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Home My WebLink AboutWPO201700036 Calculations Minor Amendment 2018-06-22 i SCS ENGINEERS ter. a ,r" - x, x 5 i SFE. - Stormwater Report Drainage Calculations New Ivy Solid Waste Transfer Station Presented to: or Ar,./42 _II IIIfl A G71 N\N' 3G1 COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, North Wing Charlottesville, VA 22902-4126 Presented by: SCS ENGINEERS 2877 Guardian Lane Suite 1-F Virginia Beach, Virginia 23452 (757) 466-3361 July 14, 2017 Revised May 31, 2018 APPROVED File No. 02216108.01 by the Albemarle County — Community Devlooment Department DateOffices Nationwide www.scsengineers.com Elle --03----Q— l3 d-0 Li O 0(� i Drainage Calculations New Ivy Transfer Station SCS ENGINEERS Table of Contents Section Page Stormwater Management 1 Drainage Areas 1 Water Quality BMPs 1 Filtering Practices 1 Sand Filter A 2 Sand Filter B 2 Sand Filter C 2 Sand Filter D 3 Channels 3 Storm Drains 3 Storm Drain Pipes 3 Trench Drain 3 Drop Inlets 4 Outlet Protection Calculations 4 Stormwater Basin 4 Appendices A. Water Quality BMPs (Revised) B. Sand Filter A C. Sand Filter B D. Sand Filter C E. Sand Filter D F. Channels(Revised) G. Storm Drains H. Trench Drains(Revised) I. Drop Inlets(Revised) J. Outlet Protection K. Existing Stormwater Basin t 1 L Drainage Calculations New Ivy Transfer Station SCS ENGINEERS II STORMWATER MANAGEMENT The post-development stormwater management system is shown on Drawing SW2, Stormwater Management Plan and Drainage Areas. The main transfer station road was realigned, which caused revisions to the stormwater management plan. Revisions include: • The removal of the Two VDOT paved channels A18, A21 • The removal of drop inlet and culvert structures A16, A17 and P12 1 • An additional trench drain was added across the main transfer station road Due to the revisions,the total drainage area captured is reduced and the previous calculations 1 submitted provide more conservative estimate of the quantity of water conveyed downstream, therefore no revisions are necessary to any downstream features. However, the change in drainage area and change in impervious area requires an additional water quality treatment. Changes to the stormwater report are denoted in red text or dashed red text for features that have been deleted. b ' Components of the stormwater management system include: w • Water Quality BMPs (Sand Filters) • Channels e. • Storm Drains with Trench Drains • Existing Stormwater Basin ill Drainage Areas L The drainage areas were delineated in order to find the peak flow hydrographs for a given storm event. The stormwater management system was sized to handle the peak discharge for a 10-year, Li 24 hour rain event. Drainage areas are shown on Drawing SW2. WATER QUALITY BMPS am Filtering Practices To comply with the water quality criteria(9VAC25-870-65), the Virginia Runoff Reduction es Method (VRRM)was utilized in order to determine the appropriate best management practices (BMPs) for pollutant removal. The main purpose of the VRRM is to compute the required nutrient load reduction based on hydrologic soil groups and three categories of developed land im cover of the site. The three categories of developed land are Forest/Open Space (F/O), Managed Turf(MT), and Impervious Cover (IC). iii w UN Drainage Calculations New Ivy Transfer Station SCS ENGINEERS The Virginia DEQ Stormwater Design Specification No. 12 Filtering Practices, was chosen as the method of pollutant removal since filtering methods are more suitable to provide treatment at stormwater hotspots. Under the VRRM, BMPs that are not wet ponds, have some type of vegetative cover, and do not replace an otherwise impervious surface can be treated as Forest/Open Space (F/O). Therefore, a layer of topsoil with grass will be placed on the proposed sand filters and their areas will be considered as Forest/Open Space (F/O). The north portion of the project area contained impervious covers that will be altered during land-disturbing activities, therefore from (9VAC25- 870-63 A 2) for defining redevelopment the site qualifies to use the redevelopment VRRM spreadsheet for water quality calculations. The summary of the VRRM redevelopment spreadsheet is provided in Appendix A. Things to note from the summary attached in Appendix A,the total drainage site area(shown on drawing SW2) is 5.29 4.65 acres while the treated drainage area is/1.28 3.56 acres,the remaining 1.01 1.09 acres discharges as overland flow out of the project area. Drainage Area A Summary, 14.b Manufactured Treatment Device- Filtering ' was manually inputted to represent Sand Filter D to act in series with Sand Filter A. This is also true under the Drainage Area B Summary sheet- 14.b Manufactured Treatment Device-Filtering was manually inputted to represent Sand Filter C in series with Sand Filter B. The sand filters were sized to accommodate a specified Treatment Volume. The volume to be treated by the filtering device is a function of the storage depth above the filter and the surface area of the filter as outlined in Equation 12.1 of the VA DEQ Stormwater Design Specification No. 12. The calculation to determine storage depth for each sand filter is provided in Appendix A. With, the change in drainage areas, an additional 0.46 lbs/yr phosphorus treatment is needed as noted in the revised Appendix A. Nutrient credits will be purchased to offset the 0.46 lbs. Sand Filter A I To meet the pretreatment requirement for Sand Filter A, a combination of a forebay and level spreader were used. The forebay was designed to accommodate 25% of the total treatment volume (inclusive), and the level spreader was used to distribute the flow from a one inch storm event evenly over the filter surface. Calculations are provided in Appendix B. Sand Filter B ' It was determined that a level spreader is sufficient for Sand Filter B, since it is in series with Sand Filter C. Level spreaders were designed using VA DEQ Stormwater Design specifications No. 2 in order to spread channel flow out evenly over the sand filters. The length of the required level spreader needs to be a minimum of 13 ft/cfs of discharge using an intensity of 1 in/hour as outlined in specification No. 2 of the VA DEQ Stormwater Design Specifications. Calculations are provided in Appendix C. Sand Filter C t A gravel diaphragm will be used as pretreatment for Sand Filter C since the majority of flow comes from sheet flow off of impervious cover. The remaining flow comes from a trench drain and will have the diaphragm extended to its outlet to disperse the concentrated flow. With the minimal discharge velocities, pea gravel will adequately handle the discharge energy. g 2 L Drainage Calculations New Ivy Transfer Station SCS ENGINEERS r Sand Filter D LLike Sand Filter C, use a gravel diaphragm to pretreat sheet flow from impervious covers. Extend the pea gravel to the outlet of the contributing trench drain to disperse the concentrated flow. With the minimal discharge velocities, pea gravel will adequately handle the discharge energy. to CHANNELS Channels are designated as follows: L . A l8(Section 1) A standard VDOT type "A l"paved channel with a depth of 6 inches side slopes. iliii • A 18 (Section 2) -A V-ditch Flexamat® lined channel with geometry of 3:1 side slopes and a depth of l foot. F • A 19 -A V-ditch Flexamat® lined channel with geometry of 3:1 side slopes and a depth of 1.5 feet. L • A20 - Grass V-Ditch with a channel geometry of 3:1 side slopes and a depth of 9 inches. Temporary Erosion control matting(VDOT EC-2)will be installed to protect the channel until a good stand of grass is established. • A21 - A standard VDOT type "A 1" paved channel with a depth of 6-inches that discharges into a V-ditch Flexamat® lined channel with geometry of 6:1 and 4:1 side slopes. i v Each channel was designed to have the capacity to handle a 10-year 24 hour event. Channel linings were designed to minimize scour based on peak velocities for the 10-year 24 hour event. w Channel capacity and liner adequacy calculations are provided in Appendix F. STORM DRAINS tra Storm Drain Pipes to To account for a variety of structural conditions, various classes of reinforced concrete pipes are to be used in the stormwater management system. A schedule of these pipes can be found on Drawing SW I. The calculations for determining the required class of reinforced concrete pipe is provided in Appendix G. Trench Drain los Two trench drains are located at the building entrance to collect stormwater before it enters the transfer station . ••:•. •• : •• :-. -: . - . --• -- . : - - . .•- . iiii, . They are sized to handle 0.22 cfs and are recommended to 3 1 Drainage Calculations New Ivy Transfer Station SCS ENGINEERS 1 be impact resistant due to heavy traffic loading. The first trench drain will split the flow into sand filters, C and D, while the second trench drain will discharge to the managed turf area on the west side of the site and into Sand Filter D on the east side of the transfer station. Trench drain calculations are provided in Appendix H. Drop Inlets ' Drop inlets will be used as the outfall structures for the proposed sand filters and drainage areas. In order to calculate the sizing required for drop inlets in the BMP's, Appendix 9c-13 from the VDOT Drainage Manual was used to decide whether a VDOT standard DI-1 with 50-percent clogging is adequate. A single drop inlet is adequate for use in Sand Filters B, C and D. Due to its larger flow, Sand Filter A requires two DI-1's. Calculations are provided in Appendix I. The elevations of the drop inlet structures A4, A9, and Al2 are set at 6 inches above grade,to allow for filtering of the water quality storm. Structure A3 will be set at 0.55 feet above the filtering surface to allow for filtering of the water quality storm event. 1 to the transfer station. Outlet Protection Calculations Outlet protection was determined using outlet velocities from storm drains. Riprap will be used 1 for the outlet into the existing stormwater basin. Where storm drains discharge into channels,the channels will be lined with Flexamat®. Where storm drains discharge into sand filters,there will be a 3 inch pea gravel layer of outlet protection. Trench drains discharging into open space and sand filters, gravel diaphragms will be used. The calculations for all outlets are attached in Appendix J. STORMWATER BASIN The existing zero discharge stormwater basin was designed to provide irrigation water for the 1 landfill. The stormwater basin will be utilized in the erosion and sediment control plan during construction activities as a sediment basin in lieu of sediment traps. It is adequately sized as a sediment basin. Calculations provided in Appendix K. The storm water basin maintains its 1 capacity to have zero discharge for the 1, 2, 10, and 100-year storm events. Calculations provided in Appendix K. I 1 4 1 1 APPENDIX A ' Water Quality BMPs (Sand Filters) SCS ENGINEERS t Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Water Quality Compliance NTJ 5/31/2018 Checked Date Purpose: Determine the size of the BMPs to comply with the water quality criteria of(9VAC25-870-65). Given: 1.Drainage areas are deliniated on Drawing SW2 of the Final Site Design. 2.Hydrologic Soil Classification taken from Nationa Resources Web Soil Survey updated 2013. Assumptions: 1.The project area contains impervious covers that will be altered in land disturbing activites and qaulifies the area as redevelopment. 2.Sand Filters will be used since the project area is considered a"Hot Spot". 3.The Sand Filter BMPs are in series. 4.The Sand Filter BMPs area contribute to Open Space area in the calculations. 5.The entire site will be classified with Hydrologic Soil Classification of"C". Calculations: Calculations for nutrient removal are provided on the DEQ Virginia Runoff Reduction Method Re-Development Spreadsheet-Version 3.0. Conclusions: The site requires 4 BMPs,where Sand Filter A and D are in series and Sand Filter B and C are in series. Total TP Load Reduction Required(Ib/yr)=2.93 Total TP Load Reduction achieved(Ib/yr)=2.47 Remianing TO Load Reduction(Lb/yr)=0.46 1 1 1 1 1 a Soil Map—Albemarle County,Virginia h t° k k 705750 705800 705850 705900 705950 706000 706050 38°1,20"N 38°1'20'N i A a �" v — ~° s 4 0 8 , i'.i N a (4 rt ,,.^ e � r, 0 mo m e. ',04 at . Yi + „ f/ .rJ I : 1 it >: ;, 41 ., kp 37C3 ) _,' , g a ° t,} f'! F41 I f ro `uf N 368 36c PIi ,,,,,-___-- Q- a I38°1'5'N ` 38°1,5'N 705750 705800 705850 705930 709930 706000 706060 3 3 Map Scale:1:2,160 If printed on A portrak(8.5"x 11")sheet, I nN 030 -- - 60 120 Meters 180 it �_._._ 0 100 200 400 600 g Map projection:Web Mercator Conor coordinates:WGS84 Edge tics:UTM Zone 17N WGS84 tlspp Natural Resources Web Soil Survey 7/6/2016 •moi Conservation Service National Cooperative Soil Survey Page 1 of 3 p i I I �� Q O an N N o = O) i N co V C aa = C , O LO. O N 00 m N 'Ll.- co n 0) ID-1-- N O N Ira U N O CO 47 13 7 .D N a a O V O C N O OI 2 0 U a) N p) N O c c �o � D cm NEDm a 'So,EyE O N a)D � a o °� ' - ma Q 3m n c ` m a)D ai ° omE .5 2 C) Q! D o0 m T N n o Z mai a mO ° NVcoE am c 2 `' a N 7 U LrQ S E D f0 Q) o- L T7 c aaiCOZ a(N NN Q E 3y o � � � DL ° ` 1Q Yom ( n N m �a y = > 3 ai m rop°) m E U.Nw O a p o nn.cto Oa- m Lm3m ` N ucm omQa Ce o N E 3 m teo r- a) im . c a) O p 3 ma of roO O = 01 O o T > -O L $ - ` Tv ` CN m - 3 aa oE2a) LL a) a) N rCNd ZaON Eoc S Z N o DO N N . 0 -L U O m d N m ` O N N DVCa) 1 _ > ` & m E c � o a) o m � •o a o DDw ,6 D p E I a. ON N a.0 a) `: N .o> a) N Dny N QUm _ .0 0 J upNCN .7.7) <7 Nza) c .g2 E a0-a) tZ� a2Qom= a)- o Om £ n om > - DE cro o m EEmmOaN 0 :° m ` Dc c L Li U • ) � . EE 0.,cu mT ,N � - > 0)1.) U m ,,,3 . T O�o _2 c O. T a) 7 m co o 'Nm p n C 73 OD � f � 2 >, ii, n N 00 j T E _cE N = C 7 CD � O CO 'c yc ) o-o .0 N am — m � � � a - > Q CI D � 7, r� n NC 01 Eag. NN p U C . n `naE2) ---- O n E c o 8 y, m 20Nama, C w > — 2 03 -LI) - m E O Cl) m Co N m. m m O ao m.O N-0 o E y O o m 0 1- E F• w E aON d E A) U n a Q H ! O) o p v 1- 0- 0 ro > o, 2 co 2` TO a 0 2 .) o > Uco O m co n E d oa a m 3U is L 3 n U c m uO r a ara _ a o is 0 O . Jc 0 4am m .c Z V) m o N a OT3 c N >a L a N - O as a) U J Q u) cn > > 0 u) .E a ryC N t O LL1 ' o : I ro 0 3 r m w J a. om Mba Q OQo, w 5 4 m m p o a d N a N a) 'Z' c c r, w N N J o o Y. > > aa o N n 0 mmmo vLoy 3 cn '0 3 m = ° t O 1) cQo 2 2 u. O 15 N N a) )) O v )1)i - - - 30mN O m t6 C > C VN O m m W C -2 O Le ¢ cn Cl) um U 0 c0 -1 - 2 2 a ea Cl) N u) in Cl) CO m a) a- U C N E 15 v7 ® Xo } _ 0 -4440 ) ; > 60 .* 00 w CJ a 7 c d o O O Q N a)z W m a) m d = N a C m O Z L) 1 SI Soil Map—Albemarle County.Virginia Map Unit Legend .._____...... .. .... Albemarle County,Virginia(VA003) Map Unit Symbol Map Unit Name Acres in AO1 Percent of AOI 1B Abell silt loam,2 to 7 percent 0.0 0.1% slopes 14C Chester loam,7 to 15 percent 1.2 5.3% slopes 19B Cullen loam,2 to 7 percent 8.3 35,9% slopes 20C3 Cullen clay loam,7 to 15 2.0 8.8% percent slopes,severely eroded 20D3 Cullen clay loam,15 to 25 0.0 0.0% percent slopes,severely eroded 36B Hayesville loam,2 to 7 percent 1.6 6.8% slopes 36C Hayesville loam,7 to 15 percent 3.4 15.0% slopes 37C3 Hayesville clay loam,7 to 15 6.0 26.2% percent slopes,severely eroded 37D3 Hayesville clay loam, 15 to 25 0.4 1.9% percent slopes,severely eroded Totals for Area of Interest 23.0 100.0% USDA Natural Resources Web Soil Survey 7/6/2016 "all Conservation Service National Cooperative Soil Survey Page 3 of 3 II 1992 I Soil name surftex hydgrp kfact wtdepl wtdeph I COTACO CB-FSL C 0.24 1.50 2.50 COTACO FSL C 0.37 1.50 2.50 COTACO L C 0.37 1.50 2.50 IICOTACO SIL C 0.37 1.50 2.50 COTACO VARIANT CB-L C 0.24 2.00 3.00 COTACO VARIANT SIL C 0.43 2.00 3.00 COURSEY L C 0.32 2.00 3.00 IICOWES CH-L B 0.20 6.00 6.00 COXVILLE FSL D 0.24 0.00 1.50 COXVILLE L D 0.24 0.00 1.50 II CRAIGSVILLE CB-FSL B 0.28 6.00 6.00 CRAIGSVILLE CB-SL B 0.20 6.00 6.00 CRAIGSVILLE CB-SL B 0.28 6.00 6.00 CRAIGSVILLE CBV-L ill 0.10 6.00 6.00 IICRAIGSVILLE GR-FSL B 0.17 6.00 6.00 CRAIGSVILLE L B 0.28 6.00 6.00 CRAIGSVILLE SL B 0.17 6.00 6.00 CRAVEN CL C 0.37 2.00 3.00 IICRAVEN FSL C 0.32 2.00 3.00 CRAVEN L C 0.32 2.00 3.00 CRAVEN SCL C 0.37 2.00 3.00 IICRAVEN SIL C 0.32 2.00 3.00 CREEDMOOR FSL C 0.28 1.50 2.00 CREEDMOOR GR-FSL C 0.28 1.50 2.00 CREEDMOOR GRV-SL C 0.28 1.50 2.00 I CREEDMOOR L C 0.28 1.50 2.00 CREEDMOOR SL C 0.28 1.50 2.00 CREEDMOOR VARIANT FSL C 0.37 0.50 1.50 CREEDMORE FSL C 0.28 1.50 2.00 II ' CROTON SIL D 0.37 0.00 1.50 CROTON SIL D 0.43 0.00 0.50 CUL:..iiJ CT, C 0.24 6.00 6.0o- CULLEN L C 0.37 6.00 6.00 CULPEPER CL C 0.37 6.00 6.00 CULPEPER FSL C 0.37 6.00 6.00 CULPEPER L C 0.37 6.00 6.00 DALEVILLE L D 0.32 0.00 1.00 DALEVILLE SIL D 0.32 0.00 1.00 DANDRIDGE SH-SICL D 0.17 6.00 6.00 DAVIDSON C B 0.28 6.00 6.00 DAVIDSON CL 8 0.24 6.00 6.00 DAVIDSON CL B 0.28 6.00 6.00 DAVIDSON CL 9 0.37 6.00 6-00 DAVIDSON ST-CL B 0.20 6.00 6.00 DAWHOO VARIANT PSL 0.17 DECATUR CL 8 0.32 6.00 6.00 DEKALB CB-FSL C 0.17 6.00 6.00 DEKALB CB-L C 0.17 6.00 6.00 DEKALB CB-SL C 0.17 6.00 6.00 DEKALB CN-FSL C 0.17 6.00 6-00 DEKALB CN-L C 0.17 6.00 6.00 DEKALB CN-SL C 0.17 6.00 6.00 DEKALB FSL C 0.24 6.00 6.00 DEKALB RB-FSL C 0.17 6.00 6.00 VI - 58 i it it ir 1r 1r r r a Imo ~ 0 w ` a m >o w m m I O aa Mr w o c z r:, a C a Ili E v. o m > T, Z- r, a d o Q pm co a a a 1110 m i.c t E' c w m .-. 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G` m 1-O F !O- A 10- a i i . j j i 1 i 1 1 1 1 A 1 I00000 o 0 0 0 0 0 I Y i v o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o .0 o 0 0 0 0 0 2 -0 0 j o u - a a m ! a o 0 0 0 0 0 c w o 0 0 0 0 0 0 0 0 0 0 D i , C I m o 0 0 0 0 0 N 1 m i a cm . m I E m a > . to a 03 of m m m 0) c I o m 0 I a I E a mI m `�°, m ro o � �� m co m I ami �' �° .-� .1m I N O E `; _ d ` .. v ` , v ° u 3 » 3 3 ~ 3 3 " I 0 o °6 - zR s a m s T1 I O M m 3 v 3 > u 3 z u 7, rl Kw G K 6 1 t6 1 V f4 I , u . i 1 Z -0 U -0 a g 0 'p u v a 0 a n I N a E E E c c g 1 = '_W m `m `m y 4 N y. N G 1 C v m i w H NS ur ae d r.r APPENDIX B dill Sand Filter A de ell 1111111 elil OM de did I SCS ENGINEERSi . Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.00 Subject By Date Sand Filter Drop Inlet Rim Elevations NTJ 3/9/2017 c. Checked Date Sheet 1 of 1 Purpose: Determine the Rim Elevation for drop inlets for Sand Filter A. Given: VA DEQ Stormwater Design Specification No.12 Equation 12.1. Drainage Area contributing to Filter,from Drawing SW2,A= 132890.338 sq.ft Area of the Filter Surface from drawing SW2,Af= 2899.02 sq.ft Runoff Coefficient(From VRRM),Rv= 0.38 VA DEQ Stormwater Design Specification No.12 Equation 12.2. / ' Assumptions. VA DEQ Stormwater Design Specification NO.12 Equation 12.1 Af=(TV)(df)/((K)(hf+df)(tf)) where: Af= Surface Area of Filter Filter Media depth,df: 2 ft Coefficient of permeability(partially clogged sand),K: 3.5 ft/day Allowable Drawdown time,tf: 1.67 days hf= Depth of water above filter bed Storage volume of Forebay= 1060 cu.Ft. Calculations: Treatment Volume,TV: =[1.0(Rv)(A)]/(12) 4208.19 cu.Ft Adjust equation 12.1 to solve forAverage Height of Water above Filter bed,hf: hf=(TV)(df)/((Af$tf*K))-df 4.50 ft Using Equation 12.2,Volume of Storage,Vs: =.75*TV 3156.15 cu.Ft Required rim elevation,Hr= =Vs-Forebay Volume 2096.15 cu.Ft. using Storage Curve from Hydragraphs,Hr= 0.55 ft Conclusions: From Equation 12.1,the average depth of water above the filter bed is 4.50 ft. This means all of the runoff will be stored bellow the filter bed surface. From equation 12.2,the storage volume required in order to capture the volume from high intensity storms prior to filtration and avoid premature bypass is 2096.15 cu. Ft.including the storage volume of the forebay.The required rim elevation of the drop inlet is 0.55 ft above filter bed. For design set the rim at 0.55 ft or 7 inches above filter bed. I I I I I s NM Pond Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Friday,03/10/2017 ow Pond No.I- Sand Filter A Pond Data Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=704.00 ft im Stage/Storage Table Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cult) eia 0.00 704.00 2,899 0 0 2.00 706.00 4,841 7,657 7,657 Culvert I Orifice Structures Weir Structures rets [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise(in) = 0.00 0.00 0.00 0.00 Crest Len(ft) = 0.00 0.00 0.00 0.00 Span(in) = 0.00 0.00 0.00 0.00 Crest EL(ft) = 0.00 0.00 0.00 0.00 NA No.Barrels = 0 0 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert EL(ft) = 0.00 0.00 0.00 0.00 Weir Type = - -- -_ - Length(ft) = 0.00 0.00 0.00 0.00 Multi-Stage = No No No No Slope(X) = 0.00 0.00 0.00 n/a iss N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfl).(in/hr) = 0.000(by Contour) Multi-Stage = n/a No No No TW Elev.(ft) = 0.00 ari Note:CulvertOrlfice outflowsare analyzed under inlet(rc)and outlet(oc)control.Weir risers checked for orifice conditions(lc)and submergence(s). MI Stage(ft) Stage/Storage Elev(ft) 2.00 706.00 MI 1.80 705.80 Ms 1.60 705.60 1.40 705.40 iiie 1.20 705.20 ow 1.00 705.00 0.80 704.80 re `!O S0.60 704.60 ell 0.40 77,°°' 704.40 0.20 704.20 NM 0.00 704.00 0 800 1,600 2,400 3,200 4,000 4,800 5,600 6,400 7,200 8,000 hire Storage Storage(cuft) #Iocb CJ, t- 1 SCS ENGINEERS Client Project Job No. o- Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Required Foreay size NTJ 1/30/2017 Checked Date Sheet 1 of 2 Purcose: Determine the required storage capacity of the forebay Given' Total Treatment volume From sand filter DI rim elevations calculation,Tv: 4208.19 cu.Ft. 1 AssumptionsDesign specification No.12 sediment chanmbers must be sized to accommodate at least 25%of the total treatment volume 1 Calculations: Total storage volume of pretreatment,Tp: 1052.0475 cu.Ft 39.0 cu.Yds. =TV".25 Forbay Hydraflow Hydrographs Extension Elevation to achieve storage volume,EL= 707.25 = 1060 cu.Ft. Conclusions: Sand Filter A Forebay needs 39.0 cu.Yards of storage. I 1 , 1 1 1 1 1 1 Pond Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Wednesday,01/25/2017 Pond No. 1 - Forebay Pond Data Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=706.00 ft Stage/Storage Table Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft) .. 0.00 706.00 600 0 0 1.00 707.00 1,000 791 791 1.25 707.25 1,152 269 1,060 1.50 707.50 1,265 302 1,362 „M 2.00 708.00 1,500 690 2,053 2.50 708.50 1,767 816 2,868 2.75 708.75 1,905 459 3,327 3.00 709.00 2,000 488 3,815 Culvert I Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise(in) = 24.00 Inactive Inactive 6.00 Crest Len(ft) = 6.28 0.00 0.00 0.00 Span(in) = 24.00 0.00 0.00 6.00 Crest El.(ft) = 708.00 0.00 0.00 0.00 No.Barrels = 1 0 0 1 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El.(ft) = 706.00 0.00 0.00 707.25 Weir Type = 1 - -- - Length(ft) = 65.00 0.00 0.00 0.75 Multi-Stage = Yes No No No Slope(%) = 3.17 0.00 0.00 n/a N-Value = .024 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000(by Contour) Multi-Stage = n/a No No Yes TW Elev.(ft) = 0.00 Note Culvert/Orilice outflows are analyzed under inlet Oct and outlet(oc)control. Weir risers checked for orifice conditions(ic)and submergence(0). Stage/Storage/ Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cult ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 706.00 0.00 --- -- 0.00 0.00 - - - --- - 0.000 1.00 791 707.00 0.00 - - 0.00 0.00 - - - - - 0.000 1.25 1,060 707.25 0.00 - --- 0.00 0.00 - - - -- - 0.000 ANS 1.50 1,362 707.50 0.11 ic - -- 0.11 0.00 - - - - - 0.105 2.00 2,053 708.00 0.56 ic - --- 0.55 0.00 - - - - - 0.546 2.50 2,868 708.50 8.49 ic - --- 1.09 7.39 - - - - -- 8.486 2.75 3,327 708.75 14.27 ic -» --- 0.69 13.58 - - - - -- 14.27 r 3.00 3,815 709.00 18.33 ic - --- 0.32 18.01 s - - - - --- 18.33 AIM MIN 4111. AM MN AIM AM I Pond Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Wednesday,01/25/2017 Pond No. 1 - Forebay Pond Data I Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=706.00 ft Stage/Storage Table I Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cult) Total storage(cuft) 0.00 706.00 600 0 0 1.00 707.00 1,000 791 791 1.25 707.25 1,152 269 1,060 I 1.50 707.50 1,265 302 1,362 2.00 708.00 1,500 690 2,053 2.50 708.50 1,767 816 2,868 2.75 708.75 1,905 459 3,327 3.00 709.00 2,000 488 3,815 ' Culvert/Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] I Rise(in) = 24.00 Inactive Inactive 6.00 Crest Len(ft) = 6.28 0.00 0.00 0.00 Span(in) = 24.00 0.00 0.00 6.00 Crest El.(ft) = 708.00 0.00 0.00 0.00 No.Barrels = 1 0 0 1 Weir Coeff. = 3.33 3.33 3.33 3.33 I Invert El.(ft) = 706.00 0.00 0.00 707.25 Weir Type = 1 -- --- --- Length(ft) = 65.00 0.00 0.00 0.75 Multi-Stage = Yes No No No Slope(%) = 3.17 0.00 0.00 n/a N-Value = .024 .013 .013 n/a I Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(inlhr) = 0.000(by Contour) Multi-Stage = n/a No No Yes TW Elev.(ft) = 0.00 Note.Culvert/Orifice outflows are analyzed under inlet(ic)and outlet(oc)control Weir risers checked for orifice conditions(c)and submergence(s) I Stage(ft) Stage/Discharge Elev(ft) I 3.00 ti 1 709.00 i 2.00 --" . ' 708.00 I I 1.00 r"--------- ' 707.00 I I 0.00 - _.______ 706.00 I 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 Discharge(cfs) Total Q Culv A Prf Riser Struct HG Weir A II rlll Ma 0 i s C C Y 0 N TT O T /0 at Q O O CS! m a Q CO N 4- N 0,::,.; 8 ? c a ci a N U a m Ce O Q 0 N II > OM C L co a o P2 N J S' c 3 0 v` v o co 00 L a •a G c W 0j m .c CI. a m v C o o S 15 °o /l/ 0 ami OW E alw a o8,.. z" c a g on C om 0 F w .47. fy 1- i N Z OM 00 OD 0 ti . y >I! to CO Q L C 0- I:0 OCIS a ai U. rn • `N N 7 r uVo 2 411. d.f" c dC Z N O O p 8 0 F. u_ AO V 6 N 0 Vw v a a 1 Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date BMP Level Spreader Length NTJ 1/20/2017 Checked Date Sheet 1 of 1 Puroose: Determine the Level Spreader length required for Sand Filter A ' Given: Total Area,A: 3.06 acre Impervious area,Ap: 0.56 acre Good stand grass area,Ag: 2.50 acre Assumptions Rainfall Intensity,is 1.00 in/hr Use 1 in/hour as instructed by DEQ design specification No.2 Use 13 ft level spreader length per 1 cfs of discharge from DEQ Design Specification No.2. C value for impervious area,Cp: 0.90 C value for grass area,Cg: 0.35 Calculations: Weighted Ave.Runoff Coefficent,C: =((Ap*Cp)+(Ag'Cg))/A 0.451 Peak Flow,Qp: Qp=C*i*A 1.38 cfs Minimum Level Spreader Length,L: L=13*Qp 17.93 ft Conclusions_ Use a level spreader with a minimum length of 18 ft. 1 t I I'I I I I SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Trasnfer station 02216108.01 Subject By Date Erosion Control Measures for Sand Filter Surface NTJ 3/9/2017 Checked Date Sheet 1 of 1 Purpose Receiving areas downstream of the discharging pipe in Sand Filter A to handle the force of flow. — Given: 1.10 year,24 hour storm event used to determine peak flow.See Area A storm drain calculations.Qp=9 cfs. Assumptions: 1.Channel Lining Velocity Ranges: Velocity Lining 0-3 ft/sec Grass 0-4 ft/sec EC-2(VDOT Matting) 4-10 ft/sec EC-3(VDOT Matting) 10+ft/sec Flexamatm Calculations: See attached express calculations,for Velocities. Velocity do 3.48 ft/sec Conclusions: The velocity discharging into Sand Filter A is 3.48 ft/sec peagravel layer is adequate to handle discharge velocity. i i Ian i tan MO I anning's n Values Page 4 of 5 • - _ Subdrain 0.017 0.019 0.021 Stormdrain 0.021 0.024 0.030 6. Cement: I Neat Surface 0.010 0.011 0.013 _ Mortar 0.011 0.013 0.015 7.Concrete: I Culvert, straight and free of debris 0.010 0.011 0.013 Culvert with bends, connections, and some 0.011 ,013 0.014 debris 1 Finished 0.011 0.012 0.014 _ Sewer with manholes, inlet, etc., straight 0.013 0.015 0.017 Unfinished, steel form 0.012 0.013 0.014 1 Unfinished, smooth wood form 0.012 0.014 0.016 Unfinished, rough wood form 0.015 0.017 0.020 8.Wood: I Stave 0.010 0.012 0.014_ Laminated, treated _ 0.015 0.017 0.020 9.Clay: Common drainage tile 0.011 0.013 0.017 Vitrified sewer 0.011 0.014 0.017 Vitrified sewer with manholes, inlet, etc. 0.013 0.015 0.017 Vitrified Subdrain with open joint 0.014 0.016 0.018 10.Brickwork: Glazed _ 0.011 0.013 0.015 I Lined with cement mortar 0.012 0.015 0.017 0016 Sanitary sewers coated with sewage slime 0.012 0.013 . with bends and connections I Paved invert, sewer, smooth bottom 0.016 0.019 0.020 Rubble masonry, cemented 0.018 0.025 0.030 Manning's n for Corrugated Metal Pipe (AISI, 1980). I Type of Pipe, Diameter and Corrugation Dimension n 1 1.Annular 2.67 x 1/2 inch (all diameters) 0.024 2. Helical 1.50 x 1/4 inch 8"diameter 0.012 10"diameter 0.014 - I 3. Helical 2.67 x 1/2 inch 12"diameter 0.011 18"diameter 0.014 I ----------- 24" diameter 0.016 36"diameter 0.019 48"diameter 0.020 60"diameter 0.021 4. Annular 3x1 inch (all diameters) 0.027 5. Helical 3x1 inch I 48diameter _ 0.023 54"diameter 0.023 60"diameter 0.024 I 66"diameter 0.025 hftn://www fcl nrct PrI11/QPnwatar/I-W1/11a1r,/2 LI,..1,..,,,1:.. Dot;.«,....,,../11.i,.......:...- __ -r-i-i-- , . „n.nn.. I Culvert Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Friday,Mar 10 2017 A14 Culvert Invert Elev Dn (ft) = 704.00 Calculations Pipe Length (ft) = 65.00 Qmin (cfs) = 9.00 Slope (%) = 3.17 Qmax (cfs) = 9.00 Invert Elev Up (ft) = 706.06 Tailwater Elev (ft) = (dc+D)/2 Rise (in) = 24.0 - Shape = Circular Highlighted Span (in) = 24.0 Qtotal (cfs) = 9.00 No. Barrels = 1 Qpipe (cfs) = 9.00 n-Value = 0.013 Qovertop (cfs) = 0.00 Culvert Type = Circular Concrete Veloc Dn (ft/s) = 3.48 Culvert Entrance = Square edge w/headwall (C) Veloc Up (ft/s) = 5.26 Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 HGL Dn (ft) = 705.54 HGL Up (ft) = 707.13 Embankment Hw Elev (ft) = 707.61 Top Elevation (ft) = 709.00 Hw/D (ft) = 0.77 Top Width (ft) = 0.00 Flow Regime = Inlet Control Crest Width (ft) = 0.00 E+ev(6) sName> Hw Depth(n) 710.00 rI_._. 191 6.9709.00--- -- 2.91 708.00 __ 1.94 r499,961r f.. am ::: . ..._-.-_ _ 3 094 .. _._. -Jam_..__ AM 706.00-.____ •�-1^ _._... _.. _108 :.. 706.00 ti1'"*" .2.06 MI 703.00 -3.06 0 5 10 16 20 25 3C 36 40 46 60 65 63 65 70 75 BO 85 Circular Culvert HGL. Embank Reoch(R) OM NM I 111 1 APPENDIX C Sand Filter B 1 1 I 1 1 I rr SCS ENGINEERS a Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.00 Subject By Date Sand Filter Drop Inlet Rim Elevations NTJ 3/9/2017 Checked Date Sheet 1 of 1 Purpose: Determine the Rim Elevation for drop inlets for Sand Filter B. W Given: VA DEQ Stormwater Design Specification No.12 Equation 12.1. Drainage Area contributing to Filter,from Drawing SW2,A= 40295.66 sq.ft Area of the Filter Surface from drawing SW2,Af= 2161.899 sq.ft Runoff Coefficient(From VRRM),Rv= 0.38 VA DEQ Stormwater Design Specification No.12 Equation 12.2. Assumptions: 1.VA DEQ Stormwater Design Specification NO.12 Equation 12.1. Af=(TV)(df)/((K)(hf+df)(tf)) um where: Af= Surface Area of Filter Filter Media depth,df: 2 ft Coefficient of permeability(partially clogged sand),K: 3.5 ft/day er Allowable Drawdown time,tf: 1.67 days hf= Depth of water above filter bed 2.When calculating rim elevation assume sand filter has vertical side slopes. Calculations: Treatment Volume,TV: =[1.0(Rv)(A)]/(12) 1276.03 cu.Ft Adjust equation 12.1 to solve forAverage Height of Water above Filter bed,hf: hf=(TV)(df)/((Af*tf•K))-df -1.80 ft sir Using Equation 12.2,Volume of Storage,Vs: =.75*TV 957.02 cu.Ft r Required rim elevation,Hr= =Vs/Af 0.44 Conclusions: From Equation 12.1,the average depth of water above the filter bed is-1.8 ft. r� This means all of the runoff will be stored bellow the filter bed surface. From equation 12.2,the required storage volume required in order to capture the volume from high intensity storms prior to filtration and avoid premature bypass is 957.02 cu.Ft. The required rim elevation of the drop inlet is 0.44 ft above filter bed. For design set the rim at 0.50 ft. +w irr Oil rrr irr err Client Project Job No. Rivanna Solid Waste Authority NeW Ivy Solid Waste Transfer Station 02216108.01 Subject By Date BMP Level Spreader Length NTJ 1/20/2017 Checked Date Sheet 1 of 1 PurposeDetermine the Level Spreader length required for Sand Filter B. Given; Total Area,A: 1.22 acre Impervious area,Ap: 0.68 acre Good stand grass area,Ag: 0.54 acre Assumotiorts: Rainfall Intensity,i: 1.00 in/hr Use 1 in/hour as instructed by DEQ design specification No.2 Use 13 ft level spreader length per 1 cfs of discharge from DEQ Design Specification No.2. C value for impervious area,Cp: 0.90 C value for grass area,Cg: 0.35 Calculations; Weighted Ave.Runoff Coefficent,C: =((Ap*Cp)+(Ag*Cg))/A 0.657 Peak Flow,Qp: Op=C`I*A 0.80 cfs Minimum Level Spreader Length,L: L=13*Qp 10.41 ft Conclusions; Use a level spreader with a minimum length of 18 ft. • I 1 rr ISI w rw APPENDIX D Sand Filter C SIS w SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.00 Subject By Date Sand Filter Drop Inlet Rim Elevations NTJ 3/9/2017 Checked Date Sheet 1 of 1 Purpose: Determine the Rim Elevation for drop inlets for Sand Filter C. Given: VA DEQ Stormwater Design Specification No.12 Equation 12.1. Drainage Area contributing to Filter,from Drawing SW2,A= 12846.95 sq.ft Area of the Filter Surface from drawing SW2,Af= 1574.851 sq.ft Runoff Coefficient(From VRRM),Rv= 0.38 VA DEQ Stormwater Design Specification No.12 Equation 12.2. Assumptions: 1.VA DEQ Stormwater Design Specification NO.12 Equation 12.1. Af=(TV)(df)/((K)(hf+df)(tf)) where: Af= Surface Area of Filter Filter Media depth,df: 2 ft Coefficient of permeability(partially clogged sand),K: 3.5 ft/day Allowable Drawdown time,tf: 1.67 days hf= Depth of water above filter bed 2.When calculating rim elevation assume sand filter has vertical side slopes. Calculations: Treatment Volume,TV: =[1.0(Rv)(A))/(12) 406.82 cu.Ft Adjust equation 12.1 to solve forAverage Height of Water above Filter bed,hf: hf=(TV)(df)/((Af*tf*K))-df -1.91 ft Using Equation 12.2,Volume of Storage,Vs: =.75*TV 305.12 cu.Ft Required rim elevation,Hr= =Vs/Af 0.19 Conclusions: From Equation 12.1,the average depth of water above the filter bed is-1.91 ft. This means all of the runoff will be stored bellow the filter bed surface. From equation 12.2,the required storage volume required In order to capture the volume from high intensity storms prior to filtration and avoid premature bypass is 305.12 cu.Ft. The required rim elevation of the drop inlet is 0.19 ft above filter bed. For design set the rim at 0.50 ft. 1 1 1 rr r NMI rr int APPENDIX E Sand Filter D r. r• • Mil I SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.00 Subject By Date Sand Filter Drop Inlet Rim Elevations NTJ 3/9/2017 Checked Date Sheet 1 of 1 Purpose: Determine the Rim Elevation for drop inlets for Sand Filter D. Given: VA DEQ Stormwater Design Specification No.12 Equation 12.1. Drainage Area contributing to Filter,from Drawing SW2,A= 10460.64 sq.ft Area of the Filter Surface from drawing SW2,Af= 1107.194 sq.ft Runoff Coefficient(From VRRM),Rv= 0.38 VA DEQ Stormwater Design Specification No.12 Equation 12.2. Assumptions: 1.VA DEQ Stormwater Design Specification NO.12 Equation 12.1. Af=(TV)(df)/((K)(hf+df)(tf)) where: Af= Surface Area of Filter Filter Media depth,df: 2 ft Coefficient of permeability(partially clogged sand),K: 3.5 ft/day Allowable Drawdown time,tf: 1.67 days hf= Depth of water above filter bed 2.When calculating rim elevation assume sand filter has vertical side slopes. Calculations: Treatment Volume,TV: =[1.0(Rv)(A)]/(12) 331.25 cu.Ft Adjust equation 12.1 to solve forAverage Height of Water above Filter bed,hf: hf=(TV)(df)/((Af`tf*K))-df -1.90 ft Using Equation 12.2,Volume of Storage,Vs: =.75*TV 248.44 cu.Ft Required rim elevation,Hr= =Vs/Af 0.22 Conclusions: From Equation 12.1,the average depth of water above the filter bed is-1.90 ft. This means all of the runoff will be stored bellow the filter bed surface. From equation 12.2,the required storage volume required in order to capture the volume from high intensity storms prior to filtration and avoid premature bypass is 248.44 cu.Ft. The required rim elevation of the drop inlet is 0.22 ft above filter bed. For design set the rim at 0.50 ft. I I I I I 1r ■r rri APPENDIX F Channels SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Startion 02216108.01 Subject By Date Channel A18 NTJ/DCC 7/14/2017 Checked Date Sheet 1 of 1 AST 7/14/2017 Purpose: Channel geometry,and lining adequacy for channel A18. Given: 1.Channel Geometry,V-ditch 1 foot depth,3:1 side slopes: 2.Flow from Area A peak flow calculations, Qp= 9 cfs 3.Average slope of channel,S= 5 Assumptions: 1 1.mannings number= 0.035 2.Channel Lining Velocity Ranges Velocity Lining 0-3 ft/sec Grass 0-4 ft/sec EC-2 VDOT matting 4-10 ft/sec EC-3 VDOT matting 10+ft/sec Flexamat° Calculations: See attached Hydraflow express calculations: Velocity= 4.81 ft/sec Conclusions: The channel can adequatly handle the peak flow of 9.0 cfs,and Flexamat' should be used as the lining. I 1 1 I 1 1 I I .� Precipitation Frequency Data Server Page 1 of 4 NOAA Atlas 14,Volume 2,Version 3 4" Location name:Charlottesville,Virginia,USA* ir' ' '' Latitude:38.0253°,Longitude:-78.6538° a ' �7t Elevation:662.27 ft" W. r ;�"a�` -source-.ESR!Maps "source_USGS POINT PRECIPITATION FREQUENCY ESTIMATES G M.Rennin,D Marlin,9.Lin,T.Parzybok,M.Yekta,and D.Riley AM NOAH,National Weather Service,Silver Spring,Maryland PF tabular l PF graphical l Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals (in inches/hour)' Average recurrence interval(years) 1 10urati0ni 1 11 2 i� 5 -1 10 r 25 ___I _ 50 It 100 1[ ZDO 500 10001 5-min 4.12 4.92 [(5.2:54i 5.80 6.63 7.37 8.02 8.63 9.20 9.901 10.6 (3.72-4.57) (4.45.5.45) (5 2 5 E 41) (5.88-7_21) (6.60-8.11) (7.15-8.83) (7.64.9.52) (8.09-10.2) (8.60-11 0) (9.00-11.7) 10-min 3.29 3.94 4.64 5.87 6.38 6.86 7.30 7.83 8.24 (2.98-3.65) (3.56-4.36) (4.19-5.13) I(4.70-5.76). (5.26-6.47) (5.69-7.03) (6.08-7.66) (6.41-8.06) (6.80-8.69) (7.09-9.19) ...ma 2.74 3.30 3.921r 4.40 4.96 5.39 II 6.78 6.14 6.57 6.90 15-min I (2.48-3.04)1 (2.99-3.65) (3.54.4. 3.97-4.86) (4.45-5.48) (4.80-f,rill ' ?r,37) (5.40-6.78) (5.71-7.29) (5.93.7.69) 30-min (1.70-2.08) 2.28 2.78 3.19 3.67 (x4.06 4.42 4.78 5.23 5.69 (1.70-2.08) (2.06-2.52) (2.51-3.07) (2.87-3.52) (3.29-4.05) x,.92-4.88) (4.20-5.28) (4.54-5.80) (4.80-6.23) 50-min 1.17 1.43 1.78 2.08 2.45 2.75 3.06 3.36 3.75 4.08 a _ ---= (1.06-1.30) (1.29-1-58) (1.61-1.97) (1.87-2.29) (2.19-2/01 JI_... ._ x2.70-3.36) (2.95-3.70) (3.26-4.16) (3.51.4.55) 2-hr ! 0.700 0.852 1.07 1.26 1.50 1.70 1.91 2.12 2.42 2.67 i(0.622.0.792)(0.756-0.961) (0.948.1.20) (1.12-1.41) (1,32.1.68) (1.49-1.91) (1.66-2.14) (1.83-2.38) r (2.06.2.73) (2.25-3.02) 3-hr ' 0.511 0.621 0.778 0.914 1.09 1.24 1.39 1.55 1.77 1.96 (0.454-0.582)(0.549.0,705)(0,687-0.884) (0.805-1.04) (0.956.1.23) (1.08.1.40) (1.21-1.58) (1.33.1.78) (1.50.2.02) (1.64.2.2411 me s 0.331 0.401 0.498 0.687 0.706 0.809 0.918 1.04 - 1.20 1.36 6-hr (0.296-0.374)(0.357-0.452)(0.442.0.561)(0.518.0.660)(0.619.0.793)(0.704-0.908).(0.791-1.03) (0.882-1.17) (1.01-1.36) (1.12-1.53) 12-hr� 0.209 0.252 0.316 0.372 0.453 0.625 ' 0.603 0.689 0.817 0.932 J (0.186-0.238)(0.224-0.288)(0.278.0.358)(0.328-0.423)(0.396-0.514)(0.453.0.595),(0.514.0.684)(0.579-0782) (0.671.0,931) (0.753-1.07) 24-hr 0.127 0.154 0.196 0.231 0.284 0.329 0.378 0.433 0.514 0.583 dois (0.114-0.142)(0.138-0.17211(0.176.0.219))(0.207-0.25811(0.252-0.316) 0.289.0.365)(0.330-0.420)(0.374.0.479) (0.436.0.570)(0.488.0.647) 2-day 0.076 0.091 0.115 0.135 0.164 0.188 0.215 0.243 0.285 0.320 ,(0.067-0.083)(0.081-0.101)(0.103-0.128))(0.121-0.151)(0.146-0.183)(0.166-0.209)(0.188.0.239)(0.211.0.271)1(0.244.0.318)1((0.271.0.35811 3-da 0 063 0.064 0.082 0.096 0.116 0.133 0.162 0.172 0.201 0.226 3-day (0.048.0.059)(0.058.0.071)(0.074.0.090)(0.086-0.106)(0.104-0.128)(0,119.0.147)(0.134-0.168)(0.151-0.190)2(0.174-0.223)(0.193-0.251) i 4-day 0.042 0.061 0.065 0.076 0.092 0.106 0.120 0.136 0.159 0.178 L. (0.039-0.047) 0.047.0.0561(0.059.0.072) 0.069-0.084)(0.083-0.101)(0.095-0.116)(0.107-0.132)(0.120-0.150)(0.139-0.175)1(0.154-0.197) 7-day 0,028 0.034 0.042 0.049 0.069 0.067 r 0.076 0.085 0.098 0.109 (0.028-0.031)(0.031.0.037)(0.039.0.046)(0,0450.053)(0.053-0.064)(0.060.0.073)(0.066-0.083)(0.075.0.093)(0.086.0.108)1(0.095.0.120- 0.022 0.027 0.033 0.038 0.046 0.0510.057 0.063 0.072 0.079 MO10 day (0. 020-0.024)(0.025-0.029)(0.030-0.036)(0.035-0 041)(0.041-0.049)(0.046.0.055)!(0.051-0.061)(0.057-0.068)(0.064.0.078)(0.070.0.086) 20-day 0.015 0.017 0.021 0.024 0.028 0.031 0.034 0.037 0.041 0.044 (0.014-0.016)(0.016-0.019)(0.020-0.023)(0.022.0.026)(0.026-0.030)(0,028-0.033)(0,031.0.036)(0.034.0.040)(0.037.0.044)(0,040.0.048) 30-da 0.012 0.014 0.017 0.019 0.021 0.023 0.025 0.027 0.029 0.031 _._.__ y 1(0011-0.013)(0.013.0.015)2(0.016-0.018)(0.017-0.020)(0,020.0.023)(0.022-0.025)(0.023-0.027)(0.025-0.029)(0.027-0.031),(0.026.0.033) 45-day 0.010 0.012 0.014 0.015 0.017 0.018 0.020 - 0.021 0.023 0.024 (0.009.0.011)(0.011-0.012��(0.013-0.015)(OA14.0.016)'(0.016-0.018)(0.017-0.020),(0.018.0.021)(0.020-0.022)l�(0.021.0.024)(0.022-0.026) f 0.009 0.010 0.012 0.013 0.014 0.016 0.017 0.018 0.019 0.020 60-day (0.008-0.009)(0.010.0-011)(0011-o.ots�(0o12.o.O14) (0 014.0.015)(0.015-0.016)1(0,016-0.018) 0.016-0.019)(0.018.0.0201 (0.018.0.021) 'Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values !Please refer to NOAH Atlas 14 document for more information _ J-M_ Back to Top http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0253&lon=-78.6538&dat... 11/21/2016 6.4-Design Concepts -_------ The ------ ---._ The Rational Method Formula is expressed as follows: Q = CfCiA (6.4) Where: Q = Maximum rate of runoff, cubic feet per second (cfs) Cf = Saturation factor C = Runoff coefficient representing a ratio of runoff to rainfall (dimensionless) i = Average rainfall intensity for a duration equal to the time of concentration for a selected return period, inches per hour (in/hr) A = Drainage area contributing to the point of study, acres (ac) Note that conversion to consistent units is not required as 1 acre-inch per hour approximately equals 1 cubic foot/second. 6.4.4.1.5 Infrequent Storm The coefficients given in Appendix 6E-1 are for storms with less than a 10-year recurrence interval. Less frequent, higher intensity storms will require modification of the coefficient because infiltration and other losses have a proportionally smaller effect on runoff (Wright-McLaughlin 1969). The adjustment of the Rational Method for use with larger storms can be made by multiplying the right side of the_ Rational Formula by a saturation factor, Cf The product of Cf and C should not :.: 1.0. Table 6-2 lists the saturation factors for the Rational Method. Table 6-2. Saturation Factors For Rational Formula Recurrence Interval (Years) Cf I2, 5, and 10 1.0 25 1.1 501.2 100 — 1.25 Note: Cf multiplied by C should not 1.0 6.4.4.1.6 Time of Concentration The time of concentration is the time required for water to flow from the hydraulically most remote point in the drainage area to the point of study. Use of the rational formula requires the time of concentration (tc) for each design point within the drainage basin. The duration of rainfall is then set equal to the time of concentration and is used to estimate the design average rainfall intensity (i) by using the B, D, & E factors in the procedure described in Appendix 6C-1. A table showing the B, D, & E factors for Virginia counties and larger cities is presented in Appendix 6C-2. * Rev 4/10 VDOT Drainage MalTilal Chapter 6—Hydrology 6-16 of 57 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use C 111 Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 IIHealy soil, average, 2-7% 0.18-0.22 Heavy soil, steep, 792 0.25-0.35 USE✓ 0.3 Residential: Agricultural land: • Single-family areas 030-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows * Heavy soil, no crop 0.30-0.60 * Heavy soil, with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 `Woodlands 0.05-0.25 II II Industrial: Streets: Light areas 0.50-0.80 Asphaltic 0,.70.0.95 ""' Heavy areas 0.60-0.90 Concrete 0.80-0.95 O'to Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The designer must use judgement to select the appropriate "C value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. Source: American Society of Civil Engineers V - 29 Manning's n Values Page 1 of 5 Show Manning's n Values 411 03 Reference tables for Manning's n values for Channels, Closed Conduits Flowing Partially Full, and Corrugated Metal Pipes. Use 0.031" -' 4 t.cov.u`TS G3(1- .� -` (20,004t ow/ iRtr. 4f Manning's n for Channels (Chow, 1959). Type of Channel and Description Minimum Normal Maximum MO Natural streams - minor streams (top width at floodstage < 100 ft) 1. Main Channels a. clean, straight, full stage, no rifts or deep pools 0.025 0.030 0.033 b. same as above, but more stones and weeds 0.030 0 035 0.040 c. clean, winding, some pools and shoals 0.033 _ 0.040 0.045 d. same as above, but some weeds and stones 0.035 0.045 0.050 • e. same as above, lower stages, more ineffective 0.040 0.048 0.055 slopes and sections f. same as"d" with more stones 0.045 0.050 0.060 I g. sluggish reaches, weedy, deep pools 0.050 0.070 0.080 h. very weedy reaches, deep pools, or floodways 0.075 0.100 0 150 with heavy stand of timber and underbrush I 2. Mountain streams, no vegetation in channel, banks usually steep, trees and brush along, banks submerged at high stages i a. bottom: gravels, cobbles, and few boulders -.. 0.030 0.040 0 050 I b bottom: cobbles with large boulders 0.040 0.050 0.070 3. Floodplains I a. Pasture, no brush 1.short grass 0.025 0.030 0.035 2. high grass 0.030 0.035 0.050 b. Cultivated areas 1. no crop 0.020 0.030 0.040 2. mature row crops 0.025 0.035 0.045 I 3. mature field crops 0.030 0.040 0.050 c. BrushI 1. scattered brush, heavy weeds 0.035 0.050 0.070 2. light brush and trees, in winter 0.035 0.050 0.060 3. light brush and trees, in summer 0.040 0.060 0.080 j I I 4. medium to dense brush, in winter 0.045 0 070 0.110 I 5 medium to dense brush, in summer 0.070 0.100 0.160 I d. Trees 1. dense willows, summer, straight 0.110 0.150 0.200 a http://www.fsl.orst.edu/geowater/FX3/help/8_Hydraulic_Reference/Mannings__n_Tables.... 11/10/2016 Channel Report Hydraflow Express Extension for Autodeske AutoCADe Civil 3De by Autodesk,Inc. Friday,Mar 3 2017 Channel A18 Flexamat Lined Ii Triangular Highlighted Side Slopes (z:1) = 3.00, 3.00 Depth (ft) = 0.79 Total Depth (ft) = 1.00 Q (cfs) = 9.000 Area (sqft) = 1.87 Invert Elev (ft) = 1.00 Velocity (ft/s) = 4.81 0 L Slope (%) = 5.00 Wetted Perim (ft) = 5.00 N-Value = 0.035 Crit Depth, Yc (ft) = 0.90 Top Width (ft) = 4.74 .. Calculations EGL (ft) = 1.15 Compute by: Known Q Known Q (cfs) = 9.00 Elev (ft) Section Depth (ft) 3.00 — - 2.00 i I 2.50 1.50 a. • 2.00 - - -- — 1.00 77 1 li 1.50 0.50 III 1.00 - 0.00 1 II y.. 0.50 — -. .___ __ -0.50 0 1 2 3 4 5 6 7 8 Reach (ft) 1 i SCS ENGINEERS 1 Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Startion 02216108.01 Subject By Date Channel A19 NTJ/DCC 7/14/2017 Checked Date 1 Sheet 1 of 1 AST 7/14/2017 Purpose: Channel geometry,and lining adequacy for channel A19. Given: I 1.Channel Geometry,V-ditch 1.5 foot depth,3:1 side slopes: 2.Flow from Area A peak flow calculations, Qp= 9 cfs 3.Average slope of channel,S= 8 Assumptions: ' 1.mannings number= 0.035 2.Channel Lining Velocity Ranges Velocity Lining 0-3 ft/sec Grass 0-4 ft/sec EC-2 VDOT matting 4-10 ft/sec EC-3 VDOT matting 10+ft/sec Flexamat° Calculations: See attached Hydraflow express calculations: Velocity= 5.79 ft/sec Conclusions: The channel can adequatly handle the peak flow of 9.0 cfs,and Flexamat'x should be used as the lining. 1 i Precipitation Frequency Data Server Page 1 of 4 a NOAA Atlas 14,Volume 2,Version 3 C\\'' Location name:Charlottesville,Virginia,USA° .r..` 121) Latitude:38.0253°,Longitude:-78.6538° f' ' ' r Elevation:662.27 ft" spf 'source:ESRI Maps l -`source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES w G M.Bonnin,0 Martin,B Lin,T Parzybok,M Yekta,and 0 Riley NOAA,National Weather Service,Silver Spring,Maryland III PF tabular 1 PF Oraphical1 Maps & aerials PF tabular _ - PDS-based point precipitation frequency estimates with 90% confidence intervals(in inches/hour)1 ll Average recurrence interval(years) t- l Duration , - 1 �� I 1 2 5 10 25 50 100 200 500 1000 5-min 4.12 4.92 5.80 6.53 7.37 8.02 8.63 9.20 9,90 10,5 (3,72-4,57) (4.45-5.45) (5.23-6.41) .(5.88.7 21) 1 (6.60.8.11)_.T(7.15-8.83) (7.64-9.52) (8,09.10.2) (8.60-11.0) (9.00.11.7) , 10-min 3.29 3.94 4.64 - 2" 6.87 6.38 6.66 7.30 7.83 8.24 (2.98-3,65) (3.56-4.36) (4.19-5.13) (4.70-5.76) (5.28-5,47) (5.69-7.03) C • -(6.08-7.56) (6.41-8.06) (6.80-8.69) (7.09-9.19), a 15-min 2.74 3.30 3.92 4.40 4.96 5.39 I 5.78 6.14 6.57 6.90 (2.48-3.04) (2.99.3.65) (3.54-4.32) (3.97-4.86) (4,45.5,46) (4.80-5.04) (5,12.6.37) (5.40-6.78) (5.71-7.29) (5.93-7.69) 30-min 1.88 2.28 2.78 3.19 3.67 4.06 4.42 4.78 5.23 6.69 (1.70.2.08) (2.06.2.52) (2.51-3.07) (2.87.3.52) (3.28.4-05) (3,62.4.47) (3,92.4.88) (4,20.5.28) (4.54.5,80) (4,80.6.23) 1.17 1.43 1.78 2.08 2.45 2.76 ' 3.06 3.36 3.75 4.08 iimi 60-min (1.06-1.30) (1.29-1.58) (1.61-1.97) (1,87-2.29) (2.19-2.70) (2.45-3.03) (2,70-3.36) (2.95-3.70) (3.26-4.16) (3.51-4.55) 0.700 0.852 1.07 1.26 1.50 1.70 1.91 2.12 2.42 2.87 * 2-hr (0,022-0.792)(0,756.0.981) (0.948-1.20) (1.12-1.41) (1.32.1.68) (1.49-1,91) (1.86-2.14) (1,83-2.38) (206-2.73) (2.25-3.02) 0.611 0.621 0.778 0.914 1.09 1.24 1.39 1.55 1.77 1.96 `3-hr I(0-454-0,582)(0.549-0.705)(0-687-0-884) (0.805-1.04) (0.956.1.23) (1.08-1.40) (1.21-1.58) (1.33-1,76) (1.50-2.02) (1.64-2.24), 0.331 0.401 0.498 0.587 0.705 0.809 0.918 1.04 1.20 1.35 6-hr (0-296-0.374)(0.357-0.452)(0.442-0.561)(0.518-0.660)((0.619-0.793)(0.704-0.908) (0.791-1.03) (0,882.1.171 (1.01-1.36) (1.12-1.53)1 C 12-hr 0.209 0.252 0.316 0.372 ' 0.453 0.525 0.603 0.689 0.817 0.932 (0-186.0.238)(0.2240.288)(0.278.0.358)(0.328-0.4231)(0.396-0.514)(0.453-0,595)(0.514-0.684)(0.579.0.782)(0.671.0.931) (0.753.1.07) 0.127 0,154 0.196 0.231 0,284 0.329 0.378 0.433 0.514 0.583 iw 1-24-hr 1(0.114-0.142)(0.138-0.172)(0.176-0.219)(0.207-0.258)(0.252.0.318)(0.289.0.365)(0.330-0.420)(0.374-0.479)(0,436.0.570)(0.488-0.647)1 2-day 0.075 0.091 0.115 0.135 0.164 0.188 0.215 0.243 0.285 0.320 (0.067-0.083)(0.081-0.101)(0.103-0.128)(0.121-0.151) (0.146-0.183)(0.166.0.209)(0.188-0.239)(0.211-0.271)(0.244.0.318)(0271.0.358) 3-day 0:053 0.064 0.082 0.096 0.116 0.133 0.162 0.172 0.201 pi-jib (0.048.0.059)(0,058.0,071)(0.074-0.090)(0.086.0.106) (0.104-0.128 (0.119-0.147)(0,134.0.168)(0.151-0.190)(0.174-0.223) 93-0.251)am ! 4-day 0.042 11 0.061 0.065 0.076 0.092 0.106 0.120 0.136 0.159 0.178 (0.039.0.047 0.047-0.050 (0.059-0.072) 0.069-0.084)(0.083-0.101)(0.095-0,116).(0.107-0.132)(0.120-0.150)(0.139-0.175)(0.154-0.197) 7-day 0.028 0.034 0.042 0.049 0.059 0.067 0.076 0.086 0,098 0.109 (0.026-0.031)(0.031.0.037)(0.039-0.046) 0.045.0.053)(0.053-0.064)(0.060-0,073)(0.068.0.083)(0.075-0.093)(0.086-0.108)(0.0950.120) NM 10-day 0.022 0.027 0.033 0.038 0.045 0.051 0.057 0.063 0.072 0.079 • (0.020_0024)(0.025.0 029)(0.030.0.036) 0,035-0.041)(0.041.0.049)(0.046.0.055);(0,051-0,061)(0.057-0.068)(0.064.0.078)(0.070-0.086) 20-day 0.015 0.017 0.021 0.024 0.028 0.031 0.034 0.037 0.041 0.044 (0.014-0.016) (0.016-0.019)(0.020-0.023)(0.022.0.026) (0.026.0.030)(0.028.0.033)(0.031.0,036)(0-034-0,040).(0.037.0.044)(0.040-0.046) (� 1 0.012 0.014 0.017 0.019 0,021 0.023 0.025 0.027 0.029 0,031 +� 130-day (0.011-0.013)(0.013-0.015)(0,018-0.018)(0.017-0.020)(0.020-0.023) (0.022.0.0254(0.023- 0.027)(0.025-0.029)'(0.027-0.0.311(0.029.0.0331 1 45-d ay 0.010 0.012 0.014 0.015 0.017 0.0180.020 0.021 0.023 0.024 (0.009.0.011)(0.011.0,012)(0.013-0.015)(0.014.0.016)(0.016-0.018)(0.017.0-020)(0.018.0,021)(0.020-0.022)(0.021.0.024)(0.022.0.026) 60-da 0.006 0.010 0.012 1 0.013 0.014 0.016 r 0.017 0.018 0.019 0.020 it y (0.008-0.009)(0.010-0,011) (4011-0.013)1(0.012-0.014)(0.014-0.015(0.015-0.015)(0.016.0.018)(0.016-0.0191(0.018.0.020)(0.018-0 021) '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 I (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower hound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top 1 111 II a II i ps http://hdsc.nws.noaa,gov/hdsc/pfds/pfdsprintpage.html?lat=38,0253&ion=-78,6538&dat.., 11/21/2016 Willi i 6.4-- Design Concepts The Rational Method Formula is expressed as follows: Q = CfCiA (6.4) Where: Q = Maximum rate of runoff, cubic feet per second (cfs) Cf = Saturation factor C = Runoff coefficient representing a ratio of runoff to rainfall (dimensionless) i = Average rainfall intensity for a duration equal to the time of concentration for a selected return period, inches per hour (in/hr) A = Drainage area contributing to the point of study, acres (ac) Note that conversion to consistent units is not required as 1 acre-inch per hour I approximately equals 1 cubic foot/second. 6.4.4.14 Infrequent Storm The coefficients given in Appendix 6E-1 are for storms with less than a 10-year recurrence interval. Less frequent, higher intensity storms will require modification of the coefficient because infiltration and other losses have a proportionally smaller effect on runoff (Wright-McLaughlin 1969). The adjustment of the Rational Method for use with larger storms can be made by multiplying the right side of the Rational Formula by a saturation factor, Cf The product of Cf and C should not - , 1.0. Table 6-2 lists the saturation factors for the Rational Method. Table 6-2. Saturation Factors For Rational Formula Recurrence Interval (Years) cf__! 2, 5, and 10 1.0 25 11.1 50 100 125 Note: Cf multiplied by C should not 1.0 644.1.6 Time of Concentration The time of concentration is the time required for water to flow from the hydraulically most remote point in the drainage area to the point of study. Use of the rational formula requires the time of concentration (tc) for each design point within the drainage basin. The duration of rainfall is then set equal to the time of concentration and is used to estimate the design average rainfall intensity (i) by using the B, D, & E factors in the procedure described in Appendix 60-1. A table showing the B, D, & E factors for Virginia counties and larger cities is presented in Appendix 60-2. ' Rev 4/10 VDOT Drainage antral hapter B—Hydrology 6-16 of 57 we amp 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA [end Use C Land Use C ass Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat,2% 0.05-0.10 .. Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 .. m steep,7% O5535 OS6 0.3: Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows .� * Heavy soil, no crop 0.30-0.60 * Heavy soil,with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 Industrial: Streets: Light areas 0.50-0.80 Aspic ‘ZE r., Heavy areas 0.60-0.90 Concrete 0.80-0.95 0'40 Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 1111 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The designer must use judgement to select the appropriate "C" value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. �- Source: American Society of Civil Engineers V - 29 Manning's n Values Page 1 of 5 ,,,,, F Show Manning's n Values 401 4. Reference tables for Manning's n values for Channels, Closed Conduits Flowing Partially Full, and Corrugated Metal Pipes. Use 0irsc -., 4Lcov.oIS tea- .. - glk < (701.Acs w)L IR 1,- Manning's n for Channels (Chow, 1959). Type of Channel and Description I Minimum Normal Maximum la Natural streams - minor streams (top width at floodstage < 100 ft) 1. Main Channels 1 II a. clean, straight, full stage, no rifts or deep pools 0.025 0.030 0.033 b. same as above, but more stones and weeds 0.030 0.035 0.040 I c. clean, winding, some pools and shoals 0.033 0.040 0.045 d. same as above, but some weeds and stones 0.035 0.045 0.050 e. same as above, lower stages, more ineffective 0.040 1 0.048 0.055 slopes and sections f. same as"d"with more stones 0.045 0.050 0.060 g. sluggish reaches, weedy.. deep pools 0.050 0.070 0.080 W h. very weedy reaches, deep pools, or floodways 0.075 0.100 0.150 with heavy stand of timber and underbrush 2. Mountain streams, no vegetation in channel, banks usually steep,trees and brush along, banks submerged at high stages a. bottom: gravels, cobbles, and few boulders 0.030 0.040 0.050 1 b. bottom: cobbles with large boulders 0.040 0.050 0.070 3. Floodplains -_ a. Pasture, no brush 1.short grass 0.025 0.030 0.035 2. high grass 0.030 0.035 ' 0.0501 b. Cultivated areas 1. no crop 0.020 0.030 0.040 2. mature row crops 0.025 0.035 0.045 3. mature field crops 0.030 0.040 0.050 c. Brush I 1. scattered brush, heavy weeds 0.035 0.050 0.070 2. light brush and trees, in winter 0.035 0 050 0.060 3. light brush and trees, in summer 0.040 0.060 0.080 I 4 medium to dense brush, in winter 0.045 0.070 I 0.110 5. medium to dense brush, in summer 0.070 0.100 0.160I d. Trees _ 1. dense willows, summer, straight 0.110 0.150 0.200 hltp://www.fsl.orst.edu/geowater/FX3/help/8_Hydraulic_Reference/Mannings__n_Tables.... 11/10/2016 Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Friday,Mar 3 2017 Channel A19 Flexamat Lined Triangular Highlighted Side Slopes (z:1) = 3.00, 3.00 Depth (ft) = 0.72 Total Depth (ft) = 1.50 Q (cfs) = 9.000 Area (sqft) = 1.56 Invert Elev (ft) = 1.00 Velocity (ft/s) = 5.79 Slope (%) = 8.00 Wetted Perim (ft) = 4.55 N-Value = 0.035 Crit Depth, Yc (ft) = 0.90 Top Width (ft) = 4.32 Calculations EGL (ft) = 1.24 Compute by: Known Q Known Q (cfs) = 9.00 Elev (ft) Depth ft( ) Section 3.00 2.00 2.50 — 1.50 2.00 — - 1.00 1.50 -- 0.50 1.00 — 0.00 0.50 -0.50 0 1 2 3 4 5 6 7 8 9 10 11 Reach (ft) Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Channel A20 NTJ/DCC 7/14/2017 Checked Date Sheet 1 of 1 AST 7/14/2017 Purpose: Determine the adequacy of Channel A20 for a 10 year storm event.And required liner type. 1 Given: Contributing Drainage Area,A: 7844.419 sq.ft. 0.18 acre Channel Size 3:1 Sides slopes Depth,D: 9 inches Slope of Channel 8.1 Assumptions: Rainfall Intensity(Atlas 14),is 6.53 in/hr use 5 min duration 1 Roughtness Coefficent,C: 0.90 mannings roughness: 0.035 Velocity Lining 0-3 ft/sec Grass 0-4 ft/sec EC-2 VDOT matting 4-10 ft/sec EC-3 VDOT matting 10+ft/sec Flexamat* ' Calculations: Peak Flow Qp=C*i*A 1.06 cfs Depth of Water in Channel 0.33 ft from express calculations Velocity 3.24 fps from express calculations Conclusions: Channel A20 is adequately size to handle the 10 year storm event. Use EC-2 VDOT Matting for 3.24 fps. ' 1 1 1 1 a Precipitation Frequency Data Server Page 1 of 4 NOAA Atlas 14,Volume 2,Version 3 Location name:Charlottesville,Virginia,USA* 4,0e/70.."-, Latitude:38.0253°,Longitude:-78.6538° � Elevation:662.27 ft'" «,�, �+„ . Location ESRI Maps ,�^ MN `-source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnie,D.Martin,B,Lin,T.Parzybok,M.Yekta,and D.Riley ar NOAA,National Weather Service.Silver Spring,Maryland PF tabular I PF graphical i Maps & aerials PF tabular In PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches/hour)1 Average recurrence interval(years) Duration I 1 2 5 1 10 25 50 100 200 500 1000 ma 4.12 4.92 6.80 7.37 8.02 8.63 9.20 9.90 10.5 5-min (3.72-4.57) (4.45-5.45) (5.23-6.41) _ (6.60-8.11) (7.15-8.83) ; (7.64.9.52) (8.09-10.2) (8.60-11.0) (9.00.11.7) 10-min 3.29 3.94 4.64 5.22 5.87 6.38 I 6.86 7.30 7.83 8.24 (2.98-3.65) (3.56-4.36) (4.19-5.13) (4.70-5.76) (5.26-6.47) (5.69-7.03) (6.08-7.56) (6.41-8.06) (6.80-8.69) (7.09-9.19) 15-min 2.74 3.30 3,92 4.40 4.96 5.39 5.78 6.14 6.57 6.90 it (2.48-3.04) (2.99-3.65) (3.54-4.32) (3.97-4.86) (4.45.5.46) (4.80-5.94) (5.12-6.37) (5.40.6.78) (5.71-7.29) (5.93-7.69) 30-min 1.88 2.28 2.78 3.19 3.67 4.06 4.42 4.78 5.23 5.59 (1.70-2.08) (2.06-2.52) (2.51-3.07)_ (2.87-3.52) (3.29.4.06) (3.62-4.47) (3.92-4.88) (4.20-5.28) (4.54.5.80) (4.80.6.23) 60-min 1.17 1.43 1.78 2.08 2.45 2.75 3.06 3.36 3.76 4.08 (1.06-1.30) (1.29-1.58) (1.61-1.97) (1.87-2.29) (2.19.2.70) (2.45-3.03) (2.70.3.36) (2.95-3,70) (3.26-4.16) (3.51-4.55) am 2-hr 0.700 0.862 1.07 1.26 1.50 1.91 2.12 2.42 2.67 (0.622-0.792)(0.756-0.961) (0.948-1.20) (1.12-1.41) (1.32-1.68) (1.66-2.14) (1.83.2.38) (2.06-2.73) (2.25-3.02) 3-hr 0.511 0.621 0.778 0.914 1.09 1.24 1.39 1.56 1.77 1.96 (0.454-0.582)(0.549-0.705)(0.687-0.884) (0.805-1.04) (0.956-1.23) (1.08-1.40) (1.21-1.58) (1.33-1.76) (1.50-2.02) (1.64.2.24) 6-hr 0.331 0.401 0.498 0.587 0.705 0.809 0.918 1.04 1.20 1.36 OM (0.296-0.374) (0.357-0.452 (0.442.0.561)(0.518-0.660)(0.619-0.793)(0.704-0.908) (0.791-1.03) (0.882-1.17) (1.01-1.36) (1.12-1.53) 12-hr 0.209 0.252 0.316 0.372 0.463 0.625 0.603 0.689 0.817 0.932 (0.186-0.238)(0.224.0.288)(0.278-0.358)(0.328-0.423)(0.396-0.514 (0.453-0.595)(0.514-0.684)(0.579-0.782) (0.671-0.931) (0.753-1 07) 24-hr 0.127 0.154 0.196 0.231 0.284 0.329 0.378 0.433 0.514 0.583 (0.114-0,142)(0.138-0.172)(0.176-0.219)(0.207.0.258)1(0252.0.316 10.289.0.365)(0.330-0.420)(0.374-0.479)(0.436-0.570)(0.488-0.647) 2-day 0.075 0.091 0.115 0.135 0.164 0.188 0.215 0.243 0.286 0.320 (0.067-0.083)(0.081-0.101)(0.103.0.128)(0.121-0.151)(0.146-0.183)(0.166-0.209)(0.188-0.239)(0.211-0.271)(0.244.0.318)(0.271-0.358) 3-day 0:053 0.064 0.082 0.096- 0.116 0.133 * 0.152 0.172 0.201 0.225 (0.048.0.059)(0.058-0.071)(0.074-0.090)(0.086.0.106)(0.104-0.128)(0.119-0.147)(0.134-0.168) 0.151.0.190)(0.174.0.223)(0,193-0,251) i 0.042 0.061 0.065 0.076 0.092 0.106 0.120 0.136 0,169 0.178 4-day (0.039.0.047)(0.047.0.056)(0.059.0.072)(0.069-0.084)(0.083.0.101)(0.095-0.116)(0.107-0.132)(0.120-0.150)`(0.139.0.175)(0.154-0.197) 7-day 0.028 0.034 0.042 0.049 0.059 0.067 0.076 0.085 0.098 0.109 (0.026-0.031)(0.031.0.037)(0.039.0.046)(0.045.0.053)(0.053-0.064)(0.060-0.073)(0.068-0.083)(0.075.0.093)(0.086-0.108)(0.095-0.120) 10-day0.022 0.027 0.033 0.038 0.045 0.051 0.067 0.063 0.072 0.079 a (0.020-0.024)(0.020-0.024)(0.025.0.029)(0.030-0.036)(0.035-0.041)(0.041.0.049) (0.046-0.055),(0.051-0.061)(0.057-0.068)(0.064-0.078)(0.070-0.086) 20-da 0.015 0.017 0.021 0.024 0.028 0.031 0.034 0.037 1 0.041 0.044 - (0.014-0.016)(0.016-0.019)(0.020.0.023)1[0.022-0.026)(0.026-0.030)(0.028-0.033)(0.031.0.036)(0.034.0.040)1(0.037.0.044)(0.040-0.048) 30-day 0.012 0.014 0.017 0.019 0.021 0.023 0.026 0.027 0.029 0.031 (0.011-0.013)(0.013.0.015)(0.016-0.018)(0.017.0.020)(0.020.0.023)(0.022.0.025)°(0.023.0.027) 0.025.0.029)(0027-0.031)(0.029.0.033)1 45-day 0.010 0.012 0.014 0.015 0.017 0.018 0.020 0.021 0.023 0.024 MOS5 - 0.009-0.011))(0.011-0.012 (0.013-0.015)(0.014.0,016)(0.016-0.018)(0.017-0,020)(0.018.0.021)100.020.0.022)1(0.021--00.024 (0.022-0.026) I60-day 0.009 0.010 0.012 0.013 0.014 0.016 0.017 0.018 0.019 0.020 (0.008.0.009) (0.010.0.011)(0.011-0.013)(0.012-0.014)(0.014-0.015)(0.015.0.016)(0.016.0.018)(0.016-0.010)(0.018.0.020)(0.018.0.021) a 'Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAH Atlas 14 document for more information. a Back to Too Mil a a http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0253&lon=-78.6538&dat... 11/21/2016 a 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use C Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat,2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 Heavy soil, steep, 7% 254 Oct JSP 0.3' Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows * Heavy soil, no crop 0.30-0.60 * Heavy soil, with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 111Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 Industrial: Streets: Light areas 0.50-0.80 Asphaltic 030-0.95 Heavy areas 0.60-0.90 Concrete 0.80-0.95 O'1 Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85^ • Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 ai Note: The designer must use judgement to select the appropriate "C" value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, or moderate to steep slopes, and sparse vegetation should be assigned the highest C values. is Source: American Society of Civil Engineers V - 29 Channel Report Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Thursday,Jul 6 2017 ill Channel A20 Adequacy and Liner Type "s Triangular Highlighted Side Slopes (z:1) = 3.00, 3.00 Depth (ft) = 0.33 Total Depth (ft) = 0.75 Q (cfs) = 1.060 lig Area (sqft) = 0.33 Invert Elev (ft) = 1.00 Velocity (ft/s) = 3.24 Slope (%) = 8.10 Wetted Perim (ft) = 2.09 N-Value = 0.035 Crit Depth, Yc (ft) = 0.38 Top Width (ft) = 1.98 Calculations EGL (ft) = 0.49 Compute by: Known Q Known Q (cfs) = 1.06 iii I IElev (ft) De Depth p (ft) Section 1 2.00 1.00 1 1.75 0.75 I I1.50 0.50 v ik 1.250.25 I I 1.00 0.00 I 0.75 -0.25 I0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 I Reach (ft) Client Project Job No. Rivanna 'lid Waste Authority New Ivy Solid Waste Transfer Station 02216108.011�► Subject By 1" e A18/A21 Pay- VDOT Channel NTJ/DCC 7/14/2017 BIM Checked Date 1 of 1 AST 7J14J2017 Purpose: Det- ine Peak Flow for a 10 yr storm for Channel A21 Given: Total Drainag- rea,A: 5767.579 sq.ft. 0.13 acre Assumptions: Assume 5 minute. ation therefore,Rainfall Intensity,i= 6.53 in/hr Runoff Coefficent,C: 0.90 as e entire area paved. Channel Dimensions pe DOT Standard Paved Ditch PG-2A,Type Al Calculations: Peak Flow Qp=C*i*A 78 cfs use 2 cfs for design. Conclusions: Channel A21 lined with VDOT type Al is• -quate to handle the design peak fl. Also,use PG-2A type Al paved ditch for cha el A18(smaller drainage area ism MIS MO Olt NI MR MS Eli 'r ip tat en -re•ue c D. a erver Page 1 of4 ". NOAA Atlas 14,Volume 2,Version 3 '',\ Location name:Charlottesville,Virginia,USA' f Latitude:38.0253°,Longitude:-78,6538° 4 Elevation:662.27 ft** W •source 1St,Maps WI •le -•source ttSGF POINT PRECIPITATION FREQUENCY ESTIMATES G M Bonnin,D Martin,B Lin,T Parzybok,M Yekta,and D Riley i NOAA,National Weather Service,Silver Spring,Maryland PF tabular(PF graphical i Maps & aerials PF tabular PDS-based poin orecipitation frequency estimates with 90% confidence intervals in inches/hour)1 i Duration,I' - ..(` Average recurrence interval(years) 1 !� 1 im._L__ 5 -�1 25 50_� 100 -_ 201 500 1000 a 4.12 • ,fI 5.80 II 6.53 7.37 8.02 111111- 8.63 • 0 9.90 10.5 Ii 5-min (3.72-4.57) 1 (5.23-6.41)f 15 88-7.21) (6.60-8.11) ( (7.15-8.83) (7.64-9.52) (: •-10.2) (8 60-11 0)J (9.00-11.7) J 10-min 3.29 3.94 4.64 8:22"' 5.87 6.38 6.86 / 7.30 7.83 8. (2.98-3.65) (3.56.4.36) 19-5 13)_, (4.70-5.76) (5 26 6 47J24 ( 5.69-7.03) (6.08-7-56) (6.41-8.06) (6.80-8.69) (7.09-9.19) 15-min 2.74 3.30 92 4.40 4.96 6.39 riffirAl 6.14 6.57 6.90 A. (2.48-3.04) (2.99-3.65) (35 ,.32J (3.97-4.86) (445.546)1 (4.80-5.94) (5.40-6.78) (5.71-7.29) (5.93.7,69) I 30-min 1.88 2.28 3.19 3.67 4.06 4.78 5.23 5.59 1 (1.70.2.08) (2.06-2.52) IiiiL (2.87-3.52) (3.29-4,05) (3.62-4.47) (4.20-5.28) (4.54-5.80) (4.80.6.23) -__ 60-min 1.17 1.43 1.78 2.08 2.45 / 3.06 3.35 3.76 4.08 (106.1.30) (1.29.1.58) (1.81.1.97) k 1.87-2.29) (2-19-2.70) r ' (2.70-3,36) (2.95.3.70) (3.26-4.16) (3.51-4.55) - 0.700 0.862 1.07 26 1.50 1.91 2.12 2.42 2.67 2-hr (0.622-0.792)(0.7500.961) (0.948.1.20) 1.41) (1.32.1,68) • ) (1.66-2.14 .06-2 (1.83-2.38) (2 .73} (2.25-3.02) 3-hr 0.611 0.621 0.778 0.9(0.454-0.582) 1.09 1.39 1.65 1.77 1.96 (0.454-0.582)(0.549.0.705)(0.687-0,884) (0.805-1 ,• (0.956-1.23) IF -1.40) (1.21-1.58) (1.33-1.76) (1 50-2.02)1 (1.64-2.24) ar. 6-hr 0.331 0.401 0.498 0.687 0.705 -1.809 1----0.918 1.04 1.201.36 (0.296-0.374)(0.357-0.452)(0.442.0.561) 0.518-0.6601,1,619-0 793). .704-0.908)1(0.791-1 03) (0.882-1.17) ((1.01-1.36) (1.12-1.53) 12-hr 0.209 0.262 0.315 0.372 111:...453 453 0.525 0.603 0.689 0.817 0.932 (0.186.0.238)(0.224.0.288)(0.278.0.358)(0.328-0.423) c .-0 ,�(0.453 0 595)1(0.514-0 684),(0.579-0.782)(0.671-0.931) (0.753.1,07) 24-hr 0.127 0.1541 0.196 0.231 0.1"1. 1 0.329 0.378 0.433 0.514 0.583 AO [(0,114.0.142)(0.138-0,1 (0.176-0.219) 0.207-0.2581(0.25 '16)1(0.289 0 365)1(0.330-0.420)`(0.374-0 479)(0.436.0.570)((0.488-0 647) 2-day 0.075 0.091 0.115 0.135 •.164 0.188 0.216 0.243 0.286 0.320 (0067.0.083)(0.081-0.10141(0.103.0.128)(0.121-0.151), '. 46-0.183 0.166-0.209)((0.188-0.239)1(0.211-0271)(0.244-0.318)(0.271-0,35d 3-day 0.063 0.064 0.082 1 0.096 ' 0.0 0.116 0.133 0.162 0.172 0.201 0.225 (0.048-0.059)(0.058-0.071)(0.074.0.090) 86-0.11- (0.104-0128)(0. 9.0147),(0.134-0.168)(0.151-0.190)(0.174-0.223),(0153-0251) 4-day 0.042 0.061 0.066 0.00.092 0. r 6 _ 0.120 0.136 0.159 0.178 (0.039.0.047)(0.047.0.056)(0.059-0.072) 0.06 •.084)1(0.083.0 101)1((0.095. t 16)(0.107.0.132)(0.120.0.150)(0.139.0.175)1(0 154-0.197)1 7-day 0.028 0.034 0.042 Cr .049 0.069 0.06 1 0.076 0.055 0.098 0.109 _ (0.026.0.031)(0.031.0.037)(0.039.0.046) 45-0.053)(0.053-0.064) 0.060.0.07 (0.068-0.083 (0.075-0.093)(0.088.0.108) 0.095-0.120) MN*0.022 0.027 38 46 0.051 67 AM 0.072 0.079 10-day (0020-0 024j(0025.0 020 (0.030 0.0 v 0.0.033 36 0 041) (004 00.049) 0.046-0.0551i ,'51-0 061)(0.057-0.068).063 (0.064-0.078) 0.070-0.086) 20-day 0.016 0.017 0.0 28 0.024 0.0 0.031 I 1 34 0.037 0.041 0.044 (0.014.0.016)(0.016-0.019)(0.020 I(0.022-0.026) (0.026.0.030)(0.028-0.033)(0.031 '.036)((0.034.0.040)(0.037-0.044)(0.0400.048 30-day 0.012 0.014 • ,17 0.019 0.021 0.023 0,02 0.027 0.029 0.031 .(0.011-0.013)(0.013-0.015)(0 6-0.018) 0.017.0.020)(0,020-0.023)(0.022-0,025)(0.023-0.0 - [(0.025-0.029)(0.027-0.031),(0.029-0.033)1 a 145-da� 0.010 0.012 emu l 0.015 0.017 0.018 0.020 0.021 l 0.023 ( 0.024 1 l y (0-009.0.011)(0.011-0.01,,(0.013.0.015)((0.014-0.016)(0.016.0.018) 0.017-0.020)(0.018 0.021)in120-0.022)((0.021-0.024) 0.022-0.026) 60-day 0.009 ` 0,011 0.012 0.013 0.014 I 0.016 0.017 0.019 0.020 (0.008-0.009)(0 010 r r 11 (0 011-0.013)(0.012-0.014)(0.014-0.015)K0.015-0.016)11(0.016.0.018)1 1B 0.01. 1.019)(0.018.0.020)(0.018-0.021)1 JIM 'Precipitation frequency(PF):.imates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are' estimates at lower and upper bounds of the 90%confidence interval The probability that plea.'anon frequency estimates (for a given duration and- rage recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%. ,imates at upper bounds are not checked against obeble maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. ® Please refer to NOAA las 14 document for more information Back to Top I I I t1.://1d .n s.•oa-.g•v/ .sc pfds/pfds printpage.litml?Iat=38.0253&ton=-78.6538&dat... 11/21/2016 1/1 .11111 i 1 199 ' TABLE 5-2 ' VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use Business: Lawns: Downtown area. 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 Neighborhood arr 0.50-0.70 Sandy soil, average, 2-7 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 I Leavy soil, avera , 2-7% 0.18-0.22 Heavy soil, steep.;7° 025-035 OS ; 0.3; - Residential: Agricultural lard: Single-family areas 0.30-0.50 Bare pack-, soil Multi units, detached 0.40-0.60 : Smo,di 0.30-0.60 Multi units, attached 1.60-0.75 * Re gh 0.20-0.50 Suburban 0.' -0.40 Culti .ted rows ` eavy soil, no crop 0.30-0.60 Heavy soil, with crop 0.20-0.50 '' Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 Sandy soil 0.05-0.25 ands 0.05-0.25 Industrial: Streets: Light areas 1.50-0.80 Asphaltic. 0.70-0.95 `I'6 Heavy areas 0.60-0.90 Concrete 0.80-0.95 C3•1° Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved area 0.10-0.30 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The desigr'-r must use judgement to select the appropriate "C" value witt'' the range. Generally, larger areas with permeable soils, flat slopes and dense vegeta*ion should have the lowest C values. Smaller areas with dense soils, r, mod.,rate to steep slopes, and sparse vegetation should be assigned the highes va1aes. /Somerican Society of Civil Engineers ., 101 V - 29 .. Channel Report ',m Hydraflo Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Friday,M. 2017 Channe . 21/ A18 VDOT STD Paved Ditch Type A alMI Triangular Highlighted Side Slopes (z: = 6.00, 4.00 Depth (ft) 0.21 Total Depth (ft) = 0.50 Q (cfs) = 2.000 Area (sqft) = 0.22 Invert Elev (ft) = 1.00 Velocity (ft/s) = 9.07 Slope (%) = 13.30 Wetted Perim (ft) = 2.14 N-Value 0.013 Crit Depth, Yc ( = 0.40 Top Width (ft) = 2.10 Calculations EGL (ft) = 1.49 Compute by: Kno , Q Known Q (cfs) = 2.0. Elev (ft) Depth (ft ectio 2.00 — V 1.00 s I I 1.75 0.75 1.50 — , 0.50 r 4 1.250.25 V I tOo — ®_ — 0.00 III 0.75 -- _.v -0.25 i 1 2 3 4 5 6 I Reach (ft) r 1 APPENDIX G Storm Drains ' I 1 SCS ENGINEERS Client Project Job No Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Storm Drains NTJ 3/13/2017 Checked Date MEPurpose: Establish storm drain size and adequacy for 10 year storm event for drains in Drainage Area A. Given: Reinforced concrete pipe and concrete manhole design. Drainage area to storm drain is deliniated on Drawing SW2. 1rr Assumpi ons 1.Manning's number(n)=0.013 2.For hydrualic grade line calculations,HGL set to crown of pipe at discharge point. w Calculations: 1.See attached dydrology cacluations for drainage areas. Peak Flows Drainage Area,A= 9 cfs 2.See attached hydrualic calculations for Strom drain hydualic gradient and capacity. Conclusions: The storm drain as designed has adequate capacity to handle the 10-year storm event without causing a pressure situation in the pipes. also the HGL is below ground surface,therefore manholes will not be overtopped. ■r 111/111 OM MN 1111111 am SCS ENGINEERS Client Project Job No Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Storm Drains NTJ 3/3/2017 Checked Date Purpose: Calculate the peak discharge for Drainage Area A for a,0 year event Given: 1 Use 10 year storm for design 2 Areas Taken from autocad Drawings SW2 Assumptions: 1 Use NOAA Atlas 14 for intensity 2 TR55 used to find time of concentration 4.Cf value From VDOT Drainage Manual= 5 C values taken from page V-29 Table 5-2 of the VESCH Calculations: Cumulative"C" C=((A1`C1)+(A2*C2)+, +(An+Cn))/(A1+A2+. +An) Peak Flow Q10=C*i*A"Cf Area A=A1+A2+. +An Contributing Drainage Area Area(ac) Assmued C Value Impervious Area 0 56 0.90 Pervious Area 2 50 0.35 Intensity-assume 5 min duration 6 53 in/hr Total Area: =lmpervous+pervious 3.06 acres Cumulative"C" C=((A1"C1)+(A2'C2)+, +(An+Cn))/(A1+A2+. . +An) 045 Peak Discharge,Q10: Q10=Cf*ASW1*C1 9 0 cfs Conclusion: The peak flow for drainage area A is 9 0 cfs Use this peak flow for calculating structure sizes 3 Soil Map—Albemarle County,Virginia p �, a R R lk 705750 L * S 7058(70 705850 705900 705950 706000 706050 38° 120N 38°127'N p dim !SR 4 Q* r ! y, m s + + ' Aini A.0U*5 *'A , .. , ma t'' °i ` �., ,4i' .a T$a , ,„: • e( ' , >, K ' ' 4-1.,,,,t."' Jc ` % }' jia T' , :,' . ' - , '3 i � A }yp ,` ta. 7y tt, 1. q„, -tti..."..t4t.4..-"' ,-- *fr ' t ' 'tt.- '.**St y v. 4O ,. x'a •,r i >17 'R; reg moi- _+ * .. =y( ,,.% a - ,F �: i 9 3133 r a 3B°1'S'N ,. 38°15'N 53 "� 705750 705800 705850 705900 705950 706000 706050 3 3 Map Scale:1:2,160(prated on A porteR(8.5"x 11")sheet. — ,Meters kA N o 30 --60 180 k — ,Feet 0 100 200 400 600 map prom:Web Mercator Comer coordinates:WGS84 Edge tics:WTI Zone 17N WG584 U Natural Resources Web Soil Survey 7/6/2016 — Conservation Service National Cooperative Soil Survey Page 1 of 3 — I I I I Sod Map—Albemarle County,Virginia 1 MAP LEGEND MAP INFORMATION Area of Interest(AOl) g4 Spoil Area The soil surveys that comprise your A01 were mapped at 1:15,800. Area of Interest(ACI) Stony01) . I.� Warning:Soil Map may not be valid at this scale i Soils CO Very Stony Spot J Soil Map Unit Polygons Enlargement of maps beyond the scale of mapping can cause 1, Wet Spot misunderstanding of the detail of mapping and accuracy of soil line ii ...i Soil Map Unit Lines placement The maps do not show the small areas of contrasting 4% Other soils that could have been shown at a more detailed scale © Sot Map Unit Points —_ a Special Line Features Special Point Features Please rely on the bar scale on each map sheet for map to Blowout Water Features measurements Streams and Canals ® Borrow Pit Source of Map: Natural Resources Conservation Service Transportation Web Soil Survey URL. http:ftwebsoilsurvey nres.usda.gov Clay Spot � r-e-t Rails Coordinate System: Web Mercator(EPSG:385 I 0 Closed Depression ra interstate Highways Maps from the Web Soil Survey are based on the Web Mercator x Gravel Pit US Routes projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Gravelly Spot Major Roads Albers equal-area conic projection,should be used if more accurate O LandfillLocal Roads calculations of distance or area are required.A. I Lava Flow This product is generated from the USDA-NRCS certified data as of Background the version date(s)listed below Marsh or swamp . Aerial Photography Soil Survey Area. Albemarle County,Virginia ▪ Mine or Quarry Survey Area Data: Version 10.Dec 11,2013 O Miscellaneous Water Soil map units are labeled(as space allows)for map scales 1:50,000 O Perennial Water or larger. i Rock Outcrop Date(s)aerial images were photographed: May 9,2011—Jun 4, 2011 -f Saline Spot The orthophoto or other base map on which the soil lines were Sandy Spot compiled and digitized probably differs from the background .s3 Severely Eroded Spot imagery displayed on these maps.As a result,some minor shifting i of map unit boundaries may be evident 0 i,j) Slide or Slip O Sodic Spot i i USDA Natural Resources Web Soil Survey 716/2016 ME Conservation Service National Cooperative Soil Survey Page 2 of 3 i Nib Mb NMI i Soil Map—Albemarle County,Virginia ' Map 9 Unit Legend ■ U Albemarle County,Virginia(VA003) Map Unit Symbol Map Unit Name Acres In AOI I Percent of AOI 1B Abell silt loam,2 to 7 percent 0.0 0.1% slopes I 14C Chester loam,7 to 15 percent 1.2 5.3% slopes 4 I 19B Cullen loam,2 to 7 percent 8.3 35.9% slopes 20C3 Cullen clay loam,7 to 15 2.0 8.8% percent slopes,severely IN eroded 20D3 Cullen clay loam, 15 to 25 0.0 0.0% percent slopes,severely I I eroded 3 P Hayesville loam,2 to 7 percent 1.6 6.8% slopes 36C Hayesville loam,7to 15 percent 3.4 15.0% slopes 371:3 Hayesville clay loam.7 to 15 6.0 26.2% percent slopes,severely eroded 111 37D3 Hayesville clay loam, 15 to 25 0.4 1.9% percent slopes,severely eroded Totals for Area of Interest 23.0 100.0% 1 � L IMO MA Natural Resources Web Soil Survey 7/6/2016 "1llag Conservation Service National Cooperative Soil Survey Page 3 of 3 I111 1992 Soil name surftex hydgrp kfact wtdepl wtdeph GLENWOOD CB-L B 0.20 6.00 6.00 GLENWOOD VARIANT RB-L B 0.05 6.00 6.00 GOLDSBORO FSL B 0.20 2.00 3.00 GOLDSBORO SL B 0.20 2.00 3.00 GOLDSTON CN-L C 0.15 6.00 6.00 GOLDSTON CN-SIL C 0.15 6.00 6.00 GOLDSTON CNV-SIL C 0.05 6.00 6.00 IIGOLDSTON SIL C 0.15 6.00 6.00 GOLDVEIN GRF-SIL C 0.28 1.00 2.00 GOLDVEIN GRITTY GRF-SIL C 0.28 1.00 2.00 GORESVILLE* GR-SIL B 0.24 6.00 6.00 IIGREENLEE STV-L B 0.10 6.00 6.00 GRIMSLEY CB-L B 0.20 6.00 6.00 GRIMSLEY CB-SL 8 0.20 6.00 6.00 GRIMSLEY ST-L B 0.20 6.00 6.00 GRIMSLEY STX-L B 0.20 6.00 6.00 GRITNEY FSL C 0.20 6.00 6.00 GRITNEY GR-FSL C 0.15 6.00 6.00 GROSECLOSE GR-L C 0.28 6.00 6.00 GROSECLOSE GR-SIL C 0.28 6.00 6.00 GROSECLOSE L C 0.43 6.00 6.00 GROSECLOSE SICL C 0.32 6.00 6.00 GROSECLOSE SIL C 0.43 6.00 6.00 GROVER FSL B 0.24 6.00 6.00 GROVER SCL B 0.28 6.00 6.00 GROVER SL B 0.24 6.00 6.00 IIGUERNSEY SIL C 0.43 1.50 3.00 GULLIED LAND VAR 6.00 6.00 GULLION L C 0.32 1.50 3.00 IIGULLION SIL C 0.32 1.50 3.00 GUNSTOCK CN-L C 0.37 6.00 6.00 GUNSTOCK SL C 0.28 6.00 6.00 IIGUYAN SIL C 0.32 0.50 1.50 GWINNETT VARIANT CL B 0.28 6.00 6.00 HAGERSTOWN SIL C 0.32 6.00 6.00 HAGERSTWON SIL C 0.32 6.00 6.00II HALEWOOD L B 0.32 6.00 6.00 HALEWOOD STV-FSL C 0.24 6.00 6.00 HARTLETON CN-L B 0.20 6.00 6.00 II STV-L B 0.15 6.00 6.00 HATBORO L D 0.49 0.00 0.50 HATBORO SIL D 0.49 0.00 0.50 HAWKSBILL CB-L B 0.17 6.00 6.00 HAWKSBILL CBV-L B 0.17 6.00 6.00 HAWKSBILL STX-L B 0.17 6.00 6.00 HAYESVILE L B 0.20 6.00 6.00 HAYESVILLE CB-L B 0.20 6.00 6.00 HAYESVILLE CL B 0.20 6.00 6.00 HAYESVILLE CL B 0.24 6.00 6.00 HAYESVILLE FSL B 0.20 6.00 6.00 HAYESVILLE GR-FSL B 0.20 6.00 6.00 HAYESVILLE L B 0.20 6.00 6.00 HAYESVILLE STV-FSL C 0.15 6.00 6.00 HAYESVILLE STV-L C 0.15 6.00 6.00 VI - 63 1992 Soil name surftex hydgrp kfact wtdepl wtdeph HAYESVILLE STV-L C 0.24 6.00 6.00 FLAYESVILLE STV-SCL C 0.32 6.00 6.00 HAYMARXET SIL D 0. 32 5.00 6.00 HAYTER CB-L B 0.20 6.00 6.00 HAYTER CBV-L B 0.15 6.00 6.00 HAYTER L B 0.28 6.00 6.00 HAYWOOD L B 0.24 6.00 6.00 HAZEL CN-L C 0.24 6.00 6.00 HAZEL L C 0.32 6.00 6.00 HAZEL SIL C 0.32 6.00 6.00 HAZEL ST-L C 0.24 6.00 6.00 HAZEL STV-L C 0.24 6.00 6.00 HAZEL CHANNERY CN-SIL C 0.32 6.00 6.00 HAZELTON STV-L B 0.15 6.00 6.00 HAZLETON CN-SL B 0.17 6.00 6.00 HAZLETON ST-SL B 0.15 6.00 6.00 HAZLETON STV-SL B 0.15 6.00 6.00 HAZLETON STX-SL B 0.15 6.00 6.00 HELENA CL C 0.28 1.50 2.50 HELENA FSL C 0.20 1.50 2.50 HELENA FSL C 0.24 1.50 2.50 HELENA GR-COSL C 0.15 1.50 2.50 HELENA GRF-FSL C 0.15 1.50 2.50 HELENA L C 0.20 1.50 2.50 HELENA L C 0.24 1.50 2.50 HELENA SL C 0.20 1.50 2.50 HELENA SL C 0.24 1.50 2.50 HERNDON L B 0.43 6.00 6.00 HERNDON SICL B 0.49 6.00 6.00 HERNDON SIL B 0.43 6.00 6.00 HERNDON VFSL B 0.43 6.00 6.00 HIWASSEE CB-FSL B 0.28 6.00 6.00 HIWASSEE CB-SL B 0.24 6.00 6.00 HIWASSEE CL B 0.28 6.00 6.00 HIWASSEE FSL B 0.28 6.00 6.00 HIWASSEE GR-L B 0.24 6.00 6.00 hi HIWASSEE L B 0.28 6.00 6.00 HIWASSEE SIL B 0.32 6.00 6.00 II HIWASSEE VARIANT L B 0.32 6.00 6.00 HOADLY L C 0.28 0.50 1.50 HOBUCKEN L D 0.10 HOGELAND* CB-SIL C 0.24 6.00 6.00 IIHOLLYWOOD CL D 0.32 6.00 6.00 HUNTINGTON L B 0.28 6.00 6.00 HUNTINGTON SIL B 0.28 6.00 6.00 II HYATTSVILLE FSL B 0.28 4.00 6.00 HYDE SIL B/D 0.17 0.00 1.50 HYDRAQUENTS SL B 0.37 4.00 6.00 HYDRAQUENTS SL D 0.37 li INGLEDOVE L B 0.32 6.00 6.00 IREDELL CL C/D 0.32 1.00 2.00 IREDELL FSL C/D 0.28 1.00 2.00 IREDELL L C/D 0.32 1.00 2.00 11 IREDELL SIL C/D 0.32 1.00 2.00 IIVI - 64 i 1992 II Soil name surftex hydgrp kfact wtdepl wtdeph CATOCTIN STX-SIL C 0.20 6.00 6.00 II FS A 0.10 4.00 6.00 CATPOINT LS A 0.10 4.00 6.00 CAVERNS SL B 0.20 6.00 6.00 I CECIL CB-FSL B 0.28 6.00 6.00 CECIL CL B 0.24 6.00 6.00 CECIL CL B 0.28 6.00 6.00 CECIL FSL B 0.20 6.00 6.00II CECIL FSL B 0.28 6.00 6.00 CECIL GR-FSL B 0.15 6.00 6.00 CECIL GR-SL B 0.15 6.00 6.00 CECIL GRF-SL B 0.28 6.00 6.00 CECIL L B 0.28 6.00 6.00 CECIL SCL S 0.28 6.00 6.00 CECIL SL B 0.28 6.00 6.00 II CECIL VFSL B 0.28 6.00 6.00 CHAGRIN FSL B 0.32 4.00 6.00 CHAGRIN L B 0.32 4.00 6.00 IICHAGRIN SIL B 0.32 4.00 6.00 CHAGRIN VARIANT LS A 0.10 6.00 6.00 CHAPANOKE SIL C 0.43 0.50 1.50 CHASTAIN L D 0.32 0.00 1.00 , CHASTAIN SICL D 0.32 0.00 1.00 CHASTAIN SIL D 0.32 0.00 1.00 CHATUGE L D 0.32 1.00 2.00 CHATUGE SL D 0.32 1.00 2.00 CHAVIES FSL B 0.24 6.00 6.00 CHAVIES SL B 0.24 6.00 6.00 CHAVIES VARIANT SL B 0.24 3.50 3.50 CHENNEBY L C 0.37 1.00 2.50 CHENNEBY SIL C 0.37 1.00 2.50 CHESTER CB-L B 0.32 6.00 6.00 CHESTER CN-L B 0.28 6.00 6.00 CHESTER L B 0.32 6.00 6.00 mi. CHESTER SIL B 0.32 6.00 6.00 CHESTER SL B 0.32 6.00 6.00 I CHESTER STV-L B 0.24 5.00 5.00 CHESTER STV-L 6 0.32 5.00 5.00 CHESTER LOAM L B 0,32 6.00 6.00 IICHEWACLA FSL C 0.24 0.50 1.50 CHEWACLA L C 0.28 0.50 1.50 CHEWACLA L C 0.49 1.00 2.00 CHEWACLA SIL C 0.28 0.50 1.50 CHEWACLA SIL C 0.49 1.00 2.00 CHICKAHOMINY L D 0.37 CHICKAHOMINY L D 0.37 0.00 0.50 CHICKAHOMINY SIL D 0.37 0.00 0.50 CHILHOWIE C C 0.37 6.00 6.00 CHILHOWIE CN-SICL C 0.20 6.00 6.00 CHILHOWIE CN-SICL C 0.37 6.00 6.00 CHILHOWIE SIC C 0.37 6.00 6.00 CHILHOWIE SICL C 0.37 6.00 6.00 CHINCOTEAGUE SIL D 0.32 CHIPLEY S C 0.10 2.00 3.00 VI - 56 1992 Soil name surftex hydgrp kfact wtdepl wtdeph COTACO CB-FSL C 0.24 1.50 2.50 COTACO FSL C 0.37 1.50 2.50 COTACO L C 0.37 1.50 2.50 COTACO SIL C 0.37 1.50 2.50 COTACO VARIANT CB-L C 0.24 2.00 3.00 COTACO VARIANT SIL C 0.43 2.00 3.00 COURSEY L C 0.32 2.00 3.00 COWEE CH-L B 0.20 6.00 6.00 COXVILLE FSL D 0.24 0.00 1.50 COXVILLE L D 0.24 0.00 1.50 CRAIGSVILLE CB-FSL B 0.28 6.00 6.00 CRAIGSVILLE CB-SL 8 0.20 6.00 6.00 CRAIGSVILLE CB-SL 8 0.28 6.00 6.00 CRAIGSVILLE CBV-L 0 0.10 6.00 6.00 CRAIGSVILLE GR-FSL B 0.17 6.00 6.00 CRAIGSVILLE L B 0.28 6.00 6.00 CRAIGSVILLE SL B 0.17 6.00 6.00 CRAVEN CL C 0.37 2.00 3.00 CRAVEN FSL C 0.32 2.00 3.00 CRAVEN L C 0.32 2.00 3.00 CRAVEN SCL C 0.37 2.00 3.00 CRAVEN SIL C 0.32 2.00 3.00 CREEDMOOR FSL C 0.28 1.50 2.00 CREEDMOOR GR-FSL C 0.28 1.50 2.00 CREEDMOOR GRV-SL C 0.28 1.50 2.00 CREEDMOOR L C 0.28 1.50 2.00 CREEDMOOR SL C 0.28 1.50 2.00 CREEDMOOR VARIANT FSL C 0.37 0.50 1.50 CREEDMORE FSL C 0.28 1.50 2.00 CROTON SIL D 0.37 0.00 1.50 CROTON SIL D 0.43 0.00 0.50 CULLEN CL c 0.24 6.00 6.00 CULLEN L C 0.37 6.00 6.00 CULPEPER CL C 0.37 6.00 6.00 CULPEPER FSL C 0.37 6.00 6.00 CULPEPER L C 0.37 6.00 6.00 DALEVILLE L D 0.32 0.00 1.00 DALEVILLE SIL D 0.32 0.00 1.00 DANDRIDGE SH-SICL D 0.17 6.00 6.00 DAVIDSON C B 0.28 6.00 6.00 DAVIDSON CL B 0.24 6.00 6.00 DAVIDSON CL B 0.28 6.00 6.00 DAVIDSON CL B 0.37 6.00 6.00 DAVIDSON ST-CL B 0.20 6.00 6.00 DAWHOO VARIANT FSL 0.17 DECATUR CL B 0.32 6.00 6.00 DEKALB CB-FSL C 0.17 6.00 6.00 DEKALB CB-L C 0.17 6.00 6.00 DEKALB CB-SL C 0.17 6.00 6.00 DEKALB CN-FSL C 0.17 6.00 6.00 DEKALB CN-L C 0.17 6.00 6.00 DEKALB CN-SL C 0.17 6.00 6.00 DEKALB FSL C 0.24 6.00 6.00 DEKALB RB-FSL C 0.17 6.00 6.00 VI - 58 1992 I TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA ' 1 Land Use C Land Use C 1 Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 I Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 Heavy soil, steep, 7% 0.25-0.35 \A6 03" Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows * Heavy soil, no crop 0.30-0.60 * Heavy soil, with crop 0.20-0.50 w * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture no * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 1.1 Industrial: Streets: Light areas 0.50-0.80 Asphaltic 0.70-0.95 'y'`' Heavy areas 0.60-0.90 Concrete 0.80-0.95 0'4° Brick 0.70-0.85 ma Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 Playgrounds -0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The designer must use judgement to select the appropriate "C" value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. Source: American Society of Civil Engineers r V - 29 .„ Precipitation Frequency Data Server Page 1 of 4 AM NOAA Atlas 14,Volume 2,Version 3 " 4 Location name:Charlottesville,Virginia,USA* '- "" Latitude:38.0253°,Longitude:-78.6538° . Elevation:662.27 ft"` - i 1110140) . r,* �'e -source:ESRI Maps mas "source.USGS 4"^'{ POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnin,D.Marlin,B.Lin,T.Parzybok,M.Yekta,and D.Riley AIN NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches/hour)1 [ Average recurrence interval(years) *�J Duration 1 2 1 1[ 5 [ 10 IJ 25 i[ 50 100 200 [ 500 I 1000 5-min MI 4.12 4.92 6.80 __ ,4 1., 7.37 8.02 1 8.63 9.20 9.90 10.6 (3.72.4.57) (4.45.5.45) (5.23-6.41) ° (660-8.11) (7.15-8.83) (7 64-9.52) (8.09.10.21 (8.60-11.0) (9.00-11.7) 10-min 3.28 3.94 4.64 6.22 5.87 6.38 6.86 7.30 7.83 8.24 (2.98-3.65) (3.56.4.38) (4.19-5.13) (4.70-5.76) (5.26-6.47) (5.69-7.03) (6.08-7.56) (6.41-8.06) (6.80-8.69) (7.09-9.19) 15-min 2`74 3.30 3.92 4.40, = 4.96 5.39 jI 5.78 6.14 6.57 6.90 INN (2.48-3.04) (2.99-3,65) (3.54-4.32) 91� (4.45.5.46) (4.80-5.94) II (5.12-6.371 ) (5.40-6.78) (5.71-7.29) (5,93-7.69) 30-min 1.88 228 2.78 3.19 3.67 4.06 4.42 4.78 5.23 5.59 (1.70.2.08) (2.08-2.52) (2.51-3.07) (2.67-3.52) (3.29.4.05) (3.62-4.47) (3.92-4.88) (4.20-5.28) (4.54-5.80) (4.80-6.23) 60-min 1.17 1.43 1.78 2.08 2.46 2.76 3.06 3.36 3.76 4.08 (1.06.1.30) (1.294.58) (1.61.1.97) (1.87.2.29) (2.19.2.70) (2.45.3.03) (2.70-3.36) (2.95-3.70) (3.26.4.16) (3.51.4.55) mei 0.700 0.862 1.07 1.26 1.60 1.70 41.91 2.12 2.42 2.67 2-hr (0.622-0.792)(0.756-0.981 (0.948-1.20) (1.12-1.41) , (1.32.1.68) (1.49-1.91) (1.66.2.14) (1.83.2.38) (2.06-2.73) (2.25-3.02) 3-h r 0.611 0.621 0.778 0.914 1.09 1.24 1.39 1.55 1.77 1.96 (0.454-0.582)(0.549.0.705)(0.687-0.884) (0.805-1.04) (0.956-1.23) (1.084.40) (1.21-1.58) (1.33-1,76) (1.50.2.02) (1.64-2.24) MI 6-hr 0.331 0.401 0.498 0.687 0.706 0.809 0.918 1.04 1.20 1.35 (0.296.0.374)(0.357-0.452)(0.442-0.561)(0.518.0.660){0.619.0.793)(0.704-0.908) (0.791-1.03) (0.882-1.17) (1.01-1.36) (1.12-1.53) 12-hr 0.209 0.262 0.316 0.372 0.453 0.626 0.603 0.689 0.817 0.932 (0.186-0.238)(0.224.0.2 (0.278.0.358)(0.328-0.423)(0.396.0.514)(0.453-0.595)(0.514.0.684)(0.579.0.782)(0.671.0.931) (0353-1.07) i ( 24-hr 0.127 0.164 0.196 0.231 0.284 0.329 0.378 0.433 0.614 0.583 r (0.114-0.142) 0.138.0.172 (0.176-0219)(0.20741258)(0.252-0.316)(0.289-0.365)(0.330.0.420)(0.374-0.479)(0.438.0.570)(0.488-0.647) 2-day 0.076 0.091 0.116 0.135 0.164 0.188 0.215 0.243 0.286 0.320 (0.087-0.083)((0.081-0.101 (0.103.0.128)(0.121-0.151) 0.1460.183)(0.166-0.209)(0.188.0.239)(0.211.0.271)(0.244.0.318)(0.271.0.358) 3-day 0.063 0.064 0.082 0.096 0.116 0.133 0.162 0.172 0.201 0.226 (0.048.0059)(0058.0.071)(0.074-0.090)(0.086-0.106)(0.104-0.128)(0.119-0.147)(0.134-0.168)(0.151.0.190)(0.174-0.223)(0.193-0.251) +44 0.042 0.061 0.086 0.076 0.092 0.106 0.120 0.136 0.169 0.178 4-day (0.039-0.047)(0.047.0.056)(0.059-0.072)(0.069-0.064)(0.083.0.101)(0.095-0.116)(0.107-0.132)(0.120-0.150)(0.139-0.175)(0.154.0.197) 7-day 0.028 0.034 0.042 0.049 0.059 0.067 0.076 0.086 0.098 0.109 (0.0260.031) 0.031.0.037 (0.039-0.046)(0.045-0.053)(0.053-0.064)(0.060-0.073)(0.068-0.083)(0.075-0.093)(0.086.0.108)(0.095-0.120) 10-day0.022 0.027 0.033 0.038 0.046 0.061 0.067 0.083 0.072 0.079 mol (0.020.0.024) 0.025.0.029 (0.030.0.036)(0.035.0.041)(0.041.0.049)(0.046.0.055)(0.051.0.061)(0.057-0.068)(0.064.0.078)(0.070-0.086) 20-day 0.016 0.017 0.021 0.024 0.028 0.031 0.034 0.037 0.041 0.044 (0.014.0.016)(0.016.0.019)(0.020-0.023)(0.022-0.026) (0.026.0.030)(0.028-0.033)(0.031-0.036) 0.034.0.040)(0.037.0.044 (0.040-0.048) 30-da 0.012 0.014 0.017 0.019 0.021 0.023 0.026 0.027 0.029 0.031 y (0.011-0.013)(0.013-0.015)(0.016.0.016)(0.017-0.020)(0.020-0.023)(0.022.0.025)(0.023-0.027)(0.025.0.029)(0.027.0.031)(0.029-0.033) AM 45-day 0.010 0.012 0.014 0.015 0.017 0.018 0.020 0.021 0.023 0.024 _ay(0.009-0.011)(0.011-0.012)(0.013-0.015)11{0014-0.01fi)(0.016-0.018)(0.017-0.020)(0.018.0.021)(0.020.0.022)((0.021-0.024)(0.022.0.026) 60-day 0.009 0.010 0.012 0.013 0.014 0.016 0.017 0.018 0.019 0.020 (0.008.0.009) (0.010-0.011)(0.011-0.013)(0.012-0.014)(0.014-0.015)(0.015-0.016)(0.016-0.018)(0.016-0.019)(0.018-0.020)(0.018-0.021) i 'Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. ® Back to Top a r http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?tat=38.0253&lon=-78.6538&dat... 1 1/21/2016 N O W e al a. c o I u u € c o m m N -�r m m W M CD 0 N 03 M 0 m C m ccZ W - ,- .. m c o u m 0 I °c H ^ `0 M co i M 111I[ 8 N L7 O. p •- O C X 3 re. N- N. N- d cry) O O E J F3O 7 Z 7 O ^ O h. Ip _____ M (O N. m a. C)) 8 '8c0q - o .J V)2_ , 0 N C V = Oa) O O C uj= co r n o a n m 0 0) '- 0) C W mir ti co M N N- O C C^ 0) M N m C 0 U U U r z b ^... 0 Q N N N r d C N U) o C 7 MK iiiC E S .r m N C CO m C C ._ L G > T 0 _ o C To • o a J J 'GAs _ 0 V/ d a a m C Y E ' -- - -- ----_.–.__..— -- LL ui t LU p Q 0 a Zill 4.0 m C 6 — N M V, Jz a -0- it, E. N .. ..,,: - cz D -- csi r-- B Co lit 0_ O 0 ' 8 N 01 0 N- 10 ........ 1`, C.1 CI C) C) C:1 Ci , c ....a.... c; a c) c) CI C' CI CI 1 0 to oz.) 6 r‘i to c--.1 tz ..,— c) to C5 F- F- tO LO V 0 C1 .c ..--... 0C M CN 0 CI) Ce) .... o..., C, ........ .1 C. TD ( 1.>-.... . c = 6 ..,— t a ..- .• C7 i Alin : = . 4-0 ....., (--, •• . C:1 CL) : cn i LO 0 : l ''. CS i 0 LO a_ g 6 D c) . 1 r.... ..... : . -5 c) 2 + ›.., c) I N.. co • re) . C ....a. t, ...., . 0 ----- Cr) . 00 .. N.,..10 ci Irm•0 I 0 ' [-NJ. . . 0 a •,--- — . cs • ...... co CI) . c . . ._ . ,.. , > , ; 0.1 0 .., :. , LL aim • a) is. ... .. C7 ... 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F a) C ..- ...., -- „., •.... - - - - 0 r -J ........ „....... 0 CD .4- . •.- a o tri 0 8 8 CS C) t-D Cs 1-D 1... Cn, .. CD • lio. ca Cri rsi u-i Co , V. Ir. 4.7..) GS ES .g r-- N Nr. I--- c0 ma CD 4t (NI C CD C 0- •,.... ..: ...J ... a .. cq to D ti 0 o 01U a C) CS cs C) Q O 0 Ni KC; lai {y14'5 00 � i c�a to I -- — m 0 3 M Otla • Ct U = top p 8 N > W CA (si W Ml Oc 4 0 1 N , N MO0 O) (h CT a) ti C J _ J o O • v Z K3 2 O Aoa?r V a � r o .5 r 1 fi to 2? o ••••••• c n C'''') .0 AN J o O , `o .. o •1 4 L j i r-- " Q o 0 N E0 N M to a c 0 M w ,�. m o > cc; III c t� 1 Cc. s 0 ? Q o 0 a; cri a) i T - - LL C * co 0 a) a. J m P SCS ENGINEERS ' Cheat Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108 01 Subject By Date Storm Drains NTJ 3/13/2017 Checked Date Purpose: Establish storm drain size and adequacy for 10 year storm event for drains in Drainage Area B. ' iv n: Reinforced concrete pipe and concrete manhole design. Drainage area to storm drain is deliniated on Drawing SW2. Assure ns 1.Manning's number(n)=0.013 2.For hydrualic grade line calculations,HGL set to crown of pipe at discharge point. Calculations: 1.See attached dydrology cacluations for drainage areas. Peak Flows Drainage Area,A= 5.23 cfs 2.See attached hydrualic calculations for strom drain hydualic gradient and capacity. Conclusions: The storm drain as designed has adequate capacity to handle the 10-year storm event without causing a pressure situation in the pipes. also the HGL is below ground surface,therefore manholes will not be overtopped. SCS ENGINEERS Client Project Job No R vanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Storm Drains NTJ 3/3/2017 Checked Date Purpose: Calculate the peak discharge and storm structure size for pipes in Drainage Area B for a 10 year event Given: 1 Use 10 year storm for design 2 Areas Taken from autocad Drawings SW2 Assumptions: 1 Use NOAA Atlas 14 for intensity 2 TR55 used to find time of concentration 4 Cf value From VDOT Drainage Manual= 1 5 C values taken from page V-29 Table 5-2 of the VESCH Calculations: Cumulative"C" C=((A1'C1)+(A2•C2)+ +(An+Cn))/(A1+A2+ _A-An) Peak Flow Q10=C*i*A'Cf Area A=Al+A2+. +An Contributing Drainage Area Area(ac) Assmued C Value Impervious Area 0 68 0 90 Pervious Area 0 54 0 35 Intensity-assume 5 min duration 6 53 in/hr Total Area: =lmpervous+Pervious 1 22 acres Cumulative"C" C=((A1'Cl)+(A2'C2)+ +(An+Cn))/(A1+A2+.. +An) 066 Peak Discharge,Q10: Q10=Cf'A'C'i 5 2 cfs Conclusion: The peak flow for drainage area b is 5 2 cfs Use this peak flow for sizing storm structures in this area Soil Map—Albemarle County,Virginia t to kl IP k k 705800 maw 705 705 706 0 705750 38°1 20"N I Iv 38°1'20'N 'i;, 0 I o iv 368 l" 8 q t.' �b kt *» I s e • > ,, 1913 � 8 n 1 1 - ttF"µ '0 I I . t } 1,4t g t. 7., a` X it (}C 3 , 2. '3703 i $ c a t r"' 4 F „:#''' �� 5 �X q��vjot yr��.T. .q;ry1 3GRabC Fi b. 3e°i'S'N 00 706050 7060 705750 705800 705850 7000 3 3 b0 N Map Scale:1:2,160 if printed on A Portrait(8.5'x 11")sheet ---,MeOas N 0 30 60 120 180 -- 600 100 200 A Map pn3jection:Web Mercator Comer coordinates:WGS84 Edge�:llTM Zone 17N WGS84 7/6/2016 Web Soil Survey v�sppqq Natural Resources Page 1 of 3 Conservation Service National Cooperative Soil Survey MIN Soil Map—Albemarle County,Virginia nla MAP LEGEND MAP INFORMATION Area of Interest(Aol) gl Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. Area of Interest(AOI) on Spot 4 Stony Warning:Soil Map may not be valid at this scale. Soils 65 Very Stony Spot Li Soil Map Unit Polygons Enlargement of maps beyond the scale of mapping can cause Wet Spot misunderstanding of the detail of mapping and accuracy or soil line .-.� Soil Map Unit Lines placement..The maps do not show the small areas of contrasting n, Other ,soils that could have been shown at a more detailed scale. 0 Soil Map Unit PointsAMU . Special Line Features Special Point Features Please rely on the bar scale on each map sheet for map (o) Blowout Water features measurements. Streams and Canals C. Borrow Pit - Source of Map: Natural Resources Conservation Service Transportation Web Soil Survey URL: http:/twebsoilsurvey.nres.usda.gov 1� clay spot i-f-s Rails Coordinate System: Web Mercator(EPSG.3B57) closed Depression en/ Interstate Highways Maps from the Web Sod Survey are based on the Web Mercator X Gravel Pit US Routes projection,which preserves direction and shape but distorts distance and area A projection that preserves area,such as the Graveay Spot Major Roads Albers equal-area conic projection,should be used if more accurate O Landfill Local Roads calculations of distance or area are required iLava Flow Background This product is generated from the USDA-NRCS certified data as of A. g the version dale(s)listed below. • Marsh or swamp 11111 Aerial Photography Soil Survey Area: Albemarle County,Virginia • Mine or Quarry Survey Area Data: Version 10,Dec 11,2013 O Miscellaneous Water Soil map units are labeled(as space allows)for map scales 1:50,000 larger. • Perennial Water or lar 9 N., Rock outcrop Date(s)aerial images were photographed: May 9,2011—Jun 4, 2011 + Saline Spot Sandy Spot The ortnopholo or other base map on which the soil lines were compiled and digitized probably differs from the background Severely Eroded Spot imagery displayed an these maps.As a result,some minor shifting of map unit boundaries may be evident. • Sinkhole O. Slide or Slip Ae Sodic Spot man USDA Natural Resources Web Soil Survey 7/6/2016 .rr Conservation Service National Cooperative Soil Survey Page 2 of 3 I Soil Map—Albemarle County,Virginia I Map Unit Legend Albemarle County,Virginla(VA003) r I Map Unit Symbol Map Unit Name L. Acres In AO1 Percent of AOI 1B Abell silt loam,2 to 7 percent 0.0 0.1% I slopes ' ; 4< Chester loam,7 to 15 percent 1.2 5.3% slopes talk Cullen loam,2 to 7 percent 8.3 35.9% slopes r MO Cullen clay loam,7 to 15 2.0 8.8% percent slopes,severely eroded 20D3 Cullen clay loam,15 to 25 0.0 0.0% .... percent slopes,severely eroded . Hayesville loam,2 to 7 percent 1.6 6 8% slopes 36C Hayesville loam,7 to 15 percent 3.4 15.0% slopes SSW Hayesville clay loam,7 to 15 6.0 26.2% percent slopes,severely eroded 37D3 Hayesville clay loam, 15 to 25 0.4 1.9%' percent slopes,severely eroded Totals for Area of Interest 23.0 100.0% ow Natural Resources Web Soil Survey 7/6/2016 USDAPage 3 of 3 Sim Conservation Service National Cooperative Soil Survey 1992 Soil name surftex hydgrp kfact wtdepl wtdeph GLENWOOD CB-L B 0.20 6.00 6.00 GLENWOOD VARIANT RB-L B 0.05 6.00 6.00 GOLDSBORO FSL 8 0.20 2.00 3.00 GOLDSBORO SL B 0.20 2.00 3.00 GOLDSTON CN-L C 0.15 6.00 6.00 GOLDSTON CN-SIL C 0.15 6.00 6.00 GOLDSTON CNV-SIL C 0.05 6.00 6.00 GOLDSTON SIL C 0.15 6.00 6.00 GOLDVEIN GRF-SIL C 0.28 1.00 2.00 GOLDVEIN GRITTY GRF-SIL C 0.28 1.00 2.00 GORESVILLE* GR-SIL B 0.24 6.00 6.00 GREENLEE STV-L B 0.10 6.00 6.00 GRIMSLEY CB-L 8 0.20 6.00 6.00 GRIMSLEY CB-SL B 0.20 6.00 6.00 GRIMSLEY ST-L B 0.20 6.00 6.00 GRIMSLEY STX-L B 0.20 6.00 6.00 GRITNEY FSL C 0.20 6.00 6.00 GRITNEY GR-FSL C 0.15 6.00 6.00 GROSECLOSE GR-L C 0.28 6.00 6.00 GROSECLOSE GR-SIL C 0.28 6.00 6.00 GROSECLOSE L C 0.43 6.00 6.00 GROSECLOSE SICL C 0.32 6.00 6.00 GROSECLOSE SIL C 0.43 6.00 6.00 GROVER FSL 8 0.24 6.00 6.00 GROVER SCL B 0.28 6.00 6.00 GROVER SL B 0.24 6.00 6.00 GUERNSEY SIL C 0.43 1.50 3.00 GULLIED LAND VAR 6.00 6.00 GULLION L C 0.32 1.50 3.00 GULLION SIL C 0.32 1.50 3.00 GUNSTOCK CN-L C 0.37 6.00 6.00 GUNSTOCK SL C 0.28 6.00 6.00 GUYAN SIL C 0.32 0.50 1.50 GWINNETT VARIANT CL B 0.28 6.00 6.00 HAGERSTOWN SIL C 0.32 6.00 6.00 II HAGERSTWON SIL C 0.32 6.00 6.00 HALEWOOD L 8 0.32 6.00 6.00 HALEWOOD STV-FSL C 0.24 6.00 6.00 II HARTLETON CN-L B 0.20 6.00 6.00 HARTLETON STV-L B 0.15 6.00 6.00 HATBORO L D 0.49 0.00 0.50 HATBORO SIL D 0.49 0.00 0.50 HAWKSBILL CB-L B 0.17 6.00 6.00 HAWKSBILL CBV-L B 0.17 6.00 6.00 HAWKSBILL STX-L B 0.17 6.00 6.00 t HAYESVILE L B 0.20 6.00 6.00 HAYESVILLE CB-L B 0.20 6.00 6.00 MAAYESVILLE CL S 0.20 6.00 6.00 HAYESVILLE CL 8 0.24 6.00 6.00 HAYESVILLE FSL 8 0.20 6.00 6.00 HAYESVILLE GR-FSL B 0.20 6.00 6.00 HAYESVILLE L B 0.20 6.00 6.00 HAYESVILLE STV-FSL C 0.15 6.00 6.00 II HAYESVILLE STV-L C 0.15 6.00 6.00 II VI - 63 1992 Soil name surftex hydgrp kfact wtdepl wtdeph HAYESVILLE STV-L C 0.24 6.00 6.00 i1AYESVILLE STV-SCL C 0.32 6.00 6.00 HAYMARKET SIL D 0.32 6.00 6.00 HAYTER CB-L B 0.20 6.00 6.00 HAYTER CBV-L B 0.15 6.00 6.00 HAYTER L B 0.28 6.00 6.00 HAYWOOD L B 0.24 6.00 6.00 HAZEL CN-L C 0.24 6.00 6.00 HAZEL L C 0.32 6.00 6.00 HAZEL SIL C 0.32 6.00 6.00 HAZEL ST-L C 0.24 6.00 6.00 HAZEL STV-L C 0.24 6.00 6.00 HAZEL CHANNERY CN-SIL C 0.32 6.00 6.00 HAZELTON STV-L B 0.15 6.00 6.00 HAZLETON CN-SL B 0.17 6.00 6.00 HAZLETON ST-SL B 0.15 6.00 6.00 HAZLETON STV-SL B 0.15 6.00 6.00 HAZLETON STX-SL B 0.15 6.00 6.00 HELENA CL C 0.28 1.50 2.50 HELENA FSL C 0.20 1.50 2.50 HELENA FSL C 0.24 1.50 2.50 HELENA GR-COSL C 0.15 1.50 2.50 HELENA GRF-FSL C 0.15 1.50 2.50 HELENA L C 0.20 1.50 2.50 HELENA L C 0.24 1.50 2.50 HELENA SL C 0.20 1.50 2.50 HELENA SL C 0.24 1.50 2.50 HERNDON L B 0.43 6.00 6.00 HERNDON SICL B 0.49 6.00 6.00 HERNDON SIL B 0.43 6.00 6.00 HERNDON VFSL B 0.43 6.00 6.00 HIWASSEE CB-FSL B 0.28 6.00 6.00 HIWASSEE CB-SL B 0.24 6.00 6.00 HIWASSEE CL B 0.28 6.00 6.00 HIWASSEE FSL B 0.28 6.00 6.00 HIWASSEE GR-L B 0.24 6.00 6.00 HIWASSEE L B 0.28 6.00 6.00 HIWASSEE SIL B 0.32 6.00 6.00 HIWASSEE VARIANT L B 0.32 6.00 6.00 HOADLY L C 0.28 0.50 1.50 HOBUCKEN L D 0.10 HOGELAND* CB-SIL C 0.24 6.00 6.00 HOLLYWOOD CL D 0.32 6.00 6.00 HUNTINGTON L B 0.28 6.00 6.00 HUNTINGTON SIL B 0.28 6.00 6.00 HYATTSVILLE FSL B 0.28 4.00 6.00 HYDE SIL B/D 0.17 0.00 1.50 HYDRAQUENTS SL B 0.37 4.00 6.00 HYDRAQUENTS SL D 0.37 INGLEDOVE L 8 0.32 6.00 6.00 IREDELL CL C/D 0.32 1.00 2.00 IREDELL FSL C/D 0.28 1.00 2.00 IREDELL L C/D 0.32 1.00 2.00 IREDELL SIL C/D 0.32 1.00 2.00 VI - 64 1992 Soil name eurftex hydgrp kfact wtdepl wtdeph CATOCTIN STX-SIL C 0.20 6.00 6.00 CATPOINT FS A 0.10 4.00 6.00 CATPOINT LS A 0.10 4.00 6.00 CAVERNS SL B 0.20 6.00 6.00 CECIL CB-FSL B 0.28 6.00 6.00 CECIL CL B 0.24 6.00 6.00 CECIL CL B 0.28 6.00 6.00 CECIL FSL B 0.20 6.00 6.00 CECIL FSL B 0.28 6.00 6.00 CECIL GR-FSL B 0.15 6.00 6.00 CECIL GR-SL B 0.15 6.00 6.00 CECIL GRF-SL B 0.28 6.00 6.00 CECIL L B 0.28 6.00 6.00 CECIL SCL $ 0.28 6.00 6.00 CECIL SL B 0.28 6.00 6.00 CECIL VFSL B 0.28 6.00 6.00 CHAGRIN FSL B 0.32 4.00 6.00 CHAGRIN L B 0.32 4.00 6.00 CHAGRIN SIL B 0.32 4.00 6.00 CHAGRIN VARIANT LS A 0.10 6.00 6.00 CHAPANOKE SIL C 0.43 0.50 1.50 CHASTAIN L D 0.32 0.00 1.00 CHASTAIN SICL D 0.32 0.00 1.00 CHASTAIN SIL D 0.32 0.00 1.00 CHATUGE L D 0.32 1.00 2.00 CHATUGE SL D 0.32 1.00 2.00 CHAVIES FSL B 0.24 6.00 6.00 CHAVIES SL B 0.24 6.00 6.00 CHAVIES VARIANT SL B 0.24 3.50 3.50 CHENNEBY L C 0.37 1.00 2.50 CHENNEBY SIL C 0.37 1.00 2.50 CHESTER CB-L B 0.32 6.00 6.00 CHESTER CN-L B 0.28 6.00 6.00 CHESTER L B 0.32 6.00 6.00 CHESTER SIL B 0.32 6.00 6.00 CHESTER SL B 0.32 6.00 6.00 CHESTER STV-L B 0.24 5.00 5.00 CHESTER STV-L 13 0.32 5.00 5.00 II CHESTER LOAM C 8 0. 32 6.00 6.00 CHEWACLA FSL C 0.24 0.50 1.50 CHEWACLA L C 0.28 0.50 1.50 II CHEWACLA L C 0.49 1.00 2.00 CHEWACLA SIL C 0.28 0.50 1.50 CHEWACLA SIL C 0.49 1.00 2.00 CHICKAHOMINY L D 0.37 I II CHICXAHOMINY L D 0.37 0.00 0.50 CHICKAHOMINY SIL D 0.37 0.00 0.50 CHILHOWIE C C 0.37 6.00 6.00 CHILHOWIE CN-SICL C 0.20 6.00 6.00 I CHZLHOWIE CN-BICC C 0.37 6.00 6.00 CHILHOWIE SIC C 0.37 6.00 6.00 CHILHOWIE SICL C 0.37 6.00 6.00 CHINCOTEAGUE SIL D 0.32 CHIPLEY S C 0.10 2.00 3.00 VI - 56 1 ' I 1992 II Soil name surftex hydgrp kfact wtdepl wtdeph IICOTACO CB-FSL C 0.24 1.50 2.50 COTACO FSL C 0.37 1.50 2.50 COTACO L C 0.37 1.50 2.50 COTACO SIL C 0.37 1.50 2.50 I COTACO VARIANT CB-L C 0.24 2.00 3.00 COTACO VARIANT SIL C 0.43 2.00 3.00 COURSEY L C 0.32 2.00 3.00 COWEE CH-L B 0.20 6.00 6.00 II COXVILLE FSL D 0.24 0.00 1.50 COXVILLE L D 0.24 0.00 1.50 CRAIGSVILLE CB-FSL B 0.28 6.00 6.00 I CRAIGSVILLE CB-SL B 0.20 6.00 6.00 CRAIGSVILLE CB-SL B 0.28 6.00 6.00 CRAIGSVILLE CBV-L @ 0.10 6.00 6.00 CRAIGSVILLE GR-FSL B 0.17 6.00 6.00 CRAIGSVILLE L 8 0.28 6.00 6.00 II CRAIGSVILLE SL B 0.17 6.00 6.00 CRAVEN CL C 0.37 2.00 3.00 CRAVEN FSL C 0.32 2.00 3.00 CRAVEN L C 0.32 2.00 3.00 CRAVEN SCL C 0.37 2.00 3.00 CRAVEN SIL C 0.32 2.00 3.00 CREEDMOOR FSL C 0.28 1.50 2.00 CREEDMOOR GR-FSL C 0.28 1.50 2.00 CREEDMOOR GRV-SL C 0.28 1.50 2.00 CREEDMOOR L C 0.28 1.50 2.00 CREEDMOOR SL C 0.28 1.50 2.00 0.37 0.50 1.50 CREEDMOOR VARIANT FSL C 0.28 1.50 2.00 CREEDMORE FSL C CROTON SIL D 0.37 0.00 1.50 CROTON SIL D 0.43 0.00 0.50 C 0.24 6.00 6.00 CULLLLEN L C CEN 0.37 6.00 6.00 CULPEPER CL C 0.37 6.00 6.00 CULPEPER FSL C 0.37 6.00 6.00 CULPEPER L C 0.37 6.00 6.00 DALEVILLE L D 0.32 0.00 1.00 DALEVILLE SIL D 0.32 0.00 1.00 DANDRIDGE SH-SICL D 0.17 6.00 6.00 DAVIDSON C B 0.28 6.00 6.00 DAVIDSON CL B 0.24 6.00 6.00 DAVIDSON CL B 0.28 6.00 6.00 DAVIDSON CL 8 0.37 6.00 6.00 DAVIDSON ST-CL B 0.20 6.00 6.00 DAWHOO VARIANT FSL 0.17 DECATUR CL B 0.32 6.00 6.00 CB-FSL C 0.17 6.00 6.00 DEKALB DEKALB CB-L C 0.17 6.00 6.00 DEKALB CB-SL C 0.17 6.00 6.00 DEKALB CN-FSL C 0.17 6.00 6.00 DEKALB CN-L C 0.17 6.00 6.00 CN-SL C 0.17 6.00 6.00 DEKALB DEKALB FSL C 0.24 6.00 6.00 DEKALB RB-FSL C 0.17 6.00 6.00 VI - 58 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use C Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 Heavy soil, steep, 7%, 0.25-0.35 1/4.)%6 0.3 Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows * Heavy soil, no crop 0.30-0.60 * Heavy soil, with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 Industrial: Streets: Light areas 0.50-0.80 Asphaltic 0.70-0.95 `S" Heavy areas 0.60-0.90 Concrete 0.80-0.95 O'1° Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 ® Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 I Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The designer must use judgement to select the appropriate "C" value within the P range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. 1 Source: American Society of Civil Engineers I V - 29 Precipitation Frequency Data Server Page 1 of 4 I NOAA Atlas 14,Volume 2,Version 3 -'tN, Location name:Charlottesville,Virginia,USA' , .,, ` .r Latitude:38.0253',Longitude:-78.6538° u°1 , I� i Elevation:662.27 ft'" ill" I 1: 'source:ESRI Maps ,{ "source.USGS POINT PRECIPITATION FREQUENCY ESTIMATES I G.M Bonnie,D Martin,B Lin,T Parzybok,M Yekta,and D Riley NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials PF tabular I PDS-based point precipitation frequency estimates with 90%confidence intervals(in inchesthour) 1 , II Aveiaite recurrence interval(years) __ 1 1 Duration 2 I 5 10 25 Ji 50 100 1P 200 1l 500 1000 l111 _.. .......... ( 5-min 4.12 4.92 5.80 6.36 7.37 8.02 8.63 9.20 9.90 10.5 (3.72-4.57) (4.45-5.45) (5.23.6.411 f'15.96 t 211 I t6.60.0 11)1 (7.15-8.83) (7.64-9.52) �(8 09-10.2)_.� (8.60-11.0) (9,00-117) 10-min 3.29 3.94 4.64 5.22 6.87 6.38 6.86 7.30 7.83 8.24 fL (2.98-3.65) (3.56.4.36) (4.19-5.13) (4.70-5.76) (5.26-6.47) (5.69-7.03) (6.08-7.56) (6.41-8.06) [(6.80-8.69) [( .09-9.19) 1 15-min 2.74 3.30 3.92 4.96 6.39 5.78 6.14 6.67 6.90 L ttt (2.48.3.04) (2.99.3-65) (3-54.4-32) (4.45-5.46) (4.80-5.94) (5.12-6.37) (5.40.6.78) (5.71-7,29) (5,93.7.691 30-min 1.88 2.28 2.78 3.19 3.67 4.06 4.42 4.78 5.23 5.59 (1.70-2.08) (2.06-2.52) (2.51.3.07) (2.87-3.52) (3.29.4.05) (3.62-4.47) (3.92-4.88) (4.20-5-28) 1 (4.54-5.80) (4.80-6.23) 1 60-min 1.17 1.43 1.78 2.08 2.45 2.75 3.05 3.35 3.75 4.08 I (1.06-1.30) (1.29-1.58) (1-61-1.97) (1.87-2.29) (2.19-2.70) (2.45-3.03) (2.70-3.36) (2.95.3.70) (3.264.16), (3.51.4.55)1 2-hr 0.700 0.852 1.07 1.26 1.50 ' 1.70 1.91 2.12 2.42 2.67 (0.622-0.792)(0.756-0.961)L(0.948-1.20) (1,12-1.41) (1.32-1.68) (1.49-1.91) (1.66-2.14) (1.83-2.38) (2.06-2 73)�f(2.25-3.02) 3-hr 0.511 0.621 0.778 0.914 1.09 1.24 1.39 1.55 1.77 1.96 II (0.454-0.582)10649-0705)(0.687.0.884) (0.805.1.04) (0.956-1.23) (1.08-1.401 (1.21-1.58) (1.33-1.76) (1.50.2.02) (1.64-2.24) III 0.331 0.401 0.498 0.587 0.705 0.809 0.918 1.04 1.20 1.35 1 Nil 6-hr (0.296-0.374) 0.357-0.4521)(0.442-0.561)(0.518.0.660)(0.619.0.793)(0..704-0.908) (0.791-1.03) (0.882-1.17) (1.01-1.36) 1(1.12-1.53) 12-hr 0.209 0.252 0.316 0.372 0.453 0-525 0.603 0.689 0.817 0.932 (0.186-0.238)(0.224-0.288)(0.278-0.358)(0.328-0.423)(0.396-0.514)(0.453-0.595)(0.514-0.684)(0.579.0.782)(0.671.0931) (0.753-1.07) 24-hr 0.127 0.154 0.196 0.231 0.284 0.329 0.378 0.433 0.514 0.583ill (0,114-0.142)(0.138-0.172) (0.176-0.219)(0.207-0.258)(0.252.0.316)(0.289-0.365)(0.330-0.420)(0.374.0.479)(0436.0.570)10.488-0647) 2-day 0.075 0.091 0.115 0.135 0.164 0.188 0.215 0.243 0.285 0.320 (0.067-0.0831(0.081-0.101)(0.103-0.128)(0.121-0.151)(0.146-0.183)0.166-0.209) (0.188-0.239)(0.211-0.271)(0.244-0.318)((0.271.0.3581 3-day 0.063 0.064 0.082 0.096 0.116 0.133 0.162 0.172 0.201 0.225 I (0.048.0.059}(0.058.0.071)(0.074.0.090)(0.086-0.106)(0.104-0.128)(0.119-0.147)'(0.134-0.168)(0.151-0.190)(0.174-0.223)(0.193-0.251) 4-day 0'042 0.061 0.066 0.076 0.092 0.108 0.120 0.136 0.159 0.178 (0.039-0.047)(0.047.0.058)(0.059-0.072)(0.069.0.084)(0.083-0.101)(0.095.0.116)(0.107-0.132)(0-120-0.150)(0139-0.175)(0.154-0.197) 7-day 0.028 0.034 0.042 0.049 0.059 0.067 0.076 0.085 0.098 0.109 II (0,0260.031)(0.031-0.037)(0.039.0.046)(0.045-0.053),(0.053-0.064)(0.080-0.073)(0.068-0.083)(0.075.0.093)'(0.086.0.108)(0.095-0.120) 10-day 0.022 0.027 0.033 0.038 ) 0.046 0.061 0.067 0.063 0.072 0.079 (0.020.0.024)(0.025-0.029)(0.030-0.036)(0.035-0.041 (0.041.0.049)(0.046-0.055)(0.051.0.061 (0.057.0.0681.(0.064-0.078)(0,070-0.086) L20-day 0.016 0.017 0.021 0.024 0.028 0.031 0.034 0.037 0.041 0.044 (0.014-0.016)(0.016.0.019)(0.020-0.023)(0.022.0,026),(0.026-0.030)(0.028.0.033))(0.031-0.036)(0.034-0.040)(0037.0.044)(0.040-0.048) 30-day] 0.012 0.014 0.017 0.019 0.021 0.023 0.025 0.027 0.029 0.031 J](0.011-0.013)(0.013-0.015)(0.016-0.018)(0.017-0-020)(0.020-0.023)(0.022 0.025)(0.023.0.027)(0.025.0.0291(0.027-0.031)(0.029.0,033) F F _ _ .. .__-_- ... -. - - .- 0.010 0.012 0.014 0.015 0.017 0.018 0.020 0.021 0.023 0.024 45-day (0.000-0-011)(0.011.0.012)(0.013.0.015)(0.014-0.016)(0.016-0.018)C(0.017.0.020)(0.018-0.021)(0.020.0.022)(0.021-0.024)(0.022.0.026) 0.014 I .020 I 60-day I(0,008-0,000)1(0,010-0.011).009 00.(0.011-0.013)12 0.012-0.014)013 I(0.014-0.015)10.015-0.016)0.016 (0,016-0018) (0,0.017 0.018 16.0 019)(0.00.019 18 0 020)(0.018-0 021) _ mic 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 1(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NA Atlas 14 document for more information, Back to Top or nik s http://hdsc.nws-noaa.gov/hdsc/pfds/pfds_printpage.html?tat=38.0253&ton=-78.6538&dat... 11/21/2016 S w a) a) a) 0 " C II € C C c c 0- a 2 0 C 1 ao n in J Z CO w N CO m tOO c r it) CO N M CO n CCii n N m co m on J = to N N6 O _-.) N. N- n n n r- I i- Cto (0 (0 CO (U Cu C C C C C O 1 : L !) 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'' 1/4 e :dailb... ii.c. _ .4444...... .la ., ! a.,,,..r it:., +� ate. o j ° I i i . 0 eil, Ii70 14i1 ' $IFa B . I � { II I IFi' • 14t1 16 '' '. ■r i' t tO i . \..•� ii!f2hc: IN) X J/I < _-X5-401101, .!",00...° ,,, er / ., n�y.. 61'43-----,,,,,,... „.„4„...g7"ii ,,. �(Jj; r rt'� t' `yy. 17 ` ... f r . r APPENDIX H Trench Drains Client Project Job No. ' Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Trench Drains NTJ 1/20/2017 Checked Date Sheet 1 of 1 Purpose: Determine Peak Flow for a 10 yr storm for Typical Trench Drain. Given: Largest drainage area contributing to a trench drain: Total Area,A: 3454.893 sq.ft. 0.08 acre Assumptions: Rainfall Intensity(Use a S min duration),i: 6.53 in/hr Runoff Coefficent(impervious runoff),C: 0.90 ' Calculations: Peak Flow Qp=C*i*A 0.47 cfs Conclusions: Peak flow to a trench drain will have a peak flow of 0.47 cfs. Using an ACOUSA FlowDrain FG200 with a 6"outlet can be designed for flows of 0.77 cfs. Use ACOUSA FlowDrain FG200 or simular. i 1 1 I W Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Trench Drains NTJ/DCC 7/14/2017 Checked Date Sheet 1 of 1 AST 7/14/2017 Purpose: Determine Peak Flow for a 10 yr storm for Trench Drain at North entrance road. Given: Largest drainage area contributing to a trench drain: Total Area,A: 5819.793 sq.ft. 0.13 acre Assumptions: Rainfall Intensity(Use a S min duration),is 6.53 in/hr Runoff Coefficent(impervious runoff),C: 0.90 Calculations: Peak Flow Qp=C*i`A 0.79 cfs Conclusions: Peak flow to a trench drain will have a peak flow of 0.79 cfs. Using a Dura Trench DTPF10-HDBP 10"Precast trench drain can handle a flow rate of 1.21 at 1%slope should adequatly handle the job. Use a Dura Trench DTPF10-HDBP 10"precast trench drain or simular.Capacity calculations provided by manufacturer. d�� i 1 i 1 1 1 APPENDIX I Drop Inlets ' I ii SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 as Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date AST 7/14/2017 MI Purpose: Size the Drop inlet A3 to protect from overtopping the berm around Sand Filter A. 1 Given: Height of Berm at Sand Filter A: 2 ft Rim elevation above Sand Filter Surface,= 0.55 ft Assumptions: 1.Peak Flow from Drainage Area A(see Drainage Area A calculations)= 9 cfs 2.Use Performance Curve DI-1 in a Sump,From Appendix 9C-13 of the VDOT Drainage Manual. 1 3.Intalling multiple drop inlets at the same elevation will divide flow evenly. Calculations: I Two Drop inlets Used,Qd= Qd=Q10/2 4.5 cfs See calcualtions on Appendix 9C-13. Depth of water 0.65 ft Rim Elevation+Depth of water= 1.2 Conclusions: Two drop inlets are required to keep the depth of water to 0.65ft. With the rim set 0.55 ft above filter bed surface 1 and depth of water being 0.65 ft above the rim,the water elevation will be 0.8 ft bellow top of berm. 1 1 I I I I I I I SCS ENGINEERS i Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Storm Drains NTJ 3/3/2017 Checked Date Purpose: Calculate the peak discharge for Drainage Area A for a 10 year event Given: 1.Use 10 year storm for design. 2 Areas Taken from autocad Drawings SW2. Assumptions: 1 Use NOAA Atlas 14 for intensity 2.TR55 used to find time of cpncentration. 4.Cf value From VDOT Drainage Manual= 1 5 C values taken from page V-29 Table 5-2 of the VESCH Calculations: Cumulative"C C=((A1`C1)+(A2"C2)+..+(An+Cn))/(A1+A2+....+An) Peak Flow 010=C"i"A"Cf Area A=A1+A2+. +An Contributing Drainage Area Area(ac) Assmued C Value Impervious Area 0.56 0.90 Pervious Area 2 50 0.35 Intensity-assume 5 min duration. 8.53 inihr Total Area: =lmpervous+pervious 3.06 acres Cumulative"C C=((A1"C1)+(A2"C2)+. .+(An+Cn))/(A1+A2+. ..+An) 0.45 Peak Discharge,010: 010=Cf ASW/*C*i 90 cfs Conclusion: The peak flow for drainage area A is 9.0 cfs Use this peak flow for calculating structure sizes. Precipitation Frequency Data Server Page 1 of 4 NOAA Atlas 14,Volume 2,Version 3 ,,,��+++ Location name: Charlottesville,Virginia,USA' �`� Latitude:38.0253°,Longitude:-78.6538° Elevation:662.27 ft" 11 "'O •source-ESRI Maps ,fr.-1 "source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES G M Bonin,D Martin,8.Lin,T.Parzybok,M Yekta,and 0 Riley A. NOM,National Weather Service,Silver Spring.Maryland PF tabular I PF graphical I Maps & aerials am PF tabular [PDS-based point precipitation frequency estimates with 90% confidence intervals(in incheslhour)1 1 • Average recurrence interval(years) Duration ell1 I 2 MI-jI 10 jr 25 IF- 50 -I 100 200 r---8-0-0----1 loon 5-min 4.12 4.92 6.80 6.53 7.37 8.02 8.63 9.20 9.90 10.5 (3.72-4.57) (4,45-5,45) (5.23-6.41) (5.88-7.21) (6.60-8.11) 1(7.15-8.83) (7.64-9.52) (8.09-10.2) (8,60-11.0) (9.00-11.7) 10-min 3.29 3.94 4.64 5.87 6.38 6.86 7.30 7.83 8.24 (2,98.3.65) (3.56.4.36) (4.19-5.13) (4.70-5.76) (5.26-6,47) (5.69-7.03) (6.08-7.56) (6.41-8.06) (6.80-8.69) (7.09-9.19) 15-min 2`74 3,30 3.92 4.40 I 4.96 5.39 5.78 6.14 6.57 6.90 (2.48.3.04) (2.99-3.65) (3.54-4.32) (3.97-4.86) I (4.45.5.46) 14.80-5.94) (5.12.6.37) [(5.40-6.78) I (5.71-7.29) (5,93.7.69) 30-min 1.88 2.28 2.78 3.19 3.67 4.06 4.42 4.78 5.23 6.59 - (1.70-2.08) (2.06-2.52) (2.51.3,07) (2.87-3.52) (3.29-4.05) (3.62-4.47) (3.92.4.88) (4.20-5.28) (4.54.5.80) (4.80.6.23) 60-m(n 1.17 1.43 1.78 2.08 2,45 2.75 3.06 3.35 3.75 4.08 OW (1.06-1.30) (1.29-1.58) (1.61.1.97) (1.87-2.29) (2.19-2.70) (2.45.3.03) (2.70.3.36) (2,95-3.70) (3.26-4.16) (3,51.4.55) 2-hr 0.700 0.852- 1.07 1.26 1.50 1.70 1.91 2.12 2.42 2.67 (0.622.0.792)(0.756.0.961) (0.048-1.20) (1.12-1.41) (1.32-1.68) (1.49-1.91) (1-66-2.14) (1.83-2.38) (2.08-2.73) (2.25-3.02) 3-hr 0.611 0.621 0.778 0.914 1.09 1.24 1.39 1.65 1.77 1.96 (0.4540.582)(0.549-0.705)(0.687-0.884) (0,805-1.04) (0.956-1.23) (1.08-1.40) , (1.21-1,58) (1.33-1.78) (1.50-2.02) (1.64-2.24) a 6-hr 0.331 0.401 0.498 0.587 0.706 0.809 ' 0.918 1.04 1.20 1.35 (0.296.0.374) 0.357-0.452)(0.442-0.561)(0.518.0.660)(0.619.0.793)(0.704-0.908) (0.791-1.03) (0.882.1.17) (1.01.1.36) (1.12-1 53) 12-hr 0.209 0.252 0.315 0.372 0.463 0.526 0.603 0.689 0.817 0.932 (0.186.0.238)(0.224.0.288)(0.278.0.358) 0.328-0.423)(0.396.0.514 (0.453-0.505)(0.514-0.684)(0.579-0.782)(0.671.0.931) (0.753.1.07) .w 24-hr 0.127 0.154 0.196 0.231 0.284 0,329 0.378 0.433 0.514 0.583 (0.114-0.142)(0.138-0.172)(0.176-0.219) 0.207.0.258)(0.252.0.316 (0.289.0.365)(0.330-0.420)(0.374.0.479)(0.436-0.570)(0.488.0.647) 0.075 0.091 0.115 0.135 0.164 0.188 0.215 0.243 0.285 0.320 L 2-day](0.067-0.083)(0.081.0.101)(0.103-0.128)(0.121-0.151)(0.146-0.183)(0.166-0.209)(0.188.0.239)(0.211.0.271)(0.244-0.318)(0.271-0.350 3-day J 07063 0.064 0.082 0.096 0.116 0.133 0.152 0.172 0.201 0.225 MO (00 . 48.0.059)(0.058-0.071)(0.074-0.090)(0.086-0.106)(0.104-0.128)(0-119-0.147) 0.134-0.168)(0.151.0.190(0.174-0.223)(0.193-0.251) 4-day 0.042 0.061 0.066 0.076 0.092 0.108 0.120 0.136 0.159 0.178 (0.039-0.047)(0.047-0.056)(0.059-0.072)(0.069.0.084))(0.083.0.101))(0.095-0.116),(0.107-0.132)(0.120-0.150((0.139-0.175)(0.154-0.197) 7-day 0.028 0.034 0.042 0.049 0.059 0.067 0.076 0.085 0.098 0.109 (0.026.0.031)(0.031-0.037X(0.039-0.046)(0.045-0.053) (0.053.0.064)(0.060.0.073)(0.068-0.083)10.075-0,093)(0.086.0.108)(0,095.0.120) "' 10-day 0.022 0.027 0.033 0.038 0.045 - 0.051 0.057 0.063 0.072 0.079 (0.020.0.024)(0.025-0.029)(0.030-0.036)(0.035-0.041)(0.041-0.049) (0.046-0.055)(0.051-0.061)(0.057-0.068) (0.064-0.078)(0.070.0.086) 20-day 0.015 0.017 0.021 0.024 0.028 0.031 1 0.034 0.037 0.041 0.044 (0.014-0.016)(0.016.0.019)(0.020.0.023)(0.022.0.026)(0.026-0.030)(0.028-0.033)(0031-0,036)(0,034.0.0401 (0.037.0.044)(0.040.0.048) 30-day 0.012 0.014 0.017 0.019 0.021 0.023 0.025 0.027 0.029 0,031 a (0.011-0.013)(0.013.0.015)(0016-0.018) 0_017.0.020))(0.020-0.023)(0.022.0,025)5(0.023-0.027)(0.025-0029)(0.027-0.031)(0.029-0.033) 45-day 0.010 0.012 0.014 0.016 0.017 0.018 0.020 0.021 0.023 0.024 J(0.009-0.011)(0.011-0.012j�(9.013.0.015)(0.014.0.018) (0.016-0,018) (0.017.0.020)(0.018-0.021)(0.020.0.022)(0.021-0.024)(0.022-0.026)) 60-day 0.009 0.010 0.012 0.013 0.014 0.016 0.017 0.018 0.019 0.020 (0.008-0.009)((0.010-0.011)f(0.011-0.013)(0.012-0.014)((0.014-0.015) (0.015-0.016)(0.016.0.018)(0.016-0.019)(0.018-0.020)(0.018.0.0211 .. 1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values, r Please refer to_NOAH Atlas 14 document for more information. Back to Top http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?1at=38.0253&Ion=-78.6538&dat... 11/21/2016 6.4— Design Concepts The Rational Method Formula is expressed as follows: Q = CfCiA (6.4) Where: ' Q = Maximum rate of runoff, cubic feet per second (cfs) Cf. = Saturation factor C = Runoff coefficient representing a ratio of runoff to rainfall (dimensionless) i = Average rainfall intensity for a duration equal to the time of concentration for a selected return period, inches per hour (in/hr) A = Drainage area contributing to the point of study, acres (ac) Note that conversion to consistent units is not required as 1 acre-inch per hour I approximately equals 1 cubic foot/second. 6.4.4.1.5 Infrequent Storm The coefficients given in Appendix 6E-1 are for storms with less than a 10-year recurrence interval. Less frequent, higher intensity storms will require modification of the coefficient because infiltration and other losses have a proportionally smaller effect on runoff (Wright-McLaughlin 1969). The adjustment of the Rational Method for use with larger storms can be made by multiplying the right side of the Rational Formula by a saturation factor, Of The product of Cf and C should not t . 1.0. Table 6-2 lists the saturation factors for the Rational Method. Table 6-2. Saturation Factors For Rational Formula Cf —I Recurrence Interval (Years) C_ i 2, 5, and 10 1.0 25 �1.1 50 1.2 100 1.25 Note: Cf multiplied by C should not 1,0 6.4.4.1.6 Time of Concentration The time of concentration is the time required for water to flow from the hydraulically most remote point in the drainage area to the point of study. Use of the rational formula requires the time of concentration (tc) for each design point within the drainage basin. The duration of rainfall is then set equal to the time of concentration and is used to estimate the design average rainfall intensity (i) by using the B, D, & E factors D, & E factors for the procedure described in Appendix 6C-1 . A table showing the B, Virginia counties and larger cities is presented in Appendix 6C-2. ' Rev 4/10 VDOT Drainage ManualChapter 6-Hydrology 6-16 of 57 eas +� 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use C Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 ,. Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil,steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 *WV SOB,steep,7% 015435 USC o.3 Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil as Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows .. * Heavy soil, no crop 0.30-0.60 * Heavy soil,with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 Industrial: Streets: Light areas 050-0.80 Asphaltic 0.70.0.95 M6 a. Heavy areas 0.60-0.90 Concrete 0.80-0.95 0'10 Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 J r Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Note: The designer must use judgement to select the appropriate "C"value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. Source: American Society of Civil Engineers V - 29 III Chapter 9- Storm Drains 1 Appendix 9C-13 Performance Curve DI-1 in a Sump r(( 4 S.V2.\ ~CU .E A 3 I QDEC‘tAl = 'LC c S I It f . / — V I I j I • t l'i M i~' e�.y j!u W 1 -.! .. LL 7 W ! r .. t_1 doe•Wc.' ---- O 0, 5, ! . I — I ...,:..>"..,..7-v ... 'y' OPEN AREA = 2.33 FT2 PERIMETER = 9.00 FT r 0I I I I 1 i f H 5j0 I IL)1Ii — OtSC' S LiI '1,1:Hr"'ik'G;E ( i=F'=, i . i 1) - L7I.-I 1)11v' IN L-EIS V SEb FLtt i•A SJ tV‘0 tr KA) -t- 0 . .. Source: VDOT Transportation Research Council publication "HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 ss es 1 of 1 VDOT Drainage Manual rr r w „l SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date AST 7/14/2017 Purpose: Size the Drop inlet A4 to protect from overtopping the berm. Given: Height of Berm at Sand Filter B: 4 ft Rim Elevation(From Sand Filter Rim Elevations) 0.5 ft I Assumptions: 1.Peak flow from Drainage Area B(see Drainage Area B Calculations)= 5.2 cfs Ii.Assume a design flow of: 6.0 cfs 2.Use Performance Curve DI-1 in a Sump From Appendix 9C-13 of the VDOT Drainage Manual. 4.Assume 50%clogged. I Calculations: See calcualtions on Appendix 9C-13. Depth of water 1.1 ft IWater Surface height=Depth of Water+Rim Elevation 1.6 Conclusions: One drop inlet is required to keep the depth of water to 1.6 ft which is less than the Sand Filter berm. I 1 1 I I I I I I I Chapter 9— Storm Drains 1 Appendix 9C-13 Performance Curve DI-1 in a Sump 1 "F.017- s"r(tVCTvP- A N I DzsiGiU = 6.o (C5 Non Numumma / 141111111111MIII■ ■ CC■■■■.M■�C■■■■: C" ■■■■■l Fail■■■C Mill s • IIIIIIIIII(<-I• .1111111111111111 1 j �v W =MIS11 111 mili � 11t Li mon1101WMISIIIIII5 ■a 0/ ■■■■�■rIII �. 1111 .11111111J11 ii r■iI 11111110.11111 1 II la r111111 1 . ry i ... OPEN AREA = 2.33 FT2 1 PERIMETER = 9.00 FT I Li. I F, Ll r--,r 11.0(f CO Qi DIGCHARGE ( CFS ) I I Source: VDOT Transportation Research Council publication"HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 j 1 of 1 VDOT Drainage Manual is is SCS ENGINEERS Client Project Job No. If Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 it Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date IAST 7/14/2017 Purpose: Size the Drop Inlet A7 yard drain to prevent overtopping into the tunnel access road. Given: Height to roadway surrounding yard inlet= 0.75 ft IAssumptions: 1.Peak Flow from Drainage Area C(drainage area smaller)= 1.2 cfs I2.Assume a design flow of= 2.0 cfs 3.Use Performance Curve DI-1 in a Sump,From Appendix 9C-13 of the VDOT Drainage Manual. 4.Assume 50%clogging: Calculations: 1 See calcualtions on Appendix 9C-13. Depth of water 0.25 ft IConclusions: The water will pool to 0.25 feet above the rim of the drop inlet and not run into the roadway for a 10 year storm event. I I I I I I I I I I I Chapter 9—Storm Drains I Appendix 9C-13 Performance Curve DI-1 in a Sump I S-02.U c,'1 U{1-E A '4- I Q at-.sie,") 2 c9_s Cf` mlimi MINIM i �I�I•I•M ■ I �■1111111■■■■•1a011MiINME■■■ ■■�■■■■■■■■■ �� ■■■■■■ ■ 5a C, — I 11111 Ci. IJ_ LiL 1 e 0 ■1.1.■111>• ■■ri�11111 ■�.��I.■■.�.�. LI ■ ■ �IN B /11!i i/ ■■■■■■■ 1■11 MINIM li< Pill 111.11.1111111 ,- 'Y OPEN AREA = 2.33 FT2 PERIMETER = 9.00 FT r; 121 r,r'I I 00 alla ticS ; D I .,C HAP[.F ( [IFS ) Source: VDOT Transportation Research Council publication "HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 i of 1 VDOT Drainage Manual iw imi SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date AST 7/14/2017 Purpose: Size the Drop inlet A9 to protect from overtopping the berm of Sand Filter C. 1 Given: Height of Berm at Sand Filter C: 2 ft IRim Elevation above Sand Filter Surface= 0.5 ft Assumptions: Ii.Peak Flow from Drainage Area C= 1.2 cfs 2.Assume a design flow of: 2.0 cfs 3.Use Performance Curver DI-1 in a Sump From Appendix 9C-13 of the VDOT Drainage Manual. 4.Assume 50%Clogging. I Calculations: See calcualtions on Appendix 9C-13. Depth of water 0.25 ft I Water Surface Height=Rim Elevation+Depth of Water 0.75 Conclusions: 1 The Water Surface Height is 0.75 ft and will not overtop the Sand Filters Perimeter Berm. 1 I I I I I I I I 1 SCS ENGINEERS ' Client Project Job No Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 111Subject By Date Storm Drains NTJ 3/3/2017 Checked Date Purpose: Calculate the peak discharge for Drainage Area C for a 10 year event Given: 1.Use 10 year storm for design. 2.Areas Taken from autocad Drawings SW2. Assumptions: 1.Use NOAA Atlas 14 for intensity 2.Assume a Time of Concentration of 5 min. 4.Cf value From VDOT Drainage Manual= 1 5.C values taken from page V-29 Table 5-2 of the VESCH Calculations: Cumulative"C" C=((A1"C1)+(A2"C2)+, ,+(An+Cn))/(A1+A2+.,..+An) Peak Flow Q10=C"i*A"Cf Area A=A1+A2+ +An Contributing Drainage Area Area(ac) Assmued C Value Impervious Area 0.13 _ 0.90 Pervious Area 0.17 0.35 Intensity-5 min duration 6.53 in/hr Total Area: =lmpervous+Pervious 0 30 acres Cumulative"C" C=((A1"C 1)+(A2"C2)+...+(An+Cn))/(A1+A2+. ..+An) 0.59 Peak Discharge,Q10: Q10=Cf A"C"i 1 2 cfs Conclusion: The peak flow for drainage area c is 1.2 cfs and need a minimum pipe diameter of 6 inches to support peak discharge. ' 1 I 1 I - Precipitation Frequency Data Server Page 1 of 4 mg NOAA Atlas 14,Volume 2,Version 3 Location name:Charlottesville,Virginia,USA* :, Latitude:38.0253°,Longitude:-78.6538° 0 Elevation:662.27 ft** o'S .*` Imo *+, 0 'source:ESR[Maps '.,`� f "source.USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnin,D.Martin,B.Un,T.Parzybok,N.Yekla,and D.Riley •isa NOAA,National Weather Service,Silver Spring,Maryland PF tabular 1 PF graphical I Maps 8. aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals (in inchesihour)1 Average recurrence interval(years) Duration 1 2 5 1 10 25 50 D 100 200 �1 500 lI 1000 NM 5-min 4.12 4.92 6.80 6.63 7.37 8.02 8.63 9.20 9.90 10.5 (3.72.4.57) (4,45.5.45) (5.23-6.41) .(5.88-7.21) (6.60.8.11) (7.15-8.83) (7,64-9,52) (8.09-10.2) (8.60-11.0) (9.00-11.7) 10-min 3.29 3.94 4.64 "" 5.87 6.38 6.86 7.30 7.83 8.24 (2.98-3.65) (3.56.4.36) (4.19-5.13) (4.70-5.76) I (5.26-6.47) (5.69-7.03) (6.08-7.56) (6.41-8.06) (6.80-8.69) (7.09-9.19) 2.74 3.30 3.92 4.40 4.96 5.39 5.78 6.14 6.57 6.90 N (2.48-3.04) (2.99.3.65) (3.54-4.32) (3.97.4.86) (4.45.5.46) (4.80-5.94) (5.12-8.37) (5.40.6.78) (5.71-7.29) (5.93-7.69) 30-min 1.88 2.28 2.78 3.19 3.67 4.06 4.42 4.78 5.23 6.69 (1.70-2.08) (2.06-2.52) (2.51-3.07) (2.87-3.52) (3.29.4.05) (3.62-4.47) (192-4138) I(4.20.5.28) (4,545.80) (4.80-6.23) 60-min 1.17 1.43 1.78 2.08 2.46 2.76 ' 3.05 3.35 3.76 4.08 (1.06-1.30)a (1.29-1,58) (1.61-1,97) (1.87-2.29) (2.19-2.70) (2,45-3.03) (2.70-3.36) (2.95-3.70) (3.26-4.16) (3.51-4.55)IN . 0.700 0.852 1.07 1.26 1.50 1.70 1.91 2.12 2.42 2.67 2-hr I(0.622-0.792)(0,756-0.961) (0,948-1.20) (1.12-1.41) (1.32-1.68) (1.49-1.91) (1,66-2,14) (1.83-2.38) (2.06-2.73) (2.25.3.02) 3-hr 0.611 0.621 0.778 0.914 1.09 1.24 1.39 1.55 1.77 1.96 (0.454.0-582)(0.549-0.705)(0.687.0.884) (0.805-1.04) (0.956-1.23) (1.08-1.40) (1.21-1.58) (1.33-1.76) (1.50.2.02) (1.64.2.24) 6-hr 0.331 0.401 0.498 0.587 0.705 0.809 0.918 1.04 1.20 1.36 (0.296.0.374)(0.357.0.452)(0.442-0.561)(0.518-0.660)(0.619-0.793)(0.704.0.908) (0.791-1.03) (0.882-1.17) (1.01.1.36) (1.12-1.53) 12-hr 0.209 0.252 0.316 0.372 0.463 0.526 1 0.603 0.689 0.817 0.932 ( (0.186-0.238)(0224.)286)(0.278-0.358)(0.328-0.423)(0.396-0.514)(0.453.0.595)(0.614.0.684)(0.579-0.782)(0.671-0.931) (0.753.1.07) 24-hr 0.127 0.154 0.196 0.231 0.284 0.329 0.378 0.433 0.614 0.683 (0.114-0.142)(0.138-0.172)(0.176-0.219)(0.207-0.258)(0.252-0.316)(0.289-0.365)(0.330-0.420)(0.374-0.479)(0,436-0.570)(0.488-0.647) Me �'i2-day 0.075 0.091 0.115 0.136 0.164 0.188 0.216 0.243 0.285 0.320 �(0.067-0.083)(0.081-0.101)(0.103-0.128)(0.121-0.151)(0.146-0.183)(0.166.0.209)(0.188.0.239)(0211-0271)(0.244.0.318)(0.271.0.358) 3-day 0:063 0.064 0.082 0.096 0.116 0.133 0.162 0.172 0.201 0.226 (0,048.0.059)(0.058.0-071)(0.074-0.090)(0.086-0.106)(0.104-0.128)(0.119-0.147)(0.134-0.168)(0.151-0.190)(0.174-0.223)(0.193.0.251) 4-day 0.042 0.061 0.065 0.076 0.092 0.106 0.120 0.136 0.159 0.178 (0.039-0.047)(0.047-0.056)(0.059-0.072)(0.089.0.084)(0.083-0.101)(0.095-0.116)(0.107-0.132)(0.120-0.150)(0.139-0.175)(0.154-0.197) 0.028 0.034 0.042 0.049 0.069 0.067 0.076 0.086 0.098 0.109 7-day (0.026.0.031)(0.031.0.037)(0.039-0.046)(0.045.0.053)(0.053-0.064) (0.060.0.073),(0.068.0.083)(0.075.0.093)(0.086-0.108)(0.095-0.120) 10-day 0.022 0.027 0.033 0.038 0.045 0.061 0.057 0.063 0.072 0.079 (0.020-0.024)(0.025-0.029)(0.030-0.036)(0.035-0,041)(0.041-0.049)(0.046-0.055)(0.051-0.061)(0.057-0.068)(0.064-0.078)(0.070-0.086) 20-day 0.016 0.017 0.021 0.024 0.028 0.031 0.034 0.037 0.041 0.044 (0.0144016)(0.0960.019)(0.020-0.023)(0.022-01)26) (0.026-0.030)(0.028.0.033)(0.031-0.036)(0.034-0.040)(0.037-0,044)(0.040-0.048) 30-day 0.012 0.014 0.017 - 0.019 0.021 0,023 0.025 0.027 0.029 0.031 (0.011-0,013){0.013.0.015)(0.016-0.018)(0.017-0.020)(0,020.0.023)(0.022.0.025)(0.023.0.027)(0.025.0,029)(0.027-0.031)(0.029.0.033) 45-day 0.010 0.012 0.014 0.015 I 0.017 0.018 0.020 0.021 0.023 0.024 (0.009-0.011)(0.011.0.012)(0.013-0.015).0.014-0.0161[83.016.0.018 (0.017.0.020)(0.018-0.021)(0.020.0.022)(0.021.0.024)(0.022-0.026)1 60-day 0.009 0.010 0.012 0.013 0.014 1 0. 0.017 0.018 0.019 0.020 (0.008.0.009)(0.010.0.011)(0.011.0.013) 0.012.0.014)(0.014-0.015 (0.015-0.016)(0.016-0.018)(0.016-0.019)(0.018.0.020)(0.018-0.021) r 'Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. ANN Back to Top s AM a http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0253&lon=-78.6538&dat... 11/21/2016 6.4—Design Concepts The Rational Method Formula is expressed as follows: Q=Cf CiA (6.4) 1 Where: Q = Maximum rate of runoff, cubic feet per second (cfs) Cf = Saturation factor C = Runoff coefficient representing a ratio of runoff to rainfall (dimensionless) = Average rainfall intensity for a duration equal to the time of concentration for a selected return period, inches per hour (in/hr) A = Drainage area contributing to the point of study, acres (ac) Note that conversion to consistent units is not required as 1 acre-inch per hour I approximately equals 1 cubic foot/second. 6.4,4.1.5 Infrequent Storm than a 10- I The coefficients given in Appendix 6E-1 are for storms with lessyear recurrence interval. Less frequent, higher intensity storms will require modification of the coefficient because infiltration and other losses have a proportionally smaller effect on runoff(Wright-McLaughlin 1969). The adjustment of the Rational Method for use with larger storms can be made by multiplying the right side of the Rational Formula by a saturation factor, Cf The product of Cf and C should not 1.0. Table 6-2 lists the saturation factors for the Rational Method. Table 6-2. Saturation Factors For Rational Formula Recurrence Interval (Years) Cf 2, 5, and 10 1.0 25 1.1 50 1.2 it 100 1.25 Note: Cf multiplied by C should notall.10� 6.4.4.1.6 Time of Concentration The time of concentration is the time required for water to flow from the hydraulically most remote point in the drainage area to the point of study. Use of the rational formula requires the time of concentration (tc) for each design point within the drainage basin. The duration of rainfall is then set equal to the time of concentration and is used to estimate the design average rainfall intensity (i) by using the B, D, & E factors in the procedure described in Appendix 6C-1. A table showing the B, D, & E factors for Virginia counties and larger cities is presented in Appendix 6C-2. • Rev 4/10 Chapter 6—Hydrology VDOT Drainage Manual 6-16 of 57 1992 TABLE 5-2 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA Land Use C Land Use C Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 Neighborhood areas 0.50-0.70 Sandy soil, average, 2-7% 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, average, 2-7% 0.18-0.22 Heavy soil, steep, 7% 0.25-0.35 O>, O.3 Residential: Agricultural land: Single-family areas 0.30-0.50 Bare packed soil Multi units, detached 0.40-0.60 * Smooth 0.30-0.60 Multi units, attached 0.60-0.75 * Rough 0.20-0.50 Suburban 0.25-0.40 Cultivated rows * Heavy soil, no crop 0.30-0.60 * Heavy soil, with crop 0.20-0.50 * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 * Sandy soil 0.05-0.25 Woodlands 0.05-0.25 Industrial: Streets: Light areas 0.50-0.80 Asphaltic 0.70-0.95 Heavy areas 0.60-0.90 Concrete 0.80-0.95 O'1 Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved areas 0.10-0.30 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 Not : The designer must use judgement to select the appropriate "C" value within the range. Generally, larger areas with permeable soils, flat slopes and dense vegetation should have the lowest C values. Smaller areas with dense soils, moderate to steep slopes, and sparse vegetation should be assigned the highest C values. Source: American Society of Civil Engineers V - 29 I Chapter 9—Storm Drains I Appendix 9C-13 Performance Curve DI-1 in a Sump I F"DV- S't'Q.vcTV RE pi (1 t' Si tv,J = Z C RS I MINI / I / , r :I rl; 1— f • z L 1 ❑ I am i A' .V J ..,_ ...- . .-Q --.7.--. _ ..,,,,,, ,, OPEN AREA = 2.33 FT2 i� PERIMETER = 9.00 FT — _ , I I 1 ._ I F, i 0 t70 1 00 li `D1 CHPROE ( CFS, ) Source: VDOT Transportation Research Council publication "HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 1 1 of 1 VDOT Drainage Manual els SCS ENGINEERS a Client Project Job No. 4 Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 k II Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date AST 7/14/2017 Purpose: Size the Drop Inlet All yard drain to prevent overtopping into surrounding access road. i Given: Height to roadway surrounding yard inlet= 2 ft Assumptions: 1.Peak Flow from Drainage Area C(drainage area smaller)... 1.2 cfs I 2.Assume a design flow of= 2.0 cfs 3.Use Performance Curve DI-1 in a Sump,From Appendix 9C-13 of the VDOT Drainage Manual. 4.Assume 50%clogging: ' Calculations: See calcualtions on Appendix 9C-13. Depth of water 0.25 ft IConclusions: The water will pool to 0.25 feet above the rim of the drop inlet and not run into the roadway for a 10 year storm event. I I1 I . I I I I I I I I Chapter 9—Storm Drains I Appendix 9C-13 Performance Curve DI-1 in a Sump I S'r;tucrQa� A11 I Q err-S)c�v1 = Z c kS 1e , 1 1 � � nIIm mi / K■■ _. ■ ■■•■111■■i>■■UI■ / 1/11■►i ■111■1■I■ . IlinifirimprAoream uuuii ('-V_ .-1: r �■■ 11 ■UI .,,,c i. (c.,, Li_ i . .„I LL 1 IL�LAJ ��I� I■�I♦_--I_-�� L IIIMIl'MNIMIMI-_MIMIIIIII♦I. — u ____ ■/I��•■■■•■■ ■®■■■ri111111111111■v111 c�. �, 1111111111 ��■■■■■N .... ■��■■■■u mi• I!Ufl s■ ■ v-..-- a tis liii .. OPEN AREA = 2.33 FT2 PERIMETER = 9.00 FT 0 i I 2 c-C1S DISCHARGE ( CFS ) i — Source: VDOT Transportation Research Council publication "HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 im MK of'I VDOT Drainage Manual a r. SCS ENGINEERS w Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 illi Subject By Date Drop Inlets NTJ/DCC 7/14/2017 Checked Date AST 7/14/2017 r Purpose: Size the Drop inlet Al2 to protect from overtopping the Sand Filter D Berm. IS Given: Height of Berm at Sand Filter D: 2 ft IRim Elevation of drop Inlet above filter bed(See Sand Filter D Calculations(= 0.5 ft Assu mptions: 1.Peak Flow from Drainage Area D= 1.2 cfs I 2.Assume a design flow of= 2.0 cfs 3.Use Performance Curver DI-1 in a Sump From Appendix 9C-13 of the VDOT Drainage Manual. 4.Intalling multiple drop inlets at the same elevation will divide flow evenly. I Calculations: See calcualtions on Appendix 9C-13. Depth of water 0.25 ft Water Surface Height=Rim Elevation+Depth of Water 0.75 j Conclusions: The water surface height is 0.75 ft and will not overtop the Sand Filter D perimeter berm. i I I I I I I I I SCS ENGINEERS ' Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date Storm Drains NTJ 3/3/2017 Checked Date Purpose: Calculate the peak discharge for Drainage Area D for a 10 year event ' Given: 1 Use 10 year storm for design. 2 Areas Taken from autocad Drawings SW2 Assumptions: 1 Use NOAA Atlas 14 for intensity. 2 Assume a Time of Concentration of 5 min 4.Cf value From VDOT Drainage Manual= 1 5 C values taken from page V-29 Table 5-2 of the VESCH Calculations: Cumulative"C^ C=((A1'C1)+(A2*C2)+...+(An+Cn))/(A1+A2+_...+An) Peak Flow Q10=C*i*A*Cf Area A=A1+A2+. .+An Contributing Drainage Area Area(ac) Assmued C Value Impervious Area 0.17 0.90 Pervious Area 0 08 0 35 Intensity-assume 5 min duration 6,53 in/hr Total Area: =Impervous+Pervious 0.25 acres Cumulative"C C=((A1*C1)+(A2*C2)+..+(An+Cn))/(A1+A2+...+An) 072 Peak Discharge,Q10: .. Q10=Cf A*CI 1.2 cfs Conclusion: The peak flow for drainage area D is 1.2 cfs a i a a a+a a r Chapter 9—Storm Drains Appendix 9C-13 Performance Curve DI-1 in a Sump SA-2v c'1-v2 c +4 IZ.,.,. .. / r / 4 i w r. 0 / .--,-,/ -t� iiii rjf I-- w Il •�s ._ / 1-- 1 . E / LL U / I is o _ OPEN AREA = 2.33 FT2 — il PERIMETER = 9.00 FT F 2 CSS 5 VI 11-40 IDI .CHAP'3L LF'; s. Source: VDOT Transportation Research Council publication "HYDRAULIC EFFICIENCY OF GRATE INLET", 1988 I 1 of 1 VDOT Drainage Manual I 1 SCS ENGINEERS ' Client Project Job No. Rivanna S.I.Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Al Subject By Drop Inlets NTJ/DCC 7/14/2017 Checked gate 1 AST � 7/14/2017 Purpose: Size the op Inlet A16 to protect overtoping into the north access road. 1 Given: Height of road above rim elevation= 2 ft Assumptions: 1.Peak Flow from A16= 2.8 cf 2.Assume a design flow of= 3.0 s 3.Use Performance Curve Dl-1 in a Sump,From .pendix 9C-13 of the VDOT Drainage Manual. 4.Assume 50%clogging: Calculations: See calcualtions on Appendix 9C-13. Depth of water 0.35 ft Conclusions: The water will pool to 0.35 feet above the rim o he drop inlet an. of run into the roadway for a 10 year storm event. ' MO 1 - r am SCS ENGINEERS C -nt Project Job No. Ri :nna Solid Wa: •Authority 'Project Ivy Solid Waste Transfer Station 102216 •t.01 S •••ct By Date S••rm Drains NTJ 3/3/2017 Checked Date P ••se: Calculate the peak d harge for drainage area contributing to structure Alb on the the landfill cap for a 10 year event G en: 1. _ e 10 year storm for design. 2 reas Taken from autocad Drawings S A= mptions: 1 se NOAA Atlas 14 for intensity 2 - ume a Time of Concentration of 5 min. 4 f value From VDOT Drainage Manual= 1 5. values taken from page V-29 Table 5-2 of the VESC C. culations: r C lative"C" C=((A1`C1)+(A2*C2) .+(An+Cn))/(A1+A2+ +An) P:•. Flow Q10=C*i*A'Cf Ar a A=A1+A2+ .+An Contributing Drainage Area Area(ac Assmued C Value Impervious Area 0 09 , 0 90 Pervious Area 1 00 0 35 Ti of Concentration,TC= 5 00 In sity-assume 5 min duration 6 in/hr T.al Area: =lmpervous+Pervious 1.09 acres C ulative"C" C=((A1`C1)+(A2`C2)+ +(An+Cn))/(A1+A2+. +An) 040 '� P==k Discharge,Q10: 010=Cf ASW1'C`i 2 8 cfs r. C lusion: T =peak flow for drainage area to structure A16 is 2 8 cfs use a de-.n of 3.0 cfs. _______ ___. ....•_.... ........... . __ __ . _. ________ _ . No Ns ..- , -- N\ a u) cni—CO ir (A i ..C\,\"\ '' • . Ii. _----—— -', ,- ..._.....--- , I, . .-- , ,'; I - - -- -- ----.. ..--0•°- i 11 ' .: ' 41:: N \ 4. II ' .,7-.:-.„ i(.7c- \ I ——— o 11 g \ 1 Qiirl I SC L- '''' t / (.... I --- I 1 I II: ,--- (--- --V '.. '-rt < u) 00 LT(i) < •.Lr) a 1_ o Lli 0 .. •rz,... z•— I (y. , , •w ... -1,,, 0 ic,,,T, ii," iz ..,0 ... . L- L.I.J V--I V !' ki , IJ--• .. • , ... . I :: /' .. Ur) 0 i I y.. A `t... II 'v) 1 -0— i\.-• PO , Ld H.-cd ii.i r, I I u_ cn N Ch 1161 /\ 1,J v- A' 0 :4 if* ! I ...... . . , il ' Ili I N I' - - I NY , . k I AIM recipi ation requency Data Server Page 1 of 4 NOAA Atlas 14,Volume 2,Version 3 _ r1' Location name:Charlottesville,Virginia,USA' '�011M1'S Latitude: 3°,Longitude:-78.6538° ' � 4 ,t Elevation:662.27 ft** •source ESR{Maps .„. a "source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES G Bonnin,D Martin,B Lin,T Parzybok,M Yekta,and D Riley ./ AM NOAA,National Weather Seance,Silver Spring,Maryland PF tabular 1 PF graphical I Maps & aerials PF tabular PDS-based point ,recipitation frequency estimates with 90% confidence intervals-lin incheslhour)1] Aver rge recurrence interval(years) Duration ': - .-1 1 �1► 1 5 10 25 50 100 IL 201 500]L 1000 i r 93 7.37 8.02 8.63 0 9.90 10.5 MIN 5-min 4.12 4.92 b.8044 (3 72.4.57) (4,45-5.45 (5.23-6.41) ', (1,83 -_-ill I (6 60.8.11) (7.15-8.83) f�(7.64-9.52) (; •'-102) (8.60-11.0) (9.00.11.7)) 1 3.29 3.94 4.64 5.22 5.87 6.38 6.86 r 7.30 7.83 8.24 10-min II I( (2 98-3.65) (3.56.4,36) 19-5,13) (4.70-5 76) (5.26-6.47) (5.69.7.03) (6,08-7.55) (6.41-806) (6.80.8.69) (7.09-9.19) 15.m in-1 2.74 3.30 •2 Z40 4.96 5.39 5.76 6.14 6.57 6.90 i -11(248.3.04) (2.99.3.65) I.32) (3.97-4:88) (4.45-5.46) (4.80.5.94) (5.12-• )J�(5.40.6.78) (5-71-7.29) (5,93.7.69) 1.88 2.28 2.7: 3.19 3.67 4.06 • 2 4.78 5.23 5.59 30-min J (1.70.2.08) (2.06-2.52) (2.51-3.0, (2.87-3.52) (3.29.4.05)I (3.62-447) (3 -4.88) (4.20-5.28) (4,54.5,80) (4.80-6.23) L60-min ( 1.17 1.43 1.78 2.08 2.45 2.75 3.06 3.35 3.75 4.08 ___1 (1.06-1.30) (1.29-1.58) (1.61-1.97) , .87-2.29) (2,19-2.70) (2.45-3.03) (2.70.3.36) (2.95-3.70) (3.26-4.16) (3.51.4.55) Sill 0.700 0.852 1.07 1.50 1.70 1.91 2.12 2.42 2.67 2-hr 1(0.622-0.792) 0.756-0,961 (0.948-1.20) (1. (1-32-1.68) (1.49-1,' (1.66-2.14) (1.83-2.38) (2.06.2.73) (2.25-3.02) L-3-hr 0.511 0.621 0.778 0.9 1.09 1 • 1.39 1.56 1.77 1.96 (0.454-0.582)(0.549.0.705)(0.687.0.884) (0,805.1 (0.956-1.23)I (1,1' (1.21.1.58) (1.33-1.76) (1.50-2.02) (1.64.2.24) +n 6-hr 0.331 0.401 1111 0.498 0.587 ' 0.706 /1.809 { 0.918 1.04 .1.20 1.35 _ _(0.296.0.374)(0.357-0.452 (0.442.0.561) 0.518-0.660)�0.619.0,793)PP 704.0.908)(0.791.1.03) (0.882.1.17) (1.01-1.36) (1.12-1.63) [ 12-hr_ 0.209 0.252 0.315 0.372 1.453 0.526 ^0.603 0.689 0.817 0.932 (0.186.0.238)(0.2.24.0.288) (0.278.0.358)(0.328-0.423)(0. .•-O.', 0.453.0.595)(0.514-0.684)40.579.0.782)(0.671-0.931) (0.753.1,07) 24-hr 0.127 0.154 0.196 0.231 0 ". 0.329 0.378 0.433 0.514 0.583 MIK (0.114-0.142)(0.138-0,172)(0.176-0.219) 0.207-0.2581 (0.25, {0.289.0.365)(0.330-0.420)(0.374.0.479)(0.436.0.570){x0.488-0.647), [2-day 0.075 ) O.D91 0.115 0.135£ 164 0.215 0.243 0.285 0.320 -](0.067.0.083 (0.061.0,101 (0.103-0,128)•0.121-0-161) 46.0.18 0.10561.80.8209);(0.188-0.239)(0211-0.271)(0.244-0.318)(0.271.0.358) 3-day 0:053 0.064 0.082 0.096 0.116 0.133 0.152 0.172 0.201 0.225 fr 1 -](0.048-0.059)(0.058.0.071)(0.074.0.090) 0.086-0,11,(0.104-0.128)�'9-0,147) (0.134-0.168-(0.151-0.190)(0.174.0.223)(0.193-0.251)) i 4-day ) 0.042 0.051 0.065 0.0 0.092 0. 16 0.120 0.136 0.159 I 0.178 (0.039-0.047)(0.047.0.056)(0.059.0.072)-0,061 1 1 - (0,083.0.101) 0.095.' 16),(0.107-0.132 (0.120-0.150)(0.139-0.175)I(0.154-0.197) 7-day 0.028 0.034 0.042 !Il1 .049 1 0.059 0.06 0.076 0.085 0.098 0.109 (0.026-0.031)(0,031-0.037)(0.039.0.046) .5.0.053)(0.053-0.064) 0,060-0.07 1 (0.068-0.083 (0.075-0.093)(0.086-0.108) 0.095-0.120) 10-day 0.022 0.027 0.033 0.038 0.045 0.051 , 0.057 0.063 0.072 0.079 AIM (0.020-0.024)(0,025.0.0291(0,030-0.0 , 0.035-0,041)(0.041-0.049).0.046-0.055))(1 51-0.061`(0.057.0.068)(0.064.0.078)(0.070.0.086) 20-day 0.016 0.017 0.0 0.024 0.028 0.031 r 10.037 0.041 0.044 (0.014-0.018)(0.016-0.019)(0.020' 1 1 '.(0.022-0.026)(0.026-0.030)(0.028.0.033) (0.034-0.040)(0.037-0.044)(0.040.0.048) 30-day 0.012 0.014 17 0.019 0.021 0.023 0.02. 0.027 0.029 0.031 (0.011-0.013)(0.013-0.015 *6.0.018)(0,017.0 020)`(0.020-0.023)(0.022-0.025)(0.023-0.0.'(0.025.0.029)(0.027-0.031)(0.029.0.0331) AM 45-day 0.010 0.012 ' 0.014 [ 0.015 0.017 0.018 , 0.020 0,021 0.023 0.024 (0,008.0.0111 0,011-0.01 (0.013-0.015)((0.014.0,016)(0.016.0.018) 0.017-0.020)l(0.018.0.021 ,'20.0.022)(0.021.0.024)(0.022.0.0[6)1 60-da 0.009 0.011 0.012 II 0,013 0.014 0.016 0.017 018 0.019 0.020 y (0.008-0009) 0.010.+ 411.(0.011-0.011)1i(00120.014)(0,014.0.015):0.015-0.016)(0.01s-0.018 . ..019)(0.018.0.020),(017)00.021) ® ,Precipitation frequency(PF): imates in this table are based on frequency analysis of partial duration series(PBS). Numbers in parenthesis are' estimates at lower and upper bounds of the 90%confidence interval.The probability that prec -alien frequency estimates I k (for a given duration and a -rage recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%. stimates at upper bounds are not checked against• obabte maximum precipitation(PMP)estimates and maybe higher than currently valid PMP values _-A' Please refer to NOAH las 14 document for more information. pack to Top I I 111i rr - s ...a. :. is sf's/s ds pr-ntpage.html?tat=38.0253&ton=-78.6538&dat... 11/21/2016 I 19' 1 TABLE 5-2 1 VALUES OF RUNOFF COEFFICIENT (C) FOR RATIONAL FORMULA I :nd Use C Land Use •-' I 1 Business: Lawns: Downtown areas 0.70-0.95 Sandy soil, flat, 2% 0.05-0.10 1 Neighborhood are. 0.50-0.70 Sandy soil, average, 2-7'. 0.10-0.15 Sandy soil, steep, 7% 0.15-0.20 Heavy soil, flat, 2% 0.13-0.17 Heavy soil, aver ig,',2-7% 0.18-0.22 1 Heavy soil, steer, 7' 0 0.25-0.35 VSt .3" Residential: Agricultural 1. :"d: Single-family areas 0.30-0.50 Bare pack:. soil Multi units, detached 0.40-0.60 * Smo- h 0.30-0.60 •• Multi units, attached % •1-0.75 * R..gh 0.20-0.50 Suburban 0.`-,-0.40 Cult .ted rows * eavy soil, no crop 0.30-0.60 Heavy soil, with crop 0.20-0.50 g` * Sandy soil, no crop 0.20-0.40 * Sandy soil, with crop 0.10-0.25 Pasture * Heavy soil 0.15-0.45 Sandy soil 0.05-0.25 Wo,'lands 0.05-0.25 I. Industrial: Streets: Light areas 0.50-0.80 Asphatti " 0,70-0.695 �6q0 Heavy areas 0.60-0.90 Concrete 0.80-0.95 r Brick 0.70-0.85 Parks, cemeteries 0.10-0.25 Unimproved area 0.10-0.30 Playgrounds 0.20-0.35 Drives and walks 0.75-0.85 "' Railroad yard areas 0.20-0.40 Roofs 0.75-0.95 or Note: The desic,ner must use judgement to select the appropriate "C" value wit ' the range. Jenerally, larger areas with permeable soils, flat slopes and dense vege,,a tion should have the lowest C values. Smaller areas with dense soils, or m•.erate to steep slopes, and sparse vegetation should be assigned the highest ues. \ ern So ce: American Society of Civil Engineers .■ ma - 9 Am a Chapter 9- Storm Drains Appendix 9C-13 Performance Curve DI-1 in a Sump Alb '.?0i Ai1- (-; A 0 'c'Esq,• N . 3 c-i-.51 0 . i 5e 'I _ f/ {i:2 •,a' I— — E-4/ u_ > i _ „f LL IJ a ,/ OP' AREA = 2.33 FT2 PERI TER = 9.00 FT I:A, 1 II I I I i 0S, 10 50 1 1:00 R* G 1 in DIST HAPC,E t CP_. _ I I I Source: VDOT Transportation Research Council publication "HYDRAULI EFFIC NCY OF GRATE INLET", 1988 II 1 of 1 VDOT Drainage Manual 1 1 II APPENDIX J ' Outlet Protection ' 1 t ire SCS ENGINEERS ow Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 Subject By Date ail Storm Drain Outlet Protection NTJ/DCC 7/14/2017 Checked AST 7/14/2017 Purpose: Determine adequate outlet protection into to the Stormwater Basin for a 10 year event. Given: I 1.Use 10 year storm for design. 2.Outlet Pipe Size= 24 inches Assumptions: 1. Use the Peak Dishcarge From Structure Al Fomr the Storm Sewers Extension. Q= 14.4 cfs 2.Assume Minimum Tailwater Condition. Calculations: Using Plate 3.18-3 From VESCH d50= 0.5 ft IWidth= 14 ft Conclusion: The peak flow for the project area is 14.4 cfs and need a minimum pipe diameter of 24 inches to support peak discharge. I Class Al Standard VDOT riprap will be needed for the outlet protection for a minimum distance of 14 feet. For design,the riprap will extend to the permanent pool elevation. I I I I I I I o n i) Ia N — N > ti O U ,n N 0 O .. i r.i U) m N sa C. Co 0 ham-- h.- F N. (0 t0 V CC QCc� °' O I C7 NJ 0 Mill O M v I 11, O ® IIIIII 1 � t,„ cc, so g Z a o fik. OE I I O D 1 R0 ,c--,..., ,, Ct I r` I Mf. 'rTEM IMO , CV i I Oio (fla. �. i �I_ ' MM 1 cal.. ! _ _ _ ..s "zi imalui. I 2 0 LI IIIEN , E. ,.... M CS ,- co NMI IN ' a � ! F- M c Milli imi 1_ fl N- r o co I 1111101- 1 CD CO I c m V" �� w Q 1 CD of C � jCZ ii lik N Nr' L LL CL N 1--,i 4s- 'r-- t'? C U CD * 01 = a> a , J i iii 1992 3.18 ?'Cy 4' „N gaaj. `azis de.ad[u 05p a' th N O O ',:, ..::'........"Ma 14r� .�SGA ' •, i s ma=-+V- g m11111 CD ei:�Nld aIt 3@s=__liaises 3'. •• 6 Ea$:xn �' i a-6 i gyres. .swag.{ i — �--. i ss� �� -�=mss-�� _ MUS"' "`' 1. B eH=r�i=--=t610 c. -4 h .:_-:g.==– - Au. - mE= _- � sa- -ate d ,9 + ....____ r) 11` A - c. • Ff_.. --1.64.1.36—t* z-, _— C )ice CLs a. _ �MIME MIMI !ice _ 144140. �; �� • SSS • 1,14 _ 4 vow, iemumm sim s suss �t N s% •7sa1�s.s r ar `•-..OMNI .�■ri►�amme►lri�irprr�r rr/rrrrN ........ . +�'\\r\�iii..i■ i / "CC:03- ,: : in !.....-*,-....OnglinIWIR11111111111 , all _ __ al _' em-•A iiiiiiniNi ,� `'sii�siis Ira-i.ira r _ o '� ---- ----samommos _.ams--�ssswas 4 _ �n L. SP ot41 � IillY l `ij►ill i®i H ' _ u uNNWEn Ce v_ r/� W W "- .i-:Li1111•n r.."s..��..CV mus":remisaisi sss5USSSUS 211111111111.110111111111H111111 •-- �e 1 M �, 1 0-W O rrr r■rrr \` \',011=1•111 :1111113•mUur•ersss., p _� `� 5- Q- yt' .risrrrsrr r ■wrrr�i _ oq� �— lQ o CR C)-J 0 >eiJ 11116111 .. ■..iii....i.m N 43111}1111111111111111 • r i 7 \;.:• 1J!!!! !!!!!!!!!I!!!!.! "1 AN o II 11 — �� . I 'b liiIEnialilllililililflliltil_ F 0 N r J~ M =111l!l��i111I1!!1!!1II 1 p�_:: 111M1111111111111111ue . -- C'U F w l o iii ..k"i.....li...am :ii..il, M O M L 0 0 0 4.1- +.0 4. O W • CD M .. • oao LU-. o= b b e 11 `\ V d ie 2 ab Source: USDA-SCS Plate 3.18-3 III - 164 i�,TG�� 2oT �/oma fog , CL4-5S A I - �, t-c Chapter 7-Ditches and Channels >St I40424F ?Gila T3isc/mat*" ACiiv Appendix 7D-3 Standard VDOT Riprap Classifications, Weights, and Blanket Thickness Classification D50 (ft) W50 (lbs) T (in) Class Al 0.8 50 20 Class I 1.1 100 26 _.......__..__ Class II 1.6 j 300 38 Class Ill 2.2 1000 53 Type I 2.8 2000 I 60 Type II 4.5 8000 97 1 of 1 VDOT Drainage Manual 1 SCS ENGINEERS Client Project Job No. Rivanna Solid Waste Authority New Ivy Solid Waste Transfer Station 02216108.01 I Subject By Date Trench Drain Gravel Diaphragm Outlet Protection DCC 7/14/2017 Checked Date AST 7/14/2017 I Purpose: Determine adequate outlet protection for the trench drains. • Given: I 1.Use 10 year storm for design. 2.Outlet Pipe Size= 6 inches 3.Drainage area used as surrogate for all drainage areas going to trench drains: 0.08 acres 4.Trench drain has slope of 1.0%slope. 5.Mannings(in trench drain pipe),n: 0.013 Assumptions: 1. Use 5-Minute time of concentration. 2.Rainfall Intensity(NOAA Atlas 14 for Charlottesville,VA),i: 6.53 in/hour I 3.Runoff Coefficient(Table 5-2 for"Asphalt Streets"),C: 0.9 Calculations: Rational Method Qpeak=CiA Qpeak= 0.5 cfs IVpeak= 3.2 fps Conclusion: The peak flow for the surrogate area to the trench drain is 0.5 cfs.At the peak,a velocity of 3.2 fps is obtained. i Based on the peak velocity,VDOT#78,#8,or#8P pea gravel shall be used for outlet protection I I I I I I I I I 1 I I I I APPENDIX K I Storm Basin I ha SCS ENGINEERS la Client Project Job No. Rivanna Solid Waste Authority New Solid Waste Transfer Station 02216108.01 iii Subject By Date Exising Zero Discharge Sediment basin discharge DCC 7/14/2017 Checked Date Sheet 1 of 1 ill Purpose: Determine the existing sediment basin discharge during a 1,2,10,25,100 year storm event. Given: Existing water elevation= 693.6 ft From Topograph dated 7/7/99. 3 Emergency Spill way elevation= 697.9 ft From Joyce Engineering dated 1998 Drainage Area= 11.03 acres From Drawing G2. Assumptions: 1.Existing water elevation acts as drainage basin bottom. I 2.Contours taken from drawing G2 Property Information 1. 3.Distribution Type II 4.Shape Factor 484 5.24 hour storm duration. Calculations: Composite curve number= 77 From Hydrograph No.1 Rivanna Stormwater Basin-Inflow Time of Concentration= 18.3 min From Hydrograph No.1 Rivanna Stormwate. Water Elevation for 1 year strom= 694.06 ft Water Elevation for 2 year strom= 694.26 ft I Water Elevation for 10 year strom= 694.85 ft Water Elevation for 25 year strom= 695.43 ft Water Elevation for 100 year strom= 696.08 ft I Conclusions: The existing stormwater basin will not discharge during a 24 hour 1,2,10,25,or 100 year storm event. I I I I I I I I I upO > (J C coN ' v 0 T T O O p p(7- O u) O N N > w >. > m Fw m o N jI O ' 3 N >> NO C0 CI) U m ro m r' I 2 v C -o O > co O! N > p o a) T m w =C 0 - Z5 O- o CO o-- a C o °� to 2 O` N U w w W III a o _ate 21> T I O L 11I Ciill ccN >. S j y' Q)C t✓01 i , .-1-2 > 0 7 I 9w+ J C , o I- e. Z MI C IM Cl) m/ CO ^^,, r ,W Cl) co CD C a m T"' 1c TA IMI Y) ) Z 0 C p o 0 0 0 ti h C7 N C Ir i i I 1 i t I I i I i .�l 1 I I i I I I I I I mo i i Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD©Civil 3D®2016 by Autodesk,Inc.v10.5 Monday,03/13/2017 Hyd. No. 2 Stormwater Basin-Inflo Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 100 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 1 - Rivanna Stormwater Basin-kitInvElevation = 696.08 ft Reservoir name = Rivanna Sed Basin Max. Storage = 247,960 cuft Storage Indication method used. Stormwater Basin-Inflo Elev(ft) Hyd. No. 2--100 Year Elev(ft) 698.00 -- 698.00 a 697.00 — 697.00 a 696.00 696.00 a 695.00 -- 695.00 a 694.00 694.00 a 693.00 --- - 693.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Time(hrs) 1. Rivanna Sed Basin a a I Hydrograph Report I Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Monday,03/13 1 2017 Hyd. No. 2 I Stormwater Basin-Inflo Hydrograph type = Reservoir Peak discharge = 0.000 cfs I Storm frequency = 10 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 1 - Rivanna Stormwater Basin lmElevation = 694.85 ft Reservoir name = Rivanna Sed Basin Max. Storage = 122,288 cuftI Storage Indication method used I 1 Stormwater Basin-Inflo Elev(ft) Elev(ft) Hyd. No. 2--10 Year 696.00 696.00 MI Mt 695.00 - 695.00 a a a 694.00 694.00 ' r Ns 693.00 — 693.00 a0 2 4 6 8 10 12 14 16 18 20 22 24 26 Time(hrs) 1. Rivanna Sed Basin OS UM Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD®CMI 3D®2016 by Autodesk,Inc.v10.5 Monday,03/13/2017 Hyd. No. 2 Stormwater Basin-Inflo Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 1 - Rivanna Stormwater Basin-kitlE lElevation = 694.26 ft Reservoir name = Rivanna Sed Basin Max. Storage = 62,272 cuft Storage Indication method used. Stormwater Basin-Inflo Elev(ft) Hyd. No. 2--2 Year Elev(ft) 696.00 696.00 a .. 695.00 695.00 694.00 694.00 693.00 —._ — L 693.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Time(hrs) 1. Rivanna Sed Basin 1 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v11 Thursday,07/6/2017 I Hyd. No. 2 Stormwater Basin-Inflo I Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a I Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 1 - Rivanna Stormwater Basin InElevation = 694.06 ft Reservoir name = Rivanna Sed Basin Max. Storage = 42,396 cuft I Storage Indication method used. 1 I Stormwater Basin-Inflo Elev(ft) Elev(ft) Hyd. No. 2-- 1 Year 696.00 696.00 I I 1 695.00 695.00 I I 694.00 694.00 t I I 693.00 693.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 I Time(hrs) 1. Rivanna Sed Basin Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Monday,03/13/2017 Hyd. No. 1 Rivanna Stormwater Basin-Inflow Hydrograph type = SCS Runoff Peak discharge = 82.42 cfs Storm frequency = 100 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 247,960 cuft Drainage area = 11.030 ac Curve number = 77* Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 18.30 min Total precip. = 9.07 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 •Composite(Area/CN)=[(1.220 x 87)+(3.060 x 78)+(6-750 x 74)J/11.030 Rivanna Stormwater Basin-Inflow Q(cfs) Hyd. No. 1 -- 100 Year Q(cfs) 90.00 — - — 90.00 a 80.00 + ---- -- 80.00 a 70.00 70.00 a 60.00 — 60.00 50.00 50.00 40.00 40.00 30.00 30.00 20.00 20.00 10.00 :::0 0.00 ti - 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time(hrs) I Hydrograph Report I Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk:Inc.v10.5 Monday,03/13/2017 Hyd. No. 1 I Rivanna Stormwater Basin-Inflow Hydrograph type = SCS Runoff Peak discharge = 41.29 cfs I Storm frequency = 10 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 122,289 cuft Drainage area = 11.030 ac Curve number = 77* I Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 18.30 min Total precip. = 5.55 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 I •Composite(Area/CN)_[(1.220 x 87)+(3.060 x 78)+(6.750 x 74)]/11.030 I., Rivanna Stormwater Basin-Inflow Q (cfs) Q(cfs) Hyd. No. 1 —10 Year 50.00 - 50.00 a 40.00 I 40.00 a 30.00 30.00 a 20.00 - 20.00 a sii 10.00 10.00 r ,-..-9 L--- ''' 0.00 a 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Time(hrs) Hyd No. 1 a 1 ! a Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 Monday.03/13/2017 Hyd. No. 1 Rivanna Stormwater Basin-Inflow Hydrograph type = SCS Runoff Peak discharge = 20.81 cfs Storm frequency = 2 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 62,272 cuft Drainage area = 11.030 ac Curve number = 77* Basin Slope = 0.0 % Hydraulic length = 0 ft - Tc method = TR55 Time of conc. (Tc) = 18.30 min Total precip. = 3.69 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 *Composite(Area/CN)=[(1.220 x 87)+(3.060 x 78)+(6.750 x 74)1/11.030 a Rivanna Stormwater Basin-Inflow <- Q (cfs) Hyd. No. 1 --2 Year Q(cfs) 21.00 il 21.00 a111 18.00 18.00 a 15.00 15.00 a 12.00 12.00 a 9.00 - 9.00 6.00 6.00 — 3.00 3.00 a 0.00 :_... _ 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time(hrs) 1 ' Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v11 Thursday,07/6/2017 I Hyd. No. 1 Rivanna Stormwater Basin-Inflow I Hydrograph type = SCS Runoff Peak discharge = 13.88 cfs Storm frequency = 1 yrs Time to peak = 725 min I Time interval = 1 min Hyd. volume = 42,396 cuft Drainage area = 11.030 ac Curve number = 77* Basin Slope = 0.0 % Hydraulic length = 0 ft I Tc method = TR55 Time of conc. (Tc) = 18.30 min Total precip. = 3.00 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 I *Composite(Area/CN)=[(1.220 x 87)+(3.060 x 78)+(6.750 x 74)]/11.030 I Rivanna Stormwater Basin-Inflow I Q (cfs) Q (cfs) Hyd. No. 1 -- 1 Year 14.00 14.00 I 12.00 1 12.00 10.00 1 10.00 I 8.00 8.00 I 6.00 6.00 I 4.00 4.00 I 2.00 2.00 1 0.00 \--- 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 I Time (min) Hyd No. 1 I I Ili SEDIMENT BASIN ADEQUACY CHECK as Project: New Ivy Solid Waste Transfer Station Location:Existing Zero Discharge Sediment Basin Total design area draining to basin: 11.3 acres. III Basin Volume Design Wet Storage: ,' 1.Minimum required Volume=67 cu.Yds.X Total Drainage Area(acres). 67 cu.Yds X 11.3 acres= 757.1 cu.Yds. 2.Available Basin Volume= 19360.0 cu.Yds at elevation 693.6 ft. (From Joyce Engineering,INC.Water Storage Pond Drawings,dated 1998) Dry Storage: 3.Minimum required Volume=67 cu.Yds.X Total Drainage Area(acres). 67 cu.Yds X 11.3 acres= 757.1 cu.Yds. 4. Total available dry storage basin volume at maximum allowable water level= 11454.6 cu.Yds at elevation 696.40 ft. (From Joyce Engineering,INC.Water Storage Pond Drawings,dated 1998) Minimum=134 cu.Yds./acre of total drainage area. Required Total Storage= 1514.2 cu.Yds. 1 Available Total Storage= 30814.6 cu.Yds. i t i i i I ) I t III 1 I I Runoff Volume and Curve Number Cakulat[ons eider design dorm rainfall depth)(in): I I. Roue 1 0 00.0 00. 04... awn.Viva.14/Rtwpww.4444.0OrknaC1,411 4tew(R0•le4K `ellµ d - +R.+•As••evaR rnwewr.nn,«Zway .0.04••0 I p1R +r w 1,004 deve ..a. eta e < n.tnna.noaain ue+nrea,m.er„RNOa .res ot.)na only 0n aw,n the,,,,,,y Caw(auaeo hon he pne. .e a a 4. halo.,1.10407.1000.. `•m01 wont he mulltoitt4dc11.1,000 ' I.r. ,0 r n ,,.,.eraw w. ea wn,n.,a a ,., ,noel au An,:e,nd.e m,aovm , nt t to,Vetaw (mem is xno<ana,. s Drainage area Curve N umbers and Runoff Depths" I Curve n0+ntren(CK[Noe/dead runoffdepthl(NV.,_,,,,,(aro<0nyuud wi(1 and...ahoy(mrdweelerpmetia1. 00*0.te A .__ .004 .4_ c0nut ..,. Diverr tOd lure Omni AOR 0 C.10 0.0u saaR MOWmn 'pe,,,,,,,,,,,, aa0 V.twq'! 0 Vry« 0.x •.., OW 0W 200 0.00 •e,i.,.,, 0.W 0.W 0.56 0.00 tt_ , I wplenw.._,11rM0mlw Ia.pCO las 0. IN.w,00,110$0hw R.0**0+00.awn 0.d.40500• __ _ Ita 1a trv<...T.(w0ntM4.rd verb Aan0NA0dn0100' ewe ter III hdM4d(N•..._.,a a n Sec Noes above 13.01E0 A.0• ,. ♦S.ne •te•. (Sat DSO& Iot *t,� Ill ,,vol«-500.. ...001t.a.r*0,..0 N.4:y1I . 11m am nos .1111 we,u..sen4e,OtOr_1.04-w LL._ .'w •' •* M'* 0 u•••••f.r Vu e,RM. re 00S_+kr,000 000 005 0.00 tI V. O tw4.e-, .Cor til 10 i e, 0 CO 0 be L,-..7/71 I wL0.I ._I.1MrtNnn Minim'non. •V.,,,...,l.r01M.MtIl 000 i.O 0Nret.404000• 00 x0 .01 _.....v..___.._....e. <.- 0va.,,,,s,„Avant..4wa woman* leder i',•Lin ).0 .0 _ Arbntr•CA' I. re 0 n -,re Nates above 00.0•011.“..0' 15010 -91-00;-1-- Cie:» O]sn. 14N«w«3 0100 or n0oeres04 1,0010040 rem... •r,,,,,, ono 0.00 000 0.00 Ru001111.101.000 000 0 0* nou* 0000044 I, ,o *4 0 000......04-00.0008 r*dee.00w0.la 1`000 a.F4'r!_.. 0.00 am am u.W .."".....!...C a,*ow. O. 0100 OW R t 05at( tn.,,,,, I- _ .o _- 2n0R,*0.__x_4.0 gar.,_ 1?3«r 04041._ Ovpn„n,0(••ua.arararN.03..•a.a11AWa0m• 0a! HO 004 11041,,0.we0.0.40004.0 01014.0 l 4010450.0• 000..- 000. 000 A*01N CN• ~ to • • `S«Mull 00000 0e0Atone 40 0.000 r AS. .0. tSO* 0050 { rW Jee.y1re.i 0A0 ' „nahlawnboon w+aa 0,90.0« ono 000 000 040 Runnel R.avTan _..4x7`na've..... Vv...m4 ��yntm,xs_,s=.Wee r.inne0d Zn n an 0 -_0 0.inner ono Ml ne CAS__ 0.W aW O.UD ., ".""'ee/"'°°qn rr Le.nn_ •, om 1•ea5.•0teer - ..n , .1,e.w tam •V4,•,..00.00004 nou*00 n0 Muonn.ee.00n• 000 000" aR •nt, ,.ef...w.N0 we/WId.•u0wN nneNd00•__ 0.04 003 I 0.00 n.lo,red CO 4 a • 0 Wy.S.Aw.OS 500 ASO.* ep.m I (0.04 OSHA ' 1040, HMO«r 000 00.0000m0 Lore u.N,:0l001.ma. ` •,,,,,.0- OW uw Obs 0.m aa.neen.nw w.wtranannen r,.N.n44 w , 17 Ye waw arl o . manwa 7, 4.0+0,01.000.,5,0«a.e.. n0hr•1.41 e1.er, Vw 0W 0.00 0. ..0/00*00a ...._ a .. ... .. .ill.+. ....,... .nee•w.e OW 000 aW W0 1,0000 S[Ons xyea10050^10year seam 00e,a,../water.*00h0 00100.0•00.00*0,0000, 0011 000 000 Avo,,,,.,ON«unMrtN•001010•9111194411a111100. OW one 00) Adpw44 tn. e • • •See Notes above 4 O. Chapter 2 Estimating Runoff Technical Release 55 s Urban Hydrology for Small Watersheds CO (IU E 10 2 �� 'T �V\i A)61:1 ?-2e A MI Table 2-2d Runoff curve numbers for arid and semiarid rangelands 11 mennomm Curve numbers for Cover description -- hydrologic soil group Hydrologic Cover type condition v A3/ B C D Herbaceous—mixture of grass,weeds,and Poor 80 87 93 low-growing brush,with brush the Fair 71 81 89 .. minor element. Good 62 Ott/ 85 Oak-aspen—mountain brush mixture of oak brush, Poor 66 74 79 aspen,mountain mahogany,bitter brush,maple, Fair 48 57 63 and other brush. Good 30 41 48 Pinyon-juniper—pinyon,juniper,or both; Poor 75 85 89 grass understory. Fair 58 73 80 Good 41 61 71 Sagebrush with grass understory. Poor 67 80 85 r Fair 51 63 70 Good 35 47 55 ® Desert shrub—major plants include saltbush, Poor 63 77 85 88 greasewood,creosotebush,blackbrush,bursage, Fair 55 72 81 86 Ipalo verde,mesquite,and cactus. Good 49 68 79 84 1 Average runoff condition,and Ie,=0.2S.For range in humid regions,use table 2-2c. 2 Poor: <30%ground cover(litter,grass,and brush overstory). I Fair: 30 to 70%ground cover. Good: >70%ground cover. 3 Curve numbers for group A have been developed only for desert shrub. I ii I I I I 2-8 (210-VI-TR-55,Second Ed.,June 1986) TR55 Tc Worksheet Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2016 by Autodesk,Inc.v10.5 I Hyd. No. 1 Rivanna Sed Basin I Description A B C Totals I Sheet Flow Manning's n-value = 0.240 0.011 0.011 I Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 5.55 0.00 0.00 Land slope (%) = 2.00 0.00 0.00 I Travel Time (min) = 14.99 + 0.00 + 0.00 = 14.99 Shallow Concentrated Flow t Flow length (ft) = 150.00 0.00 0.00 Watercourse slope (%) = 8.00 0.00 0.00 Surface description = Unpaved Paved Paved II Average velocity (ft/s) =4.56 0.00 0.00 Travel Time (min) = 0.55 + 0.00 + 0.00 = 0.55 .a Channel Flow X sectional flow area (sqft) = 1.87 2.15 0.00 Wetted perimeter (ft) = 5.00 3.74 0.00 Channel slope (%) = 5.00 1.00 0.00 Manning's n-value = 0.035 0.015 0.015 Velocity (ft/s) =4.93 -. 6.85 0.00 Flow length (ft) ({0})520.0 400.0 0.0 Travel Time (min) = 1.76 + 0.97 + 0.00 = 2.73 Total Travel Time, Tc 18.27 min Chapter 3 Time of Concentration and Travel Time Technical Release 55 Urban Hydrology for Small Watersheds Sheet flow For sheet flow of less than 300 feet,use Manning's kinematic solution(Overtop and Meadows 1976)to Sheet flow is flow over plane surfaces.It usually compute Tt: occurs in the headwater of streams.With sheet flow, 80. the friction value(Manning's n)is an effective rough- _0.007(nL) ness coefficient that includes the effect of raindrop Tt (P `0.5604 [eq.3-31 • impact;drag over the plane surface; obstacles such as 21 litter,crop ridges,and rocks;and erosion and trans- where: portation of sediment.These n values are for very shallow flow depths of about 0.1 foot or so.Table 3-1 Tt = travel time(hr), gives Manning's n values for sheet flow for various n = Manning's roughness coefficient(table 3-1) surface conditions. L =flow length(ft) P2 =2-year,24-hour rainfall(in) s = slope of hydraulic grade line Table 3-1 Roughness coefficients(Manning's n)for (land slope,ft/ft) Nommilml sheet flow This simplified form of the Manning's kinematic solu- Surface description n tion is based on the following: (1)shallow steady uniform flow, (2)constant intensity of rainfall excess Smooth surfaces(concrete,asphalt, (that part of a rain available for runoff), (3)rainfall Ale gravel,or bare soil) 0.011 duration of 24 hours,and(4)minor effect of infiltra- Fallow(no residue) 0.05 tion on travel time.Rainfall depth can be obtained Cultivated soils: from appendix B. Residue cover 52095 0.06 Residue cover>20% 0.17 Shallow concentrated flow Grass: Short grass prairie 0.15 After a maximum of 300 feet,sheet flow usually be- Dense grasses .24 comes shallow concentrated flow.The average veloc- Bermudagrass. 0.41 ity for this flow can be determined from figure 3-1,in Range(natural) 0.13 which average velocity is a function of watercourse Woods:2 slope and type of channel.For slopes less than 0.005 ISM Light underbrush 0.40 ft/ft,use equations given in appendix F for figure 3-1. Dense underbrush 0.80 Tillage can affect the direction of shallow concen- trated flow. Flow may not always be directly down the 1 Then values are a composite of information compiled by Engman watershed slope if tillage runs across the slope. (1986). 2 Includes species such as weeping lovegrass,bluegrass,buffalo grass,blue grams grass,and native grass mixtures. After determining average velocity in figure 3 1,use s When selecting n,consider cover to a height of about 0.1 ft.This equation 3-1 to estimate travel time for the shallow is the only part of the plant cover that will obstruct sheet flow. concentrated flow segment. Open channels Illa Open channels are assumed to begin where surveyed cross section information has been obtained,where channels are visible on aerial photographs,or where a blue lines(indicating streams)appear on United States Geological Survey(USGS)quadrangle sheets. Manning's equation or water surface profile informa- tion can be used to estimate average flow velocity. Average flow velocity is usually determined for bank- full elevation. (210-VI-TR-55,Second Ed.,June 1986) 3-3 a 0 1 Channel Report 0c- c im1Jav c_ Hydraflow Express Extension for Autodesk®AutoCAD®Civil 3D®by Autodesk,Inc. Tuesday,Jan 24 2017 Channel 1 East of Site I Triangular Highlighted Side Slopes (z:1) = 3.00, 3.00 Depth (ft) = 0.79 Total Depth (ft) = 1.00 Q (cfs) = 9.000 Area (sqft) = 1.87 Invert Elev (ft) = 1.00 Velocity (ft/s) = 4.81 Slope (%) = 5.00 Wetted Perim (ft) = 5.00 N-Value = 0.035 Crit Depth, Yc (ft) = 0.90 Top Width (ft) = 4.74 Calculations EGL (ft) = 1.15 I Compute by: Known Q Known Q (cfs) = 9.00 I Elev (ft) Depth (ft; Section 3.00 -- 2.00 2.50 1.50 i 2.00Ns,— 1.00 ea v No 1.50 0.50 N. 1.00 -- 0.00 r ift 0.50 -0.50 0 1 2 3 4 5 6 7 8 Reach (ft) Figure B-2 Approximate geographic boundaries for NRCS(SCS)rainfall distributions iii "x i i'f'-'7-7 / ill l IA/ .-1 -i T--- ‘ f � 1 /17 III -T % ' '`' 1 jii___._ -- - '-- A III ' ! ---1 lot � Rainfall •,, ..,„„:,,....: Distribution L �,� '! ,: . MI Type I _.__ r , �t © Type IA y ,• 'y -- = Type II w `\. Ill Type III VA I fpIII id • '0oma in d Rainfall data sources This section lists the most.current 24-hour rainfall data Commerce,National Weather Service,NOAA Atlas 2. published by the National Weather Service(NWS)for Silver Spring,MD. various parts of the country.Because NWS Technical Paper 40(TP-40)is out of print,the 24-hour rainfall Alaska .. maps for areas east of the 105th meridian are included Miller,John F. 1963.Probable maximum precipitation here as figures B-3 through B-8.For the area generally and rainfall-frequency data for Alaska for areas to 400 west of the 105th meridian,TP-40 has been superseded square miles,durations to 24 hours and return periods by NOAA Atlas 2,the Precipitation-Frequency Atlas of from 1 to 100 years.U.S.Dept. of Commerce,Weather .. the Western United States,published by the National Bur.Tech.Pap. No.47. Washington,DC.69 p. Ocean and Atmospheric Administration. Hawaii East of 105th meridian Weather Bureau. 1962.Rainfall-frequency atlas of the Hershfield,D.M. 1961.Rainfall frequency atlas of the Hawaiian Islands for areas to 200 square miles,dura- United States for durations from 30 minutes to 24 tions to 24 hours and return periods from 1 to 100 hours and return periods from 1 to 100 years.U.S. years.U.S. Dept.Commerce,Weather Bur.Tech.Pap. . Dept.Commerce,Weather Bur.Tech.Pap.No.40. No.43.Washington,DC.60 p. Washington,DC. 155 p. Puerto Rico and Virgin Islands West of 105th meridian Weather Bureau. 1961.Generalized estimates of prob- .. Miller,J.F.,R.H. Frederick,and R.J.Tracey. 1973. able maximum precipitation and rainfall-frequency Precipitation-frequency atlas of the Western United data for Puerto Rico and Virgin Islands for areas to 400 States.Vol.I Montana;Vol. II,Wyoming;Vol III,Colo- square miles, durations to 24 hours,and return periods - rado;Vol.IV,New Mexico;Vol V,Idaho;Vol.VI,Utah; from 1 to 100 years.U.S. Dept. Commerce,Weather Vol.VII, Nevada;Vol.VIII,Arizona;Vol.IX,Washing- Bur.Tech.Pap. No.42. Washington,DC.94 P. ton;Vol.X,Oregon;Vol.XI,California. U.S. Dept.of B-2 (210-VI-TR-55,Second Ed.,June 1986) Precipitation Frequency Data Server Page 1 of 4 I NOAA Atlas 14,Volume 2,Version 3 Location name:Charlottesville,Virginia,USA° Latitude:38.0253°,Longitude:-78.6538° . 0 Elevation:662.27 ft** I 'source.ESRI Maps t' -source source'.USGS POINT PRECIPITATION FREQUENCY ESTIMATES G M Bennis,D Martin,B Lin.T Parzybok,M Yekla,and 0 Riley I NOM,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials PF tabular I PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches)1 Acurrence interval(years) l verage re Durations 1 I 2 I 5 I 10 25 II 50 II 10011-1073-1-5-61)-11---7-1000 5-min 0.3430.410 0.483 0.544 0.614 0.668 0.719 0.767 0.825 0.873 (0.310.0.381)(0.371-0.454)((0.436.0.534)(0.490-0.601)I(0.550-0.676)(0.596.0.736),(0.637.0.793)40.674.0.847)(0.717-0.915)(0.750-0.973) - 10-min 0.648 0.656 0.774 0.870 0.978 1.06 1.14 1.22 1.31 1.37 ' (0.496.0.608)(0.594-0.727)(0.699.0.855)(0.784-0.960) (0.877-1.08) (0.949.1.17) (1,01.1.26) (1.07-1.34) (1,13-1.45) x(1.18-1.53) 15-min 0.686 0.826 0.979 1.10 1.24 1.36 1.44 1.54 1.64 1.73 (0.620-0.760)(0.747-0.913 (0.884-1.08) (0.992-1.22),, (1.11-1.37) (1.20-1.48) (1.28.1.59) (1.35-1.70) (1,43-1.82) (1.48-1.92) I 30-min 0.940 1.14 1.39 1.69 1.84 2.03 2.21 2.39 2.61 2.79 (0.849-1.04) (1.03-1.26)I (1.26-1.54) (1,44-1.76) (1.65-2.02) (1.81-2.24) (1.96-2.44) (2.10-2.64) (2.27-2.90) i2 1t 1.17 1.43 1.78 2.08 2.46 2.76 3.05 3.36 3.76 4.08 I 60-min (1.06-1.30) (1.29-1.58) (1.61-1.97) (1.87-2.29) (2.19-2.70) (2.45.3.03) (2.70-3.36) (2.95-3.70) (3.26-4.16)Ir 4.08 j 2-hr 1.40 1.70 2.14 2.51 3.00 3.40 3.81 4.24 4.84 6.34 (1,25-1.59) (1.51-1.92) (1.90-2.41) (2.23-2.83) (2.64-3.37) (2.98-3.82) (3.32.4.28) (3.66-4.77) , (4,12-5.45) (4-49-6.04) 3-hr 1.54 1.87 2.34 2.74 3.28 3.72 4.18 4.66 6.33 6.89RI (1.36-1.75) (1.65-2.12) (2.06-2.66) (2.42-3.11) (2.87-371) (3.24-4.21) (3.62.4.73) (4.00-528) (4.50.5.05) (4.92.6.71) 6-hr 1.99 2.40 2.98 3.61 4.22 4.86 5.60 6.20 7.21 8.10al (1,77-2.24) (2,14-2.71) (2.65-3,36) (3,10-3.96) (3.714.75) (4.22-5.44) (4.74-6.18) (5.28.6.98) (6.04-8.14) (6.68-9.17) 12-hr 2.52 3.04 3.79 4.49 5.46 6.33 7.27 8.31 9.84 11.2 (2.24.2.87) (2.70-3.46) (3.35-4.32)I (3.95-5.10) (4.77-6.19) (5.46.7.17) (6.19-8.24) (6.98-9.42) (8.09.11.2) (9.07-12.8) 24-hr 3.05 3.694.70 5.55 6.81 7.89 9.07 10.4 12.3 14.0 (2,74-3.41) (3.32.4.13)I (4.22-5.26) (4.96-6.20) (6.04-7.59) (6.95-8,77) (7.92-10.1) (8.96-11.5) (10.5-13,7) (11.7-15.5) 1111 2-day 3.69 4.36 6.62 6.48 7.88 10.3 13.7 16.4 � (3.23-4.01) (3.91.4.86) (4.96-6.16) (5.80-7.23) (7.00-8.76) (7368.-0160.0) (9.02-11.5) (10111-.173,0) (11.7-15.3) (13.0-17,2) 3-day 3.82 4.63 6.87 6.89 8.36 9.59 10.9 12.4 14.5 16.2 (3.46-4.24)1 (4.195.14) (5.31-6.51) (6.22-7.63) (7,50-9.25) (8.55-10.6) (9,66-12.1) (10.9-13.7) (12.5-16.0) (13.9-18.0) F4-day 4.06 4.91 6.22 7.29 8.84 10.1 11.5 13.0 15.2 17.1 _ (3.704.48) (4A8.5.41) (5.67-8.86) (6.63-8.03) (8,01-9.74) (9.12-11.2) (10.3-12.7) (11.6-14.4) (13.4-16.8) (14.8-18.9) 7-day 4.70 6.66 7.07 8.23 9.87 11.2 12.7 14.2 15.5 18.3 L ,j (4.31-5,14) (5.19.6.19) (6.47.7.73) (7.51.8.99) (8,97-10.8) (10.1-12.3) (11.4-13.9) (12.7-15.6) (14.5.18.1) (15.9-20.2) 11 FO-day 6.34 .W _ 6.40 7.90 9.10 10.8 12.1 13.6 16.1 17.2 19.0 LLL (4.91-5.79) (5.90.6.94) r(7.27.8.55) (8.35-9.85) 19.85-11.7) (11.0-13.2) a(12.3-14.7) (13.6-16.4) (15.3-18.7) (16,7-20.7) NI 20-dad ( 7.00 8.35 10.1 11.4 13.3 14.7 16.2 17.7 19.7 21.3 6.54.7.53) 17.80.8.97) (9.40.10.8) (10.6.12.3) (12.3-14.2) (13.6-15.8) (14.9.17.4) (16.2-19.0) (17.9-21.3) (19.2-23.0) 0-day 8.60 10.2 12.0 13.4 15.3 16.7 18.0 19.4 21.1 22.4 L3-.. (8.07.9.17) (9.57-10.9) (11.3-12.8) (12.6-14.3) (14.3-16.3) (15.5.17.881 (16.8-19.2) (17.9-20.7) (19.5-22.7) (20.6-24.1) 1. 45-day 10.7 12.7 14.8 16.4 18.4 19.9 21.4 22.7 24.6 26.9 (10.1-11.4) (12.0-13.5) (13.9-15.7) (15.4-17.4) (17.3-19.5) (18.7-21.1) (20.0-22.7) (21.2-24.2) (22.7-26.2) (23.9-27.7) 60-day 12.6 14.8 17.1 18.8 20.9 22.4 23.9 25.3 27.1 28.4 (11.9-13.3) (14.0-15.6) (16.1-18.0) (17.7-19.8) (19.7-22.0) (21.1-23.7) (22.5-25.3) (23.7-26.8) (25.3-28.7) (26.4-30.2) 'Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). NA Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates (for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. _ .__ Back to Top r r MIN i http://hdsc.nws,noaa.gov/hdsc/pfds/pfds_printpage-html?tat=38.0253&ton=-78.6538&dot.-. 11/21/2016 atm Precipitation Frequency Data Server Page 2 of 4 AIM 4111. PF graphical PDS-based depth-duration-frequency(DDF)curves Latitude:38.0253°,Longitude:-78.6538° a. 30 - r I r II I r r III if III Average recurrence 25 - interval me f (years) La 20 /..._.7,,..<„,,,,..„,„„V------- 2 /7; a5 rim -0 0 •+ / - 26 f ra — 50 10 M! - _r - 100 N a — 200 5 500 yY_.'��.:".�:- ..._ — 1000 0 - r--:- 1 1 I I t I 1 III t 1 II INN C C C C C L tLT r,A >, T T T >,7• . E _ E L fr4LD N V � r�am 'm m m m Z m rr1 m 2 O d '"� N N fel n "r ry rr1 O O O V t� DurationOM 30 i r ! I r I I 25 - r� i C r20 - �,,;..•----"�' _ Duration iu 5 — 2--day v -- 1 to _-- 3-day 'WIL _ 15-min -- 4-day �. s"„�~ `� 30-min — 7-day 10 � r '',,. — 60 rtun — 1D day 2-hr — 20-day IIS s_.�.. —-_.— 3-hr — 30-day — 6-ttr — 45-day — 12-hr — 50-day 0 t __— r I __,...y 24-hr 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval(years) I NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Mon Nov 21 16:29.22 2016 Back to Top I I I I JIM http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0253&lon=-78.6538&dat... 11/21/2016 Precipitation Frequency Data Server Page 3 of 4 I Maps&aerials I Small scale terrain I I* , J MOUNTAIN J I 101•1111 NNW I f,.....,' x . I. — I patesville Jkosii ILarge scale terrain - '.• ' WiShingt011,D. , .. ,. rsarrisorkurg, t ' „ . Stsuinit L VIRGINIA '41A ' . Rich .44, . , . Lynchburg 4.r. P tm 1 I %dc sil urt (,,.. Roanoke letThip ., k (lbw N. I w. Large scale map 'ycro \ , Washington 4 I I r 1:i.wrisonbing fftialrat ONO•OUP Richt I Lyn chk.urg Black„Awry Roanoke t nOkon / Ii He bool I I I http://hdsc.nws.noaa.gov/hdsc/Pfds/pfdsprintpage.html?lat=38.0253&lon=-78.6538&dat... 11/21/2016 ea Precipitation Frequency Data Server Page 4 of 4 Large scale aerial - Z ,Watilincit,in i i �m�Mws u}LJJ Pi — 1 KIiL....I c l t f Back tc lop WIII 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.Questionsertoaa.rwv Disclaimer aro http://hdsc.nws.noaa.gov/hdsc/pfds/pfdsprintpage.htm 1?lat=38.0253&lon=-78.6538&dat... 11/21/2016