Loading...
HomeMy WebLinkAboutWPO202200004 Correspondence 2022-02-07 (2)Crozet Square and Oak Street Improvements Proiect # 1217-002-R71 Hydraulic Design Report Albemarle County, Virginia January 27, 2021 Prepared by: Kimley-Horn & Associates, Inc. 1700 Willow Lawn Dr., Suite 200 Richmond, VA 23230 Owner: Albemarle County Michael R. Mitchell Uc. No. 058634 Kimley-Horn and Associates, Inc. Richmond,VA Kimley>>> Horn The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and adaptation by Kimley-Horn and Associates, Inc. shall be without liability to Kimley-Horn and Associates, Inc. The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 TABLE OF CONTENTS DRAINAGE NARRATIVE APPENDIX A: SITE INFORMATION USDA Soil Survey Maps & Data NOAA Precipitation Frequency Maps & Data APPENDIX B: DRAINAGE AREA MAPS Pre -Development Drainage Area Map (Quality) Pre -Development Drainage Area Map (Quantity) Post -Development Drainage Area Map (Quality) Post -Development Drainage Area Map (Quantity) APPENDIX C: WATER QUALITY Water Quality Compliance Summary Water Quality Compliance Calculations APPENDIX D: WATER QUANTITY Water Quantity Compliance Summary Energy Balance Summary Applicable Hydrographs APPENDIX E: STORM DRAINAGE SYSTEM COMPUTATIONS Storm Sewer and Hydraulic Grade Line Computations Curb Inlet Spread and Throat Length Computation The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 ICY Y 311111�71 Y [I]i;l Project Description This report has been prepared for the Albemarle County Facilities Planning and Construction Department in support of The Square and Oak Street Parking and Roadway Improvements project in Albemarle County, Virginia. It is assumed that the design for the improvements will be in general conformance to that proposed within the Neighborhood Improvements Funding Initiative (NIFI) Design Consultant Study for The Square and Oak Street dated October 2017 prepared by Kimley-Horn under a separate contract. Following two milestone plan submissions, design consideration conversations held with Albemarle County and the Virginia Department of Transportation (VDOT) have necessitated design changes not anticipated during the initial study. The proposed improvements total approximately 610 linear feet and involve improvements to The Square (entire length) and Oak Street (between Library Avenue and The Square). Overall, the improvements will consist of the design of curb & gutter, full depth pavement, storm sewer, pavement markings, signs, and maintenance of traffic. Most construction is anticipated to occur within existing right of way, Albemarle County property, and/or the Barnes Lumber property limits. It is expected that temporary construction easements will be required throughout the project limits. Improvements along The Square total 300 linear feet and will consist of a 8' concrete sidewalk along existing businesses on The Square, perpendicular parking on both sides of the roadway, and channelizing island at the Crozet Avenue intersection. The channelizing island will make access to The Square from Crozet Avenue a Right -In Right -Out (RIRO) intersection by restricting left turns from both the westbound The Square to southbound Crozet Avenue movement and the southbound Crozet Avenue to eastbound The Square movement. The existing traffic signal will be modified to accommodate this intersection modification. Improvements along Oak Street total 310 linear feet and will consist of a 5' concrete sidewalk along the western side of the roadway, reconstruction of the alley entrance perpendicular to Oak Street, and perpendicular parking along the eastern side of the roadway with ADA accessible parking areas and curb ramps. The Square (Route 1217) is an urban local street running for approximately 300 linear feet northwest to southeast from Crozet Avenue (Route 240) before terminating at a parking area on the Barnes Lumber property. Ultimately, this terminus will become the unsignalized intersection of The Square & Oak Street. The intersection of The Square & Crozet Avenue is currently controlled by a traffic signal. The Square is an undivided facility with one unmarked lane in each direction with perpendicular parking on each side. The existing parking along the south side is an asphalt surface with marked parking stalls while the north side parking is a mix of gravel and asphalt with no stall markings. The parking along The Square serves businesses on the south side of the roadway and throughout downtown Crozet. A two-way public alley that runs north -south through downtown Crozet can be accessed from south side of The Square. The property north of The Square is owned by CSX Transportation Inc. (CSX). The railroad tracks on the CSX property are accessed from The Square and are currently operated by Buckingham Branch Railroad. The Square currently has no posted speed limit. The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 Oak Street is a paper street not currently dedicated to public use within the Barnes Lumber property running approximately 400 linear feet southwest to northeast from Library Avenue to The Square. While this stretch of roadway is currently not dedicated to public use, Oak Street is frequently used by motorists to circulate downtown Crozet. Oak Street within the project limits is an undivided facility with one unmarked lane in each direction. Oak Street was recently improved between Library Avenue and approximately 150 linear feet north of Library Avenue. These improvements include an entrance to the Piedmont Place development, curb & gutter, closed drainage system, and concrete sidewalks. Project Area Kimley-Horn conducted its analysis for SWM requirements using guidance from VDOT Instructional and Informational Memorandum (I&IM) IIM-LD-195.12, dated July 2019, which details new requirements for Erosion and Sediment Control and Stormwater Management Plans. Per Scenario 3 of this I&IM, full depth reconstruction of pavement within the exiting pavement footprint that maintains the original purpose of construction is considered disturbed area for E&S purposes, but not for SWM purposes. The applicable project site area ("A -Site") that is likely to be disturbed during construction and is not considered maintenance per Scenario 3 of the aforementioned I&IM, is approximately 0.47 acres. This area is used for SWM Quality calculations. The applicable project site ("A -Site") that is likely to be disturbed during construction and where contributing drainage areas are changing due to the proposed roadway and storm sewer design, is approximately 2.07 acres. This area is used for SWM Quantity calculations. See Appendix B for more information. ExistingDrainage rainage Conditions In the existing condition, all the stormwater runoff within the project limits is ultimately captured by drop inlets and conveyed to one of three outfalls. These outfalls are located within the Mechums River — Beaver Creek watershed (HUC 12/VAHU6 = 020802040102/JR02). • Outfall A o This outfall is an existing manmade drainage inlet located at the southeast quadrant of the intersection of Crozet Avenue and Three Notched Road/Railroad Avenue. The inlet discharges into a manmade closed storm sewer network and continues north. o In the existing condition, this outfall collects stormwater runoff from a portion of the CSX rail yard perpendicular to Crozet Avenue, The Square's parking stalls and roadway, and the right side of the roadway of Crozet Avenue crown line. • Outfall B o This outfall is an existing manmade grate inlet located approximately 185' south of the intersection of The Square and The Alley (as referred to on the construction plans). The inlet discharges into a manmade closed storm sewer network and continues south where it combines with Outfall C along the south side of Library The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 Avenue. The drainage trunk line collects additional runoff from Crozet Avenue, and a series of developed parcels adjacent to Crozet Avenue and Library Avenue that ultimately discharges into a manmade channel adjacent to Jarmans Gap Road. In the existing condition, this outfall collects stormwater runoff from a portion of the CSX rail yard, The Square's parking stalls and roadway, The Alley's entire roadway width, and roof drain systems associated with the buildings adjacent to The Square (Mudhouse, Stevens & Company Realtors, Crozet Hardware, and New China). • Outfall C o This outfall is an existing manmade drop inlet located approximately 150' north of the intersection of Oak Street and Library Avenue. The inlet discharges into a manmade closed storm sewer network and continues south where it combines with Outfall B along the south side of Library Avenue. The drainage trunk line collects additional runoff from Crozet Avenue, and a series of developed parcels adjacent to Crozet Avenue and Library Avenue that ultimately discharges into a manmade channel adjacent to Jarmans Gap Road. o In the existing condition, this outfall collects stormwater runoff from a portion of PROPOSED DRAINAGE IMPROVEMENTS Overview In the post -development condition, all stormwater runoff will continue to be captured by drop inlets and conveyed to one of three outfalls. The proposed drainage improvements are as follows: • Outfall A o Proposed sidewalk, curb returns, and curb and gutter combination improvements will be installed along The Square and at the intersection of Crozet Avenue and The Square for the conveyance of stormwater runoff into proposed drop inlets. o In conjunction with the aforementioned site improvements, the reconstruction of The Square will result in regrading of the existing topography effectively diverting runoff from the existing drop inlet (Outfall A) to Structure 3-1 in the post -development condition. The drop inlet (Structure 3-1) will be installed at the termini of the curb return from Crozet Avenue onto The Square and ultimately connected to the proposed closed storm sewer network. This proposed network will connect a series of proposed drop inlets until reaching the termini of the proposed storm sewer improvements at Structure 3-8 (effectively Outfall C). At this point, Structure 3-8 will tie to the existing storm sewer trunk line that outfalls at the manmade channel adjacent to Jarmans Gap Road. o The existing drop inlet located at the intersection of Crozet Avenue and Three Notched Road/Railroad Avenue will remain in place and unaltered in the post - developed (See Water Quantity Section — Outfall A for further justification). • Outfall B The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 The proposed improvements outlined above for Outfall A have an alike effect on Outfall B in the post -development condition. The proposed grading of The Square will divert the pre -developed runoff from the existing grate inlet in The Alley towards the proposed drop inlets along The Square in the post -development condition. The proposed drainage improvements will introduce two additional drop inlets (Structure 3-2 and 3-3) within this outfall that will capture runoff and convey it to the proposed storm sewer network that will connect to the existing storm sewer trunk line and ultimately outfall at the channel near adjacent to Jarmans Gap Road. • Outfall C o Proposed sidewalk, curb returns, and curb and gutter combinations improvements will be installed along The Square and Oak Street for the conveyance of stormwater runoff into proposed drop inlets. o The proposed drainage improvements will capture runoff via drop inlets from The Square and Oak Street and convey it to the proposed storm sewer network until it reaches the existing storm sewer trunk line approximately 150' north of the intersection of Library Avenue and Oak Street. o Some additional off -site runoff will contribute to Outfall C through the redevelopment of parcel TMP 56A2-01-71 in the post -development condition. o The regrading of The Square, the revised Oak Street roadway profile, the proposed drainage improvements, and the regrading of the Barnes Lumber parcel adjacent to Oak Street (UPC 113385) will all have an influence on the land cover and drainage area of Outfall C in the post -development condition (See Appendix B for the Water Quantity drainage maps depicting this scenario). Methodology All drainage calculations follow the standards and procedures in the VDOT Drainage Manual. Inlet, storm sewer, and hydraulic grade line calculations were performed using the Rational method. Curb inlet calculations were done under a design stone intensity of 4 inches/hour using Flowmaster. Storm sewer and hydraulic grade line calculations were done under a 10-year design stone. Storm sewer calculations were performed using StormCAD. HGL calculations were performed with VDOT methodology via the data output from StormCAD. The preceding calculations are presented in Appendix E. Times of concentration for overland flow were calculated using the Seelye method. Times of concentration for shallow concentrated flow were calculated using the TR-55 method. Times of concentration for off -site storm sewer were calculated manually, assuming an average velocity of 6 ft/s. Water Quantity compliance calculations were performed using the NRCS Method. Hydraflow Hydrographs Extension software was used to model overall outfall locations (see Appendix D). The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 Design Parameters Design Storms: 1-Year; 2-Year; 10-Year Manning's n-Values: Use n-Value Concrete Pipes 0.013 Pavement/Gutter Flow 0.015 CN Values(NRCS Method): Land Cover A -Soils B-Soils C-Soils D-Soils Forest/Open Space 30 55 70 77 Managed Turf 39 61 74 80 Impervious 98 98 98 98 24-Hour Precipitation Depth [Inches7 (MRCS Method): ]-Year 2-Year 10-Year 3.07 3.71 5.58 Source: NOAA (https://hdsc.nws.noaa.pov/hdsc/pfds/pfds map cont.html?bkmrk=va) C-Values (Rational Method): Inwervious Managed Tuff Forest/ Open S ace 0.9 0.5 0.3 B, D, and E Factors Rational Methods . Return Period B D E 2-Year 49.020 10.500 0.820 10-Year 46.950 9.500 0.730 Source: GEOPAK Drainage Library — Rainfall Data for Albemarle County Minimum Storm Pipe Size: 15" Minimum Proposed Pipe Slope: 0.30% WATER QUANTITY COMPLIANCE This project must comply with part RB of the VSMP regulations, which stipulates post - development stormwater runoff must meet Channel Protection criteria and Flood Control criteria. These criteria are addressed at each outfall as follows: • Outfall A is an existing manmade drop inlet. Due to proposed drainage improvements and the proposed grading of The Square, this outfall achieves water quantity compliance via a reduction of the drainage area and through the betterment of the "A -Site" land cover. The overall drainage area reduces from 0.11 acres in the pre -development The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 condition to 0.04 acres in the post -development condition. The 1-year Q for the post - development runoff from the project site at Outfall A is 0.10 cfs, which is less than the 1.67 cfs maximum allowed by the result of the Energy Balance formula using an Improvement Factor of 0.8. Therefore, this outfall meets Channel Protection criteria. The overall 10-year Q in the post -development condition at Outfall A is 3.21 cfs, which is less than the 3.84 cfs in the pre -development condition. Therefore, this outfall meets Flood Protection criteria. These calculations are included in Appendix D. Outfall B is an existing manmade grate inlet. Due to proposed drainage improvements and the proposed grading of The Square, this outfall achieves water quantity compliance via a reduction of the drainage area and through the betterment of the "A -Site" land cover. The overall drainage area reduces from 0.61 acres in the pre -development condition to 0.07 acres in the post -development condition. The 1-year Q for the post - development runoff from the project site at Outfall A is 0.28 cfs, which is less than the 24.00 cfs maximum allowed by the result of the Energy Balance formula using an Improvement Factor of 0.8. Therefore, this outfall meets Channel Protection criteria. The overall 10-year Q in the post -development condition at Outfall B is 3.28 cfs, which is less than the 7.59 cfs in the pre -development condition. Therefore, this outfall meets Flood Protection criteria. These calculations are included in Appendix D. Outfall C is an existing manmade drop inlet. Due to proposed drainage improvements and the proposed grading of The Square, this outfall achieves water quantity compliance via a reduction of the drainage area and through the betterment of the "A -Site" land cover. The largest influence on Outfall C achieving water quantity compliance in the post development condition is the concurrent project adjacent to Oak Street (UPC 113385). Per the By -Others improvement project, approximately 1.11 acres of Outfall C will be diverted from its original outfall location in the pre -development condition to a series of drop inlets that ultimately connect to a closed storm sewer trunk line running southeast towards Hill Top Road. The proposed grading By -Others of the adjacent parcel (TMP 56A2-01-71) to Oak Street will also establish a new highpoint that will split Outfall C's watershed in the post -development condition effectively removing more runoff in the post -development condition. Thus, the site analysis has taking into consideration the change in the drainage pattern from the improvements associates with these two concurrent projects. The overall drainage area reduces from 1.34 acres in the pre - development condition to 0.85 acres in the post -development condition. The 1-year Q for the post -development runoff from the project site at Outfall C is 3.46 cfs, which is less than the 9.81 cfs maximum allowed by the result of the Energy Balance formula using an Improvement Factor of 0.9. Therefore, this outfall meets Channel Protection criteria. The overall 10-year Q in the post -development condition at Outfall A is 13.40 cfs, which is less than the 16.66 cfs in the pre -development condition. Therefore, this outfall meets Flood Protection criteria. These calculations are included in Appendix D. Summary water quantity tables and calculations are presented in Appendix D. The Square and Oak Street Improvements State Project # 1217-002-R71 UPC 113188 WATER QUALITY COMPLIANCE This project was analyzed under the guidance from VDOT Instructional and Informational Memorandum (I&IM) IIM-LD-195.12, dated July 2019 (See Project Area on page 5 of this report for further discussion). Thus, the total disturbed "A -Site" area used for SWM water quality analysis in confined to the limits outlined in Scenario 3 of the I&IM. The improvements associated with this project reduces the total phosphorus load for the "A -Site" by 0.09 LB/YR through the construction of pervious area in a project site area overwhelmingly dominated by impervious area. Therefore, this project satisfies Water Quality Criteria. The following table summarizes the pre -development and post -development site conditions and phosphorus loading conditions. Additional water quality calculations are included in Appendix C. "A -SITE" MANAGED FORESTED ADJUSTED IMPERVIOUS Total Load Reduction SCENARIO [AREA] TURF AREA AREA PLOAD -0.09 AREA (AC.) Required (lb/yr) (AC.) (AC.) (AC.) (LB/YR) PRE- Total Load Reduction DEVELOPMENT 0.47 0.44 0.03 0.00 0.64 Provided by BMPs (lb/yr) 0.00 POST- Remaining TIP Credits to be DEVELOPMENT 0.47 0.26 0.21 0.00 1.63 Purchased (lb/yr) -0.09 10 APPENDIX A 0 38° 419'N W 358'N ]01300 MAD M500 3 Map Sale: 1:3,100 ff printed on B landsape (17' x 11") sheet Meters N 0 45 90 18D 270 A0 150 30D E00 9m Map p tjedian: N@b MwzbDr Com cwr inks: VJCS84 Edge tics: U1M Zane 17N VJG584 LISDA Natural Resources Conservation Service Hydrologic Soil Group —Albemarle County, Virginia (Report) Web Soil Survey National Cooperative Soil Survey S W4car N y W 3%N 3 A 1 /27/2021 Page 1 of 4 MAPLEGEND Area of Interest (A01) F7 Area of Interest (A01) Soils Soil Rating Polygons 0 A Q A/D e . B/D o C ® C/D ® D Not rated or not available Soil Rating Lines A i A/D Y B ry B/D aV C .con C/D N D . n Not rated or not available Soil Rating Points ■ A ■ A/D ■ B ■ B/D Hydrologic Soil Group —Albemarle County, Virginia (Report) MAP INFORMATION C The soil surveys that comprise your AOI were mapped at 1:15,800. 13 C/D 0 D Warning: Soil Map may not be valid at this scale. p Not rated or not available Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil Water Features line placement. The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed scale. Transportation f..fy Rails Please rely on the bar scale on each map sheet for map �y Interstate Highways measurements. US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Major Roads Coordinate System: Web Mercator (EPSG:3857) Local Roads Maps from the Web Soil Survey are based on the Web Mercator Background projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the . Aerial Photography Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Albemarle County, Virginia Survey Area Data: Version 14, Jun 3, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 20, 2019—Aug 1, 2019 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. USDk Natural Resources Web Soil Survey 1/27/2021 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group —Albemarle County, Virginia Report Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 5B Belvoir loam, 2 to 7 D 1.9 2.3% percent slopes 7B Braddock loam, 2 to 7 B 32.8 39.3% percent slopes 8C3 Braddock Gay loam, 7 to B 11.6 14.0% 15 percent slopes, severely eroded 36C Hayesville loam, 7 to 15 B 6.5 7.8% percent slopes 81 B Thurmont loam, 2 to 7 B 3.5 4.2% percent slopes 88 Udorthents, loamy, 2 to 27.0 32.4% 25 percent slopes Totals for Area of Interest 83.4 100.0% i ti)� Natural Resources Web Soil Survey 1/27/2021 M1111111111 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Albemarle County, Virginia Report Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff., None Specified Tie -break Rule: Higher OSDA Natural Resources Web Soil Survey 1/27/2021 Conservation Service National Cooperative Soil Survey Page 4 of 4 Precipitation Frequency Data Server Page 1 of 4 NOAA Atlas 14, Volume 2, Version 3 Location name: Crozet, Virginia, USA" �,t� Latitude: 38.0692°, Longitude:-78.6999° Elevation: 723.7 ft"" i & 'source: ESRI Maps " source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonin, D. Martin, B. Lin, T. Parzybok, M.Yekra, 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)' Average recurrence interval (years) Duration�0� 10 25 50 101 200 500 1000 5-min 0.338 (0.308-0.374) 0.404 (0.366-0.447) 0.477 (0.431-0.527) 0.538 0.485-0.594) 0.608 (0.545-0.669) 0.661 0.590-0.729) 0.713 (0.632-0.787) 0.762 (0.669-0.842) 0.820 (0.712-0.912) 0.868 (0.746-0.970) 10-min 0.539 (0.488-0.597) 0.646 (0.585-0.715) 0.764 (0.691-0.844) 0.860 0.776-0.949) 0.968 (0.869-1.07) 1.05 ) (0.940-1.18 ( 1.13 ) 1.00-1.25 ( 1.21 ) 1.06-1.34 ( 1.30 ) 1.13-1.44 ( 1.37 ) 1.17-1.53 15-min 0.674 (0.610-0.746) 0.812 (0.736-0.899 0.966 (0.874-1.07) 1.09 (0.982-1.20) 1.23 (1.10-1.35) 1.33 (1.19-1.47) 1.43 (1.27-1.58) 1.52 (1.34-1.68) 1.63 (1.42-1.82) 1.72 (1.47-1.92) 30-min 0.924 (0.836-1.02) F 12 (1.02-1.24) 7137 (1.24-1.52) 1.58 (1.42-1.74) F 1.82 (1.63-2.00) 7201 (7.79-2.21) 2.19 (1.942A2) 7237 (2.08-2.62) 2.60 (2.26-2.89) 2.78 (2.39-3.11) 60-min 1.15 (7 .041.27) 1.41 1 (1.27-1.56) 1.76 (1.59-1.94) 2.05 1 (1.85-2.27) 2A2 1 (2.17-2.67) 2.72 (2.433.00) 3.02 1 (2.68-3.33) 11 3.33 (2.92-3.68) 3.73 1 (3.244.14) 4.06 4 (3.48.53) 2-hr 1.38 (1231.55) 1.68 (1.50-1.88) 2.11 (1.88-2.36) 2.48 (2.21-2.77) 2.96 (2.62-3.30) 3.35 (2.953.75) 3.76 (3.294.21) 4.19 ) (3.634.69 ( 4.78 4.09-5.3 ( 5.28 ) 4.465.96 3-hr 1.35-1'71 1.64-2408 2652.67 2.40-3.05 2.8 3364 . 24874 3.604.66 3: 8-521 44 8-5.98 4.9D-6.64 6-hr 1.96 (1.75-2.20) 2.37 1 (2.12-2.67) 11 2.95 (2.62-3.31) 3.47 1 (3.073.90) 4.17 1 (3.674.68) 11 4.78 (4.17-5.37) 5.43 1 (4.69-6.10) 11 6.137.13 (5.23-6.90) (5.98-8.06) 8.011 (6.62-9.10) 12_hr 2.49 (2.2-2.83) 3.00 (2.68-3.41) 11 3.75 (3.324.26) a43 (3.91-5.03) 5.39 1 (4.72-6.11) 11 6.25 (5.40-7.08) 7.18 1 (6.138.14) 11 8.21 (6.90-9.32) 9.74 1 (8.00-11.1) 11.1 1 (8.97-12.7) 2Fi7.90 4-hr 3.07 (2.76-3.43) 3.71 (3.344.15) 4.73 (4.245.29) 5.58 (4.W6.23) 6.83 (6.06-7.60) (6.96-8.78) 9.08 (7.9310.1) 4 10. (8.96-11.5) 12.3 ( 10.5-13. ( 10.0 ) 11.7-15.6 2day 32 64.03 3: 54.88 5605.79 5.84725 .048.79 8.02-070.1 9.08-13.5 10.2- 3.0 11.73- 5.3 13.0-17.3 3day 2.1 16.3 34 94.27 4. 3567 5: 55.55 62 6-7 67 .54 929 869- 0.6 9: 0- 1 9� 3.7 12.6- 6.1 13.9-18.1 4-day 4.08 (3.734.51) 4.94 (4.51-5.45) 6.26 (5.715.91) 7.34 (6.67-8.08) 8.89 (8.04-9.79) 10.2 (9.16-11.2) 11.6 ( 10.3-12.8) 11 13.1 ( 11.6-14.4) 15.3 ( 13.4-16.9) 17.2 ( 14$19.0) 7day C74 (4 .345.18) F 5.71 1 (5.23-6.24) 11 F 7.13 (6.53-7s0) 8.29F 1 (7.57-9.06) 9.94 1 (9.03-10.9) 11 F 1.3 (10.2-12.4) 12.8 (11.4-14.0) 11 14.3 (12.7-15.7) 16.6 (14.6-18.2) 18.4 1 (16.0-20.3) 10-tlay 4.966884 5: 5-7..00 7. 2 &63 8.41 9.93 (9.91-- 1.7 11'? 3.2 12314.8) 136516.4 75'3 8.8 0-1 16.17- 0.8 20-day 669-7..59 7.879?04 9.4 - 0.9) (10.7- 2A 12.414.3 13] 5.9) 15.0-17.5 16.3- 9.1 18.0-21.4 19.3-3.2 30-day 8.66 (8.739.25) 10.3 1 (9.6411.0) 11 12.1 (11.4-12.9) 13.5 (12.7-14.5) 15.4 (14A-16.4) 11 16.8 (15.6-17.9) 18.2 1 (16.479A) 11 19.5 (18.0-20.9) 21.3 (19.6-2.8) 22.6 1 (20.7-24.3) 45-day 10.8 (102-11.5) 12.8F (12.0-13.6) 14.9 (14.0-15.8) 16.5 (15.5-17.5) 18.57200. (17.4-19.7) (18.8-21.3) 21.5 (0.1-22.8) 11 22.9 (21.3-24.4) 24.7 ( 2.9-26.4) 26.0 (24.0-27.9) 60-day 22.7 (120-13.4) 14.9 (14.1-15.8) 17.2 (16.2-18.1) 18.8 (176-19.9) 21.0 1 (19.8-22.1) 22.5 (21.2-23.8) 24.0 (2.5-25.4) 25.4 (23.8-26.9) 27.2 (25.4-28.8) 28.5 1 (26.5-30.2) 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 (far a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atias 14 document for more information. Back to Too https://hdsc.nws.noaa. gov/hdsc/pfds/pfds_printpage.html?lat=38.0692&lon=-78.6999&dat... 1 /25/2021 Precipitation Frequency Data Server Page 2 of 4 PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 38.0692', Longitude:-78.6999" 30 25......... .:......:.....:.....:...:... c_ t 20...... ........... :.....:.....:...:.....:.......... 6 W a e 15....: ...:.....:.....:.....:...:................ a a 0 E E E E E Lir fi a vv v i v c av at .�i A �i �$ N 'i y ^� N A d n o C5 �i a Duration Eel 2 c L 2 5 10 25 50 100 200 Sao 101 Average recurrence interval (years) NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Mon Jan 25 18:57:18 2021 Back to Too Average recurrence interval (years) - 1 2 5 10 25 50 100 200 500 1000 Duration — 5-min — 2-day — 10mm — 3-day - 15+nm — 4-day — 30min — 7-day — 60-min — 10day — 2-hr — 20-day — 3-hr — 30-day — 6-0r — 45Aay — 12dr — 60day — 24-hr https://hdsc.nws.noaa. gov/hdsc/pfds/pfds_3rintpage.html?lat=38.0692&lon=-78.6999&dat... 1/25/2021 Precipitation Frequency Data Server Page 3 of 4 Maps & aerials z kI 1'three Notcney Rp v Crozat��—'" Ro4fish Ga Tke + ` It UM RM; mi — Large scale terrain Washington, D.C.' Harrisonburg. S taunlpn ' VIRGINIA NIA • Rind [Mury A, lack sburg Rom I 60mi e� sr _. Large scale map Washington H irri sonb uu) -: t o II It'll I \'ll •Ill il� j' LYnchburg Blacksburg' ,� wnoke 100km 0 M https://hdsc.nws.noaa. govlhdsc/pfds/pfds_printpage.html?lat=38, 0692&lon=-78.6999&dat... 1 /25/2021 Precipitation Frequency Data Server Page 4 of 4 Back to Too US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HOSC.Questions(dnoaa.pov Disclaimer https://hdsc.nws.noaa. govlhdsc/pfds/pfds_printpage.html?lat=38.0692&lon=-78.6999&dat... 1 /25/2021 APPENDIX B EVEN'I. .� �' I�� �I.��h - II��[`�I -�D�I �'l:I (�)1"��� A'I� t((�)� .• I II'I "> LEGEND PROJECT AREA (A-STE') PRE -DEVELOPMENT OVERALL DRAINAGE AREA PRE -DEVELOPMENT 'A -SITE' (OUALITY) IMPERVIOUS LAND COVER �1 0l'.�l'' - �""I II:�'1:1.(�)I''�II;'V"1� �(�)�.� "[�II"il'Y) LEGEND PROJECT AREA (A-STE' - QUANTITY) PRE -DEVELOPMENT OVERALL DRAINAGE AREA PRE -DEVELOPMENT 'A -SITE' (QUANTITY) IMPERVIOUS LAND COVER DRAINAGE AREA A MAP - POST -DEVELOPMENT 1 O1''M1 VT (GUA 1.,11TY) LEGEND PROJECT AREA (A -SITE) POST -DEVELOPMENT OVERALL DRAINAGE AREA PRE -DEVELOPMENT 'A -SITE' (OURYTY) IMPERVIOUS LAND COVER QI''�11:'V'11` LEGEND PROJECT AREA ('A -SITE' - OUANT/TY) POST -DEVELOPMENT OVERALL DRAINAGE AREA PRE -DEVELOPMENT 'A -SITE' (QUANTITY) IMPERVIOUS LAND COVER APPENDIX C Virginia Runag Reduction Method! Wonsheet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet -Version 3.0 BMP Design Specifications List: 2013 Draft Stds & Specs Site Summary - Linear Development Project*** Total Rainfall (in): 43 Total Disturbed Acreage: 0.47 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) Asoils BSolls CSolis DSoils Totals %of Total Forest/Open(acres) O.o0 0.00 0.00 0.00 0.00 0 Managed Turf (acres) I O.o0 0.00 0.00 0.03 0.03 6 Impervious Cover (acres) IO.o0 0.00 0.00 0.44 0.44 94 0.47 100 Post-ReDevelopment Land Cover (acres) Asoils BSol is CSuils DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 1 0.00 0.00 0.21 0.21 45 Impervious cover (acres) 0.00 0.00 0.00 0.26 0.26 55 0.47 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post- Post- AdjustedPre- (&NeieDevelapment ReDevelopment Development ReDevelopment &New lm ervlous p ) (New Impervious) Site Rv 0.64 0.64 - 0.91 Treatment Volume(fts) 1,087 1,087 - 1,545 TP Load (lb/yr) 0.68 0.69 - 0.97 Total TP Load Reduction Required (lb/yr) -0.09 N/A*** N/A*** ***This is a linear developmentproject Final Post -Development Load (Post-ReDevelopment&New Impervious) Pre- ReDevelopment TN Load (lb/yr) 4.89 6.94 Pre ReDevelopment Final Post -Development Post-ReDevelopment TP TP Load per acre TP Load per acre toad per acre (lb/acre/yr) (lb/acre/yr) Ib acrer 2.06 1.45 1.45 Sura nary Print om otranla Funofferama on MetMe Be,acearkdment Cwnplbnre somaNMet - Version so O Nnr mile 5uMWa-a sreanorMna OO 201a mam BMP asmarda rot seetlMnem Pmle The sm..Zoak enemlmprmre ul° xlh ]/26/2021 Linear Development Project, Y¢ Site Information Post -Development Project (Treatment Volume and Loads) Enter Total Oisturbel Area (acres) i flrM: a MP OH Spe f t seduareaftedid.asionce IND Landon PWect, 0 LmremPermemenxrm.r.:nry, y y TnmleMwbetl men e.aeer 1P IORo RFgKipN No! PEQI/M® Pre-keoeveloPment Land Cover larnxl wb oADD wm/ge.sr=a lazraal-� r,�4 -iorri &mr µa­mm� are Am ar DID np Par"Dewlopmmm land Cnvm )arm) AWN DWI, cema DWI, wm/ge. sere yeml- murr4 ADD ac�an.aboeal-4iammea ®�m� ro.a.la�l 6xa NMI, i de.R Oe. on .a. PmmNC .n. M .nalla a as AWN I. C I.-eas—Mral 1. -Ism. a. a. wlgmpwnelnlnc D'an rrmaiiun Dss D. 0.n —liarrearrialtairLTDAI iL err-- AID der 0.x Imallya=aMl LAND COVER SUMMARY PRE REDEVELOPMENT r avn um ran-xeoe,.mvmam Par.oe.enemem ne.lmvarvm weaVora•sP=� aon �exWa� un ws eea.n r a11 meroe:lm dYe�wes a.wnl .11 am T.,I Psz azs "e ce^"P1S °" aao �elaaes a .Imla�l emsummmv»e vaar([mnl rrc.mm.aya waynpa.sPara...l=�e=1 om veVOPar to ern•Purl Oro vrtCtlmeHramy ear as 7 as en�e�TrTrmlarrl am na.¢ew ens"We"a,erl n�tnmtle.u.m nu vwa aTw eemndfTn .s are-sar„ero-wa o.m oaa wee--ca,.er 0-4 "'aYe—,vWr.. am mywel �..ea a.m1 a GA, ae. AD Volume and Nutrient Load Mnwrv+alDID al-) m�PrrD :.r .ry ..elaaal ams nw--a-B. Trndtment Volume and NUWanI Load Tralment aeeoeaevP'a�a erexvw.m and, mad a on. rt ao ako.W aa. mre m m� nm v. - aya vmeem a va laoe.p Iaa.W aaer�.rPo.mTaam.�avamm` e'ebmem nk•nraanl +lemwlwmem yn.,em k.u=aerl Lzas Isas aria w r,nr T Te a I,rm k•ealmeie .. T tLeala knl Nor Famil Te rrwau/nP mmRVB�mmRW coneconeconW pm 1 o.69 me P I®elnl _ u® we near)rib R ce= ena^ abMlmn rma-liareer m rva naamea=ma,,.mr.P...re IanWn :na ,� ®a OeMl am ecru. gxee IouwreNnaPaieumprc,me.emmemaeaunuunamra do Wial_ ma a�saoraasm,ae...Pe,.iammal .�r.earan Inde maa. ,er�ru - wvrlMam/¢mm=n A- as.yeryrareaaarm�apaew.era.n. meae dam -0.a9 narriaew 0 rvemrca Prlle/Yrl Inn.l ngmc0.mmla�urmmnememememm.ePnmma.eae (..am axve gaewnmr.ammal ..nmryae.mrre..mmm(M.eeo. �..xpem me.v,. L o m xym./ae�.l Post -Development Requirement for Site Area TP Loatl keduttlon 0.epulredllb/Vr d.09 NNroaa Loads (Informational Purposes Only) nm-m.eLvaeam Pmmm,Maemmmrmdnsml aw mm+meremmemaraalaP�..rl a.. IbVI APPENDIX D SWIM QUANTITY SUMMARY SCS PRE -DEVELOPMENT Outfall Area (acres) CN Tc (minutes) 2-yr Q (cfs) I 10-yr Q (cfs) A 0.51 96.6 5 2.52 3.84 B 1.00 98.0 5 5.02 7.59 C 2.20 97.5 5 POST -DEVELOPMENT 10.99 16.66 Outfall Area (acres) CN Tc (minutes) 2-yr Q (cfs) 10-yr Q (cfs) A 0.43 95.5 5 2.09 3.21 B 0.44 95.3 5 2.13 3.28 C 1.79 95.9 5 8.79 13.40 ENERGY BALANCE SUMMARY SCS PRE -DEVELOPMENT Outfall Area (acres) CN Tc (minutes) (ac-ft) Runoff Volume]617 A 0.11 95.4 5 0.022 B 0.61 98.0 5 0.135 C 1.34 97.8 5 0.295 POST -DEVELOPMENT Outfall Area (acres) CN Tc (minutes) Runoff Volume (ac-ft) 1-yr Q (cfs) 1-yr C. Allowable (cfs) A 0.04 83.4 5 0.005 0.10 1.67 B 0.07 93.8 5 0.013 0.28 24.00 C 0.85 94.6 5 0.164 3.46 9.81 Hydrograph Summary Report Hydranow Hydmgraphs Extension for Autodesk® Civil 3DO by Autodesk, Inc. v202o Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (tuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 0.435 2 716 958 — — — Outfall A - Site - Pre 2 SCS Runoff 0.103 2 716 208 Outfall A - Site - Post 3 SCS Runoff 2.065 2 716 4,659 Outfall A - Overall - Pre 4 SCS Runoff 1.702 2 716 3,759 Outfall A - Overall - Post 5 SCS Runoff 2.525 2 716 5,891 Outfall B - Site - Pre 6 SCS Runoff 0.266 2 716 571 Outfall B - Site - Post 7 SCS Runoff 4.139 2 716 9,658 — Outfall B - Overall - Pre 8 SCS Runoff 1.734 2 716 3,816 -- — Outfall B - Overall - Post 9 SCS Runoff 5.532 2 716 12,840 — Outfall C - Site - Pre 10 SCS Runoff 3.285 2 716 7,137 Outfall C - Site - Post 11 SCS Runoff 9.044 2 716 20,831 Outfall C - Overall - Pre 12 SCS Runoff 7.133 2 716 15,839 Outfall C - Overall - Post K:\RIC_CM113038 - Albemarle Cty On -Call 32!gftDzfk##dart'Tz0neering\C PAzWzW`i8lWftHdMater Quantity Summa (Site Hydrograph Report 2 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 1 Outfall A - Site - Pre Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 0.110 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs 0.0 2.0 Hyd No. 1 Tuesday, 01 / 26 / 2021 Peak discharge = 0.435 cfs Time to peak = 11.93 hrs Hyd. volume = 958 cuft Curve number = 95.4 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Outfall A - Site - Pre Hyd. No. 1 -- 1 Year Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 000 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time (hrs) Hydrograph Report 3 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 2 Outfall A - Site - Post Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 0.040 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs 0 2 4 Hyd No. 2 Tuesday, 01 / 26 / 2021 Peak discharge = 0.103 cfs Time to peak = 11.93 hrs Hyd. volume = 208 cuft Curve number = 83.4 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Outfall A - Site - Post Hyd. No. 2 -- 1 Year Q (cfs) 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 3 Outfall A - Overall - Pre Hydrograph type = SCS Runoff Peak discharge = 2.065 cfs Storm frequency = 1 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 4,659 cuft Drainage area = 0.510 ac Curve number = 96.6 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.07 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (Cfs) 3.00 2.00 1.00 0.00 0.0 2.0 Hyd No. 3 Outfall A - Overall - Pre Hyd. No. 3 -- 1 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 3.00 2.00 1.00 � 0.00 20.0 Time (hrs) Hydrograph Report 5 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 4 Outfall A - Overall - Post Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 0.430 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs Q (cfs) 2.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Outfall A - Overall - Post Hyd. No. 4 -- 1 Year Tuesday, 01 126 / 2021 = 1.702 cfs = 11.93 hrs = 3,759 cuft = 95.5 = Oft = 5.00 min = Type II = 484 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Hyd No. 4 Q (cfs) 2.00 1.00 � 0.00 20.0 Time (hrs) I Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 5 Outfall B - Site - Pre Hydrograph type = SCS Runoff Peak discharge = 2.525 cfs Storm frequency = 1 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 5,891 cuft Drainage area = 0.610 ac Curve number = 98 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.40 min Total precip. = 3.07 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (Cfs) 3.00 2.00 1.00 0.00 0.0 2.0 Hyd No. 5 Outfall B - Site - Pre Hyd. No. 5 -- 1 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 3.00 2.00 1.00 � 0.00 20.0 Time (hrs) Hydrograph Report 7 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 6 Outfall B - Site - Post Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 0.070 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0.0 2.0 Hyd No. 6 Tuesday, 01 / 26 / 2021 Peak discharge = 0.266 cfs Time to peak = 11.93 hrs Hyd. volume = 571 cuft Curve number = 93.8 Hydraulic length = 0 ft Time of conc. (Tc) = 5.40 min Distribution = Type II Shape factor = 484 Outfall B - Site - Post Hyd. No. 6 -- 1 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 20.0 Time (hrs) Hydrograph Report 8 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 7 Outfall B - Overall - Pre Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 1.000 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 4.139 cfs = 11.93 hrs = 9,658 cuft = 98 = 0 ft = 5.40 min = Type II = 484 / 2021 Q (cfs) Outfall B - Overall - Pre Hyd. No. 7 -- 1 Year Q (cfs) 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 8.0 10.0 7 12.0 14.0 16.0 18.0 20.0 Time 1.00 0.00 (hrs) Hydrograph Report Vj Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 8 Outfall B - Overall - Post Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 2 min Drainage area = 0.440 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.07 in Storm duration = 24 hrs Q (cfs) 2.00 1.00 Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Outfall B - Overall - Post Hyd. No. 8 -- 1 Year Tuesday, 01 126 / 2021 = 1.734 cfs = 11.93 hrs = 3,816 cuft = 95.3 = Oft = 5.40 min = Type II = 484 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Hyd No. 8 Q (cfs) 2.00 1.00 � 0.00 20.0 Time (hrs) Hydrograph Report 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 9 Outfall C - Site - Pre Hydrograph type = SCS Runoff Peak discharge Storm frequency = 1 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 1.340 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 3.07 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 5.532 cfs = 11.93 hrs = 12,840 cuft = 97.8 = 0 ft = 5.30 min = Type II = 484 / 2021 Q (cfs) Outfall C - Site - Pre Hyd. No. 9 -- 1 Year Q (cfs) 6.00 6.00 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 4.0 6.0 — Hyd No. 9 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 10 Outfall C - Site - Post Hydrograph type = SCS Runoff Peak discharge Storm frequency = 1 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 0.850 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 3.07 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 3.285 cfs = 11.93 hrs = 7,137 cuft = 94.5 = 0 ft = 5.50 min = Type II = 484 / 2021 Q (cfs) Outfall C - Site - Post Hyd. No. 10 -- 1 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 10 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) 12 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 11 Outfall C - Overall - Pre Hydrograph type = SCS Runoff Peak discharge = 9.044 cfs Storm frequency = 1 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 20,831 cuft Drainage area = 2.200 ac Curve number = 97.5 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.30 min Total precip. = 3.07 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Overall - Pre Q (cfs) Hyd. No. 11 -- 1 Year Q (cfs) 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 — Hyd No. 11 Time (hrs) 13 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 12 Outfall C - Overall - Post Hydrograph type = SCS Runoff Peak discharge = 7.133 cfs Storm frequency = 1 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 15,839 cuft Drainage area = 1.790 ac Curve number = 95.8 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.50 min Total precip. = 3.07 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Overall - Post Q (cfs) Hyd. No. 12 -- 1 Year Q (cfs) 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 — Hyd No. 12 Time (hrs) Hydrograph Summary Report 14 Hydranow Hydrographs Extension for Autodesk® Civil 3DO by Autodesk, Inc. v202o Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (tuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 0.534 2 716 1,193 — — — Outfall A - Site - Pre 2 SCS Runoff 0.139 2 716 282 Outfall A - Site - Post 3 SCS Runoff 2.521 2 716 5,760 Outfall A - Overall - Pre 4 SCS Runoff 2.090 2 716 4,681 Outfall A - Overall - Post 5 SCS Runoff 3.063 2 716 7,216 Outfall B - Site - Pre 6 SCS Runoff 0.330 2 716 719 Outfall B - Site - Post 7 SCS Runoff 5.022 2 716 11,829 — Outfall B - Overall - Pre 8 SCS Runoff 2.131 2 716 4,758 — Outfall B - Overall - Post 9 SCS Runoff 6.717 2 716 15,747 — — Outfall C - Site - Pre 10 SCS Runoff 4.058 2 716 8,946 Outfall C - Site - Post 11 SCS Runoff 10.99 2 716 25,598 Outfall C - Overall - Pre 12 SCS Runoff 8.743 2 716 19,683 Outfall C - Overall - Post K:\RIC_CM113038 - Albemarle Cty On -Call 32!gftDzfk##da@Tz0neering\C PAzWzW`i8lWftHdMater Quantity Summa (Site Hydrograph Report 15 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 1 Outfall A - Site - Pre Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 0.110 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.71 in Storm duration = 24 hrs Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.0 2.0 Hyd No. 1 Tuesday, 01 / 26 / 2021 Peak discharge = 0.534 cfs Time to peak = 11.93 hrs Hyd. volume = 1,193 cuft Curve number = 95.4 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Outfall A - Site - Pre Hyd. No. 1 -- 2 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 20.0 Time (hrs) Hydrograph Report 16 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 2 Outfall A - Site - Post Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 0.040 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.71 in Storm duration = 24 hrs 0 2 4 Hyd No. 2 Tuesday, 01 / 26 / 2021 Peak discharge = 0.139 cfs Time to peak = 11.93 hrs Hyd. volume = 282 cuft Curve number = 83.4 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Outfall A - Site - Post Hyd. No. 2 -- 2 Year Q (cfs) 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 3 Outfall A - Overall - Pre Hydrograph type = SCS Runoff Peak discharge = 2.521 cfs Storm frequency = 2 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 5,760 cuft Drainage area = 0.510 ac Curve number = 96.6 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (Cfs) 3.00 2.00 1.00 0.00 0.0 2.0 Hyd No. 3 Outfall A - Overall - Pre Hyd. No. 3 -- 2 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 3.00 2.00 1.00 � 0.00 20.0 Time (hrs) 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 4 Outfall A - Overall - Post Hydrograph type = SCS Runoff Peak discharge = 2.090 cfs Storm frequency = 2 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 4,681 cuft Drainage area = 0.430 ac Curve number = 95.5 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (Cfs) 3.00 2.00 1.00 0.00 0.0 2.0 Hyd No. 4 Outfall A - Overall - Post Hyd. No. 4 -- 2 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 3.00 2.00 1.00 � 0.00 20.0 Time (hrs) Hydrograph Report 19 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 5 Outfall B - Site - Pre Hydrograph type = SCS Runoff Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 0.610 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 3.71 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 3.063 cfs = 11.93 hrs = 7,216 cuft = 98 = 0 ft = 5.40 min = Type II = 484 / 2021 Q (cfs) Outfall B - Site - Pre Hyd. No. 5 -- 2 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 — Hyd No. 5 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 20 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 6 Outfall B - Site - Post Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 0.070 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.71 in Storm duration = 24 hrs 0.0 2.0 Hyd No. 6 Tuesday, 01 / 26 / 2021 Peak discharge = 0.330 cfs Time to peak = 11.93 hrs Hyd. volume = 719 cuft Curve number = 93.8 Hydraulic length = 0 ft Time of conc. (Tc) = 5.40 min Distribution = Type II Shape factor = 484 Outfall B - Site - Post Hyd. No. 6 -- 2 Year Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 000 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time (hrs) Hydrograph Report 21 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 7 Outfall B - Overall - Pre Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 2 min Drainage area = 1.000 ac Basin Slope = 0.0 % Tc method = User Total precip. = 3.71 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 5.022 cfs = 11.93 hrs = 11,829 cuft = 98 = 0 ft = 5.40 min = Type II = 484 / 2021 Q (cfs) Outfall B - Overall - Pre Hyd. No. 7 -- 2 Year Q (cfs) 6.00 6.00 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 8.0 10.0 7 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) 22 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 8 Outfall B - Overall - Post Hydrograph type = SCS Runoff Peak discharge = 2.131 cfs Storm frequency = 2 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 4,758 cuft Drainage area = 0.440 ac Curve number = 95.3 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.40 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Q (Cfs) 3.00 2.00 1.00 0.00 0.0 2.0 Hyd No. 8 Outfall B - Overall - Post Hyd. No. 8 -- 2 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 3.00 2.00 1.00 � 0.00 20.0 Time (hrs) Hydrograph Report 23 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 9 Outfall C - Site - Pre Hydrograph type = SCS Runoff Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 1.340 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 3.71 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 6.717 cfs = 11.93 hrs = 15,747 cuft = 97.8 = 0 ft = 5.30 min = Type II = 484 / 2021 Q (cfs) Outfall C - Site - Pre Hyd. No. 9 -- 2 Year Q (cfs) 7.00 7.00 6.00 6.00 5.00 5.00 4.00 3.00 4.00 3.00 2.00 1.00 2.00 1.00 0.00 0.0 2.0 4.0 6.0 - Hyd No. 9 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 10 Outfall C - Site - Post Hydrograph type = SCS Runoff Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 0.850 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 3.71 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 4.058 cfs = 11.93 hrs = 8,946 cuft = 94.5 = 0 ft = 5.50 min = Type II = 484 / 2021 Q (cfs) Outfall C - Site - Post Hyd. No. 10 -- 2 Year Q (cfs) 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 10 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time 1.00 0.00 (hrs) 25 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 11 Outfall C - Overall - Pre Hydrograph type = SCS Runoff Peak discharge = 10.99 cfs Storm frequency = 2 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 25,598 cuft Drainage area = 2.200 ac Curve number = 97.5 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.30 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Overall - Pre Q (cfs) Hyd. No. 11 -- 2 Year Q (cfs) 12.00 12.00 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 - Hyd No. 11 Time (hrs) 26 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 12 Outfall C - Overall - Post Hydrograph type = SCS Runoff Peak discharge = 8.743 cfs Storm frequency = 2 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 19,683 cuft Drainage area = 1.790 ac Curve number = 95.8 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.50 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Overall - Post Q (cfs) Hyd. No. 12 -- 2 Year Q (cfs) 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 — Hyd No. 12 Time (hrs) Hydrograph Summary Report P*A Hydranow Hydrographs Extension for Autodesk® Civil 3DO by Autodesk, Inc. v202o Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to Peak (min) Hyd. volume (tuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph Description 1 SCS Runoff 0.821 2 716 1,887 Outfall A - Site - Pre 2 SCS Runoff 0.246 2 716 510 Outfall A - Site - Post 3 SCS Runoff 3.842 2 716 8,988 Outfall A - Overall - Pre 4 SCS Runoff 3.212 2 716 7,393 Outfall A - Overall - Post 5 SCS Runoff 4.631 2 716 11,090 Outfall B - Site - Pre 6 SCS Runoff 0.514 2 716 1,157 Outfall B - Site - Post 7 SCS Runoff 7.591 2 716 18,181 Outfall B - Overall - Pre 8 SCS Runoff 3.281 2 716 7,530 ---- — Outfall B - Overall - Post 9 SCS Runoff 10.16 2 716 24,255 — Outfall C - Site - Pre 10 SCS Runoff 6.290 2 716 14,283 -- Outfall C - Site - Post 11 SCS Runoff 16.66 2 716 39,558 -- Outfall C - Overall - Pre 12 SCS Runoff 13.40 2 716 30,984 Outfall C - Overall - Post K:\RIC_CM113038 - Albemarle Cty On -Call 32!gftDzfkMq dart0Bfgleering\C PutizWaW*lWftHdMater Quantity Summa (Site Hydrograph Report 28 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 1 Outfall A - Site - Pre Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 0.110 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs 0.0 2.0 Hyd No. 1 Tuesday, 01 / 26 / 2021 Peak discharge = 0.821 cfs Time to peak = 11.93 hrs Hyd. volume = 1,887 cuft Curve number = 95.4 Hydraulic length = 0 ft Time of conc. (Tc) = 5.00 min Distribution = Type II Shape factor = 484 Outfall A - Site - Pre Hyd. No. 1 -- 10 Year Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time (hrs) 29 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Tuesday, 01 / 26 / 2021 Hyd. No. 2 Outfall A - Site - Post Hydrograph type = SCS Runoff Peak discharge = 0.246 cfs Storm frequency = 10 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 510 cuft Drainage area = 0.040 ac Curve number = 83.4 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 5.58 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall A - Site - Post Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs) 0.50 0.50 0.45 0.45 0.40 0.40 0.35 0.35 0.30 0.30 0.25 0.25 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0.05 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 - Hyd No. 2 Time (hrs) Hydrograph Report 30 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 3 Outfall A - Overall - Pre Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 0.510 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 3.842 cfs = 11.93 hrs = 8,988 cuft = 96.6 = 0 ft = 5.00 min = Type II = 484 / 2021 Q (cfs) Outfall A - Overall - Pre Hyd. No. 3 -- 10 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 8.0 10.0 3 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 31 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 4 Outfall A - Overall - Post Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 0.430 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 3.212 cfs = 11.93 hrs = 7,393 cuft = 95.5 = 0 ft = 5.00 min = Type II = 484 / 2021 Q (cfs) Outfall A - Overall - Post Hyd. No. 4 -- 10 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 LL 0.00 0.0 2.0 4.0 6.0 8.0 10.0 — Hyd No. 4 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 32 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 5 Outfall B - Site - Pre Hydrograph type = SCS Runoff Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 0.610 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 5.58 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 4.631 cfs = 11.93 hrs = 11,090 cuft = 98 = 0 ft = 5.40 min = Type II = 484 / 2021 Q (cfs) Outfall B - Site - Pre Hyd. No. 5 -- 10 Year Q (cfs) 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 — Hyd No. 5 18.0 20.0 Time 1.00 0.00 (hrs) Hydrograph Report 33 Hydraflow Hydrographs Extension for Autodesk® civil 3138 by Autodesk, Inc. v2020 Hyd. No. 6 Outfall B - Site - Post Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 0.070 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.0 2.0 Hyd No. 6 Tuesday, 01 / 26 / 2021 Peak discharge = 0.514 cfs Time to peak = 11.93 hrs Hyd. volume = 1,157 cuft Curve number = 93.8 Hydraulic length = 0 ft Time of conc. (Tc) = 5.40 min Distribution = Type II Shape factor = 484 Outfall B - Site - Post Hyd. No. 6 -- 10 Year 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 20.0 Time (hrs) 34 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 7 Outfall B - Overall - Pre Hydrograph type = SCS Runoff Peak discharge = 7.591 cfs Storm frequency = 10 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 18,181 cuft Drainage area = 1.000 ac Curve number = 98 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.40 min Total precip. = 5.58 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall B - Overall - Pre Q (cfs) Hyd. No. 7 -- 10 Year Q (cfs) 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 1 Hyd No. 7 Time (hrs) Hydrograph Report 35 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 8 Outfall B - Overall - Post Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 0.440 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 3.281 cfs = 11.93 hrs = 7,530 cuft = 95.3 = 0 ft = 5.40 min = Type II = 484 / 2021 Q (cfs) Outfall B - Overall - Post Hyd. No. 8 -- 10 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.0 2.0 — Hyd No. 4.0 6.0 8.0 10.0 8 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) 36 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 9 Outfall C - Site - Pre Hydrograph type = SCS Runoff Peak discharge = 10.16 cfs Storm frequency = 10 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 24,255 cuft Drainage area = 1.340 ac Curve number = 97.8 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.30 min Total precip. = 5.58 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Site - Pre Q (cfs) Hyd. No. 9 -- 10 Year Q (cfs) 12.00 12.00 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 - Hyd No. 9 Time (hrs) Hydrograph Report 37 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 10 Outfall C - Site - Post Hydrograph type = SCS Runoff Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 2 min Hyd. volume Drainage area = 0.850 ac Curve number Basin Slope = 0.0 % Hydraulic length Tc method = User Time of conc. (Tc) Total precip. = 5.58 in Distribution Storm duration = 24 hrs Shape factor Tuesday, 01 126 = 6.290 cfs = 11.93 hrs = 14,283 cuft = 94.5 = 0 ft = 5.50 min = Type II = 484 / 2021 Q (cfs) Outfall C - Site - Post Hyd. No. 10 -- 10 Year Q (cfs) 7.00 7.00 6.00 6.00 5.00 5.00 4.00 3.00 4.00 3.00 2.00 1.00 2.00 1.00 0.00 0.0 2.0 - Hyd No. 4.0 6.0 10 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Time 0.00 (hrs) Hydrograph Report 38 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Hyd. No. 11 Outfall C - Overall - Pre Hydrograph type = SCS Runoff Storm frequency = 10 yrs Time interval = 2 min Drainage area = 2.200 ac Basin Slope = 0.0 % Tc method = User Total precip. = 5.58 in Storm duration = 24 hrs Peak discharge Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor Tuesday, 01 126 = 16.66 cfs = 11.93 hrs = 39,558 cuft = 97.5 = 0 ft = 5.30 min = Type II = 484 / 2021 Q (cfs) Outfall C - Overall - Pre Hyd. No. 11 -- 10 Year Q (cfs) 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 3.00 0.00 0.0 2.0 - Hyd No. 4.0 6.0 8.0 10.0 11 12.0 14.0 16.0 18.0 20.0 Time 3.00 0.00 (hrs) 39 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 Tuesday, 01 126 / 2021 Hyd. No. 12 Outfall C - Overall - Post Hydrograph type = SCS Runoff Peak discharge = 13.40 cfs Storm frequency = 10 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 30,984 cuft Drainage area = 1.790 ac Curve number = 95.8 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.50 min Total precip. = 5.58 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 Outfall C - Overall - Post Q (cfs) Hyd. No. 12 -- 10 Year Q (cfs) 14.00 14.00 12.00 12.00 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 - Hyd No. 12 Time (hrs) Hydraflow Rainfall Report 40 Hydrallow Hydrographs Extension for Autodesk® Civil 3138 by Autodesk, Inc. v2020 Return Period Intensity -Duration -Frequency Equation Coefficients (FHA) (Yrs) B D E (WA) 1 0.0000 0.0000 0.0000 --- 2 69.8703 13.1000 0.8658 ---- 3 0.0000 0.0000 0.0000 ----- 5 79.2597 14.6000 0.8369 ---- 10 88.2351 15.5000 0.8279 ----- 25 102.6072 16.5000 0.8217 ----- 50 114.8193 17.2000 0.8199 ------ 100 127.1596 17.8000 0.8186 ----- File name: SampleFHA.idf Intensity = B I (Tc + D)AE Tuesday, 01 / 26 / 2021 Return Penal Intensity Values (in/hr) (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15 10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46 25 825 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91 50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25 100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60 Tc = time in minutes. Values may exceed 60. MC CIV\113038-AlbemarleC On-Call\32 Crozet S uare\En ineed \Com utabons\H draulics\CrozetS uare. c Rainfall Precipitation Table (in) storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 3.07 3.71 0.00 0.00 5.58 0.00 0.00 9.08 SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff -1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hyd-raflowA,TQbleoof it ftm®nftgineering\Computations\Hydraulics\Water Quantity Summary (Site and Overall).gpw Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020 1 -Year Tuesday, 01 / 26 / 2021 SummaryReport ......................................................................................................................... 1 HydrographReports................................................................................................................... 2 Hydrograph No. 1, SCS Runoff, Outfall A - Site - Pre.............................................................. 2 Hydrograph No. 2, SCS Runoff, Outfall A - Site - Post............................................................ 3 Hydrograph No. 3, SCS Runoff, Outfall A - Overall - Pre ......................................................... 4 Hydrograph No. 4, SCS Runoff, Outfall A - Overall - Post ....................................................... 5 Hydrograph No. 5, SCS Runoff, Outfall B - Site - Pre.............................................................. 6 Hydrograph No. 6, SCS Runoff, Outfall B - Site - Post............................................................ 7 Hydrograph No. 7, SCS Runoff, Outfall B - Overall - Pre ......................................................... 8 Hydrograph No. 8, SCS Runoff, Outfall B - Overall - Post ....................................................... 9 Hydrograph No. 9, SCS Runoff, Outfall C - Site - Pre............................................................ 10 Hydrograph No. 10, SCS Runoff, Outfall C - Site - Post ........................................................ 11 Hydrograph No. 11, SCS Runoff, Outfall C - Overall - Pre ..................................................... 12 Hydrograph No. 12, SCS Runoff, Outfall C - Overall - Post ................................................... 13 2 - Year SummaryReport ....................................................................................................................... 14 HydrographReports................................................................................................................. 15 Hydrograph No. 1, SCS Runoff, Outfall A - Site - Pre............................................................ 15 Hydrograph No. 2, SCS Runoff, Outfall A - Site - Post.......................................................... 16 Hydrograph No. 3, SCS Runoff, Outfall A - Overall - Pre ....................................................... 17 Hydrograph No. 4, SCS Runoff, Outfall A - Overall - Post ..................................................... 18 Hydrograph No. 5, SCS Runoff, Outfall B - Site - Pre............................................................ 19 Hydrograph No. 6, SCS Runoff, Outfall B - Site - Post.......................................................... 20 Hydrograph No. 7, SCS Runoff, Outfall B - Overall - Pre ....................................................... 21 Hydrograph No. 8, SCS Runoff, Outfall B - Overall - Post ..................................................... 22 Hydrograph No. 9, SCS Runoff, Outfall C - Site - Pre............................................................ 23 Hydrograph No. 10, SCS Runoff, Outfall C - Site - Post ........................................................ 24 Hydrograph No. 11, SCS Runoff, Outfall C - Overall - Pre ..................................................... 25 Hydrograph No. 12, SCS Runoff, Outfall C - Overall - Post ................................................... 26 10 - Year SummaryReport ....................................................................................................................... 27 HydrographReports................................................................................................................. 28 Hydrograph No. 1, SCS Runoff, Outfall A - Site - Pre............................................................ 28 Hydrograph No. 2, SCS Runoff, Outfall A - Site - Post.......................................................... 29 Hydrograph No. 3, SCS Runoff, Outfall A - Overall - Pre ....................................................... 30 Hydrograph No. 4, SCS Runoff, Outfall A - Overall - Post ..................................................... 31 Hydrograph No. 5, SCS Runoff, Outfall B - Site - Pre............................................................ 32 Hydrograph No. 6, SCS Runoff, Outfall B - Site - Post.......................................................... 33 Hydrograph No. 7, SCS Runoff, Outfall B - Overall - Pre ....................................................... 34 Hydrograph No. 8, SCS Runoff, Outfall B - Overall - Post ..................................................... 35 Hydrograph No. 9, SCS Runoff, Outfall C - Site - Pre............................................................ 36 Hydrograph No. 10, SCS Runoff, Outfall C - Site - Post ........................................................ 37 Hydrograph No. 11, SCS Runoff, Outfall C - Overall - Pre ..................................................... 38 Hydrograph No. 12, SCS Runoff, Outfall C - Overall - Post ................................................... 39 IDFReport.................................................................................................................. 40 APPENDIX E Kimley>»Horn Hydraulic Grade Line Calculations VDOT LD-347 Project: Crozet Square and Oak Street Improvements Date: 1/27/2021 Locality: Albemarle County 10 -year storm (proposed) Angle 0 15 20 25 30 40 50 1 60 70 80 90 K 0 0.19 0.25 0.30 0.35 0.43 0.50 0.56 0.61 0.66 0.70 0.8D♦ INV (OUT) AMAL OUTLET WSE DESIGN OUTIEr WSE D. C. Le Sb 14 JUNCTION LOSS FINAL INLET WSE F/L ELEV Ve (8) H, (9) a (10) V� (11) O�V, (12) z H� Angle He H, Sudara Fan ? Facrarl 1.3� R-17 0.5 H� 2g (1) (2) (3) (4) (5) (6) (7) (13) (14) (15) (16) (17) (18) (19) (20) (21) STR. 3-6 709.42 708.34 709.42 15 5.26 97 0.0066 0.64 5.95 0.14 3.89 4.38 17.04 0.30 0.10 90 0.21 0.45 NO 0.45 NO 0.45 1.09 710.51 715.32 STR. 3-5 710.42 710.51 710.51 15 3.89 27 0.0036 0.10 4.38 0.07 3.41 3.84 13.09 0.23 0.08 90 0.16 0.31 YES 0.41 YES 0.20 0.30 710.81 715.]1 STR. 3-4 710.57 710.81 710.81 15 3.41 195 0.0028 0.54 3.84 0.06 3.47 3.91 13.57 0.24 DM 90 0.17 0.31 NO 0.31 YES 0.15 0.70 711.51 722.68 STR. 3-3 711.41 711.51 711.51 15 3.47 83 0.0029 0.24 3.91 0.06 2.08 2.97 6.18 0.14 0.05 25 0.04 0.15 YES 0.19 YES 0.10 0.34 711.84 720.07 STR. 3-2 711.78 711.84 711.84 15 2.08 58 0.0010 0.06 2.97 0.03 1.02 2.50 2.55 0.10 0.03 20 0.02 am YES 0.12 YES 0.06 0.12 711.96 719.18 STR. 3-1 ]11.95 ]31.96 ]11.96 15 1.02 109 0.0002 0.03 2.50 0.02 0.00 0.00 0.00 0.00 0.00 0 0.00 0.02 YES 0.03 YES 0.02 0.04 712.01 714.55 STR. 3-7 710.42 ]30.51 710.51 15 1.55 19 0.0006 0.01 4.21 0.0] 0.00 0.00 0.00 0.00 0.00 0 0.00 0.0] VES 0.09 VES 0.04 0.06 ]10.5] ]15.38 Kimley>»Horn Storm Drain Design Calculations VDOT LD-229 Project: Crozet Square and Oak Street Improvements Date: 1/27/2021 Locality: Albemarle County 10 -year storm (proposed) Manning n= 0.013 FROM POINT TO POINT DRAINAGE AREA RUNOFF COEFFICIENT INIETTIME RAINFALL RUNOFF INVERT ELEVATIONS LENGTH SLOPE Q/% VELOCITY FLOW TIME REMARKS into a.. upper end lower end leer so.. acres C min in/hr ON R R R % % fps min STR. 3-1 M.3-2 0.17 0.89 0.151 0.151 5.00 6.67 1.02 711.28 710.95 309 0.30% 29% 2.50 0.73 5.00 STR. 3-2 M. 3-3 0.19 0.89 0.169 0.320 5.00 6.43 2.08 710.95 710.78 58 0.30% k4.32 60% 2.97 0.33 5.73 STR. 3-3 STR.3 0.25 0.89 0.223 0.543 5.00 6.33 3.47 710.78 730.41 83 0.40% ji'n 80% 3.91 0.35 6.05 STR.3 M. 3-5 (N/A) (N/A) 0.000 0.543 0.00 6.23 3.41 730.41 709.57 195 0.40% 80% 3.84 0.85 6.40 STR. }5 STR. 3-6 0.12 0.83 0.100 0.642 5.00 6.00 3.89 709.57 709A2 27 0.fiO% 80% 4.38 0.10 7.25 M. 3-6 5TR. 3-8 (N/A) (N/A) 0.000 0.874 0.00 5.97 5.26 709A2 7p8.42 97 1.00% 80% 5.95 0.27 7.35 STR.}7 STR. 3-6 0.26 0.89 0.231 0.231 5.00 6.67 1.55 71.1 7,42 19 0.90% 25% 4.21 0.08 5.00 Worksheet for Structure 3-1 (Curb On Grade) Project Description Solve For Curb Opening Length Input Data Discharge 0.60 cis Slope 0.069 ft/ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.020 ft/ft Roughness Coefficient 0.015 Efficiency 100.00 % Local Depression 2.0 in Local Depression Width 24.0 in Results Curb Opening Length 7.9 ft Intercepted Flow 0.60 cis Bypass Flow 0.00 cis Spread 1.7 ft Depth 1.7 in Flow Area 0.1 ft2 Gutter Depression 1.5 in Total Depression 3.5 in Velocity 5.20 ft/s Equivalent Cross Slope 0.167 ft/ft Length Factor 1.000 Total Interception Length 7.9 ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.fin8 Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertovm, CT 06795 USA +1-203-755-1666 Worksheet for Structure 3-2 (Curb On Grade) Project Description Solve For Curb Opening Length Input Data Discharge 0.69 cis Slope 0.018 ft/ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.030 ft/ft Roughness Coefficient 0.015 Efficiency 100.00 % Local Depression 2.0 in Local Depression Width 24.0 in Results Curb Opening Length 5.6 ft Intercepted Flow 0.69 cis Bypass Flow 0.00 cis Spread 2.7 ft Depth 2.3 in Flow Area 0.2 ft2 Gutter Depression 1.3 in Total Depression 3.3 in Velocity 3.17 ft/s Equivalent Cross Slope 0.165 ft/ft Length Factor 1.000 Total Interception Length 5.6 ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.fin6 Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertovm, CT 06795 USA +1-203-755-1666 Worksheet for Structure 3-3 (Curb On Grade) Project Description Solve For Curb Opening Length Input Data Discharge 0.88 cis Slope 0.018 ft/ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.004 ft/ft Roughness Coefficient 0.015 Efficiency 100.00 % Local Depression 2.0 in Local Depression Width 24.0 in Results Curb Opening Length 6.7 ft Intercepted Flow 0.88 cis Bypass Flow 0.00 cis Spread 9.6 ft Depth 2.4 in Flow Area 0.3 ft2 Gutter Depression 1.9 in Total Depression 3.9 in Velocity 2.56 ft/s Equivalent Cross Slope 0.146 ft/ft Length Factor 1.000 Total Interception Length 6.7 ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.fin8 Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertovm, CT 06795 USA +1-203-755-1666 Worksheet for Structure 3-5 (Curb On Grade) Project Description Solve For Curb Opening Length Input Data Discharge 0.38 cis Slope 0.036 ft/ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.020 ft/ft Roughness Coefficient 0.015 Efficiency 100.00 % Local Depression 2.0 in Local Depression Width 24.0 in Results Curb Opening Length 5.3 ft Intercepted Flow 0.38 cis Bypass Flow 0.00 cis Spread 1.6 ft Depth 1.6 in Flow Area 0.1 ft2 Gutter Depression 1.5 in Total Depression 3.5 in Velocity 3.63 ft/s Equivalent Cross Slope 0.167 ft/ft Length Factor 1.000 Total Interception Length 5.3 ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.fin6 Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertovm, CT 06795 USA +1-203-755-1666 Worksheet for Structure 3-7 (Curb On Grade) Project Description Solve For Curb Opening Length Input Data Discharge 0.88 cis Slope 0.036 ft/ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.020 ft/ft Roughness Coefficient 0.015 Efficiency 100.00 % Local Depression 2.0 in Local Depression Width 24.0 in Results Curb Opening Length 7.6 ft Intercepted Flow 0.88 cis Bypass Flow 0.00 cis Spread 2.7 ft Depth 2.2 in Flow Area 0.2 ft2 Gutter Depression 1.5 in Total Depression 3.5 in Velocity 4.40 ft/s Equivalent Cross Slope 0.166 ft/ft Length Factor 1.000 Total Interception Length 7.6 ft Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.fin8 Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertovm, CT 06795 USA +1-203-755-1666 Worksheet for Structure 3-8 (Curb In Sag) Project Description Solve For Curb Opening Length Input Data Discharge 2.65 cis Spread 5.5 ft Gutter Width 2.00 ft Gutter Cross Slope 0.083 ft/ft Road Cross Slope 0.045 ft/ft Opening Height 0.5 ft Curb Throat Type Inclined Local Depression 2.0 in Local Depression Width 24.0 in Throat Incline Angle 45.00 degrees Results Curb Opening Length 6.0 ft Depth 3.8 in Gutter Depression 0.9 in Total Depression 2.9 in Bentley Systems, Inc. Haestad Methods Solution FlowMaster Crozet Flowmaster.finti Center [10.02.00.011 1/26/2021 27 Slemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666