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HomeMy WebLinkAboutDrainage Report 51324 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223 PHONE: (501) 214-9141 Lots 8A-8E The Crossroads at Chenal Drainage Report April 29, 2024 JOE WHITE F & ASSOCIATES,INC. #3871 OETAIFITREC NOITAZ IR OHTUAC -E N G INEERAR KANSAS 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223 PHONE: (501) 214-9141 Mr. Chris Smith, P.E. City of Little Rock Planning & Development 723 W. Markham St. Little Rock, AR 72201 RE: The Crossroads at Chenal, Lots 8A-8E Drainage Report Chenal Parkway/Lamarche Rd. Mr. Smith, Site Location/Project Description This letter containing drainage calculations is to accompany the civil plans submitted for the grading permit of Lots 8A-8E, located east of the intersection of Chenal Parkway and Lamarche Rd. The project vicinity map is shown below. This project consists of advance grading and drainage for the development of 5 commercial lots on Lot 8, Tract 1, Chenal Valley, containing +/- 10.8 acres. The rational method was used to determine peak runoff for the watersheds. The design software used in the analysis procedure include Hydraflow Hydrographs, HydraFlow Storms Sewers, and Autodesk Civil 3D. Figure 1: Vicinity Map 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223 PHONE: (501) 214-9141 Pre-Developed Drainage The site is currently undeveloped with the majority of the project area being wooded. Seven existing site discharge points within the proposed project have been identified for this report. These points have been labeled on the Existing Drainage Map. Points A-F are existing curb inlets located on the shared private drive bordering the property. Points A and B drain to existing drainage infrastructure thence into Rock Creek Tributary A. Points C-F drain to existing drainage infrastructure thence into an unnamed tributary of Rock Creek Tributary 1. Point G drains directly into the said unnamed tributary. A rational coefficient of 0.4 was used for the undeveloped area of the proposed project. Offsite rational coefficients range from 0.4-0.8 depending on the amount of development contained in the basins area. Time of concentrations were calculated using the TR-55 method and are summarized on the Existing Drainage Map drawing. The existing drainage is summarized below in Table 1 and shown on the Existing Drainage map. Table 1 : Existing Drainage Areas Release Point Drainage Basin Area (Acres) Tc (min.) Composite 'C' Q25 (cfs) Q100 (cfs) A #2 0.36 7 0.4 1.1 1.32 B Offsite A 0.2 7 0.65 0.997 1.19 #1 1.9 16 0.4 4.46 5.19 Total 4.46 5.41 C #3 1.12 15 0.4 2.7 3.27 D #4 1 17 0.4 2.29 2.78 E #5 0.13 6 0.8 0.83 0.99 F #6 0.2 5 0.8 1.32 1.57 G Offsite B 0.96 11 0.65 4.2 5.07 Offsite C 1.12 15 0.4 4.33 5.19 #7 7.53 20 0.4 16.08 19.58 Total 16.84 20.5 Total Site Discharge 29.54 35.84 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223 PHONE: (501) 214-9141 Post-Developed Drainage With the proposed development, the site drainage patterns will largely remain the same. Storm drainage and cutoff swales will be installed to convey storm water to the discharge points. A large portion of the drainage area contained in existing discharge point G will be collected and conveyed to the existing storm drainage. The site has been broken down into multiple drainage basins with corresponding hydrographs in order to evaluate the proposed and existing storm drainage infrastructure’s ability to convey the design storm. Individual users will be required to provide detention facilities in future development of the individual lots. A post development drainage summary is shown below in Table 2. A comparison between the pre-developed and post-development peak runoffs are shown below in Table 3. Table 2: Post-Development Drainage Summary Drainage Basin Release Point Area (Acres) Composite 'C' Tc (min.) Q25 (cfs) Q100 (cfs) Proposed Drainage Basin #2 A 0.190 0.7 5 1.1 1.31 Total to Release Point A 1.1 1.31 Offsite Drainage Basin A B 0.200 0.65 7 0.997 1.19 Proposed Drainage Basin #1 B 2.050 0.4 10 5.7 6.86 Proposed Drainage Basin #3 B 0.140 0.7 5 0.81 0.96 Total to Release Point B 6.27 7.54 Proposed Drainage Basin #4 C 1.610 0.4 9 4.62 5.55 Proposed Drainage Basin #5 C 0.410 0.7 5 2.37 2.82 Total to Release Point C 5.09 6.11 Proposed Drainage Basin #6 D 2.170 0.4 8 6.43 7.71 Proposed Drainage Basin #7 D 0.410 0.7 5 2.37 2.82 Total to Release Point D 7.377 8.84 Proposed Drainage Basin #11 E 0.380 0.7 5 1.96 2.62 Total to Release Point E 1.96 2.62 Offsite Drainage Basin C F 0.810 0.65 11 3.55 4.28 Proposed Drainage Basin #9 F 0.820 0.4 5 2.71 3.23 Offsite Drainage Basin B F 0.15 0.65 5 0.8 0.96 Proposed Drainage Basin #8 F 1.48 0.4 7 4.54 5.43 Proposed Drainage Basin #10 F 1.71 0.4 10 4.75 5.72 Proposed Drainage Basin #11 F 0.38 0.7 5 2.19 2.62 Proposed Drainage Basin #12 F 0.34 0.7 5 1.96 2.34 Total to Release Point F 13.4 16.07 Proposed Drainage Basin #13 G 0.52 0.4 8 1.54 1.85 Total to Release Point G 1.54 1.85 Total Site Discharge 36.74 44.34 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223 PHONE: (501) 214-9141 Table 3: Pre/Post Development Peak Runoff Comparison Release Point Storm Event (yrs.) Pre-development Discharge (cfs) Post Development Discharge (cfs) Difference (cfs) A 25 yr. 1.1 1.1 0 100 yr. 1.32 1.31 -0.01 B 25 yr. 4.46 6.27 1.81 100 yr. 5.41 7.54 2.13 C 25 yr. 2.7 5.09 2.39 100 yr. 3.27 6.11 2.84 D 25 yr. 2.29 7.38 5.09 100 yr. 2.78 8.84 6.06 E 25 yr. 0.83 2.19 1.36 100 yr. 0.99 2.62 1.63 F 25 yr. 1.32 13.4 12.08 100 yr. 1.57 16.07 14.5 Conclusion As shown above, there will be a slight increase in runoff from the site in the post developed condition. The post development flows were used to model the existing drainage infrastructure’s ability to convey the increase in run-off. As can be seen in the attached Hydraflow Storm Sewers calculations, the existing infrastructure has the capacity to convey both the 25-yr and 100-yr storm peak flows. Complete and detailed design and analysis calculations for the proposed project are attached. All drainage design and computations were performed in accordance with the City of Little Rock Drainage Manual using the Hydraflow Hydrographs Extension for AutoDesk Civil 3D. Sincerely, Jacob White, PE Attachments: Pre-Developed Drainage Basin Map Post-Developed Drainage Basin Map Stormwater Calculations 2.62 ACRESLOT 8E2.55 ACRESLOT 8ALOT 8D2.55 ACRESLOT 8C2.13 ACRESLOT 8B2.35 ACRESEXISTING OFFSITEDRAINAGE AREA AAREA: 0.20 AcreC: 0.65TOC: 7 MIN.EXISTING OFFSITEDRAINAGE AREA BAREA: 0.96 AcreC: 0.65TOC: 11 MIN.EXISTING OFFSITEDRAINAGE BASIN CAREA: 1.46 AcreC: 0.40TOC: 8 MIN.EXISTING DRAINAGEBASIN #1AREA: 1.90 AcreC: 0.40TOC: 16 MIN.EXISTING DRAINAGEBASIN #2AREA: 0.36 AcreC: 0.40TOC: 7 MIN.EXISTING DRAINAGEBASIN #3AREA: 1.12 AcreC: 0.40TOC: 15 MIN.EXISTING DRAINAGEBASIN #4AREA: 1.00 AcreC: 0.40TOC: 17 MIN.EXISTING DRAINAGEBASIN #5AREA: 0.13 AcreC: 0.80TOC: 6 MIN.EXISTING DRAINAGEBASIN #6AREA: 0.20 AcreC: 0.80TOC: 5 MIN.EXISTING DRAINAGEBASIN #7AREA: 7.53 AcreC: 0.40TOC: 20 MIN.EXISTING DRAINAGEBASIN INLET 1-AAREA: 0.24 AcreC: 0.75TOC: 0 MIN.EXISTING DRAINAGEBASIN INLET 3AAREA: 0.03 AcreC: 0.75TOC: 0 MIN.EXISTING DRAINAGEBASIN INLET 4AAREA: 2.34 AcreC: 0.75TOC: 5 MIN.EXISTING DRAINAGEBASIN INLET 5AAREA: 0.27 AcreC: 0.75TOC: 5 MIN.EXISTING DRAINAGEBASIN INLET 6AAREA: 0.16 AcreC: 0.75TOC: 5 MIN.EXISTING DRAINAGEBASIN INLET 7BAREA: 0.15 AcreC: 0.75TOC: 5 MIN.EXISTING DRAINAGEAREA INLET 7AAREA: 0.01 AcreC: 0.75TOC: 5 MIN.FLOW SEGMENT #1SCS Sheet FlowL=32 FTS=2.00%Travel Time=4.72FLOW SEGMENT #1SCS Sheet FlowL=52 FTS=2.00%Travel Time=3.94FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=11.00%Travel Time=10.22FLOW SEGMENT #1SCS Sheet FlowL=54 FTS=8.00%Travel Time=7.13FLOW SEGMENT #1SCS Sheet FlowL=73 FTS=4.00%Travel Time=11.89FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=5.50%Travel Time=13.51FLOW SEGMENT #1SCS Sheet FlowL=40 FTS=2.00%Travel Time=4.44FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=6.00%Travel Time=13.05FLOW SEGMENT #1SCS Sheet FlowL=93 FTS=2.00%Travel Time=10.93FLOW SEGMENT #3SCS Channel FlowL=76 FTS=10.00%Travel Time=0.06FLOW SEGMENT #2SCS Shallow Concentrated FlowL=67 FTS=2.00%Travel Time=0.39FLOW SEGMENT #2SCS Shallow Concentrated FlowL=445 FTS=11.00%Travel Time=4.48FLOW SEGMENT #2SCS Shallow Concentrated FlowL=175 FTS=6.00%Travel Time=2.38FLOW SEGMENT #2SCS Shallow Concentrated FlowL=527 FTS=11.00%Travel Time=5.30FLOW SEGMENT #2SCS Shallow Concentrated FlowL=72 FTS=33.00%Travel Time=0.13FLOW SEGMENT #2SCS Shallow Concentrated FlowL=138 FTS=4.50%Travel Time=2.16FLOW SEGMENT #2SCS Shallow Concentrated FlowL=233 FTS=5.00%Travel Time=3.47FLOW SEGMENT #3SCS Channel FlowL=147 FTS=2.00%Travel Time=0.33FLOW SEGMENT #1SCS Sheet FlowL=47 FTS=2.00%Travel Time=5.09FLOW SEGMENT #2SCS Shallow Concentrated FlowL=53 FTS=2.00%Travel Time=0.39FLOW SEGMENT #3SCS Channel FlowL=133 FTS=2.00%Travel Time=0.30FLOW SEGMENT #2SCS Shallow Concentrated FlowL=61 FTS=2.00%Travel Time=0.44FLOW SEGMENT #3SCS Channel FlowL=164 FTS=2.00%Travel Time=0.37FLOW SEGMENT #2SCS Shallow Concentrated FlowL=455 FTS=11.00%Travel Time=4.57FLOW SEGMENT #3SCS Channel FlowL=296 FTS=3.00%Travel Time=1.93VICINITY MAPJOE WHITEF& ASSOCIATES,INC.#3871OET A IFITREC NOITAZIROHTUAC -ENGI N EERARKANSAS FLOOD INFORMATION:25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223PHONE: (501) 214-9141CIVIL ENGINEERING - CONSULTING SERVICES - LAND SURVEYINGJOE WHITE & ASSOCIATES, INC.C5.0 - EXISTING DRAINAGE MAPAN ADDITION TO THE CITY OF LITTLE ROCKPULASKI COUNTY, ARKANSASBEING A REDIVISON OF LOT LINES OFLOT 8 OF TRACT 1, CHENAL VALLEYEX. CURB INLET #1 (RELEASE POINT A)EX. CURB INLET #3EX. CURB INLET #2 (RELEASE POINT B)EX. CURB INLET #4 (RELEASE POINT C)EX. CURB INLET #5 (RELEASE POINT D)EX. CURB INLET #6 (RELEASE POINT E)EX. CURB INLET #7 (RELEASE POINT F)RELEASE POINT G 2.62 ACRESLOT 8E2.55 ACRESLOT 8ALOT 8D2.55 ACRESLOT 8C2.13 ACRESLOT 8B2.35 ACRES624 620 615 610 605 600 595 595591595600605610614590589588587581585585 595590590585580579578572 570575580 585 582 5755705655 9 0 585580575570580581582583584581582583584581 579 578577576 596 597 598 599 594 59 3 592 27 LF of 12" HDPE28 LF of 12" HDPE24 LF of 12" HDPE53 LF of 12" HDPEPIPE #1RIM:587.09INV OUT:585.48 " (S)PIPE #2INV OUT:577.19 "PIPE #3INV OUT:576.13 "PIPE #4INV OUT:573.01 "INSTALL JUNCTIONBOXRIM:567.71INV IN:564.10 " (SE)INV OUT:564.00 " (SW)267 LF of 18" RCPINSTALL INLETRIM:589.38INV IN:582.10 " (NE)INV OUT:582.00 " (NW)333 LF of 18" RCPINSTALL HEADWALLINV OUT:587.50 "58 LF of 15" RCPOFFSITE DRAINAGEBASIN AAREA: 0.20 AcreC: 0.65TOC: 7 MIN.OFFSITE DRAINAGEBASIN BAREA: 0.15 AcreC: 0.65TOC: 5 MIN.OFFSITE DRAINAGEBASIN CAREA: 0.81 AcreC: 0.65TOC: 11 MIN.OFFSITE DRAINAGEBASIN DAREA: 1.46 AcreC: 0.40TOC: 8 MIN.PROPOSED DRAINAGEBASIN #1AREA: 2.05 AcreC: 0.40TOC: 10 MIN.PROPOSED DRAINAGEBASIN #2AREA: 0.19 AcreC: 0.70TOC: 5 MIN.PROPOSED DRAINAGEBASIN #3AREA: 0.14 AcreC: 0.70TOC: 5 MIN.PROPOSED DRAINAGEBASIN #4AREA: 1.61 AcreC: 0.40TOC: 9 MIN.PROPOSED DRAINAGEBASIN #5AREA: 0.41 AcreC: 0.70TOC: 5 MIN.PROPOSED DRAINAGEBASIN #6AREA: 2.17 AcreC: 0.40TOC: 8 MIN.PROPOSED DRAINAGEBASIN #7AREA: 0.41 AcreC: 0.70TOC: 5 MIN.PROPOSED DRAINAGEBASIN #8AREA: 1.48 AcreC: 0.40TOC: 7 MIN.PROPOSED DRAINAGEBASIN #9AREA: 0.82 AcreC: 0.40TOC: 5 MIN.PROPOSED DRAINAGEBASIN #10AREA: 1.71 AcreC: 0.40TOC: 10 MIN.PROPOSED DRAINAGEBASIN #11AREA: 0.38 AcreC: 0.70TOC: 5 MIN.PROPOSED DRAINAGEBASIN #13AREA: 0.52 AcreC: 0.40TOC: 8 MIN.PROPOSED DRAINAGEBASIN #12AREA: 0.34 AcreC: 0.70TOC: 5 MIN.FLOW SEGMENT #1SCS Sheet FlowL=32 FTS=2.00%Travel Time=4.72FLOW SEGMENT #1SCS Sheet FlowL=24 FTS=2.00%Travel Time=3.72FLOW SEGMENT #1SCS Sheet FlowL=93 FTS=2.00%Travel Time=11.00FLOW SEGMENT #1SCS Sheet FlowL=52 FTS=2.00%Travel Time=3.94FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=33.00%Travel Time=6.60FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=10.00%Travel Time=6.10FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=10.00%Travel Time=6.11FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=33.00%Travel Time=3.79FLOW SEGMENT #1SCS Sheet FlowL=92 FTS=33.00%Travel Time=3.54FLOW SEGMENT #1SCS Sheet FlowL=100 FTS=5.00%Travel Time=8.06FLOW SEGMENT #1SCS Sheet FlowL=60 FTS=11.00%Travel Time=6.84FLOW SEGMENT #2SCS Shallow Concentrated FlowL=131 FTS=10.00%Travel Time=1.38FLOW SEGMENT #2SCS Shallow Concentrated FlowL=175 FTS=6.00%Travel Time=2.38FLOW SEGMENT #2SCS Shallow Concentrated FlowL=445 FTS=11.00%Travel Time=4.48FLOW SEGMENT #2SCS Shallow Concentrated FlowL=312 FTS=2.00%Travel Time=2.45FLOW SEGMENT #3SCS Channel FlowL=174 FTS=2.00%Travel Time=0.60FLOW SEGMENT #2SCS Shallow Concentrated FlowL=285 FTS=2.00%Travel Time=2.08FLOW SEGMENT #3SCS Channel FlowL=228 FTS=2.00%Travel Time=0.79FLOW SEGMENT #2SCS Shallow Concentrated FlowL=325 FTS=2.00%Travel Time=2.38FLOW SEGMENT #3SCS Channel FlowL=39 FTS=2.00%Travel Time=0.13FLOW SEGMENT #2SCS Shallow Concentrated FlowL=191 FTS=2.00%Travel Time=1.39FLOW SEGMENT #3SCS Channel FlowL=218 FTS=2.00%Travel Time=0.76FLOW SEGMENT #2SCS Shallow Concentrated FlowL=252 FTS=2.00%Travel Time=1.84FLOW SEGMENT #3SCS Channel FlowL=152 FTS=2.00%Travel Time=0.51FLOW SEGMENT #2SCS Shallow Concentrated FlowL=294 FTS=10.00%Travel Time=0.96VICINITY MAPJOE WHITEF& ASSOCIATES,INC.#3871OET A IFITREC NOITAZIROHTUAC -ENGI N EERARKANSAS 25 RAHLING CIRCLE, SUITE A-2 LITTLE ROCK, ARKANSAS 72223PHONE: (501) 214-9141CIVIL ENGINEERING - CONSULTING SERVICES - LAND SURVEYINGJOE WHITE & ASSOCIATES, INC.PROPOSED DRAINAGE MAPAN ADDITION TO THE CITY OF LITTLE ROCKPULASKI COUNTY, ARKANSASBEING A REDIVISON OF LOT LINES OFLOT 8 OF TRACT 1, CHENAL VALLEYEX. CURB INLET #1 (RELEASE POINT A)EX. CURB INLET #3EX. CURB INLET #2 (RELEASE POINT B)EX. CURB INLET #4 (RELEASE POINT C)EX. CURB INLET #5 (RELEASE POINT D)EX. CURB INLET #6 (RELEASE POINT E)EX. CURB INLET #7 (RELEASE POINT F) 1 - EXISTING OFFSITE A2 - EXISTING OFFSITE B3 - EXISTING OFFSITE C4 - EXISTING DRAINAGE BASIN #15 - EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)6 - EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)7 - EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)8 - EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)9 - EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)10 - EXISTING DRAINAGE BASIN #711 - INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)12 - RELEASE POINT G1Watershed Model SchematicHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021Project: EXISTING DRAINAGE BASINS.gpwMonday, 04 / 29 / 2024Hyd.OriginDescriptionLegend1 Rational EXISTING OFFSITE A2 Rational EXISTING OFFSITE B3 Rational EXISTING OFFSITE C4 Rational EXISTING DRAINAGE BASIN #15 Rational EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)6 Rational EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)7 Rational EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)8 Rational EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)9 Rational EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)10 Rational EXISTING DRAINAGE BASIN #711 Combine INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)12 Combine RELEASE POINT G Hydrograph Return Period Recap2Hyd. Hydrograph Inflow Peak Outflow (cfs) HydrographNo. type hyd(s)Description(origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr1 Rational ------ ------- ------- ------- ------- 0.871 0.997 1.095 1.193 EXISTING OFFSITE A2 Rational ------ ------- ------- ------- ------- 3.652 4.204 4.637 5.068 EXISTING OFFSITE B3 Rational ------ ------- ------- ------- ------- 3.775 4.326 4.759 5.190 EXISTING OFFSITE C4 Rational ------ ------- ------- ------- ------- 3.855 4.463 4.940 5.414 EXISTING DRAINAGE BASIN #15 Rational ------ ------- ------- ------- ------- 0.965 1.104 1.213 1.322 EXISTING DRAINAGE BASIN #2 (RE6 Rational ------ ------- ------- ------- ------- 2.334 2.700 2.986 3.271 EXISTING DRAINAGE BASIN #3 (RE7 Rational ------ ------- ------- ------- ------- 1.977 2.291 2.537 2.782 EXISTING DRAINAGE BASIN #4 (RE8 Rational ------ ------- ------- ------- ------- 0.724 0.826 0.907 0.987 EXISTING DRAINAGE BASIN #5 (RE9 Rational ------ ------- ------- ------- ------- 1.158 1.320 1.447 1.573 EXISTING DRAINAGE BASIN #6 (RE10 Rational ------ ------- ------- ------- ------- 13.84 16.08 17.83 19.58 EXISTING DRAINAGE BASIN #711 Combine 1, 4, ------- ------- ------- ------- 3.855 4.463 4.940 5.414 INFLOW TO EXISTING CURB INLET12 Combine 2, 3, 10, ------- ------- ------- ------- 14.5016.84 18.68 20.50 RELEASE POINT GProj. file: EXISTING DRAINAGE BASINS.gpw Monday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Summary Report3Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum TotalHydrographNo. type flow interval Peak volume hyd(s) elevation strge used Description(origin) (cfs) (min) (min) (cuft) (ft) (cuft)1 Rational 0.997 1 7 419 ------ ------ ------ EXISTING OFFSITE A2 Rational 4.204 1 11 2,775 ------ ------ ------ EXISTING OFFSITE B3 Rational 4.326 1 8 2,077 ------ ------ ------ EXISTING OFFSITE C4 Rational 4.463 1 16 4,285 ------ ------ ------ EXISTING DRAINAGE BASIN #15 Rational 1.104 1 7 464 ------ ------ ------ EXISTING DRAINAGE BASIN #2 (RE6 Rational 2.700 1 15 2,430 ------ ------ ------ EXISTING DRAINAGE BASIN #3 (RE7 Rational 2.291 1 17 2,337 ------ ------ ------ EXISTING DRAINAGE BASIN #4 (RE8 Rational 0.826 1 6 297 ------ ------ ------ EXISTING DRAINAGE BASIN #5 (RE9 Rational 1.320 1 5 396 ------ ------ ------ EXISTING DRAINAGE BASIN #6 (RE10 Rational 16.08 1 20 19,296 ------ ------ ------ EXISTING DRAINAGE BASIN #711 Combine 4.463 1 16 4,704 1, 4, ------ ------ INFLOW TO EXISTING CURB INLET12 Combine 16.84 1 20 24,148 2, 3, 10, ------ ------ RELEASE POINT GEXISTING DRAINAGE BASINS.gpw Return Period: 25 Year Monday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 1EXISTING OFFSITE AHydrograph type = Rational Peak discharge = 0.997 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 419 cuft Drainage area = 0.200 ac Runoff coeff. = 0.65 Intensity = 7.666 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1401234567891011121314Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)EXISTING OFFSITE AHyd. No. 1 -- 25 YearHyd No. 1 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 2EXISTING OFFSITE BHydrograph type = Rational Peak discharge = 4.204 cfs Storm frequency = 25 yrs Time to peak = 11 min Time interval = 1 min Hyd. volume = 2,775 cuft Drainage area = 0.960 ac Runoff coeff. = 0.65 Intensity = 6.737 in/hr Tc by User = 11.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/150246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)EXISTING OFFSITE BHyd. No. 2 -- 25 YearHyd No. 2 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 3EXISTING OFFSITE CHydrograph type = Rational Peak discharge = 4.326 cfs Storm frequency = 25 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 2,077 cuft Drainage area = 1.460 ac Runoff coeff. = 0.4 Intensity = 7.408 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/160246810121416Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)EXISTING OFFSITE CHyd. No. 3 -- 25 YearHyd No. 3 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 4EXISTING DRAINAGE BASIN #1Hydrograph type = Rational Peak discharge = 4.463 cfs Storm frequency = 25 yrs Time to peak = 16 min Time interval = 1 min Hyd. volume = 4,285 cuft Drainage area = 1.900 ac Runoff coeff. = 0.4 Intensity = 5.873 in/hr Tc by User = 16.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1702468101214161820222426283032Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #1Hyd. No. 4 -- 25 YearHyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 5EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)Hydrograph type = Rational Peak discharge = 1.104 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 464 cuft Drainage area = 0.360 ac Runoff coeff. = 0.4 Intensity = 7.666 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1801234567891011121314Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)Hyd. No. 5 -- 25 YearHyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 6EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)Hydrograph type = Rational Peak discharge = 2.700 cfs Storm frequency = 25 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 2,430 cuft Drainage area = 1.120 ac Runoff coeff. = 0.4 Intensity = 6.026 in/hr Tc by User = 15.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/19024681012141618202224262830Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)Hyd. No. 6 -- 25 YearHyd No. 6 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 7EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)Hydrograph type = Rational Peak discharge = 2.291 cfs Storm frequency = 25 yrs Time to peak = 17 min Time interval = 1 min Hyd. volume = 2,337 cuft Drainage area = 1.000 ac Runoff coeff. = 0.4 Intensity = 5.729 in/hr Tc by User = 17.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1100246810121416182022242628303234Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)Hyd. No. 7 -- 25 YearHyd No. 7 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 8EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)Hydrograph type = Rational Peak discharge = 0.826 cfs Storm frequency = 25 yrs Time to peak = 6 min Time interval = 1 min Hyd. volume = 297 cuft Drainage area = 0.130 ac Runoff coeff. = 0.8 Intensity = 7.945 in/hr Tc by User = 6.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1110123456789101112Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)Hyd. No. 8 -- 25 YearHyd No. 8 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 9EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)Hydrograph type = Rational Peak discharge = 1.320 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 396 cuft Drainage area = 0.200 ac Runoff coeff. = 0.8 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/112012345678910Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)Hyd. No. 9 -- 25 YearHyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 10EXISTING DRAINAGE BASIN #7Hydrograph type = Rational Peak discharge = 16.08 cfs Storm frequency = 25 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 19,296 cuft Drainage area = 7.530 ac Runoff coeff. = 0.4 Intensity = 5.339 in/hr Tc by User = 20.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1130246810121416182022242628303234363840Q (cfs)0.000.003.003.006.006.009.009.0012.0012.0015.0015.0018.0018.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #7Hyd. No. 10 -- 25 YearHyd No. 10 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 11INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)Hydrograph type = Combine Peak discharge = 4.463 cfs Storm frequency = 25 yrs Time to peak = 16 min Time interval = 1 min Hyd. volume = 4,704 cuft Inflow hyds. = 1, 4 Contrib. drain. area = 2.100 ac1402468101214161820222426283032Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)Hyd. No. 11 -- 25 YearHyd No. 11Hyd No. 1Hyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 12RELEASE POINT GHydrograph type = Combine Peak discharge = 16.84 cfs Storm frequency = 25 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 24,148 cuft Inflow hyds. = 2, 3, 10 Contrib. drain. area = 9.950 ac150246810121416182022242628303234363840Q (cfs)0.000.003.003.006.006.009.009.0012.0012.0015.0015.0018.0018.00Q (cfs)Time (min)RELEASE POINT GHyd. No. 12 -- 25 YearHyd No. 12Hyd No. 2Hyd No. 3Hyd No. 10 Hydrograph Summary Report16Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum TotalHydrographNo. type flow interval Peak volume hyd(s) elevation strge used Description(origin) (cfs) (min) (min) (cuft) (ft) (cuft)1 Rational 1.193 1 7 501 ------ ------ ------ EXISTING OFFSITE A2 Rational 5.068 1 11 3,345 ------ ------ ------ EXISTING OFFSITE B3 Rational 5.190 1 8 2,491 ------ ------ ------ EXISTING OFFSITE C4 Rational 5.414 1 16 5,197 ------ ------ ------ EXISTING DRAINAGE BASIN #15 Rational 1.322 1 7 555 ------ ------ ------ EXISTING DRAINAGE BASIN #2 (RE6 Rational 3.271 1 15 2,944 ------ ------ ------ EXISTING DRAINAGE BASIN #3 (RE7 Rational 2.782 1 17 2,838 ------ ------ ------ EXISTING DRAINAGE BASIN #4 (RE8 Rational 0.987 1 6 355 ------ ------ ------ EXISTING DRAINAGE BASIN #5 (RE9 Rational 1.573 1 5 472 ------ ------ ------ EXISTING DRAINAGE BASIN #6 (RE10 Rational 19.58 1 20 23,495 ------ ------ ------ EXISTING DRAINAGE BASIN #711 Combine 5.414 1 16 5,699 1, 4, ------ ------ INFLOW TO EXISTING CURB INLET12 Combine 20.50 1 20 29,331 2, 3, 10, ------ ------ RELEASE POINT GEXISTING DRAINAGE BASINS.gpw Return Period: 100 YearMonday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 1EXISTING OFFSITE AHydrograph type = Rational Peak discharge = 1.193 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 501 cuft Drainage area = 0.200 ac Runoff coeff. = 0.65 Intensity = 9.179 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/11701234567891011121314Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)EXISTING OFFSITE AHyd. No. 1 -- 100 YearHyd No. 1 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 2EXISTING OFFSITE BHydrograph type = Rational Peak discharge = 5.068 cfs Storm frequency = 100 yrs Time to peak = 11 min Time interval = 1 min Hyd. volume = 3,345 cuft Drainage area = 0.960 ac Runoff coeff. = 0.65 Intensity = 8.121 in/hr Tc by User = 11.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1180246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)EXISTING OFFSITE BHyd. No. 2 -- 100 YearHyd No. 2 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 3EXISTING OFFSITE CHydrograph type = Rational Peak discharge = 5.190 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 2,491 cuft Drainage area = 1.460 ac Runoff coeff. = 0.4 Intensity = 8.886 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1190246810121416Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)EXISTING OFFSITE CHyd. No. 3 -- 100 YearHyd No. 3 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 4EXISTING DRAINAGE BASIN #1Hydrograph type = Rational Peak discharge = 5.414 cfs Storm frequency = 100 yrs Time to peak = 16 min Time interval = 1 min Hyd. volume = 5,197 cuft Drainage area = 1.900 ac Runoff coeff. = 0.4 Intensity = 7.124 in/hr Tc by User = 16.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/12002468101214161820222426283032Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #1Hyd. No. 4 -- 100 YearHyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 5EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)Hydrograph type = Rational Peak discharge = 1.322 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 555 cuft Drainage area = 0.360 ac Runoff coeff. = 0.4 Intensity = 9.179 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/12101234567891011121314Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #2 (RELEASE POINT A)Hyd. No. 5 -- 100 YearHyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 6EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)Hydrograph type = Rational Peak discharge = 3.271 cfs Storm frequency = 100 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 2,944 cuft Drainage area = 1.120 ac Runoff coeff. = 0.4 Intensity = 7.301 in/hr Tc by User = 15.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/122024681012141618202224262830Q (cfs)0.000.001.001.002.002.003.003.004.004.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #3 (RELEASE POINT C)Hyd. No. 6 -- 100 YearHyd No. 6 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 7EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)Hydrograph type = Rational Peak discharge = 2.782 cfs Storm frequency = 100 yrs Time to peak = 17 min Time interval = 1 min Hyd. volume = 2,838 cuft Drainage area = 1.000 ac Runoff coeff. = 0.4 Intensity = 6.956 in/hr Tc by User = 17.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1230246810121416182022242628303234Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #4 (RELEASE POINT D)Hyd. No. 7 -- 100 YearHyd No. 7 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 8EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)Hydrograph type = Rational Peak discharge = 0.987 cfs Storm frequency = 100 yrs Time to peak = 6 min Time interval = 1 min Hyd. volume = 355 cuft Drainage area = 0.130 ac Runoff coeff. = 0.8 Intensity = 9.493 in/hr Tc by User = 6.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1240123456789101112Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #5 (RELEASE POINT E)Hyd. No. 8 -- 100 YearHyd No. 8 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 9EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)Hydrograph type = Rational Peak discharge = 1.573 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 472 cuft Drainage area = 0.200 ac Runoff coeff. = 0.8 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/125012345678910Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #6 (RELEASE POINT F)Hyd. No. 9 -- 100 YearHyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 10EXISTING DRAINAGE BASIN #7Hydrograph type = Rational Peak discharge = 19.58 cfs Storm frequency = 100 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 23,495 cuft Drainage area = 7.530 ac Runoff coeff. = 0.4 Intensity = 6.500 in/hr Tc by User = 20.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1260246810121416182022242628303234363840Q (cfs)0.000.003.003.006.006.009.009.0012.0012.0015.0015.0018.0018.0021.0021.00Q (cfs)Time (min)EXISTING DRAINAGE BASIN #7Hyd. No. 10 -- 100 YearHyd No. 10 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 11INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)Hydrograph type = Combine Peak discharge = 5.414 cfs Storm frequency = 100 yrs Time to peak = 16 min Time interval = 1 min Hyd. volume = 5,699 cuft Inflow hyds. = 1, 4 Contrib. drain. area = 2.100 ac2702468101214161820222426283032Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)INFLOW TO EXISTING CURB INLET #2 (RELEASE POINT B)Hyd. No. 11 -- 100 YearHyd No. 11Hyd No. 1Hyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 12RELEASE POINT GHydrograph type = Combine Peak discharge = 20.50 cfs Storm frequency = 100 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 29,331 cuft Inflow hyds. = 2, 3, 10 Contrib. drain. area = 9.950 ac280246810121416182022242628303234363840Q (cfs)0.000.003.003.006.006.009.009.0012.0012.0015.0015.0018.0018.0021.0021.00Q (cfs)Time (min)RELEASE POINT GHyd. No. 12 -- 100 YearHyd No. 12Hyd No. 2Hyd No. 3Hyd No. 10 Hydraflow Rainfall Report29Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Return Intensity-Duration-Frequency Equation Coefficients (FHA)Period(Yrs) B D E (N/A)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: LITTLE ROCK IDF.IDFIntensity = B / (Tc + D)^EReturn Intensity Values (in/hr)Period(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 601 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.002 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.703 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.005 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.1510 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.4625 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.9150 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60Tc = time in minutes. Values may exceed 60.Rainfall Precipitation Table (in)Precip. file name: G:\DWG\2022\22-457J - Conway Westrock\Drainage Calcs\Modified Rational Method\Conway SCS.pcpStormDistribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yrSCS 24-hour 0.00 4.13 0.00 0.00 6.10 7.00 7.80 8.50SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 - OFFSITE DRAINAGE BASIN A2 - OFFSITE DRAINAGE BASIN B3 - OFFSITE DRAINAGE BASIN C4 - OFFSITE DRAINAGE BASIN D5 - PROPOSED DRAINAGE BASIN #16 - PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)7 - PROPOSED DRAINAGE BASIN #38 - PROPOSED DRAINAGE BASIN #4 (PIPE #2)9 - PROPOSED DRAINAGE BASIN #510 - PROPOSED DRAINAGE BASIN #6 (PIPE #3)11 - PROPOSED DRAINAGE BASIN #712 - PROPOSED DRAINAGE BASIN #813 - PROPOSED DRAINAGE BASIN #914 - PROPOSED DRAINAGE BASIN #10 (PIPE #4)15 - PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)16 - PROPOSED DRAINAGE BASIN #1217 - PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)18 - INFLOW TO PIPE #119 - INFLOW TO INLET20 - INFLOW TO HEADWALL21 - TOTAL TO RELEASE POINT B22 - TOTAL TO RELEASE POINT C23 - TOTAL TO RELEASE POINT D24 - TOTAL TO RELEASE POINT F1Watershed Model SchematicHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021Project: PROPOSED DRAINAGE BASINS.gpwMonday, 04 / 29 / 2024Hyd.OriginDescriptionLegend1 Rational OFFSITE DRAINAGE BASIN A2 Rational OFFSITE DRAINAGE BASIN B3 Rational OFFSITE DRAINAGE BASIN C4 Rational OFFSITE DRAINAGE BASIN D5 Rational PROPOSED DRAINAGE BASIN #16 Rational PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)7 Rational PROPOSED DRAINAGE BASIN #38 Rational PROPOSED DRAINAGE BASIN #4 (PIPE #2)9 Rational PROPOSED DRAINAGE BASIN #510 Rational PROPOSED DRAINAGE BASIN #6 (PIPE #3)11 Rational PROPOSED DRAINAGE BASIN #712 Rational PROPOSED DRAINAGE BASIN #813 Rational PROPOSED DRAINAGE BASIN #914 Rational PROPOSED DRAINAGE BASIN #10 (PIPE #4)15 Rational PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)16 Rational PROPOSED DRAINAGE BASIN #1217 Rational PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)18 Combine INFLOW TO PIPE #119 Combine INFLOW TO INLET20 Combine INFLOW TO HEADWALL21 Combine TOTAL TO RELEASE POINT B22 Combine TOTAL TO RELEASE POINT C23 Combine TOTAL TO RELEASE POINT D24 Combine TOTAL TO RELEASE POINT F Hydrograph Return Period Recap2Hyd. Hydrograph Inflow Peak Outflow (cfs) HydrographNo. type hyd(s)Description(origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr1 Rational ------ ------- ------- ------- ------- 0.871 0.997 1.095 1.193 OFFSITE DRAINAGE BASIN A2 Rational ------ ------- ------- ------- ------- 0.706 0.804 0.881 0.959 OFFSITE DRAINAGE BASIN B3 Rational ------ ------- ------- ------- ------- 3.081 3.547 3.912 4.276 OFFSITE DRAINAGE BASIN C4 Rational ------ ------- ------- ------- ------- 3.775 4.326 4.759 5.190 OFFSITE DRAINAGE BASIN D5 Rational ------ ------- ------- ------- ------- 4.954 5.695 6.276 6.855 PROPOSED DRAINAGE BASIN #16 Rational ------ ------- ------- ------- ------- 0.963 1.097 1.202 1.308 PROPOSED DRAINAGE BASIN #2 (7 Rational ------ ------- ------- ------- ------- 0.709 0.808 0.886 0.964 PROPOSED DRAINAGE BASIN #38 Rational ------ ------- ------- ------- ------- 4.022 4.616 5.083 5.547 PROPOSED DRAINAGE BASIN #4 (9 Rational ------ ------- ------- ------- ------- 2.077 2.367 2.595 2.822 PROPOSED DRAINAGE BASIN #510 Rational ------ ------- ------- ------- ------- 5.611 6.430 7.073 7.713 PROPOSED DRAINAGE BASIN #6 (11 Rational ------ ------- ------- ------- ------- 2.077 2.367 2.595 2.822 PROPOSED DRAINAGE BASIN #712 Rational ------ ------- ------- ------- ------- 3.967 4.538 4.987 5.434 PROPOSED DRAINAGE BASIN #813 Rational ------ ------- ------- ------- ------- 2.374 2.705 2.965 3.225 PROPOSED DRAINAGE BASIN #914 Rational ------ ------- ------- ------- ------- 4.132 4.751 5.235 5.718 PROPOSED DRAINAGE BASIN #1015 Rational ------ ------- ------- ------- ------- 1.925 2.194 2.405 2.616 PROPOSED DRAINAGE BASIN #1116 Rational ------ ------- ------- ------- ------- 1.723 1.963 2.152 2.340 PROPOSED DRAINAGE BASIN #1217 Rational ------ ------- ------- ------- ------- 1.345 1.541 1.695 1.848 PROPOSED DRAINAGE BASIN #1318 Combine 1, 5, ------- ------- ------- ------- 5.452 6.265 6.902 7.537 INFLOW TO PIPE #119 Combine 2, 12, ------- ------- ------- ------- 4.391 5.021 5.516 6.009 INFLOW TO INLET20 Combine 3, 13, ------- ------- ------- ------- 3.775 4.317 4.744 5.169 INFLOW TO HEADWALL21 Combine 7, 18, ------- ------- ------- ------- 5.452 6.265 6.902 7.537 TOTAL TO RELEASE POINT B22 Combine 8, 9, ------- ------- ------- ------- 4.437 5.090 5.602 6.112 TOTAL TO RELEASE POINT C23 Combine 10, 11, ------- ------- ------- ------- 6.442 7.377 8.111 8.842 TOTAL TO RELEASE POINT D24 Combine 14, 16, 19,20,------- ------- ------- ------- 11.70 13.40 14.74 16.07 TOTAL TO RELEASE POINT FProj. file: PROPOSED DRAINAGE BASINS.gpw Monday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Summary Report3Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum TotalHydrographNo. type flow interval Peak volume hyd(s) elevation strge used Description(origin) (cfs) (min) (min) (cuft) (ft) (cuft)1 Rational 0.997 1 7 419 ------ ------ ------ OFFSITE DRAINAGE BASIN A2 Rational 0.804 1 5 241 ------ ------ ------ OFFSITE DRAINAGE BASIN B3 Rational 3.547 1 11 2,341 ------ ------ ------ OFFSITE DRAINAGE BASIN C4 Rational 4.326 1 8 2,077 ------ ------ ------ OFFSITE DRAINAGE BASIN D5 Rational 5.695 1 10 3,417 ------ ------ ------ PROPOSED DRAINAGE BASIN #16 Rational 1.097 1 5 329 ------ ------ ------ PROPOSED DRAINAGE BASIN #2 (7 Rational 0.808 1 5 242 ------ ------ ------ PROPOSED DRAINAGE BASIN #38 Rational 4.616 1 9 2,493 ------ ------ ------ PROPOSED DRAINAGE BASIN #4 (9 Rational 2.367 1 5 710 ------ ------ ------ PROPOSED DRAINAGE BASIN #510 Rational 6.430 1 8 3,086 ------ ------ ------ PROPOSED DRAINAGE BASIN #6 (11 Rational 2.367 1 5 710 ------ ------ ------ PROPOSED DRAINAGE BASIN #712 Rational 4.538 1 7 1,906 ------ ------ ------ PROPOSED DRAINAGE BASIN #813 Rational 2.705 1 5 812 ------ ------ ------ PROPOSED DRAINAGE BASIN #914 Rational 4.751 1 10 2,850 ------ ------ ------ PROPOSED DRAINAGE BASIN #1015 Rational 2.194 1 5 658 ------ ------ ------ PROPOSED DRAINAGE BASIN #1116 Rational 1.963 1 5 589 ------ ------ ------ PROPOSED DRAINAGE BASIN #1217 Rational 1.541 1 8 740 ------ ------ ------ PROPOSED DRAINAGE BASIN #1318 Combine 6.265 1 10 3,836 1, 5, ------ ------ INFLOW TO PIPE #119 Combine 5.021 1 7 2,147 2, 12, ------ ------ INFLOW TO INLET20 Combine 4.317 1 5 3,153 3, 13, ------ ------ INFLOW TO HEADWALL21 Combine 6.265 1 10 4,078 7, 18, ------ ------ TOTAL TO RELEASE POINT B22 Combine 5.090 1 9 3,203 8, 9, ------ ------ TOTAL TO RELEASE POINT C23 Combine 7.377 1 8 3,797 10, 11, ------ ------ TOTAL TO RELEASE POINT D24 Combine 13.40 1 7 8,739 14, 16, 19,20,------ ------ TOTAL TO RELEASE POINT FPROPOSED DRAINAGE BASINS.gpw Return Period: 25 Year Monday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 1OFFSITE DRAINAGE BASIN AHydrograph type = Rational Peak discharge = 0.997 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 419 cuft Drainage area = 0.200 ac Runoff coeff. = 0.65 Intensity = 7.666 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1401234567891011121314Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN AHyd. No. 1 -- 25 YearHyd No. 1 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 2OFFSITE DRAINAGE BASIN BHydrograph type = Rational Peak discharge = 0.804 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 241 cuft Drainage area = 0.150 ac Runoff coeff. = 0.65 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/15012345678910Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN BHyd. No. 2 -- 25 YearHyd No. 2 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 3OFFSITE DRAINAGE BASIN CHydrograph type = Rational Peak discharge = 3.547 cfs Storm frequency = 25 yrs Time to peak = 11 min Time interval = 1 min Hyd. volume = 2,341 cuft Drainage area = 0.810 ac Runoff coeff. = 0.65 Intensity = 6.737 in/hr Tc by User = 11.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/160246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN CHyd. No. 3 -- 25 YearHyd No. 3 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 4OFFSITE DRAINAGE BASIN DHydrograph type = Rational Peak discharge = 4.326 cfs Storm frequency = 25 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 2,077 cuft Drainage area = 1.460 ac Runoff coeff. = 0.4 Intensity = 7.408 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/170246810121416Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN DHyd. No. 4 -- 25 YearHyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 5PROPOSED DRAINAGE BASIN #1Hydrograph type = Rational Peak discharge = 5.695 cfs Storm frequency = 25 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 3,417 cuft Drainage area = 2.050 ac Runoff coeff. = 0.4 Intensity = 6.945 in/hr Tc by User = 10.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1802468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #1Hyd. No. 5 -- 25 YearHyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 6PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)Hydrograph type = Rational Peak discharge = 1.097 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 329 cuft Drainage area = 0.190 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/19012345678910Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)Hyd. No. 6 -- 25 YearHyd No. 6 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 7PROPOSED DRAINAGE BASIN #3Hydrograph type = Rational Peak discharge = 0.808 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 242 cuft Drainage area = 0.140 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/110012345678910Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #3Hyd. No. 7 -- 25 YearHyd No. 7 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 8PROPOSED DRAINAGE BASIN #4 (PIPE #2)Hydrograph type = Rational Peak discharge = 4.616 cfs Storm frequency = 25 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 2,493 cuft Drainage area = 1.610 ac Runoff coeff. = 0.4 Intensity = 7.168 in/hr Tc by User = 9.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/111024681012141618Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #4 (PIPE #2)Hyd. No. 8 -- 25 YearHyd No. 8 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 9PROPOSED DRAINAGE BASIN #5Hydrograph type = Rational Peak discharge = 2.367 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 710 cuft Drainage area = 0.410 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/112012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #5Hyd. No. 9 -- 25 YearHyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 10PROPOSED DRAINAGE BASIN #6 (PIPE #3)Hydrograph type = Rational Peak discharge = 6.430 cfs Storm frequency = 25 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 3,086 cuft Drainage area = 2.170 ac Runoff coeff. = 0.4 Intensity = 7.408 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1130246810121416Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #6 (PIPE #3)Hyd. No. 10 -- 25 YearHyd No. 10 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 11PROPOSED DRAINAGE BASIN #7Hydrograph type = Rational Peak discharge = 2.367 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 710 cuft Drainage area = 0.410 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/114012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #7Hyd. No. 11 -- 25 YearHyd No. 11 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 12PROPOSED DRAINAGE BASIN #8Hydrograph type = Rational Peak discharge = 4.538 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 1,906 cuft Drainage area = 1.480 ac Runoff coeff. = 0.4 Intensity = 7.666 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/11501234567891011121314Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #8Hyd. No. 12 -- 25 YearHyd No. 12 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 13PROPOSED DRAINAGE BASIN #9Hydrograph type = Rational Peak discharge = 2.705 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 812 cuft Drainage area = 0.820 ac Runoff coeff. = 0.4 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/116012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #9Hyd. No. 13 -- 25 YearHyd No. 13 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 14PROPOSED DRAINAGE BASIN #10 (PIPE #4)Hydrograph type = Rational Peak discharge = 4.751 cfs Storm frequency = 25 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 2,850 cuft Drainage area = 1.710 ac Runoff coeff. = 0.4 Intensity = 6.945 in/hr Tc by User = 10.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/11702468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #10 (PIPE #4)Hyd. No. 14 -- 25 YearHyd No. 14 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 15PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)Hydrograph type = Rational Peak discharge = 2.194 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 658 cuft Drainage area = 0.380 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/118012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)Hyd. No. 15 -- 25 YearHyd No. 15 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 16PROPOSED DRAINAGE BASIN #12Hydrograph type = Rational Peak discharge = 1.963 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 589 cuft Drainage area = 0.340 ac Runoff coeff. = 0.7 Intensity = 8.247 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/119012345678910Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #12Hyd. No. 16 -- 25 YearHyd No. 16 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 17PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)Hydrograph type = Rational Peak discharge = 1.541 cfs Storm frequency = 25 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 740 cuft Drainage area = 0.520 ac Runoff coeff. = 0.4 Intensity = 7.408 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1200246810121416Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)Hyd. No. 17 -- 25 YearHyd No. 17 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 18INFLOW TO PIPE #1Hydrograph type = Combine Peak discharge = 6.265 cfs Storm frequency = 25 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 3,836 cuft Inflow hyds. = 1, 5 Contrib. drain. area = 2.250 ac2102468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)INFLOW TO PIPE #1Hyd. No. 18 -- 25 YearHyd No. 18Hyd No. 1Hyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 19INFLOW TO INLETHydrograph type = Combine Peak discharge = 5.021 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 2,147 cuft Inflow hyds. = 2, 12 Contrib. drain. area = 1.630 ac2201234567891011121314Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)INFLOW TO INLETHyd. No. 19 -- 25 YearHyd No. 19Hyd No. 2Hyd No. 12 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 20INFLOW TO HEADWALLHydrograph type = Combine Peak discharge = 4.317 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 3,153 cuft Inflow hyds. = 3, 13 Contrib. drain. area = 1.630 ac230246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)INFLOW TO HEADWALLHyd. No. 20 -- 25 YearHyd No. 20Hyd No. 3Hyd No. 13 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 21TOTAL TO RELEASE POINT BHydrograph type = Combine Peak discharge = 6.265 cfs Storm frequency = 25 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 4,078 cuft Inflow hyds. = 7, 18 Contrib. drain. area = 0.140 ac2402468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)TOTAL TO RELEASE POINT BHyd. No. 21 -- 25 YearHyd No. 21Hyd No. 7Hyd No. 18 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 22TOTAL TO RELEASE POINT CHydrograph type = Combine Peak discharge = 5.090 cfs Storm frequency = 25 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 3,203 cuft Inflow hyds. = 8, 9 Contrib. drain. area = 2.020 ac25024681012141618Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)TOTAL TO RELEASE POINT CHyd. No. 22 -- 25 YearHyd No. 22Hyd No. 8Hyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 23TOTAL TO RELEASE POINT DHydrograph type = Combine Peak discharge = 7.377 cfs Storm frequency = 25 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 3,797 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 2.580 ac260246810121416Q (cfs)0.000.002.002.004.004.006.006.008.008.00Q (cfs)Time (min)TOTAL TO RELEASE POINT DHyd. No. 23 -- 25 YearHyd No. 23Hyd No. 10Hyd No. 11 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 24TOTAL TO RELEASE POINT FHydrograph type = Combine Peak discharge = 13.40 cfs Storm frequency = 25 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 8,739 cuft Inflow hyds. = 14, 16, 19, 20 Contrib. drain. area = 2.050 ac270246810121416182022Q (cfs)0.000.002.002.004.004.006.006.008.008.0010.0010.0012.0012.0014.0014.00Q (cfs)Time (min)TOTAL TO RELEASE POINT FHyd. No. 24 -- 25 YearHyd No. 24Hyd No. 14Hyd No. 16Hyd No. 19Hyd No. 20 Hydrograph Summary Report28Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum TotalHydrographNo. type flow interval Peak volume hyd(s) elevation strge used Description(origin) (cfs) (min) (min) (cuft) (ft) (cuft)1 Rational 1.193 1 7 501 ------ ------ ------ OFFSITE DRAINAGE BASIN A2 Rational 0.959 1 5 288 ------ ------ ------ OFFSITE DRAINAGE BASIN B3 Rational 4.276 1 11 2,822 ------ ------ ------ OFFSITE DRAINAGE BASIN C4 Rational 5.190 1 8 2,491 ------ ------ ------ OFFSITE DRAINAGE BASIN D5 Rational 6.855 1 10 4,113 ------ ------ ------ PROPOSED DRAINAGE BASIN #16 Rational 1.308 1 5 392 ------ ------ ------ PROPOSED DRAINAGE BASIN #2 (7 Rational 0.964 1 5 289 ------ ------ ------ PROPOSED DRAINAGE BASIN #38 Rational 5.547 1 9 2,996 ------ ------ ------ PROPOSED DRAINAGE BASIN #4 (9 Rational 2.822 1 5 847 ------ ------ ------ PROPOSED DRAINAGE BASIN #510 Rational 7.713 1 8 3,702 ------ ------ ------ PROPOSED DRAINAGE BASIN #6 (11 Rational 2.822 1 5 847 ------ ------ ------ PROPOSED DRAINAGE BASIN #712 Rational 5.434 1 7 2,282 ------ ------ ------ PROPOSED DRAINAGE BASIN #813 Rational 3.225 1 5 968 ------ ------ ------ PROPOSED DRAINAGE BASIN #914 Rational 5.718 1 10 3,431 ------ ------ ------ PROPOSED DRAINAGE BASIN #1015 Rational 2.616 1 5 785 ------ ------ ------ PROPOSED DRAINAGE BASIN #1116 Rational 2.340 1 5 702 ------ ------ ------ PROPOSED DRAINAGE BASIN #1217 Rational 1.848 1 8 887 ------ ------ ------ PROPOSED DRAINAGE BASIN #1318 Combine 7.537 1 10 4,614 1, 5, ------ ------ INFLOW TO PIPE #119 Combine 6.009 1 7 2,570 2, 12, ------ ------ INFLOW TO INLET20 Combine 5.169 1 5 3,790 3, 13, ------ ------ INFLOW TO HEADWALL21 Combine 7.537 1 10 4,903 7, 18, ------ ------ TOTAL TO RELEASE POINT B22 Combine 6.112 1 9 3,842 8, 9, ------ ------ TOTAL TO RELEASE POINT C23 Combine 8.842 1 8 4,549 10, 11, ------ ------ TOTAL TO RELEASE POINT D24 Combine 16.07 1 7 10,492 14, 16, 19,20,------ ------ TOTAL TO RELEASE POINT FPROPOSED DRAINAGE BASINS.gpw Return Period: 100 YearMonday, 04 / 29 / 2024Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 1OFFSITE DRAINAGE BASIN AHydrograph type = Rational Peak discharge = 1.193 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 501 cuft Drainage area = 0.200 ac Runoff coeff. = 0.65 Intensity = 9.179 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/12901234567891011121314Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN AHyd. No. 1 -- 100 YearHyd No. 1 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 2OFFSITE DRAINAGE BASIN BHydrograph type = Rational Peak discharge = 0.959 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 288 cuft Drainage area = 0.150 ac Runoff coeff. = 0.65 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/130012345678910Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN BHyd. No. 2 -- 100 YearHyd No. 2 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 3OFFSITE DRAINAGE BASIN CHydrograph type = Rational Peak discharge = 4.276 cfs Storm frequency = 100 yrs Time to peak = 11 min Time interval = 1 min Hyd. volume = 2,822 cuft Drainage area = 0.810 ac Runoff coeff. = 0.65 Intensity = 8.121 in/hr Tc by User = 11.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1310246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN CHyd. No. 3 -- 100 YearHyd No. 3 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 4OFFSITE DRAINAGE BASIN DHydrograph type = Rational Peak discharge = 5.190 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 2,491 cuft Drainage area = 1.460 ac Runoff coeff. = 0.4 Intensity = 8.886 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1320246810121416Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)OFFSITE DRAINAGE BASIN DHyd. No. 4 -- 100 YearHyd No. 4 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 5PROPOSED DRAINAGE BASIN #1Hydrograph type = Rational Peak discharge = 6.855 cfs Storm frequency = 100 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 4,113 cuft Drainage area = 2.050 ac Runoff coeff. = 0.4 Intensity = 8.360 in/hr Tc by User = 10.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/13302468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #1Hyd. No. 5 -- 100 YearHyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 6PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)Hydrograph type = Rational Peak discharge = 1.308 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 392 cuft Drainage area = 0.190 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/134012345678910Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #2 (RELEASE POINT A)Hyd. No. 6 -- 100 YearHyd No. 6 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 7PROPOSED DRAINAGE BASIN #3Hydrograph type = Rational Peak discharge = 0.964 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 289 cuft Drainage area = 0.140 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/135012345678910Q (cfs)0.000.000.100.100.200.200.300.300.400.400.500.500.600.600.700.700.800.800.900.901.001.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #3Hyd. No. 7 -- 100 YearHyd No. 7 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 8PROPOSED DRAINAGE BASIN #4 (PIPE #2)Hydrograph type = Rational Peak discharge = 5.547 cfs Storm frequency = 100 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 2,996 cuft Drainage area = 1.610 ac Runoff coeff. = 0.4 Intensity = 8.614 in/hr Tc by User = 9.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/136024681012141618Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #4 (PIPE #2)Hyd. No. 8 -- 100 YearHyd No. 8 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 9PROPOSED DRAINAGE BASIN #5Hydrograph type = Rational Peak discharge = 2.822 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 847 cuft Drainage area = 0.410 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/137012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #5Hyd. No. 9 -- 100 YearHyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 10PROPOSED DRAINAGE BASIN #6 (PIPE #3)Hydrograph type = Rational Peak discharge = 7.713 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 3,702 cuft Drainage area = 2.170 ac Runoff coeff. = 0.4 Intensity = 8.886 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1380246810121416Q (cfs)0.000.002.002.004.004.006.006.008.008.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #6 (PIPE #3)Hyd. No. 10 -- 100 YearHyd No. 10 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 11PROPOSED DRAINAGE BASIN #7Hydrograph type = Rational Peak discharge = 2.822 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 847 cuft Drainage area = 0.410 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/139012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #7Hyd. No. 11 -- 100 YearHyd No. 11 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 12PROPOSED DRAINAGE BASIN #8Hydrograph type = Rational Peak discharge = 5.434 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 2,282 cuft Drainage area = 1.480 ac Runoff coeff. = 0.4 Intensity = 9.179 in/hr Tc by User = 7.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/14001234567891011121314Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #8Hyd. No. 12 -- 100 YearHyd No. 12 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 13PROPOSED DRAINAGE BASIN #9Hydrograph type = Rational Peak discharge = 3.225 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 968 cuft Drainage area = 0.820 ac Runoff coeff. = 0.4 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/141012345678910Q (cfs)0.000.001.001.002.002.003.003.004.004.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #9Hyd. No. 13 -- 100 YearHyd No. 13 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 14PROPOSED DRAINAGE BASIN #10 (PIPE #4)Hydrograph type = Rational Peak discharge = 5.718 cfs Storm frequency = 100 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 3,431 cuft Drainage area = 1.710 ac Runoff coeff. = 0.4 Intensity = 8.360 in/hr Tc by User = 10.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/14202468101214161820Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #10 (PIPE #4)Hyd. No. 14 -- 100 YearHyd No. 14 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 15PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)Hydrograph type = Rational Peak discharge = 2.616 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 785 cuft Drainage area = 0.380 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/143012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #11 (RELEASE POINT E)Hyd. No. 15 -- 100 YearHyd No. 15 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 16PROPOSED DRAINAGE BASIN #12Hydrograph type = Rational Peak discharge = 2.340 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 702 cuft Drainage area = 0.340 ac Runoff coeff. = 0.7 Intensity = 9.833 in/hr Tc by User = 5.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/144012345678910Q (cfs)0.000.001.001.002.002.003.003.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #12Hyd. No. 16 -- 100 YearHyd No. 16 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 17PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)Hydrograph type = Rational Peak discharge = 1.848 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 887 cuft Drainage area = 0.520 ac Runoff coeff. = 0.4 Intensity = 8.886 in/hr Tc by User = 8.00 min IDF Curve = LITTLE ROCK IDF.IDF Asc/Rec limb fact = 1/1450246810121416Q (cfs)0.000.001.001.002.002.00Q (cfs)Time (min)PROPOSED DRAINAGE BASIN #13 (RELEASE POINT G)Hyd. No. 17 -- 100 YearHyd No. 17 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 18INFLOW TO PIPE #1Hydrograph type = Combine Peak discharge = 7.537 cfs Storm frequency = 100 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 4,614 cuft Inflow hyds. = 1, 5 Contrib. drain. area = 2.250 ac4602468101214161820Q (cfs)0.000.002.002.004.004.006.006.008.008.00Q (cfs)Time (min)INFLOW TO PIPE #1Hyd. No. 18 -- 100 YearHyd No. 18Hyd No. 1Hyd No. 5 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 19INFLOW TO INLETHydrograph type = Combine Peak discharge = 6.009 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 2,570 cuft Inflow hyds. = 2, 12 Contrib. drain. area = 1.630 ac4701234567891011121314Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)INFLOW TO INLETHyd. No. 19 -- 100 YearHyd No. 19Hyd No. 2Hyd No. 12 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 20INFLOW TO HEADWALLHydrograph type = Combine Peak discharge = 5.169 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 3,790 cuft Inflow hyds. = 3, 13 Contrib. drain. area = 1.630 ac480246810121416182022Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.00Q (cfs)Time (min)INFLOW TO HEADWALLHyd. No. 20 -- 100 YearHyd No. 20Hyd No. 3Hyd No. 13 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 21TOTAL TO RELEASE POINT BHydrograph type = Combine Peak discharge = 7.537 cfs Storm frequency = 100 yrs Time to peak = 10 min Time interval = 1 min Hyd. volume = 4,903 cuft Inflow hyds. = 7, 18 Contrib. drain. area = 0.140 ac4902468101214161820Q (cfs)0.000.002.002.004.004.006.006.008.008.00Q (cfs)Time (min)TOTAL TO RELEASE POINT BHyd. No. 21 -- 100 YearHyd No. 21Hyd No. 7Hyd No. 18 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 22TOTAL TO RELEASE POINT CHydrograph type = Combine Peak discharge = 6.112 cfs Storm frequency = 100 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 3,842 cuft Inflow hyds. = 8, 9 Contrib. drain. area = 2.020 ac50024681012141618Q (cfs)0.000.001.001.002.002.003.003.004.004.005.005.006.006.007.007.00Q (cfs)Time (min)TOTAL TO RELEASE POINT CHyd. No. 22 -- 100 YearHyd No. 22Hyd No. 8Hyd No. 9 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 23TOTAL TO RELEASE POINT DHydrograph type = Combine Peak discharge = 8.842 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 4,549 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 2.580 ac510246810121416Q (cfs)0.000.002.002.004.004.006.006.008.008.0010.0010.00Q (cfs)Time (min)TOTAL TO RELEASE POINT DHyd. No. 23 -- 100 YearHyd No. 23Hyd No. 10Hyd No. 11 Hydrograph ReportHydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Hyd. No. 24TOTAL TO RELEASE POINT FHydrograph type = Combine Peak discharge = 16.07 cfs Storm frequency = 100 yrs Time to peak = 7 min Time interval = 1 min Hyd. volume = 10,492 cuft Inflow hyds. = 14, 16, 19, 20 Contrib. drain. area = 2.050 ac520246810121416182022Q (cfs)0.000.003.003.006.006.009.009.0012.0012.0015.0015.0018.0018.00Q (cfs)Time (min)TOTAL TO RELEASE POINT FHyd. No. 24 -- 100 YearHyd No. 24Hyd No. 14Hyd No. 16Hyd No. 19Hyd No. 20 Hydraflow Rainfall Report53Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 04 / 29 / 2024Return Intensity-Duration-Frequency Equation Coefficients (FHA)Period(Yrs) B D E (N/A)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: LITTLE ROCK IDF.IDFIntensity = B / (Tc + D)^EReturn Intensity Values (in/hr)Period(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 601 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.002 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.703 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.005 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.1510 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.4625 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.9150 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60Tc = time in minutes. Values may exceed 60.Rainfall Precipitation Table (in)Precip. file name: G:\DWG\2022\22-457J - Conway Westrock\Drainage Calcs\Modified Rational Method\Conway SCS.pcpStormDistribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yrSCS 24-hour 0.00 4.13 0.00 0.00 6.10 7.00 7.80 8.50SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00