Tb) = 42.50 'mini Volume 1.09 (er ft' Time Step 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier Receding Limb Factor WEIGHTED WATERSHED AREA ------------------------- Description ------------------------- Westminster (Undeveloped) Ashcroft Luxor Woods/Brush ------------------------- Overall Approximation TIME CONCENTRATION -- User Defined Time of Concentration (Tc) RAINFALL DESCRIPTION Distribution Type Total Precipitation Return Period Storm Duration 1.00 = 1.50 Area Runoff Coef --------------------------------------- 9.10 0.30 3.30 0.40 14.30 0.30 ----- --------------------------------- 26.70 0.31 - 17.00 (min) Synthetic = 1.26 (in) User Defined (yr) = 0.28 (hr) Dominion Development Resources, LLC (434)984-1599 Page 5 Luxor Subdivision Stormwater Management Facility #3 Pre -Development Hydrograph Report Name: DA-3, 100yr Type: Modified Rations! HYDROGRAPH INFORMATION Peak Flow (Qp) Time to Peak (Tp) Time of Base ITb) Volume Time Step Flow Multiplier RATIONAL HYDROGRAPH INFORMATION Flow Multiolier Receding Limb Factor WEIGHTED WATERSHED AREA ---------------------------- Description ---------------------------- Westminster (Undeveloped) Ashcroft Luxor Woods/Brush --------------------------- Overall Approximation TIME CONCENTRATION -- User Defined Time of Concentration (Tc) RAINFALL DESCRIPTION Distribution Type Total Precipitation Return Period Storm Duration = 53.73 (cfs) 17.00 lmia) 42.50 tmin) _.00 _.50 Area Runoff Coef -------------------------------------- 9.10 0.30 3.30 0.40 14.30 0.30 --------------------- ---------- 26.70 0.31 - 17.00 (min) Synthetic 1.81 (in) 100 (yr) 0.28 (hr) Dominion Development Resources, LLC Page 6 (434) 984-1599 Luxor Subdivision Stormwater Management Facility #3 Post -Development Hydrograph Report Name: DA-3, Post 2yr Type: Modified Rationa: HYDROGRAPH INFORMATION Peak Flow NO Time to Peak (Tp) Time of Base (Tb) Volume Time Step Flow Multiplier RATIONAL HYDROGRAPH INFORMATION Flow Multiplier Receding Limb Factor WEIGHTED WATERSHED AREA ----------------------------- Description ----------------------------. Pavilions -II Westminster Ashcroft Overall Approximation TIME CONCENTRATION -- User Defined Time of Concentration (Tc) RAINFALL DESCRIPTION Distribution Type Total Precipitation Return Period Storm Duration = 71. 47 (a£s) = 15.00 (min) (ac-ft) = 1.00 (min? = 1.00 = 1.50 ------------------------------- Aced ------------------------------. Runoff Coef 22.30 0.54 10.76 0.70 3.30 0.40 ---- 36.36 -------------------- 0.57 = 15.00 (min) Synthetic 0.85 (in) = 2 (yr) 0.25 (hr) Dominion Development Resources, LLC Page 7 (434)984-1599 Luxor Subdivision Stormwater Management Facility #3 Post -Development Hydrograph Report Name: DA-3, Post 10yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) Time to Peak (Tp) Time of Base (Tb) Volume Time Step Flow Multiplier RATIONAL HYDROGRAPH INFORMATION Flow Multiplier Receding Limb Factor WEIGHTED WATERSHED AREA ______________________.----- Description ---------------------------- Pavilions-II Westminster Ashcroft ---------------------------- Overall Approximation TIME CONCENTRATION -- User Defined Time of Concentration (Tc) RAINFALL DESCRIPTION Distribution Type Total Precipitation Return Period Storm Duration 99.41 Icfs) 15.00 (min) :7. 5,: = 2.57 ��._.. 1.50 --_---_---'---------- Area Runoff Coef 22.30 0.54 10.76 0.70 3.30 0.40 .______________________________________ 36.36 0.57 = 15.00 (min) = Synthetic = 1.18 (in) User Defined (yr) 0.25 (hr) Dominion Development Resources, LLC (434)984-1599 Page 8 Luxor Subdivision Stormwater Management Facility #3 Post -Development Hydrograph Report Name: DA-3, Post 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow Qp) Time to Peak (Tp) Time of Base (Tb) Volume Time Step Flow Multiplier RATIONAL HYDROGRAPH INFORMATION Flow Multiplier Receding Limb Factor WEIGHTED WATERSHED AREA ------------------------------------- Description Area ------------------------------------- Pavilions-II 22.30 Westminster 10.76 Ashcroft ------------------------------------- 3.30 Overall Approximation 36.36 142.43 Runoff Coef ----------------------------- 0.54 0.70 0.40 ----_-__-_-__ 0.57 TIME CONCENTRATION -- User Defined Time of Concentration (To) = 15.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.69 (in) Return Period = 100 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 9 (434)984-1599 Luxor Subdivision Stormwater Management Facility #3 Outlet Structure Report Type stand P_pc Name sw #3 Riser RATING CURVE LIMIT Minimum Elevation. 480.00 Maximum Elevation 496.00 Elevation Increment = 0.50 STAND PIPE=NFORMATION ORIFICE INFORMATION Diameter = 4.00 (tti Crest Length = 12.57 (ft) Effective Crest Length = 10.07 (ftl Orifice Coefficient = 0.60 Fractional Open Area = 0.83 OPTIONAL WEIR INFORMATION Type Rectangular Weir Suppressed WEIR INFORMATION Crest Length = 2.50 (ft) Crest Elevation = 492.00 (ft, Weir Coefficient = 3.33 - Exponential 1.50 . OPTIONAL ORIFICE INFORMATION Type Circular Orifice OPTIONAL ORIFICE INFORMATION Diameter = 1.00 (ft) Invert Elevation = 490.00 (ft) Orifice Coefficient = 0.60 Number of Openings = 2 Dominion Development Resources, LLC Page 10 (434) 984-1599 Luxor Subdivision Stormwater Management Facility #3 Outlet Structure Report CULVERT INFORMATION Type Circular Concrete - Square Edge with Hea.lwall OUTLET STRUCTURE 1NF'OPSSATION Diameter Invert Elevation Pipe Length S1ooe Manning's n Vaiue Orl`_1Ce Coefficient Tailwater Elevation Number of Barrels STAND PIPE STAGE VS. DISCHARGE = 36.00 45n.,� = 1 Elevation Stage weirs Orifices Stand Pipe Culvert Total_ (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 490.00 10.00 0.00 0.00 0.00 100.88 0.00 490.50 10.50 0.00 1.89 0.00 103.95 1.89 491.00 11.00 0.00 5.35 0.00 106.92 5.35 491.50 11.50 0.00 7.56 0.00 109.82 7.56 492.00 12.00 1.18 9.26 0.00 112.64 9.26 492.50 12.50 6.27 10.69 0.00 115.40 13.64 493.00 13.00 14.44 11.95 0.00 118.08 20.28 493.50 13.50 24.71 13.09 0.00 120.71 28.39 494.00 14.00 36.71 14.14 11.85 123.28 49.54 494.50 14.50 50.21 15.12 33.52 125.80 81.55 495.00 15.00 65.06 16.04 55.73 128.28 115.02 495.50 15.50 81.15 16.91 70.99 130.70 130.70 496.00 16.00 98,39 17.73 '19.37 133.08 133.08 Dominion Development Resources, LLC Page 11 (434)984-1599 Luxor Subdivision Stormwater Management Facility #3 Reservoir Report Reservoir Number: 3 Name: SW Facility #3 RATING CURVE LIMIT MLnimum Elevation 480.f- Maximum elevation 496.00 Elevation. :cerement - 53 �cora ^y:. Method: 'J szr-Cefir.ed C_2C 3e= Input Method: Area Number Elevation Area Ave Area Volume C-umulative :,,. u:o (ft) (sq ft) (sq ft) (cu ft) IC,-, fu 1 489.99 0.00 0.00 0.00 0.00 2 490.00 27952.00 13976.00 139.76 139.76 3 492.00 33606.00 30779.00 61558.00 61697.76 4 494.00 40817.00 37211.50 74423.00 136120.76 5 496.00 45510.00 43163.50 86327.00 222447.76 DISCHARGE INFORMATION Structure Number: 1 Type: Name: SWM #3 Riser RESERVOIR STAGE STORAGE/ DISCHARGE Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) y (cu ft) u (Cfs) 490.00®s= 10.00 27952.00 6988.00 0.00 490.50 10.50 29365.50 21317.37 1.89 491.00 11.00 30779.00 36353.50 5.35 491.50 11.50 32192.50 52096.37 7.56 492.00 12.00 33606.00 68546.00 9.26 492.50 12.50 35408.75 85799.69 13.64 493.00 13.00 37211.50 103954.75 20.28 493.50 13.50 39014.25 123011.19 28.39 494.00 14.00 40817.00 142969.00 49.54 494.50 14.50 41990.25 163670.81 8L.55 495.00 15.00 43163.50 184959.25 115.02 495.50 15.50 44336.75 206834.31 130.70 496.00 16.00 45510.00 229296.00 133.08 Maximum Storage 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) Dominion Development Resources, LLC Page 12 (434)984-1599 Name: Type: Luxor Subdivision Stormwater Management Facility #3 Routed Hydrograph Report S*0, 2yr Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) Time to Peak (Tp) _ Time of Base (Tb)(ailn:- Volume 1.69 (ate-Zr) Time Step = 1.00 (min) Peak Elevation = 492.03 (ft) RESERVOIR STRUCTURE INFORMATION Name SWM Facility 83 Storage Type User -Defined Area Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-3, Post 2yr Peak Flow (Qp) 71.47 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) 37.50 (min) Volume = 1.85 (ac-ft) Flow Multiplier = 1.00 Name: Type: SHH3, IOyr Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow ((p) w E Tire to Peak (Tp) _ { Time of Base (Tb) = 144U.O0 (min) Volume = 2.41 (ac-ft) Time Step 1.00 (min) Peak Elevation 492.74 (ft) RESERVOIR STRUCTURE INFORMATION Name - SWM Facility N3 Storage Type - User -Defined Area Maximum Storage - 229296.00 (cu ft) Maximum Discharge - 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name - DA-3, Post 10yr Peak Flow (Qp) - 99.41 (cfs) Time to Peak (Tp) 15.00 (min) Time of Base (Tb) - 37.50 (min) Volume = 2.57 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resew, LLC Page 13 (434)984-159e Luxor Subdivision Stormwater Management Facility #3 Routed Hydrograph Report Name: Stt43, 10Oyr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 34.50 (cfs) Time to Peak (Tp) = 32.00 min! Time of Base (Tb) = 1440.00 (m=n) Volume = 3.`__ _._-2t) Time Steo = !.:. _.-n) Peak Elevation = 493.64 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility 43 Storage Type = User -Defined Area Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-3, Post 100yr Peak Flow (Qp) = 142.43 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 3.68 (ac-ft) Flow Multiplier - 1.00 Dominion Development Resources, LLC Page 14 (434)984-1599 Hydrograph Report 15 HydraOow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd. No. 1 PostDev Luxor Hydrograph type = Mod. Rational Storm frequency = 2 yrs Time interval = 1 min Drainage area = 36.360 ac Intensity = 2.197 in/hr OF Curve = ALBEMARLE IDF.IDF Target Q =n/a Q (cfs) 50.00 40.00 30.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Storm duration Est. Req'd Storage PostDev Luxor Hyd. No. 1 -- 2 Year 0.00 r 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 Hyd No. 1 Monday, 12/12/2022 = 45.53 cfs = 0.25 hrs = 94,256 cuft = 0.57 = 15.00 min =n/a Q (cfs) 50.00 40.00 W1611A1 20.00 10.00 0.00 1 1 1 1 Time (hrs) Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3130 by Autodesk, Inc. v2023 Hyd. No. 1 PostDev Luxor Hydrograph type = Mod. Rational Storm frequency = 10 yrs Time interval = 1 min Drainage area = 36.360 ac Intensity = 2.953 in/hr OF Curve = ALBEMARLE IDF.IDF Target Q =n/a Q (Cfs) 70.00 50.00 ts� 30.00 20.00 10.00 Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Storm duration Est. Req'd Storage PostDev Luxor Hyd. No. 1 — 10 Year Monday, 12 112 / 2022 = 61.21 cfs = 0.25 hrs = 126,698 cult = 0.57 = 15.00 min = 2.3 x Tc =n/a Q (cfs) 70.00 50.00 40.00 30.00 20.00 0.00 ► I I I I I I I I I I I I I I I I I I I ' ' ' ' ' ` 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 Hyd No. 1 Time (hrs) Hydrograph Report 17 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd. No. 1 PostDev Luxor Hydrograph type = Mod. Rational Storm frequency = 100 yrs Time interval = 1 min Drainage area = 36.360 ac Intensity = 4.297 in/hr OF Curve = ALBEMARLE IDF.IDF Target Q =n/a Monday, 12 / 12 12022 Peak discharge = 89.06 cfs Time to peak = 0.25 hrs Hyd. volume = 168,326 cult Runoff coeff. = 0.57 Tc by User = 15.00 min Storm duration = ) i ,_ _ Est. Req'd Storage =n/a PostDev Luxor Q (Cfs) Hyd. No. 1 -- 100 Year Q Ids) 90.00 90.00 80.00 80.00 / F 70.00 70.00 60.00 60.00 50.00 50.00 40.00 40.00 30.00 30.00 20.00 20.00 10.00 10.00 000 V 000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 — Hyd No. 1 Time (hrs) Hydrograph Report 18 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd. No. 9 Pavilions #3 Amendment Hydrograph type = Reservoir Storm frequency = 2 yrs Time interval = 1 min Inflow hyd. No. = 1 - PostDev Luxor Reservoir name = Pond 3 Amend Storage Indication method used Q (cfs) 50.00 40.00 30.00 10.00 Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Pavilions #3 Amendment Hyd. No. 9 -- 2 Year Monday, 12 / 12 / 2022 = 9.237 cfs = 0.77 hrs = 92,812 cuft = 492.57 ft = 77,323 cuft 0.00 W 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 Hyd No. 9 — Hyd No. 1 1 I. 1 Total storage used = 77,323 cuft Q (cfs) 50.00 40.00 30.00 20.00 10.00 —1- 0.00 10.0 Time (hrs) Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3138 by Autodesk, Inc. v2023 Hyd. No. 9 Pavilions #3 Amendment Hydrograph type = Reservoir Storm frequency = 10 yrs Time interval = 1 min Inflow hyd. No. = 1 - PostDev Luxor Reservoir name = Pond 3 Amend Storage Indication method used. Q (cfs) 70.00 f.7a11n>. 40.00 30.00 20.00 10.00 0.00 -- —.= 0.0 1.0 Hyd No. 9 19 Monday, 12 112 / 2022 Peak discharge = 16.19 cfs Time to peak = 0.75 hrs Hyd. volume = 124,780 cuft Max. Elevation = 493.45 ft Max. Storage = 103,447 cuft Pavilions #3 Amendment Hyd. No. 9 -- 10 Year 2.0 3.0 4.0 Hyd No. 1 Q (cfs) 70.00 50.00 40.00 30.00 W401110>_ 10.00 0.00 5.0 6.0 7.0 8.0 9.0 Time (hrs) 1II Total storage used = 103,447 tuft 20 Hydrograph Report Hydraflow Hydrographs Extension for AutodeskO Civil 31DG by Autodesk, Inc. v2023 Monday. 12 112 / 2022 Hyd. No. 9 Pavilions #3 Amendment Hydrograph type = Reservoir Peak discharge = 46.57 cfs Storm frequency = 100 yrs Time to peak = 0.63 hrs Time interval = 1 min Hyd. volume = 165,570 cult Inflow hyd. No. = 1 - PostDev Luxor Max. Elevation = 494.15 ft Reservoir name = Pond 3 Amend Max. Storage = 125,081 cuft Storage Indication method used. Pavilions #3 Amendment Q (cfs) Hyd. No. 9 -- 100 Year Q (cfs) 90.00 90.00 80.00 80.00 70.00 70.00 60.00 60.00 50.00 50.00 40.00 40.00 30.00 20.00 30.00 10.00 20.00 000 10.00 000 0.0 1.0 Hyd No. 9 2.0 3.0 — Hyd No. 1 4.0 5.0 6.0 Total storage used = 125,081 cuft 7.0 Time (hrs) Pond Report 21 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. V2023 Monday, 12 / 12 12022 Pond No. 8 - Pond 3 Amend Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 489.43 ft Stage / Storage Table Stage (ft) Elevation (it) Contour area (sqft) Incr. Storage (cult) Total storage (cult) 0.00 489.43 20,355 0 0 0.57 490.00 21,282 11.865 11,865 2.57 492.00 27,300 48,452 60,317 4.57 494.00 32,468 59,687 120,004 6.57 496.00 36,827 69,242 189,247 Culvert / Orifice Structures Weir Structures [A] [e] [C] [PrFRSr] [A] IB] [C] [D] Rise (in) = 36.00 12.00 8.40 0.00 Crest Len (ft) = 12.57 2.50 0.00 0.00 Span (in) = 36.00 12.00 8.40 0.00 Crest El. (ft) = 493.53 492.70 0.00 0.00 No. Barrels = 1 1 1 0 Weir Coen. = 3.33 3.33 3.33 3.33 Invert El. (ft) = 480.00 489.43 489.43 0.00 Weir Type = 1 Rect - -- Length (ft) = 267.00 0.00 0.00 0.00 Multi -Stage = Yes Yes No No Slope 1%) = 8.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 E:fil.(in/hr) = 0.000 (by Contour) Multi Stage = n/a Yes Yes No TW Elev. (ft) = 0.00 Note: Cult' Ovfce wtnowa are analysed under inlet (c) and wem (m) wnVol. Wa, users Wb ed for onfim condelons (ic) and submergence Is). Stage (it) Stage / Discharge Elev (ft) 7.00 496.43 6.00 495.43 5.00 494.43 4.00 493.43 3.00 492.43 2.00 491.43 1.00 490.43 0.00 489.43 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0 130.0 Total Q Discharge (cfs)