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HomeMy WebLinkAboutAPA2565FINAL REPORT J~tiCE 'VED I' MAR 151985 ~POWmAUlltOR(l! FEBRUARY 1985 DOCUMENT No.2565 DRAIN"AGE STRUCTURE AND WATERWAY DESIGN GUIDELINES FEDERAL ENERGY REGULATORY COMMISSION PROJECT No.7114 SUSITNA HYDROELECTRIC PROJECT ';""';';':','".;_.i ,,',.,'.....~,.•' ;:',:"~ .'~~~L%=[§~~@©@ ITNAJOINT VENTURE :.J '. "~~ALASKA POWER AUTHORITY~-.j - - Document No.2565 TK \L\~ ·s~ r-=L-\1-~ Vlo ,::5 ( SUSITNA HYDROELECTRIC PROJECT DRAINAGE STRUCTURE AND WATERWAY DESIGN GUIDELINES Report by Harza-Ebasco Susitna Joint Venture Prepared for Alaska Power Authority I""", ! i I Final Report February 1985 ARLIS Alaska Resources Library &Information Services Anchorage,Alaska ..... I .... ..... - ..... - , \ ANY QUESTIONS OR COMMENTS CONCERNING THIS REPOR~SHOULD BE DIRECTED TO THE ALASXA POWER AUTHORITY SUSI'ftiA PROJECT OFFICB - -TABLE OF CONTENTS SECTION/TITLE 1.0 INTRODUCTION 1.1 Setting 1.2 Scope 1.3 Stage 1 Pre-Project Field Investigations PAGE 1-1 1-1 1-1 1-2 1.3.1 1.3.2 Engineering Activities Environmental Science Activities 1-2 1-3 1.4 Stage II Project Construction 2.0 FLOW DETERMINATION 2.1 General 2.2 Gaged Watercourses 2.3 Ungaged Watercourses 1-3 2-1 2-1 2-1 2-4 2.3.1 2.3.2 2.3.3 2.3.4 General Runoff Coefficient Drainage Area Rainfall Intensity 2-4 2-5 2-7 2-7 2.4 Example Peak Discharge Determination 2-10 2.5 Alternative Method for Determination of Minimum,Mean Annual and Flood Discharges 2-13 - 3.0 HYDRAULIC DESIGN 3.1 Introduction 3.2 Fish Passage Problems 3-1 3-1 3-1 Drainage Structure Design Criteria Waterway Hydraulics - r o 1.0 N I"'- (0 M ooo 1.0 1.0 I"'- M M 3.3 3.4 30222/TOC 841109 3.2.1 3.2.2 3.2.3 3.2.4 3.4.1 3.4.2 Excessive Water Velocity Inadequate Water Depth Excessive Hydraulic Jump Guidelines for Structures General Waterways -i- 3-2 3-2 3-4 3-4 3-5 3-7 3-7 3-7 ARLIS Alaska Resources Library &Information SerVices i\nchorage,AJaska TABLE OF CONTENTS (cont'd) Sl!;CTION/TITLE 3.4.2.1 Permissible Non-erodible Velocity Method 3.4.2.2 Tractive Force Method 3.4.3 Culverts PAGE 3-12 3-15 3-24 3.4.3.1 3.4.3.2 3.4.3.3 3.4.3.4 3.4.3.5 3.4.3.6 3.4.3.7 3.4.3.8 3.4.3.9 3.4.3.10 3.4.3.11 3.4.3.12 3.4.4 Bridges 3.4.4.1 3.4.4.2 3.4.4.3 3.4.4.4 REFERENCES Fish Passing Requirements Scope of Guidelines Culvert Hydraulics Culverts Flowing with Inlet Control Culverts Flowing with Outlet Control Computing Depth of Tailwater Velocity of Culvert Flow Inlets and Culvert Capacity Procedure for Selection of Culvert Size Inlet Control Nomographs Outlet Control Nomographs Performance Curves General Hydraulics of Constrictions in Watercourses Procedure for Design of Bridge Waterway Example 3-24 3-25 3-26 3-27 3-29 3-39 3-40 3-42 3-43 3-50 3-59 3-75 3-81 3-81 3-81 3-89 3-102 4-1 ....APPENDIX A PROJECT DRAWINGS APPENDIX B RAINFALL FREQUENCY DATA FOR ALASKA APPENDIX C TRACTIVE FORCE METHOD OF CHANNEL DESIGN USING MOST EFFICIENT SECTION A-I B-1 C-l 30222/TOC 841109 -ii- - .- ..... No" 2.3.1 2.3.2 3.2..1 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 30222/TOC 841109 TABLES TITLE Values of Relative Imperviousness Runoff Coefficients "c" Average Cross Sectional Velocities in Feet/Second Measured at the Outlet of the Culvert Typical Channel Roughness Coefficients Channel Roughness Determination Recommended Permissible Velocities for Unlined Channels Entrance Loss Coefficients Key to Tables for C'and k Values for Each Constriction Type -iii- 2-5 2-6 3-3 3-10 3-11 3-13 3-33 3-87 .... ..... ..... .... i i No. 2.3.1 2.3.2 2.3.3 2.3.4 3.4.1 3.4.2 3.4.3 3.4.4 .3.4.5 - 3.4.6 3.4.7 3.4.8 3.4,,9 3.4 ..10 3.4,,11 3.4 ..12 3.4"13 3.4.14 3.4"15 3.4.16 3.4.17 30222/TOC 841109 FIGURES TITLE Tc Nomograph for Small Watersheds Tc Nomograph for Large Watersheds Upland Method Velocity Determination Time of Concentration vs Intensity Waterway Cross Section Measurement Recommend Permissible Unit Tractive Force for Canals in Noncohesive Material Permissible Tractive Force for Coarse Noncohesive Material Angles of Repose of Noncohesive Material Tractive Force Ratio K vs Side Slope The Maximum Tractive Force on Bed and Sides Inlet Control Outlet Control Culvert Hydraulics Diagram Culvert Outlet-Submerged Culvert Outlet-Low Tailwater Hydraulic Performance Curves for 48-Inch C.M.Pipe Culvert with Projecting Inlet Definition Sketch of Flow through Constriction Constriction Types Type I Opening,Vertical Embankment,Vertical Abutment Subrupts ~&k 0 Curves for Vertical Embankment and Abutment of Type I Opening Type II Opening,Embankment Slope 1 to 1,Vertical Abutment -iv- 2-8 2-9 2-10 2-11 3-8 3-19 3-20 3-21 3-22 3-23 3-28 3-30 3-35 3-38 3-39 3-77 3-82 3-83 3-92 3-93 3-94 ..... .,.,. ..... I I r ! r- I No. 3.4.18 3.4.19 3.4.20 3.4.21 3.4.22 3.4.23 3.4.24 3.4.25 3022:2!TOC 841109 FIGURES (cont'd) TITLE Type II Opening,Embankment and Abutment Slope 2 to 1, Vertical Abutment Type III Opening,Embankment and Abutment Slope 1 to 1 Type III Opening,Embankment and Abutment Slope 2 to 1 Type IV Opening,Embankment Slope 1 to 1,Vertical Abutment with Wing Walls Type IV Opening,Embankment Slope 2 to 1,Vertical Abutment with Wing Walls Types I-IV Openings,k e , k t and k j curves The Effect of Channel Roughness on the Backwater Ratio for Basic -Type Constrictions The Effect of Constriction on the Backwater Ratio -v- 3-95 3-96 3-97 3-98 3-99 3-100 3-101 3-101 - CHART NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 DESIGN CHARTS TITLE Headwater Depth for Box Culverts with Inlet Control Headwater Depth for Concrete Pipe Culverts with Inlet Control Headwater Depth for Oval Concrete Pipe Culverts with Long Axis Horizontal with Inlet Control Headwater Depth for Oval Concrete Pipe Culverts with Long Axis Vertical with Inlet Control Headwater Depth for C.M.Pipe Culverts with Inlet Control Headwater Depth for C.M.Pipe Arch Culverts with Inlet Control Headwater Depth for Circular Pipe Culverts with Bevelled Ring Inlet Control Head for Concrete Box Culverts Flowing Full n=.012 Head for Concrete Pipe Culverts Flowing Full n=.012 Head for Oval Concrete Pipe Culverts Long Axis Horizontal or Vertical Flowing Full n=.012 Head for Standard C.M.Pipe Culverts Flowing Full n=.024 Head for Standard C.M.Pipe Arch Culverts Flowing Full n';'.024 Head for Structural Plate C.M.Pipe Culverts Flowing Full n=0.0328 to 0.0302 3-52 3-53 3-54 3-55 3-56 3-57 3-58 3-62 3-63 3-64 3-65 3-66 3-67 14 Head for Structural Plate C.M.Pipe Arch Culverts 18 ~n. Corner Radius Flowing Full n=0.0327 to 0.0306 3-68 - .... 15 16 17 30222/TOC 84H09 Q/B vs d c Critical Depth Circular Pipe Critical Depth Oval Concrete Pipe Long Axis Horizontal -vi- 3-69 3-70 3-71 ·",.. - -I ..- CHART NO. 30222/TOC 841109 DESIGN CHARTS (cont'd) TItLE -vii- 3-72 3-73 3-74 INTRODUCTION .... "... .- .- ..- DRAINAGE STRUCTURE AND WATERWAY DESIGN GUIDELINES 1.0 INTRODUCTION 1.1 SETTING This manual is.intended to be used by design engineers during the preparation of contract plans and specifications for Alaska Power Authority projects.The guidelines in the manual incorporate standard engineering practices and procedures,and also address Alaska Department of Fish and Game 1981 proposed habitat regulations where appropriate.Although the manual is organized 1n such a way that it is applicable to any Alaska Power Authority project in general,nevertheless it contains much detailed information which can be used directly 1n the preparation of contract documents for a specific project. 1.2 SCOPE The purpose of these best practices guidelines 1S to establish the proper procedures for design of drainage structures and waterways required for implementation of a construction project for the Alaska Power Authority. Drainage structures considered in these guidelines will consist of culverts, waterways,and the waterways beneath bridges which are required to implement temporary or permanent access to project features.The drainage structures and pertinent waterway work will be classified by the type of fish utilization that occurs in the watercourse where the project feature is proposed.These types are: Type A:Watercourse that is used by anadromous fish during any period of the year. Type B:Watercourse that is utilized by resident fish during any period of the year. 30222/1 841109 1-1 :.... - - - - ,.... Type C:Watercourse that has no history of being used by anadromous or resident fish. WSiterway work for Type A and B watercourses wi 11 be limited to the necessary adljustments in the watercourse at the inlet and outlet of the drainage structure to assure efficient hydraulic conditions,fish movement,and to preclude deleterious sediment transport or deposition in or around the drainage structure.Waterway work for Type C watercourses can in some cases be:more extensive in that a collector system may be required to channel surface runoff to the watercourse in question.A typical example of this is all interceptor ditch along a roadway or waterway work associated with diverting the watercourse during the construction of the drainage structure. The watercourse work will be divided into two distinct stages.Stage I will be the field investigations and design.During this stage,site specific investigation results and design criteria will be presented to secure the necessary permit s.Stage II wou ld be the construction of the drainage structure or waterway. 1.3 STAGE I PRE-PROJECT FIELD INVESTIGATIONS During the feasibility and licensing phase,certain investigations will be necessary to design and construct the Project.All such activities would be conducted under the applicable technical and regulatory permits required by Federal,State.and/or local authorities. 1.3.1 Engineering Activities The principal activity during this stage would be subsurface exploration for the major project features. The geotechnical explorations will include subsurface drilling.monitoring, dozer or backhoe excavation of inspection trenches,geophysical surveys and investigation of quarry materials and borrow materials.The above -30222/1 841109 1-2 .... activities (except for quarry and borrow area development)can be ac.complished with light equipment,helicopter transport or with special ground transport equipment.Whereas quarry and borrow area development may require heavier equipment and access crossing natural waterways or earthwork which could impede drainage courses.In these instances drainage structures will be designed and constructed using the criteria established in Section 2.0 and 3.0 of these guidelines. 1.3.2 Environmental Study Activities Environmental science activities will consist of aquatic,terrestrial,and cultural resource field investigations. Environmental science activities involve almost all areas of the Project. The biological studies encompass both aquatic and terrestrial programs.The aquatic studies are conc.entrated mainly on rivers.In addition, tributaries,lakes within the proposed project areas and streams along any proposed access road would be studied.The primary terrestrial study area would include portions of the Basin that lie within reasonable proximity to the river in question.In addition,studies would be conducted within the river floodplain.Cultural resource studies would be conducted primarily in the vicinity of project construction areas and along access and transmission line routes • Th,ese activities will not involve ground distrubance nor require culverts or bridges;hence waterways and drainage courses will not be affected. l..!j.STAGE II PROJECT CONSTRUCTION Thle Alaska Power Authority and their engineering consultant wi 11 prepare engineering design memoranda,construction drawings and specifications for thie project features.In project features requiring drainage structures or waterways,the technical criteria presented in these guidelines wi 11 be ineorporated,and used in the design memoranda,and construction contract dOl:uments. 30222/1 841109 1-3 .~FLOW:DE_TERMINATION ;,.... ,.... -- ,...,. ..... - ..... 2.0 FLOW DETERMINATION 2.1 GENERAL In this section,the methodologies for determining the flow in a waterway for a specified recurrence frequency are discussed. 2.2 GAGED WATERCOURSES The U.S.Geological Survey,1.n cooperation with the Alaska Department of Transportation and Public Facilities and other State and Federal Agencies, maintains a network of stream gaging stations and crest gages throughout the State of Alaska.The data obtained from these programs is published in Water Resources Data for Alaska,Part 1,Surface Water Records (USDOI 1984). The U.S.Geological Survey has published computer print-outs of frequency- discharge curves for all stations with satisfactory length of record.Data obt,ained from the stream gaging program has been used to formulate a report that presents regional flood frequency curves for most sites in Alaska.The publication contains magnitude and frequency of floods in Alaska south of the Yukon River (USDOI 1964). In the case where a site 1.S being investigated on a waterway that has a gage and historical records of flow,the drainage area above the construction sitl~will be compared with that above the gage to determine if there is compatibility in the factors that affect runoff for the two areas.Factors that affect runoff can be grouped into two major categories;climatic,which for the purposes of these guidelines may have little or no incidence,and physiographic.Climatic factors mainly include the effects of ral.n, temperature,and evapotranspiration,all of which exhibit seasonal changes in accordance with the climatic environment.Physiographic factors may be further classified into two kinds:basin characteristics and channel charac~eristics.Basin characteristics include such factors as size,shape, and slope of drainage area,permeability and capacity of groundwater reservoirs,presence of lakes and swamps,land use,etc.Channel - 30222/2 8412'.18 2-1 characteristics are related mostly to hydraulic properties of the channel which govern the movement and configuration of flood waves and develop the storage capacity.It should be noted that the above factors are inter- dependent to a certain extent.For clarity,the following is a list of the major factors: Meteorologic factors 1)Rainfall -2) 3) 4) a)Intensity b)Duration c)Time distribution d)Areal distribution e)Frequency f)Gl;!ographic location Snow Temperature Evapotranspiration - - Physiographic factors Basin Characteristics a)Geometric factors 1.Drainage area 2.Shape 3.Slope 4.Stream density 5.Mean Elevation b)Physical factors 1.Land use or cover Surface infiltration condition Soil type Geological condition,such as the permeability and capacity of groundwater reservoir 5.Topographical condition,such as the presence of lakes, 2. 3. 4. swamps,and glaciers • .... 30222/2 841218 2-2 a) 2)Channel characteristics Carrying capacity,considering size and shape of cross sec- tion,slope,and roughness b)Storage capacity If there is no significant difference 1n these factors for both drainage areas above the site or above the existing gage,the flow at the site can be computed for the specified frequency by multiplying the gaged flow by the ratio of the square roots of drainage areas. As 1/2 Ag 1/2 (Kirpich and Williams ) - ..... ,- - Qs =Site flow Qg =Gage flow As =Site drainage area Ag =Gaged drainage area In cases where ~ompatibility in the factors cannot be readily ascertained, the staff hydrologist should be consulted.If the staff hydrologist is not available,the flow determination may be made using the methodology for ungaged watercourses outlined in the succeeding paragraph.A comparison of the flows resulting from both methods should be made and the higher of the two values should be used unless the staff hydrologist recommends otherwise. 30222/2 841218 2-3 2.3 UNGAGED WATERCOURSES 2.21.1 General The,relation between rainfall and peak runoff has been represented by many emp,irical and semiempirica1 formulas.The rational formula which will be used in these guidelines can be taken as representative of these formulas. The rational formula is: Q =CIA (Mulvaney 1851) - I""'" I where Q is the peak discharge ~n cubic feet per second (cfs),C a runoff coefficient dependent on the physiographic conditions of the drainage area, the average rainfall intensity (I)in inches per hour and A is the drainage area in acres. In using the rational formula it is assumed that the maximum rate of flow, due to a rainfall intensity over the drainage area,is produced by that rainfall intensity being maintained for a time equal to the period of con- centration of flow at the point under consideration (T c )' The elements involved in runoff are far more complicated than the rational formula indicates.In larger drainage areas the temporary storage of storm water in overland travel toward stream channels and in these channels them- selves accounts for a considerable reduction in the peak discharge rate.It is for this reason the Alaska Department of Highways recommends that use of this method be restricted to drainage areas less than 200 acres unless no other method is available to estimate discharges. The remainder of this section will be dedicated to quantifying the para- meters used in the rational formula. 30222/2 841:218 2-4 - - .... 2.3.2 Runoff Coefficient The!rational formula runoff coefficient (C)is the ratio of runoff to the ave~rage rate of rainfall at an average intensity when all the drainage area is contributing.Since this is the only manipulative parameter in the rational formula,judgement in its selection should reflect the physiogra- phic factors listed in paragraph 2.2. Table 2.3.1 presents values of relative imperviousness for various surfaces • In Table 2.3.2 the runoff coefficient C can be determined by weighting phy'siographic factors (watershed characteristics)and summing them. Table 2.3.1 Values of Relative Imperviousness ..... Type of Surface For all watertight roof surfaces For asphalt runway pavements For concrete runway pavements For gravel or macadam pavements *For impervious soils (heavy) *For impervious soils,with turf *For slightly pervious soils *For slightly pervious soils,with turf *For moderately pervious soils *For moderately pervious soils,with turf Factor C 0.75 to 0.95 0.80 to 0.95 0.70 to 0.90 0.35 to 0.70 0.40 to 0.65 0.30 to 0.55 0.15 to 0.40 0.10 to 0.30 0.05 to 0.20 0.00 to 0.10 *For slopes from 1%to 2%(American Iron and Steel Institute 1983) ~To account for antecedent precipitation conditions,as reflected by the fre- quency of the selected rainfall intensity,a correction factor Ca (Amer- ican Iron and Steel Institute 1983)should be multiplied with the runoff coefficient C. below: Values of Ca for various recurrence intervals are listed Recurrence Interval (Years) 2 to 10 25 50 100 .£a 1.0 1.1 1.2 1.25 In no case should the product C x Ca exceed 1. 30222/2 841218 2-5 1 1 1 1 '--I I 1 J 1 -1 1 j Thble 2.3.2 RUNOFF COEFFICIENTS "c"(ADOTPF ) Runoff producing Characteristics of Watershed With Corresponding Weights Percent of Watershed N I 0\ Designation of Watershed Characteristics Relief Soil Vegetal cover Surface Storage Extreme 75 to 100% (40) Steep s rugged terrains with average slopes generally above 30%. (20) No effective soil cover; ~ither rock or thin soil mantle of negligible in- filtration capacity. (20) No effective plant cov- er;bare or very sparse cover. (20) Negligible s surface de- pressions few and shal- low;drainageways steep and small;no ponds or marshes. High 50 to 75% (30) Hilly s with average slopes of 10 to 30%. (15) Slow to take up water; clay or other soil low infiltration capacity. (15) Poor to fair;clean- cultivated crops or poor natural cover; less than ,10%of drainage area under good cover. (15) Low;well-defined sys- tem of small drainage- ways;no ponds or marshes. Normal 30 to 50% (20) Rollings with average slopes of 5 to 10%. (10) Normal;deep permeable soils. (10) Fair to good;about 50%of drainage area in good grasslands woodlands or equiva- lent cover;not more than 50%of area in clean-cultivated crops. (10) Normal;considerable surface depression storage;drainage sys- tem similar to that of typical prairie lands; lakes s ponds s and marshes less than 2% of drainage area. Low 25 to 30% (10) Relatively flat lands with average slopes of 0 to 5%. (5 ) High;sands,loamy sands and other loose,open soils. (5) Good to excellent;about 90%of drainage area in good grasslands woodland, or equivalent cover. (5) High;surface depression storage high;drainage system not sharply defined; large floodplain storage or a large number of lakes, ponds,or marshes. -~ r ! 2.3.3 Drainage Area ThE!drainage area,~n acres,which contributes to the site for which the dincharge is to be determined,can be calculated from a topographic map or from measurements taken in the field.If the former is used,a site visit shcluld be programmed to gather information to be used in determining the rUllOff coefficient C and the parameters that will affect the value of the selected rainfall intensity.Also,the site visit,literature review and di~icussions with fisheries resource managers should be used to ascertain the type of water course (see 1.2 Scope). 2.3.4 Rainfall Intensity Rai.nfall intensity,tor the drainage area in question can be estimated for specific recurrence intervals (frequency)from the isohyetal maps ~n Appendix B.The average rainfall I used in the rational formula depends Up<liU size and shape'of the drainage area,the land slope,type of surface, whe,ther flow is overland or channelized as well as the rainfall intensity. The former factors are instrumental in determining the time of concentration (T c)for the drainage area. The theory underlying the development of the rational formula is that the maximum discharge at any point in a drainage system occurs ,when: 1.The entire area tributary to the point is contributing to the flow. ~ I, 2. 30222/2 841218 The average rainfall intensity producing such flow ~s based upon the rainfall which can be expected to fall in the time required for water to flow from the most remote point of the area to the point being investigated.The "most remote point"is the point from which the time of flow is greatest.It may not be at the greatest linear distance from the point under investigation. 2-7 Nomographs for the determination of time of concentration T c for small and 1aI'ge drainage areas are presented in Figures 2.3.1 and 2.3.2 respectively. The:se nomographs utilize the length of travel (L)in feet and the difference in elevation (H)in feet between the beginning and end point. Tc,min 200 150 100 80 L,ft 10,000 60 50 40 5,000 30 c 25~o .2 20........~2,000 '"'"C 15u 1,500 ::! 1,000 ~10 '0 8-u--E i=6 500 5 4 300 3 200 150 2 100 EXAMPLE Hei,",~IOOft Len;t"'!'3,OOOft Time of concentration -14 Min 10 2 100 ................ ................E~PlE '""'................ ......-u>No~:~ UN nomOQroph Tc for natural ~ boslns with well defined channels.0 for overland flow on bar.-= earth.and for mowed graM rood-g' side channels ~ For over land flow,;rassed sur -g fac...multiply Tc by 2__.5 5 For oyerJand flow,cmfCrete or ~ ..-iiPhOit surfaces,multiply Tc ~ by 0 .... For concrete channels,multiply Tc by 0.2 ii ~ 0•>0 ~-<c '0 It. .! 0e "r--i "0; I 0~ '0 I""":c i 01 i ·'i :E: Bued on stud,b)'P.Z,lCirpicll, Ci"il Eng;n•.,infl.Vol.10,No.6.Jun.19"O,p.~62 Fig.2.3.1 Te Nomograph for Small Watersheds F'(Kirpich 1940 ) 30222/2 841218 2-8 10 40,000 10 8 30,000 6....204 20,000 3 30 2 III..40=10,000 0.: 1.0 .5 8,000 .8 u---I--__.6 80 ~6,000 -----_Exampi4 ---_e 100 =.---- 4,000 3 ---==..i 3,000 .2.... 200 2,000 0.1 300 ......400 1,000 BOO Example 600-L=1,250 ft 800600H=130ft then Tc =0.51 hr 1,000 .....Fig.2.3.2 Tc Nomograph for Large Watersheds (Kirpich 1940 ) The time of concentration of the preceeding nomographs may be calculated by the following equation: .... =.0078 [ _L J0.77 1fHiL (Kirpich 1940) where T 1S in minutes.The T calculated by the preceeding methodscc assumes a natural drainage basin with well defined channels,for overland flow on bare earth.and for mowed grass road side channels.If the overland-flow is on grassed surfaces multiply the Tc by 2.For overland flow on concrete or asphalt surfaces multiply T by 0.4.For concrete channels,c r-multiply Tc by 0.2. Alternatively travel times for overland flow 1n watersheds with a variety of land covers can be calculated by the Uplands Methods.(See Figure 2.3.3). The individual times are calculated from the velocity for e~ch ground cover slope.subarea and the summation of the time giving the time of concentration Tc • 30222/2 841218 2-9 .... --, i BIir-...s•I jlI:IlIllaI! .... ...-, Figure 2.3.3 Upland Method Velocity Determination (American Iron and Steel Institute 1983 ) With the time of concentration calculated and the rainfall intensity for the area selected (Appendix B)the average rainfall intensity for the drainage area may be determined using Figure 2.3.4.The curve for the selected one hour rainfall is followed to the right or left until reaching the calculated time of concentration and the average rainfall intensity (I)can be determined. 2.4 EXAMPLE PEAK DISCHARGE DETERMiNATION As an example of the use of the Rational Method,a hypothetical drainage are!a and its characteristics are used • 30222/2 841218 2-10 1 1 -1 1 ~'1 '1 '~]J ---J 11 '-'1 1 .•i,, M~HiH' 2 I II I I. I 'OOlIJlftIlJ .3 .1"""""1"" ·-4l fIll'4~1.,.·11.1'1'......'i J.2_ N I........ FIGURE 2.3.4 (ADOTPF ) -~ ·~ A drainage area of 40 acres with a distance from its most remote point being mtaasured as 2500 feet of which 500 feet is overland flow in forests with heavy ground litter having an average slope of 5%.The remaining 2000 feet c.!n be classified as in a natural basin with well defined channels with a drop in elevation of 150 feet. - Watershed characteristics: Relief;Flat to rolling land average slope approximately 7 percent Soil;Medium soil permeabilities Vegetal cover;25%of the area under good cover Reference Table 2.3.2 .0.15 0.13 0.13 Surface Storage;Well defined system of drainageways on 50%of area,negligible on remainder 0.17 Sum C =0.58 say 0.6 ..... ..... It 1S required to determine the runoff for recurrence periods of 2,10 and 50 years for a location 100 miles north of Anchorage.Referring to Appendix B Figures B2,B4 and B6 we estimate 0.4,0.6 and 0.7 inches per hour rE~spectively• Time of concentration (T c ) O,rerland flow Figure 2.3.3 yields a velocity of 0.6 ft/sec. TIle Remaining route of 2000 feet and 150 feet of drop from Figure 2.3.1 give 7.4 minutes. Time of concentration 500 ft=7.4 +=21.3 minutes--------- 0.6 ft/sec 60 sec 3012221 2 841218 2-12 Average Rainfall Intensity (I) RE~ferring to Figure 2.3.4 with the given rainfall intensities the average rainfall intensities (I)can be derived as follows: Frequency 2 year 10 year 50 year Runoff Calculations Two year frequency One hour Rainfall 0.4 in. 0.6 in. 0.7 in. Average Rainfall Intensity (I) 0.74 in. 1.10 in. 1.30 in. Q =CIA =0.6 x 0.74 x 40 =17.76 ft 3 /sec (say 18 ft 3/sec) TElU year frequency Q =CIA =0.6 x 1.10 x 40 =26 ft 3/sec Fifty year frequency Q =C Ca * I A =0.6 x l.~x 1.30 x 40 =37 ft 3 /sec *Antecedent precipitation correction factor see paragraph 2.3.2. 2.5 ALTERNATIVE METHOD FOR DETERMINATION OF MINIMUM,MEAN ANNUAL AND FLOOD DISCHARGES The USGS (Freethey and Scully 1980)has published equations and parameter vmlues which can be used to estimate minimum winter flows,monthly average flows,mean annual floods and floods of various recurrence intervals.The us:e of the equation for mean annual flood from this publication has been ac:cepted by ADF&G.These equations may be inappropriate for use in designing large,permanent,or important structures in larger drainage b81sins because of the large standard error.In these cases a site-specific study should be done. I""" I I 30222/2 841218 2-13 - 1.The mean annual discharge 1S defined as 0.93 P 0.22 E 0.99Q=0.0119 A a Qa =Mean annual discharge,cfsWhere A =drainage area,square miles E =mean basin elevation,feet P =mean annual precipitation,inches The standard error of the estimate is approximately 20 percent. _. The relationship was derived for basins with drainage areas between 1.7 sq. mi and 6000 sq.mi.The equation should only be applied to basins having characteristics encompassed by the data used in its derivation.Values of drainage area and mean basin elevation can be computed from available USGS topographic maps.Values of mean annual precipitation are avai lable from the National Weather Service (NWS 1972)• ...... 2.Flood discharge equations take the form: Where: Q =peak discharge having a recurrence interval of t years. ,...,A and P are as defined for Mean Annual Flood -I LP =area of lakes and ponds as a percent of the total basin. a,b,c,and d are empirically derived and have the values defined in the following table: 30222/2 841218 2-14 .- ! I - - Standard Error of t,years a b c d Estimate--- + 2 0.154 0.97 -0.31 1.28 56 36 5 0.275 0.93 -0.31 1.27 51 34 10 0.385 0.90 -0.32 1.26 52 34 25 0.565 0.88 -0.32 1.26 56 36 50 0.737 0.86 -0.33 1.25 61 38 The equation was developed using data from the same basins for which the mean annual flow equation was derived. 3.The annual low flow relationship (Freethey and Scully 1980)is based on late fall or winter minimum flows and so may not be applicable to this report. 4.The monthly average discharge relationship may provide a means of estimating an expected average flow in the watercourse and so may be useful for checking minimum depth requirements.This equation has the form: Where: A,E,LP,and P are as described previously G =Glacier area in percent of basin area J =Mean minimum January temperature (OF),calculated from Johnson and Hartmann (I 969). qn =monthly average discharge for month n,where n = I for January 30222/2 8'H218 2-15 a,b,c.d.e,f.g.are empirically derived and are given below: -Standard Error of Estimate Month n a b c d e f g + uary 1 0.0399 0.92 0 0 0 0.49 0.42 49 33 ruary 2 0.0360 0.94 0 0 0 0.42 0.44 51 34 ch 3 0.268 0.97 -0.29 0 0 0.48 0.35 49 33 il 4 1.14 0.98 -0.43 0 0 0.39 0.44 42 30 5 0.0421 1.04 0 -0.18 -0.25 1.13 0 58 37 e 6 0.000971 0.96 0.75 0 0 0.74 0 37 27 II 7 0.00150 0.95 0.68 0 0.21 0.70 0 30 23 ust 8 0.00665 0.97 0.49 0 0.30 0.59 0 36 26 tember 9 0.00832 1.00 0.22 0 0 1.11 0 43 30 ober 10 0.0194 0.99 0 0 0 0.90 0.47 40 29 ember 11 0.0200 0.92 0 0.19 0 0.72 0.54 40 29 'ember 12 0.0323 0.91 0 0.15 0 0.57 0.44 41 29 Jul Aug Sep Oct Nov Dec Mar Apr May Jun Jan Feb .- - The value.0,in a column means that the respective independent variable was not significant in the analysis and a value of 0 may be used as the exponent of that term in the equation. The designer should consult Freethey and Scully (1980)before using these equations to determine their applicability. 302:~2/2 841218 2-16 .... .... ..... Ti)estimate floodflows in ungaged basins,a regression analysis was made using the peak discharges for recurrence intervals of 2-,5-,10-,25-,and 50-years for the 50 Cook Inlet gaging stations and the basin. The final regress~on equation takes the form: Q b c d t =a A (LP+l)p Where: Q =dependent variable,the annual peak discharge in ft 3 /s t =recurrence interval,the average number of years between peak flows greater than Q. Only the independent variables that were statistically significant were used in the final equations.The results are given below. Dependent Regression Regression Coeff icient Standard Error Variable Constant of Estimate Qt a b c d + Q2 0.154 0.97 0.31 1.28 56 36 Q5 .275 .93 .31 1.27 51 34 QlO .385 .90 .32 1.26 52 34 Q 25 .565 .88 .32 1.26 56 36 Q50 .737 .86 .33 1.25 61 38 30222/2 841218 2-17 .... - 3.0 HYDRAULIC DESIGN 3,1 INTRODUCTION An effective drainage structure and waterway design process involves many f~lctors,principal of which are hydrauli c performance,structural adequacy and overall construction and maintenance costs.The design process wi 11 include an assessment by a fisheries biologist to determine whether the w~lter course is a fish stream,Type A or Type B,(see section 1.2-Scope). A fish stream is defined as any water flow that is accessible to fish and c~lpable of supporting aquatic life.This would include,but is not limited to,all Alaska Department of Fish and Game designated anadromous fish streams and all their tributaries up to impassable natural barriers (Type A).Freshwater systems above blockages may also support resident fish stocks (Type B).Evaluation and recommendations wi 11 be made by a fisheries biologist during site location to determine the presence ot fish stocks. If the waterway 1.S classified as either Type A or Type B the following cri- teria should be included in the design process. 3.2 FISH PASSAGE PROBLEMS The efficient passage of fish through a drainage structure requires close attention to the resolution of three problems: L 2" 3. Excessive water velocity Inadequate water depth Excessive hydraulic jump 30222/3 8/+1218 3-1 - - .... 3.2.1 Excessive Water Velocity Excessive water velocities can block fish movement simply by exceeding the swimming ability of fish.Swimming ability varies with species,size and age of fish,and length of drainage structure (culvert).Studies of fish movement have provided the information presented on Table 3.2.1. Slope is the most important factor determining velocity in culverts.Slopes steeper than 0.5 percent (1/2 foot drop in 100 feet)generally create exces- sive velocities for fish passage. 3.2.2 Inadequate Water Depth Fish require sufficient water depth to attain maximum swimming abilities. Thl~depth required is directly related to fish size with larger fish requir- ing deeper water.When insufficient depths are encountered,fish are unable to produce full propulsion • Causes of inadequate depth.The two most frequently encountered reasons for in:3ufficient water depth are steep slope and a wide,flat channel bottom (no low flow channel). a.All other factors being constant,the steeper the slope of a structure the shallower the water depth. b.All other factors being constant,the wider the structure bottom the shallower the water depth. 30222/3 841218 3-2 1] J - ..- Table 3.2.1 MAXIMUM ALLOWABLE AVERAGE CROSS SECTIONAL VELOCITIES IN FEET/SECOND MEASURED AT THE OUTLET OF THE CUI.VERT (Alaska Department of Fish ~lOd Game 1981) Length of Culvert in Feet Group I Upstream mi- grant salmon fry and fin- gerlings when upsteam mi- gration takes place at mean annual flood Group II Adult and juvenile slow swimmers: grayling,longnose suckers,whitefish" burbot,sheefish, Northern pike, Dolly Varden/Arctic Char,upstream migrant salmon fry and fingerlings whE!D migration not at mean annual flood Group III Adult mode- rate swim- mers:pink salmon,chum salmon,rain- bow trout, cutthroat trout Group IV Adult high performance swimmers: king salmon, coho salmon, sockeye sal- mon,steel- head 30 1.0 4.6 6.8 9.9 40 1.0 3.8 5.8 8.5 50 1.0 3.2 5.0 7.5 60 0.9 2.8 4.6 6.6 70 0.8 2.6 4.2 6.0 80 o.?2.3 3.9 5.5 90 0.7 2.1 3.7 5.1 100 0.7 2.0 3.4 4.8 150 0.5 1.8 2.8 3.7 "...200 0.5 1.8 2.4 3.1 >200 0.5 1.8 2.4 3.0 30222/3 841218 3-3 ..... - ..... ,0..... - .- Minimum water depths required for instream movement of juveniles wi 11 vary with species and size of fish present.Generally,0.2 foot (2.4 inches)is sufficient for passage.For purpose of design,minimum water depths shall be: King Salmon-0.8 feet Other salmon and trout over 20 inches-O.6 feet Trout under 20 inches-O.4 foot (Lauman,J.E.Salmonid Passage at Stream - Road Crossings:A Report with Department St,andards for Passage of Salmon- ids.1976 Department of Fish and Wildlife,Portland,Oregon). 3.2.3 Excessive Hydraulic Turbulence a.Degradation of the streambed below the structure can result in lowering of the water surface below the downstream end of a structure.This occurs most frequently in steep gradient streams with erodible bottom materials.Degradation of a receiving waterway can create a hydraulic jump at the downstream end of a structure!. b.Placement of a flat sloped structure on a steep sloped waterway also results in a hydraulic jump. 3.2.4 Guidelines for Structures Location:The guidelines for locating structures for fish passage are also coincidental with those for hydraulic design. 1.There should not be a sudden l.ncrease in velocity immediately above, below,or at the crossing. 2.Structures should not be located on a sh~lrp bend in the stream channel. 30222/3 841218 3-4 3.Structures should be designed to fit the stream channel alignment. They should not necessitate a channel change to fit a particular cross- ing design. 3.3 DRAINAGE STRUCTURE DESIGN CRITERIA All drainage structures in waterways which fish are known to frequent (Type A or B)shall be designed in accordance with the following criteria: -Flood Criteria Frequency 1 2 year *Maximum velocity per Table 3.2.1 group and depth of flow per paragnlph 3.2.2 twice the .... 2 10 years No static head at culvert:entrance 3 50 years**Allowable pondage at sitE! Drainage structures in waterways where there are no fish (Type C)will be designed for criteria 2 and 3 above.Drainage structures that are classified as temporary,meaning that they lii 11 be removed and the habitat rehabilitated within a 10 year period will be designed for criteria 1,2, and 3 except that the flood frequency of criteria 3 will be 25 years. Drainage structures in fishery streams shall be placed with the waterway substrate in its invert.In the case of culverts,at least one fifth of the diameter of each round culvert and at least 6 inches of the height of each elliptical or arch type culvert is to be S€:t below the stream bed at both the inlet and outlet of the culvert.The above is not applicable to bottom- less arch type cuI verts.In the case of a.rock substrate,a request for * ** For simplicity of computations as an approximation of the mean annual flood (2.33 year frequency) In the case that the drainage structure is at a primary road or railway the flood frequency is to be 100 years. 30222/3 841218 3-5 I I variance·should be submitted to the A1ask;i Department of Fish and Game (ADF&G)for approval. A drainage structure design data sheet,t;ibu 1ating information for each site,prepared by a fisheries biologist and a design engineer will be sub- mitted to ADF&G for review and approval prior to undertaking any construc- tion (See Section 3.4.3.9). The drainage structure design wi 11 require the following conditions to be adhered to during its construction. - - - - a. b. c. d. e. All bank cuts,slopes,fills and expo:sed earth work attributable to installation in a waterway must be stabilized to prevent erosion during and after construction. The width and depth of the temporary diversion channel must equal or exceed 75 percent of the width and the depth,respectively,of that portion of the waterway which is covered by ordinary high water at the diversion site,unless a lesser width or depth is specified by the ADF&G on the permit for activities und':!rtaken during periods of lower flow .. During excavation or construction,the temporary diversion channel must be isolated from water of the waterway,to be diverted,by natural plugs left 1n place at the upstrea~~and downstream ends of the diversion channel. The diversion channel must be constructed so that the bed and banks will not significantly erode at expected flows. Diversion of water flow into the temporary diversion channel must be conducted by first removing the downstlream plug then removing the up- stream plug]then closing the upstream l:!nd and then the downstream end, respectively]of the natural channel of the diverted waterway. - 30222/3 841218 3-6 .... "'"" .... .... .... r f.Rediversion of flow into the natural strE!am must be conducted by remov- ing the downstream plug from the natural channel and then the upstream plug,then closing the upstream end andl then the downstream end,re- spectively,of the diversion channel. g.After use,the diversion channel and the natural waterway must be stabilized and rehabilitated as may be specified by permit conditions. 3.4 WATERWAY HYDRAULICS 3.4.1 General A field inspection is basic to the design of diversion channels,culverts, and bridge encroachment into waterways,all of which encompass the drainage structures to which these guidelines are addrE!ssed. For the design of drainage structures,information on the hydraulic condition of the natural waterway upstream .!lind downstream of the proposed structure site must be known.The parameters for a typical section or sections must be measured in the field.During this inspection a check should be made of downstream controls.At times the tailwater is controlled by a downstream obstruction or by water stages in another waterway • 3.4.2 Waterways This section describes the techniques for investigation of the waterway on which a drainage structure is to be cons:tructed and the construction activities for a new waterway such as a temporary diverison channel • Hydraulic investigation and design of waterways will be based upon Manning's formula for uniform flow unless existing site conditions indicate that flows will be non uniform.A full treatment of this subject may be found in 30222/3 841218 3-7 Open-Channel Hydraulics by Ven Te Chow,Mc Graw Hill 1959. The Manning formula: -- v =1.49 R2/3 SI/2 n (Manning 1891) Where:V is the mean velocity in fps; R is the hydraulic radius ft; S is the slope of the waterway,and n is the coefficient of roughness.specifically known as Manning's n The discharge in the waterway may be deter,mined by multiplying by "A"the area of the water prism in the formula. a.Waterway Investigation A hydraulic rating curve of the waterway should be determined by measuring the waterway cross section between highwal:er marks on both sides of the waterway.If these marks are not visible a high water level should be esti- mated.Figure 3.4.1 is an example or a waterway cross section measurement • 8'/0'.'7' .. ~: .'/2' ..... Figure 3.4.1 Waterway Cross Section Measurement 30222/3 841109 3-8 ..... .... From the cross section the area and wetted perimeter should be calculated for at least 3 levels,or more if the waterway is deep,including the maxi- mum level. From the measured slope of the waterway and a determination of waterway roughness n,the discharges for the selected levels (depth of flows)can be calculated using Manning's formula.The n values for typical channel condi- tions are presented in Table 3.4.1 and a method used by the U.S.Soil Con- servation Service for computing an n value taking into consideration factors that affect n is presented in Table 3.4.2. b.Waterway Design The required capacity of the waterway should be determined by the method indicated in Section 2.0-F1ow Determination.If the waterway is to be de- signed for fish passage,the group (Table 3.2.1)and the minimum depth of flow for instream movement (paragraph 3.2.2)Elhould be determined. The design of a stable channel is accomplished by trial and error.It is reasonable to expect a channel to suffer some damage during a 50-year flood event,but one would desire a stable channel for the la-year flood event. Therefore as a trial starting point,the channel section should be designed for maximum discharge with a velocity approximately 20%higher than the velocity that.would be permissible in the ch.annel during the 10-year flood event • 30222/3 841218 3-9 ~- ..... Value of n 0.016-0.U17 0.020 0.0225 Table 3.4.1 Typical Channel Roughn,ess Coefficients (O.S.Bureau of Reclamation 1977) Channel Condition Smoothest natural earth channe:ls,free from growth,with straight alignment. Smooth natural earth channel,free from growth,little curva- ture. Small earth channels in good condition,or large earth chan- nels with some growth on banks or scattered cobbles in bed • 0.030 Earth channels with considerable growth. with good alignment,fairly constant section. channels,well maintained. Natural streams Large floodway 0.035 Earth channels considerably covered with small growth. Cleared but not continuously maintained floodways. Rivers with fairly straight Cll1 ignment and cross section, badly obstructed by small trees,very little underbrush or aqua tic growth. Rivers with irregular alignment and cross section,moderately obstructed by small trees and underbrush.Rivers with fairly regular alignment and cross se~ction,heavily obstructed by small trees and underbrush. - - - 0.040-0.050 0.060-0.075 0.100 Mountain streams in clean loose cobbles. able section an4 some vegetation growing channels with thick aquatic growths. Rivers with var1- in banks.Earth - 0.125 0.150-0.200 30222/3 841109 Rivers with irregular alignment and cross section,covered with growth of virgin timber and occasional dense patches of bushes and small trees,some logs and dead fallen rees. Rivers with very irregular alignment and cross section,many roots,trees,bushes,large logs,and other drift on bottom, trees continually falling into channel due to bank caving. 3-10 '"'" Table 3.4.2 Channel Roughness Determination (u.s.Bureau of Rec1am~tion 1977) Steps 1.Assume basin n 2.Select modifying n for roughness or degree of irregularity 3.Select modifying n for variation in size and shape of cross section 4.Select modifying n for obstructions such as debris deposits,stumps,exposed and fallen logs 5.Select modifying n for vegetation 6.Select modifying n for meandering 7.Add items 1 through 6 ~Aids in Selecting Various n Values 1.Recommended basic in values Channels in earth------------0.010 Channels in rock-------------0.015 Chan.nels in fine grave1-----------0.014 ChatllOe1s 1n coarse grave1---------0.028 2.Recommended modifying n value for degree of it'regu1arity Smooth -----------------------0•000 Mode:r a te ---------------------------0•010 Minor ------------------------0.005 -S eVE!re -----------------------------0.020 3.Recommended modifying n value for changes in size and shape of cross section Gradua1---------------------0.000 Frequent------------------0.010 to 0.015 Occasiona1-------------------0.005 Recommended modifying n value for channel mearlder Recommended modifying n value for obstruction such as debris,roots,etc. Negligible effect-----------O.OOO Appreciable effect-----------------0.030 Minor ef fect -----------------0.0 10 SeVE~re ef fect ----------------------0.060 Recommended modifying n values for vegetation Low effect----------0.005 to 0.010 High effect---------------0.025 to 0.050 Medium effect------0.Ol0 to 0.025 Very'high effect---------0.050 to 0.100 r-4. .... 5 . """ 6. ~ - Ls=Straight length of reach Lm/L s 1.0-1.2 1.2-1.5 >1.5 where ns=items 1+2+3+4+5 30222/3 841218 ~=MealOder length of reach n 0.000 0.15 times n s 0.30 times n s 3-11 - -- - - Two methods will be presented for channel design;the Permissible Velocity Method and the Tractive Force Method.Examples of their use will also be presented. 3.4.2.1.Permissible Non-erodible Velocity Method The maX1mum permissible velocity,or non-erodlible velocity is the greatest mean velocity that will not cause erosion of the channel body.In general, old and well-seasoned channels will stand mUlch higher velocities than new ones,because the old cbannel bed is usually better stabilized,particular- ly with the deposition of colloidal matter.When other conditions are the same,a deeper channel will convey water at a higher mean velocity without erosion than a shallower one. Table 3.4.3.lists the maX1mum permissible velocity for channels with erod- ible linings based on uniform flow in continuolUsly wet,aged channels. 30222/3 841218 3-12 Table 3.4.3 RECOMMENDED PERMISSIBLE VELOCITIES (ft.isec.)FOR UNLINED CHANNELS (California Department of Public Works 1963) Type of Material for Excavated Section Fine Sand (non colloidal) Sandy Loam (non colloidal) Silt Loam (non colloidal) Ordinary Firm Loam Volcanic Ash Fine Gravel Stiff Clay (colloidal) Graded Material: Loam to Gravel Silt to Gravel Gravel Coarse Gravel Gravel 'to Cobbles «611 ) Gravel to Cobbles (>6") Shales and Hardpans Clear Water Silt -Carrying Water 1.5 2.5 1.7 2.5 2.0 3.0 2.5 3.5 2.5 3.5 2.5 4.0 3.7 5.0 ].7 5.0 4·.0 5.5 5.0 6.0 5.5 6.5 6.0 7.0 7'.0 8.0 j'.O 8.0 .....,' ..... - - Using permissible velocity as a criterion,the design procedure for an un- lined channel section,assumed to be trapezoiGlal t is as follows: 1.For the given kind of material forming the channel body,estimate ,the roughness coefficient n t side slope z,and the maximum per- missible velocity,V (Table 3.4.3). 2.Compute the hydraulic radius R by U8e of the Manning formula. 3.Compute the water area required by the given discharge and per- missible velocitYt 1.e.:A =Q/(1.2V). 4.Compute the wetted perimeter,P =A/R. 30222/3 841218 3-13 5.Solve simultaneously for band y (base and depth of flow). 6.With the given section,by iteration,calculate with varying depths of flow,the depth and velocity for the 10-year flood dis- charge.Check if velocity is equal or less than the permissible. If not,change slope if possible or lower velocity and repeat 1. A calculation example follows:- 7.For fish streams,repeat 6 for the 2-year flood discharge to check if velocity is equal to or less than permissible fish pass- age velocity for the designated groll1p (Table 3.2.1)and the depth of flow is at least 50%greater them that indicated in paragraph 3.2.2.If the above are not met,a further channel revision may be required necessitating recalcul~ltion beginning with 1 or the incorporation of a low flow section in the invert of the channel. ,.". Compute the bottom width and depth of flow of a trapezoid channel laid on a slope of .0016 and carrying a design discharge of 400cfs.The channel is to be excavated in earth containing non-colloidal,gravelly silt. Solution: For the g~ven conditions,the following ~lre estimated:n =0.025,side slope z =2:1,and maximum permissible vEllocity =3.75 x 1.2 =4.5 fps. - "'"' 1. 30222/3 841218 Using the 'Manning Formula,solve for R 4.5 =1.49 R2/3 (.0016)1/2 0.025 R =2.60 ft Then A =400/4.5 =88.8 ft 2 ,and P .-A/R =88.8/2.60 =34.2 3-14 - 2.A =(b +zy)y =(b +2y)y =88.8 ft 2 and P =b +2 (1 +z2)1/2 y =[b +2(5)1/2 y ]=34.2 ft. - - 3.Solving the two equations simultaneously: (b +2y)y =88.8 (b +4.47~)=34.2 88.8 -2y =34.2y -4.47 y2 2.47 y2 -34.2y +88.8 =0 y =3.46 ft b =18.7 ft 3.4.2.2 Tractive Force Method The tractive force method takes into account physical factors of bed ma- terial.channel section.depth of flow and velocity (Lane 1937).This method will be confined to non cohesive materials for which the permissible tractive force is related to particle size and shape.and sediment load in the water.The tractive force is the unit fOl:'ce tending to cause erosion of the material forming the channel.Figure 3.4.2 shows curves for recommended values of permissible unit tractive force for particles up to about 4 inches in diameter.For coarser material.the permissible tractive force in psf is equal to 0.4 times the diameter in inches ai3 shown in Figure 3.4.3.The diameter ~s that of a particle of equivalent spherical volume.The curves in Figures 3.4.2 and 3.4.3 are based on pB,rticle sizes of which 25%by weight are larger. The limiting condition for permissible tractive force is governed by the particles on the sides rather than those on the bottom of the channel.The resistance of the material on the sides is reduced by the sliding force down the sides due to gravity.The effect of side!slopes is expressed as factor K.which is the ratio of the tractive force rE!quired to initiate motion of a particle on the sloping sides to that on a level bottom.The equation is: ( 1 -sin2 "y/2 K =sin2 e 30222/3 841218 (Fan 1947) 3-15 o =side slope angle 9 =angle of repose of the material which varies with particle size and shape as shown in Figure 3.4.4. The solution of this equation is given in Figure 3.4.5. The formula for maximum tractive force (TO)is: TO =62.4 RSl"- S =energy gradient in ft/ft (channel slope for uniform flow) R =hydraulic radius (feet) In a wide open channel,the hydraulic radius is approximately equal to the depth of flow y;hence,TO =62.4 yS. Channels in fine material less than 5 nun in diameter are designed by using the recommended values of tractive force ploted in Figure 3.4.2.In this case,"d"is the mean diameter for which 50%by weight are larger.The sliding effect of the particles down the ch,annel sides due to their own weight is neglected. An example is presented using values for;a la-year flood design,a trapezoidal channel laid on a slope of .0016,and carrying a discharge of 400 cfs.The channel is to be excavated in earth containing noncolloidal coarse gravels and pebbles,25%of which is 1.25 in or over in diameter. Manning's n =0.025. - For trapezoidal channels,the maximum unit tractive force on the sloping sides is usually less than that on the bottom (Figure 3.4.6);hence,the side force is the controlling value in the analysis.The design of the channel should therefore include:(a)the proportioning of the section dimensions for the maximum unit tractive force on the sides and (b)checking the proportioned dimensions for the maximum unit tractive force on the bottom. 30222/3 841218 3-16 ..,., a.Proportioning the Section Dimensions: 1.Assuming side slopes of 2:1 and a b/y ratio =5,the maX1.mum unit tractive force on the sloping sides (Figures 3.4.6)is .775 x 62.4 yS =.775 x 62.4 x .0016y =0.078y psf. ... .... .... ..... - 2. 3. 4. Considering a very rounded material 1.25 in.1.n diameter,the angle of repose (Figure 3.4.4)is .g =33.5.With .g =33.5 and 55 =2.1,the permissible tractive force ratio on the sloping sides (Figure ,3.4.5)il3 K =0.6.For a size of 1.25 in.,the permissible tractive force on a level bottom is T = 0.4 x 1.25 =0.5 psf (this call also be obtained from Figure 3.4.2)and the permissible tractive force on the sides is equal to 0.6 x 0.5 =0.3 psf • For a state of impending motion of the particles on side slopes,.078y =0.3 or y =3.88 ft.Accordingly,the bottom width b = 5 x 3.85 =19.3 ft.For this trapezoidal section, A =104 sq ft and R =2.85 • By the Manning equation Q =1.486 AR2/3 S1/2 tl =1.486 (104)(2.85)2/3 (.0016)1/2 =491 cfs .025 Further computation will show that for a side slope of 2:1 and b/y ratio of 4.1,b =15 ..8 ft.,Q =425 ds,which is close to the design discharge. ... ... b. 30222/3 841218 Checking the proportioned dimension~: With 55 =2:1 and b/y =4.1,the maximum unit tractive force on the channel bottom (Figure 3.4.6)is 0.97 x 62.4 x 3.85 x .0016 = 0.374 psf <0.5 psf (permissible tructive force on the bottom)• 3-17 .... 5.Determining maximum flow condit ions:with base width and side slopes determined,the dE!pth of flow required for the maximum flow conditions can be determined using the Manning formula • .... 6.For fish streams,repeat paragraph 5 for the 2-year flood discharge to check if velocity 1S equal to or less than permissible fish passage veloc:ity for the designated group (Table 3.2.1)and the depth of flow is at least 50%greater than that indicated in paragraph 3.2.2 for the fish type.If the above are not met,a further channel reV1S10n may be required,necessitating recalculation beginning with paragraph 1 or the incorporation of a low flow section in the invert of the channel. - c. 30222/3 841218 Optimum proportioning of dimensions: A method has been developed which optimizes the ratio of b/y based on the theory of most efficient hydraulic section (King 1954). This method is presented in Appendix C. 3-18 00 ~ 1;11 17 / ,) / / Hi9h content of .ttI""I .;V ~Coarse noncohesivefin.tadiment ......~/'material I ....~~~I ~-'J ". .J'"/ ~/ L-..../,./ \1_"'"~~ \-10-0"'" \..-Creor 'wat.r\ l Low content of fine .edlment I .I 02 0.4 OS 081.0 2 4 68 10 20 40 60 80 I 1.0 0.8 0.6 OA o 2.0 0.2 4.0 0.02 0.04 0.1 0.08 0.06 0D04 0.003 0.01 0.008 0.006 .- "'--~•oS .5 •ur. If I.-uar. ~ at•....-e-r. l '""'" ..,., Mean Dlamet...-mm. Figure 3.4.2 RECOMMEND PERMISSIBLE UNIT TRACTIVE FORCE FOR CANALS IN NONCIOHESI VE MATERIAL (Lane 1937 ) 3-19 I • 4 - 2 (Ill--~•.-0.8 oS "0.6 .! •0~4~.--u•.... Jl ~0.2:: i.. II~ 0.1 r 0.08 ."~ 0.06..... 0.04 / V / / / V / V .V' V . / / / V / /. 0.1 0.2 0.4 0..0.8 I 2 4.a to Diameter In Inch•••,2S%lar~r Figure 3.4.3 PERMISSIBLE TRACTIVE FORCE FOR COARSE NONCOHESIVE MATERIAL (Lane 1937 ) 3-20 ..... "" .J'io"""'"~ //1"""/~ ~//V ~ //V/ ~~~1///v II /// o~~C~IJ // {~II If/ ~e;:s;/1/1/Ci 0'"fl-j II I:\S bf/;~.V o 0/...01"1 ~II '_~II1IJ~..O §}~GoJ .:0\~~~~~~J".0 ~.~~11 _§t.~V r_lt~J:$;, Particle size in inches 0.1 0.2 0.4 QlQ.8 1.0 2D 3.0 4.0 ...1 -_.&.'--"'!~~'."".&.'..,.&.1~~.'_...I'1oooooo-i11211'12. 20 42 ~ ~.-II 40-c 0....~38=.. 0I: I:31-,..z,:;f~i.,34 '"....32~at f""..~.!O :I....0 p:'l;Q,28e-0 26 r~•JIll'-Ot 24.a 22 Figure 3.4.4 ANGLES OF REPOSE OF NONCOHESlVE MATERIAL (Lane 1937 ) 3-21 1 I I ~~ J ~'A J l)! J I I ~I ~1 I i f) ~I =t ::1-H ·1 .0/'-:::;~ 11,44:1-I 400 --:::::::::::I "oA.,le ef !-- 35_L I -- t-:3 1112:1- t--:~I "-...I Side 51_. ;;0 I I f; t-:3 H ~ ~1 314:1-30- "":l -:"30 0 a ;;0 .... (")t'Zj-2:1-II t>1 1-'0 -~~.;25- w I ~CD ~2 1"':1-I I 25- N a w J N $~221/2:1- ~l.,n _ 0 en iH 3:1- ~N en j t""'a -IS' ~•4:1-•A ......~ t"'fn 5:1- III ::l •(0 '0 I-'iii \0 W....... '-"5.1 O.I I_n~_~ 0.1 02 0.3 0.4 0.5 0.6 07 0.8 0.9 10 -:K =Permissible Tractive Force on Sid"In Fraction of Volue for Level Bottom for Noncoheslve Material rn LLJ C-rn cz« W <.Ja:: fZ w>-.... <.J <[ a: 'J- :E:;:, :E.- X <t ~ o.~G ~~~~~NO'0-000 0 000 S'.·Z9 ~o IWJ81 UI (Unll'"'XDUI)JDe..s .AHDI.~ ••:!.; I ~-.!•II ~0--'0 -I 'i -0eI:0 ---A-I -3 0 •.a '0,I "0 II NN.a --• I •0'I .1\~~.. ~;jIt, 1 i \1'". \\I \\ \\ J ~ ~'!\\~a 4 ~.~~\-~ 0\S'!,at ~c:\S'~a-Col~\• 4/1 ('~a: 4/1 \\~~\.,~, \~.,".~,~~~...., \...~1\'fA "4' ,~~.""~I:r".........Col--If')~~~a t"", ..z --....N I N .... \~I.,~--.:-~~i '"'i:-'t-_--. -"" , Figure 3.4.6 THE MAXIMUM TRACTIVE FORCE ON BED AND SIDES (Lane 1937 ) 3-23 .... ~: 3.4.3 Culverts 3.4.3.1 Fish Passing Requirements.The presentation on culvert design that begins with paragraph 3.4.3.2 below is essentially a repetition of the Hydraulic Engineering Circular No.5 pepared by the Bureau of Public Roads, U.S.Department of Commerce (USDOC 1965).As such the design criteria established are for the design of highl!1ray culverts and includes no provisions of fish passage criteria.TherE!fore,when a culvert is to be placed on a waterway that has been established to have resident fish or ~s used by anadromous fish,"this paragraph (3 .•4.3.1)will amend the culvert design procedure that begins with paragraph 31.4.3.2. In Sections 3.2,Fish Passage Problems and 3.3 Drainage Structure Design Criteria,the basic requirements were presented for the successful design of a culvert for passing fish.They were: 1.Velocity requirement per fish group (Specified ~n Table 3.2.1) 2.Place invert below waterway bed by at IE!ast 0.2 diameter -F 3.Maintain depth of flow requirement for fish type per paragraph 3.2.2 Inadequate Water Depth. ...... It can be shown that circular culvert chara,cteristics with full flow,when the lower 20%of the diameter is filled with the streambed substrate,are modified as follows: Area reduced by 14.5% Hydraulic radius reduced by 11% Average roughness coefficient n increased by 30% ..... 30222/3 841218 3-24 ~ ~...", These changes in parameters will reduce the c:ulvert capacity by about 39%. Therefore the selection of the culvert size as presented in the following text will require a correction.This correction is achieved by increasing the design discharge (full pipe flow only)by 63%before starting the design procedure indicated in 3.4.3.11 Outlet Control Nomographs. For low flow design,as 1.n the case of the 2:year flood,the culvert will flow partially full and the discharge depth for runoff discharge can be computed taking into consideration the culvert section with fill material using Manning's formula.The hydraulic radius!is accounted for by weighting the perimeter with the n's of the culvert and the substrate material as per the following equation. n =-------------- IlImportant ll (Chow 1959) Per the preceeding,culverts meeting the requirements prescribed herein should be designed for a maximum capacity equivalent to:1.63 x the cal- culated design discharge flowing through the full culvert section. 3.4.3.2 Scope of Guidelines.The following text contains a brief discus- sion of the hydraulics of conventional culverts and charts for selecting a culvert size for a given set of conditions..Instructions for using the charts are provided.Some approximations ar,e made in the hydraulic design procedure for simplicity.These approximations are discussed at appropriate points throughout the text. 30222/3 841218 3-25 "...pm:.' -""" -f For this discussion,conventional culverts include those commonly installed, such as.circular,arch and oval pipes,both metal and concrete box culverts. All such conventional culverts have a uniform barrel cross section through- out.The culvert inlet may consist of the culvert barrel projected from the roadway fill or mitered to the embankment slope.Sometimes inlets have headwalls,wingwalls and apron slabs,or standard end sections of concrete or metal.The more common types of conventional culverts are considered in these guidelines. 3.4.3.3 Culvert Hydraulics.Laboratory tests and field observations show two major types of culvert flow:(I)flow with inlet control and (2)flow with outlet control.For each type of control,different factors and formu- las are used to compute the hydraulic capacity of a culvert.Under inlet control,the cross-sectional area of the culvert barrel,the inlet geometry and the amount of headwater or ponding at the entrance are of primary 1mpor- tance.Outlet control involves the additiomll consideration of the eleva- tion of the tailwater in the outlet channel and the slope,roughness and length of the culvert barrel. It is possible by involved hydraulic computations to determine the probable type of flow under which a culvert will operate for a given set of condi- tions.The need for making these computations may be avoided,however,by computing headwater depths from the charts in this circular for both inlet control and outlet control and then using thle higher value to indicate the type of control and to determine the headwater depth.This method of de- termining the type of control is accurate eXI::ept for a few cases where the headwater is approximately the same for both types of control. Both inlet control and outlet control types of flow are discussed briefly in the following paragraphs and procedures for the use of the charts are given. 30222/3 841218 3-26 3.4.3.4 Culverts Flowing With Inlet Control.Inlet control means that the discharge capacity of a culvert is controlled at the culvert entrance by the depth of headwater (HW)and the entrance geometry,including the barrel shape and cross-sectional area,and the type of inlet edge.Sketches of inlet-control flow for both unsubmerged and submerged projecting entrances are shown in sections A and B of Figure 3.4.7.Section C shows a mitered entrance ,flowing under a submerged condition 19ith inlet control. In inlet control the roughness and length of the culvert barrel and outlet conditions (including depth of tailwater)are not factor's in determining culvert capacity.An increase in barrel slope reduces headwater to a small degree and any correction for slope can be neglected for conventional or commonly used culverts flowing with inlet conltrol. In all culvert design.headwater or depth of ponding at the entrance to a culvert is an important factor in culvert capacity.The headwater depth (or headwater HW)is the vertical distance from the culvert invert at the entrance to the energy line of the headwater pool (depth +velocity head). Because of the low velocities in most entrance pools and the difficulty in determining the velocity head for all flows,the water surface and the ener- gy line at the entrance are assumed to be I::oincident.thus the headwater depths given by the inlet control charts in this circular can be higher than will occur in some installations.For the purposes of measuring headwater, the culvert invert at the entrance is the low point in the culvert opening at the beginning of the net cross-section of the culvert barrel.(Refer to paragraph 3.4.3.1). Headwater-discharge relationships for the v'arious types of circular and pipe-arch culverts flowing with inlet control are based on laboratory re- search with models and verified in some insto!ltnces by prototype tests.This 30222/3 841218 3-27 HW -.~---- PROJECTING END .'UMSU8MERGEO E\ -1 HW I ____.£115-----------.-.~,X\\~_""- PROJECTING END -SUBl'4ERGE·O G -~---- -~\.~~V!~VAt\:.- IIIITEREO ENO -SUBMERGED ... ___~_L ---~----.-::...::-~~-..~~:..::...=..=-..: "... \ Figure 3.4.7 INLET CONTROL 3-28 ..... - - - research is reported in National Bureau of Standards Report No.44441/en- titled IIHydraulic Characteristics of COIlllnonly Used Pipe Entrances ll ,by John L.French and IIHydraulics of Conventional Highway Culverts ll ,by H.G. Bossyl/•Experimental data for box culvelrts with headwalls and wing- walls were obtained from an unpublished report of the U.S.Geological Survey. These research data were analyzed and nomographs for determining culvert capacity for inlet control were developed by the Division of Hydraulic Re- search,Bureau of Public Roads.These nomographs,Charts 1 through 6, give headwater-discharge relationships for ID.CIISt conventional culverts flow- ing with inlet control through a range of headwater depths and discharges. Chart No.7 is included to stress the import~lnce of improving the inlets of culverts flowing with inlet control. 3.4.3.5 Culverts Flowing With Outlet Control..Culverts flowing with outlet control can flow with the culvert barrel full or part full for part of the barrel length or for all of it,(see Figure 3.4.8).If the entire cross section of the barrel 18 filled with water for the total length of the bar- rel,the culvert is said to be in full flow or flowing full,Sections A and B.Two other common types of outlet-control flow are shown in Sections C and D.The procedures given in this text provide methods for the accurate determination of headwater depth for the flow conditions shown in Sections 1./Available from Division of Hydraulic Rese,arch,Bureau of Public Roads. 2/Presented at the Tenth National Conferen(:e,Hydraulics Division,ASCE., 4ugust 1961.Available on loan from Division of Hydraulic Research, Bureau of Public Roads. 30222/3 841218 3-29 - 1 - HW 1 WATER A SURFACE /' 7 8 • =~w.s. 1 HW I H -......w.s. '-..-'-'-....- - C A , H -L...w.s ......-----.... D ...J1;;.~c;~~~==:::::====::::::::=::=::=::::::::::==~=1I~HW --.-------~--.------- - - OUTLET CONT'ROL --Figure 3.4.8 3-30 .... A,Band C.The"method given for the part full flow condition,Section D, gives a solution for headwater depth that decreases in accuracy as the headwater decreases. The head H (Section A)or energy required to pass a given quantity of water through a culvert flowing in outlet control with the barrel flowing full throughout its length is made up of three major parts.These three parts are usually expressed in feet of water and include a velocity head Hv 'an entrance loss He'and a friction loss Hf •This energy is obtained from ponding of water at the entrance and expressed in equation from (1) The velocity head Hv equals V2 /2g,where V is the mean or average velocity in the culvert barrel.(The mean velocity is the discharge Q,in cfs,di- vided by the flow cross-sectional area A,in square feet,of the barrel.) The entrance loss He depends upon the geometry of the inlet edge.This loss is expressed as a coefficient k times the barrel velocity head ore He =k e V2/2g.The entrance loss coeficients k e for various types of I""'" entrances when the flow is in outlet control are given in Table 3.4.4. ..... The friction loss Hf is the energy required to overcome the roughness of the culvert barrel.Hf can be expressed in several ways.Since most engineers are familiar with Manning's equation the following expression can be derived: 30222/3 841218 H = 3-31 - Where: Where: n =Manning's roughness coefficient L =length of culvert barrel (ft) V =mean velocity of flow in culvert barrel (ft/sec) g =acceleration of gravity,32.2 (ft/sec 2 ) R =hydraulic radius or A/P (ft) A =area of flow for full cross-section (sq ft) P =wetted perimeter (ft) Substituting in equation 1 and simplifying,Wl~get for full flow .... ,.... .- 30222/3 841218 29n 2L H =(l +k +--) e Rl.33 3-32 V2 2g (2) Table 3.4.4 Entrance Loss Coefficients (USDA Forest Service) Coefficient ke to apply to velocity head vU 2g for determination of head loss at entrance to a structure,such as a culvert or conduit,operting full or partly full with control at the outlet. Entrance head loss He .-ke V2 2g-Type of Structure and Design of Entrance Coeffi- cient k e .- Pipe,Concrete Projecting from fill,socket end (groove-end)•••••••••••••• Projecting from fill,sq cut end ••••••••••••••••••••••••••• Headwall or headwall and wingwalls Socket end of pipe (groove-end)•••••••••••••••••••••••• S quare-edge ••••••••••••••••••••••••••••••••••••••••••• Rounded (radius =D/12).....................•.......... Mitered to conform to fill slope ••••••••••••••••••••••••••• *End-section conforming to fill slope •••••••••••••••••••••• Pipe,or Pipe-Arch,Corrugated Metal Projecting from fill (no headwall) Headwall or headwall and wingwalls Square-edge . Mitered to conform to fill slope ••••••••••••••••••••••••••• *End-section conforming to fill slope •••••••••••••••••••••• Box,Reinfdrced Concrete Headwall parallel to embankment (no wing1iialls) Square-edged on 3 edges •.••.•.••.•..•••••.•..•.•••.•.• Rounded on 3 edges to radius of 1/1:2 barrel dimension • Wingwalls at 30°to 75°to barrel Square-edged at crown . Crown edge rounded to radius of 1/1:2 barrel dimension. Wingwalls at 10°to 25°to barrel Square-edged at crown . Wingwalls parallel (extension of sides) Square-edged at crown .. 0.2 0.5 0.2 0.5 0.2 0.7 0.5 0.9 0.5 0.7 0.5 0.5 0.2 0.4 0.2 0.5 0.7 .... I, I *Note: 30222/3 841218 "End-section conforming to fill slopen ,made of either metal or concrete,are the sections commonly available from manufacturers. From limited hydraulic tests,they are equivalent in operation to a "eadwall in both inlet and outlet controL Some end sections, incorporating a closed taper in thl;ir design have a superior hy- draulic performance.These latter sections can be designed using the information given in 3.4.3.8 Inlets and Culvert Capacity • 3-33 ..... .... Figure 3.4.9 shows the terms of equation 2,the energy line,the hydraulic grade line and the headwater depth,HW.The energy line represents the to- tal energy at any point along the culvert ban·el.The hydraulic grade line, sometimes called the pressure line,is defined by the elevations to which water would rise in'small vertical pipes att~lched to the culvert wall along its length.The energy line and the pressure line are parallel over the length of the barrel except in the immediate 'l7icinity of the inlet where the flow contracts and re-expands.The difference in elevation between these two lines is the velocity head,V2/Z g • The expression for H is derived by equating the total energy upstream from the culvert entrance to the energy just inside the culvert outlet with con- sideration of all the major losses in energy"By referring to Figure 3.4.9 and using the culvert invert at the outlet as a datum,we get: Where:dl and d2 =depths of flow as shown in Fig.3.4.9 Y1.Z =velocity head in entrance pool 2g LSO =length of culvert times barrel slope Then:VI 2 dl +---+LSO -d2 = Zg H +H +Hfv e .... .... VIZ And:H =dl +---+LSO -dZ =Hv +He +HfZg From the development of this energy equation and Figure 3.4.9,head H ~s the difference between the elevations of the hydraulic grade line at he outlet and the energy line at the inlet.Since the velocity head in the entrance pool is usually small under ponded conditions,the water surface or headwater pool elevation can be assumed to equal the elevation of the .... 30222/3 841218 3-34 energy line.Thus headwater elevations and headwater depths,as computed by the methods given in this text,for outlet control,can be higher than might occur in some installations.Headwater depth is the vertical distance from the culvert invert at the entrance to the wate surface,assuming the water surface (hydraulic grade line)and the energy line to be coincident, d1 +V1 2 in Figure 3.4.9. 2g Figure.3.4.9 CULVERT HYDRAULICS DIAGRAM Equation 2 can be solved for H readily by the use of the full-flow nomo- graphs,Charts 8 through 14.Each nomograph is drawn for a particular bar- rel shape and material and a single value 0:E n as noted on the respective charts.these nomographs can be used for ()ther values of n by modifying the culvert length for the use of the full-flow monographs as directed in 3.4.3.11 Outlet Control Nomographs. In culvert design,the depth of headwater HW or the elevation of the ponded water surface is usually desired.Finding the value of H from the nomo- graphs or by equation 2 is only part of the solution for this headwater depth or elevation.In this case of Figure 3.4.8 Section A or Figure 3.4.9 where the outlet is totally submerged,the headwater pool elevation (assumed 30222/3 841218 3-35 - .... - - ..... - to be the same elevation as the energy line-)1.S found by adding H to the elevation of the tailwater.The headwater depth is the difference in eleva- tions of the pool surface and the culvert invlert at the entrance. When the tailwater is below the crown of the!culvert,the submerged condi- tion discussed above no longer exists and thE!determination of headwater is somewhat more difficult.In discussing outle!t-control flow for this condi- tion,tailwater will be assumed to be so low that it has no effect on the culvert flow.(The effect of tailwater will be discussed later.)The com- mon types of flow for the low tailwater condition are shown in Sections B,C and D of Figure 3.4.8.Each of these flow c:onditions are dependent on the amount of discharge and the shape of the culvert cross-section.Each condi- tion will be discussed separately. Full flow at the outlet,Section B of Figure 3.4.8 will occur only with the higher rates of discharge.Charts 15 through 20 are provided to aid in de- termining this full flow condition.The curves shown on these charts give the depth of flow at the outlet controL This depth is called critical depth d c •When the discharge is sufficient to give a critical depth equal to the crown of the culvert barrel,full .flow exists at the outlet as in Section B of Figure 3.4.8.The hydraulic grade line will pass through the crown of the culvert at the outlet for all discharges greater than the dis- charge causing critical depth to reach the crown of the culvert.Head H can be measured from the crown of the culvert in computing the water surface elevation of the headwater pool. When critical depth falls below the crown of the culvert at the outlet, the water surface drops as shown in either Sections C or D,depending again on the discharge.To accurately determine headwater for these conditions, computations for locating a backwater curve are usually required.These backwater computations are tedious and tim.:!consuming an they should be avoided if possible.Fortunately,headwater for the flow condition shown in Section C can be solved by using the nomographs and the instructions given in this text. 30222/3 841218 3-36 - ..... .... For the condition shown in Section C,the culvert must flow full for part of its length.The hydraulic grade line for the portion of the length in full flow will pass through.a point where the watler breaks with the top of the culvert as represented by point A in Section C.Backwater computations show that the hydraulic grade line if extended as a straight line will cut the plane of the outlet cross section at a point above critical depth (water surface)•This depth is at a height approximately equal to one half the distance between critical depth and the crown of the culvert.The elevaton of this point can be used as an equivalent hydraulic grade line and H,as determined by equation 2 or the'nomographs,c:an be added to this elevation to find the water surface elevation of the headwater pool. The full flow condition for part of the barrel length,Section C,will exist when the headwater depth HW,as computed from the above headwater pool ele- vation,is equal to or greater than the quantity: D +(l +k ) V 2 e 2g Where V is the mean velocity for the net cross section of the barrel;Ke , the entrance loss coefficient;and D,the inside height of the culvert.If the headwater is less than the above value,a free water surface,Figure 2D will extend through the culvert barrel. The part full flow condition of Section D must be solved by a backwwater the same as that given for the flow condition of Section C,with the reserv- ation that headwater depths become less accurate as the discharge for a par- Instead the solution used is-, computation if accurate headwater depths are this computation are not given in this text. desired.Detai Is for making ticular culvert decreases.Generally,for design purposes,this method is satisfactory for headwater depths above 0.75D,where D is the height of the culvert barrel.Culvert capacity charts found in Hydraulic Engineering Cir- cular No.10 (USDOC 1965)give a more accurate and easy solution for this free surface flow condition. 30222/3 841218 3-37 ~. ...... i I Headwater depth HW can be expressed by a common equation for all outlet- control conditions,including all depths of tllilwater.This is accomplished by designating the vertical dimension from the culvert invert at the outlet to the elevation from which H is measured as h o •The headwater depth HW elevation is: HW =H +h -LSo ()(3) ..... ~, .... All the terms in the equation are in feet.H is comptued by equation 2 or found from the full-flow nomographs.L is thE!length of culvert in feet and So the barrel slope in feet per feet.ThE!distance h o is discussed in the following paragraphs for the various conditions of outlet-control flow. Headwater HW is the distance in feet from the invert of the culvert at the inlet to the water surface of the headwater pool. When the elevation of the water surface in thE!outlet channel is equal to or above the elevation of the top of the culvert opening at the outlet,Section A of Fig.3.4.8,h o is equal to the tailwatler depth.Tailwater depth TW is the distance in feet from the culvert invlert at the outlet to the water surface in the outlet channel.The relationship of HW to the other terms in equation 3 is illustrated in Figure 3.4.10. -f --------~ JHW r-""-r-------=-~-=-=~__~r- _~TW=ho:::===~I~============L====-======-_~...j----.l- LS o Figure 3.4.10 CULVERT OUTLET SUBMERGED 30222/3 841218 3-38 ..... If the tailwater elevation is below the top of the culvert opening at the outlet,Sections B,C and D of Figure 3.4.8,h o is more difficult to de- termine.The discharge,size and shape of culvert,and the TW must be con- sidered.In these cases,h is the greater of two values (l)TW depth aso defined above or (2)(dc +D)~2.The latter dimension is the distance to the equivalent hydraulic grade line discussed previously.In this frac- tion d c is the critical depth,as read from Charts 15 through 20 and D is the culvert height.The value of d c can nelTer exceed D,making the upper limit of thi~fraction equal to D.Where 1W is the greater of these two values,critical depth 1.S submerged sufficiE!ntly to make TW effective in increasing the headwater.The sketch in Figure 3.4.11 shows the terms of equation 3 for this low tailwater condition.Figure 3.4.11 is drawn similar to Section C of Figure 3.4.8,but a change in discharge can change the water surface profile to that of Section B or D. Figure 3.4.11 CULVERT OUTLET LOW TAILWATER de +0 2 or 1= HW j1====+=~::::::=========L~==-=:..~=.:.==-----_-_-_4~ LSo ..... 3~4.3.6 Computing Depth of Tailwater.In culverts flowing with outlet con- trol,tailwater can be an important factor in computing both the headwater depth and the hydraulic capacity of a culve"rt.Thus,in many culvert de- signs,it becomes necessary to determine tailwater depth in the outlet chan- nel. ..... 30222/3 841218 3-39 .... - - - ..... .... Much enginering judgment and experience is neE!ded to evaluate possible tail- water conditions during floods.As has been mentioned previously,a field inspection should be made to check on downstream controls and to determine water stages.Often times tailwater is controlled by a downstream obstruc- tion or by water stages in another stream.Fortunately,most natural chan- nels are wide compared to the culvert and the depth of water in the natural channel is considerably less than critical depth,thus the tailwater is in- effective and channel depth computations are not always warranted. An approximation of the depth of flow 1.n a natur~l stream (outlet channel) can be made by using Manning's formula if the,channel is reasonably uniform in cross section,slope and roughness.Values of n for natural streams for use in Manning1s have been presented in Tables 3.4.1 and 3;4.2.If the water surface in the outlet channel is established by downstream controls, other means must be found to determine the tailwater elevation.Sometimes this necessitates a study of the stage-discharge relationship of another stream into which the stream in question flowB or the utilization of data on reservoir elevations if one of the dams is involved. 3.4.3.7 Velocity of Culvert Flow.A culvert,because of its hydraulic cha- racteristics,increases the velocity of flow over that in the natural chan- nel.High velocities are most damaging just downstream from the culvert - outlet and the erosion potential at this point:is a feature to be considered in culvert design. Energy dissipators for channel flow have been investigated in the laboratory and many have been constructed,especially in irrigation channels.Designs for highway use have been developed and constructed at culvert outlets.All energy dissipators add to the cost of a culvert,therefore,they should be used only to prevent or to correct a serious erosion problem (see Reference 5)• 30222/3 841218 3-40 - - The judgment of engineers working in the particular area ~s required to determine the need for energy dissipators at culvert outlets.As an aid ~n evaluating this need,culvert outlet velocities should be computed.These computed velocities can be compared with clutlet velocities of alternate culvert designs,existing culverts in the area,or the natural stream velocities.In many streams the maximum ve,locity in the main channel is considerably higher than the mean velocity for the whole channel cross- section.Culvert outlet velocities should be compared with maximum stream velocities in determining the need for channel protection.A change in size of culvert does not change outlet velocities 'ippreciably in most cases. Outlet velocities for culverts flowing with inlet control may be approxi- mated by computing the mean velocity for the culvert cross section using Manning's formula: v =1.49 R2/3 Sol/2 (Chow 1959) n Since the depth of flow is not known,the USE!of tables or charts is recom- mended in solving this equation.The outlet velocity as computed by this method will usually be high because the normal depth,assumed in using Manning's formula is seldom reached in the relatively short length of the average culvert.Also,the shape of the outlet channel,including aprons and wingwall s,have much to do with changing the velocity occuring at the end of the culvert barrel.Tailwater is not considered effective in reducing outlet velocities for most inlet control conditions. In outlet control,the average outlet velocity will be the discharge divided by the cross-sectional area of flow at the outlet.This flow area can be either that corresponding to critical depth,tailwater depth (if below the crown of the culvert)or the net cross section of the culvert barrel. 30222/3 841218 3-41 - - .- - 3.4.3.8 Inlets and Culvert Capacity.Inlet shape,edge geometry and skew of the entrance affects culvert capacity.Both the shape and edge geometry have been investigated by recent research but the effect of skew for various flow conditions has not been examined.Results show that the inlet edge geometry is particularly important to cu1vel:performance in inlet-control flow.A comparison of several types of commonly used inlets can be made by referring to Charts 2 and 5.The type of inlet has some effect on capacity in outlet control but generally the edge geometry is less important than in inlet control. As shown by the inlet control nomograph on Chart 5,the capacity of a thin edge projecting metal pipe can be increased by incorporating the thin edge in a headwall.The capacity of the same thin edged pipe can be further in- creased if the entrance is rounded,bevelled or tapered by the addition of an attachment or the building of these shap,es into a headwall.A sketch on the nomograph,Chart 7 shows the dimensions of two possible bevels.Al- though nomographs have not been prepared for other barrel shapes,the capa- city of box culverts can be increased at little cost by incorporating a bevel into the headwall.In computing headwa.ter depths for outlet control, when the above bevel is used,k e equals 0.25 for corrugated metal barrels and 0.2 for concrete barrels • 30222/3 841218 3-42 3.4.3.9 Procedure for Selection of Culvert Size Step 1:List design data.Drainage Structure Design Data Sheets 1 and 2 are provided for this (see following two pages). a.Design discharge Q,1n cfs.,for required periods (i.e.Q25 or Q50 etc). ,.... b. c. d. Approximate length L of culvert,1n feet. Slope of culvert.(If grade is given in percent,convert to slope in ft.per ft.). Allowable headwater depth,in feet,which is the vertical distance from the culvert invert (flow line)at the entrance to the water surface elevation permissible in the headwater pool or approach channel upstream from the culvert. ..... e.Mean and maximum flood velocities in natural stream. f.Type of culvert for first trLa1 selection,including barrel material,barrel cross-sectional shape and entrance type. Step 2:Determine the first trial S1ze culvert. Since the procedure given is one of trial and error,the intitia1 trial size can be determined in several ways: r I I r 30222/3 841218 a.By arbitrary selection. 3-43 F" DRAINAGE STRUCTURE DESIGN DATA SHEET 1 Location:Township --------- Section Range Meridian -------- -Project Feature:(Project access road,material site access road,etc.) Station: Type of Water Course User Fish Group (A &B Type Watercourse only) A I B II C III IV Drainage Area: Culvert Type: Size: acres Other --------------- -I Slope: V,Q2: HW/D,Q2: Attested to by: Fisheries Biologist A849/DATA-SH.l 30222/3 841218 ft/ft Length: ft/sec V,Qdesign: %HW/D Qdesign: 3-44 Design Engineer ft % ft/sec Drainage Structure Design Data Sheet 2 r PROJECT:DESIGNER: DATE: r-H'tDfQ..OGIC AND CHANNa.INFORMATION SI<ETCH STATION: El.- I""'"Ar--_L ~1.....0 1 -TW I =-±-.~-TW_Oa -TW 2 =),s • EL._ft -0EL.--L·- """ALI.OIVABI.E OUTLET VELOCITY ; HEADWATER COMPUTATION ~>r ......CULVERT HW·'H +1'1 0 -I.So Q:..1-INLET CONT.OUTLET CONTROL ...u COST COMMENTS:»0DESCRIPTIONQsized+0 g oU:WUlI HW ICe H de ...:.tr TIV h o I.So HW(ENTRANCE TYPE 0 v >.... I ~ - ""'"SUMMARY.RECOMMENDATIONS: I""" 30222/3 841218 3-45 ,~ - b.By using an approximating equation such as 10 =A from which the trial culvert dimensions are determined. c.By using inlet control nomographs (Charts 1-7)for the culvert type selected...HWIfth1smethod1Sused,an D ....., Step 3: HW ..must be assumed,say D -1.5.and the g1ven Q,a tr1al size is determined. If any trial size is too large in dimension of limited height of embankment or availability of size,multiple culverts may be used by dividing the discharge equally between the number of barrels used.Raising the embankment height or the use of pipe arch and box culverts with width greater than height should be considered. Final selection should be based on an economic analysis. Find headwater depth for trial size culvert. a.Assuming INLET CONTROL (1)Using the trial size from step 2,find the headwater depth HW by use of the o!Ilppropriate inlet control nomo- graph (Charts 1-7).Tailwater TW conditions are to be neglected in this determination.HW in this case is . .HW b .found by mult1plY1ng D 0 ta1ned by the height of culvert D. from the nomographs 30222/3 841218 (2)If HW 1S greater or less than allowable,try another trial size until HW is acceptable for inlet control before computing RW for outlet control. 3-46 - ..... b.ASSUMING OUTLET CONTROL (1)Approximate the depth of tai1water TW,in feet,above the invert at the outlet for the design flood condition in the outlet channel.(See general discussion on tai1water,3.4.3.6). (2)For tai1water TW elevation equal to or greater than the top of the culvert at the outlet set h equal to TWo and find HW by the following equation (equation 3). HW =H +h -LSo 0 where HW =vertical distance in feet from culvert invert (flow line)at entrance to the pool surface. H =head loss in feet as determined from the appropriate nomograph (Charts 8-14). h =vertical distance in feet from culvert invert at outlet to the hydraulic grade line (In this case h o equals TW,measured in feet above the culbert invert). So =slope of barrel in ft./ft. L =culvert length in ft. .....(3)For tailwater TW e1evaticIOs less than the top of the culvert at the outlet,find headwater HW by equation 3 as in b (2)above except that - - 30222/3 841218 h ==----a 2 or TW,whic:hever is the greater. 3-47 where d c =critical depth in ft ..(Charts 15 through 20 Note: d c cannot exceed D D =height o~culvert opening in ft. Outletcussionsunder3.4.3.5 Culvert falls below the value D +(1 + Note:Headwater depth determined in b (3).becomes increasingly less accurate as the headwater computed by this method V2 Ke)Zg (See dis- Flowing Full with - Control). - c.Compare the headwaters found in Step 3a and Step 3b (Inlet Control and Outlet Control).The higher headwater governs and indicates the flow control existing under the given conditions for the trial s~ze selected. d.If outlet control governs and the HW is higher than is acceptable,select a larger trial size and find HW as instructed under Step 3b.(Inlet control need not be checked, since the smaller size was satisfactory for this control as described under Step 3a). Step 4:Try a culvert of another type or shape and determine size and HW by the above procedure. - Step 5:Compute outlatvelocities for size and types to be considered in selection and determine need for channel protection. ,.... a.If outlet control governs in Step 3c above,outlet velocity equals ~,where A /Z is the cross-sectional area ofo .0 0 30222/3 841218 3-48 flow in the culvert barrel at the outlet. "... less than the corresponding to area of flow. sectional area A height of the culvert dc or TW depth,whichever Ao should not exceed of the culvert barrel. If d c or TW is barrel use Ao gives the greater the total cross- b.If inlet control governs in step 3c,outlet velocity can be assumed to equal mean velocity in open-channel flow in the barrel as computed by Manning's equation for the rate of flow, barrel size,roughness and slope of culvert selected. Note:Charts and tables are helpful in computing outlet velocities.(See COE 1944,King 1954,USDOC 1961,USDOI 1957). .... Step 6:Record final selection of culvert with size,type,required head- water,outlet velocity,and economic justification. Design examples of the above pro~edure are presented on completed examples of Drainage Structure Design Data Sheet 2 on pages 3-78,3-79 and 3-80 (USDOC 1965,Engr.Circular No.5)• 30222/3 841218 3-49 3.4.3.10 Inlet-Control Nomographs Charts 1 through 7 Instructions for Use 1.To determine Headwater (HW),given Q,and size and type of culvert. a.Connect with a straightedge the given culvert diameter or height (D)and the discharge Q,or ~for box culverts;mark . ..HW ( )1ntlersect10n of stra1ghtedge on Uscale marked 1. b.HW HWIfn-scale marked (1)represents entrance type used,read-o on scale (1).If another of the three entrance types listed on the nomograph is used,extend the point of intersection in (a) HWhorizontallytoscale(Z)or (3)and read U.Compute HW by 1 .l'HW bmut1Py1ngn-y D. 2.To determine discharge (Q)per barrel given HW,and size and type of culvert. HWa.Compute n-for given conditions b.HWLocaten-0n scale for appropriate entrance type.If scale (2)or (3)is used,extend ~Wpoint horizontally to scale (1). HWc.Connect point on n-gcale (l)as found in (b)above and the size of culveft on the left scale.Read Q or ~on the discharge scale. d.If i-is read in (c)multiply by B (span of culvert)to find Q. .- 30222/3 841218 3-50 3.To determine culvert size,given Q,allowable HW and type of culvert. a.Using a trial size,HWcompute·D HWb.Locate D on scale for appropriate entrance type.If scale (2) (3)•HW..( )or ~s used,extend DPo~nt hor~zontally to scale 1. c.•HW ( )Connect po~nt on D scale 1 as found discharge and read diameter,height or size HWi)Value. in (b)above to given of culvert required for ,..,. d. 30222/3 841218 If D is not originally assumed,repeat procedure with a new D. 3-51 -12 CHART I 600 ( I)(3) ~oo EXAMPLE 10 400 ".2'Ba.0-75c:', Q/8 -I',fI/ft.8 300 tru.t IotW IotW 10-'eet !5 6III1.15 S., 200 (2)1.90 5.B 5 (51 2.0'4.1 4 3 100 Q 2 __ "'-~ ~2 /1- ./%:1.5 ,/ .,.2 ~ /'%1.5 ....~0.'"\.~en./'2 20/ac: ~l.0... Z .9 1.0 10.......~% I-.,ft'''"Q,. 10 'lor.~W .8 .9 9 0 8 CI:w .8 ..at-.1 -«6 ~ 5 0 2 SCALE WINGWALL «.7 .7w 4 0 FLARE %.6 (II 30''0 15' 3 (21 90-aftd IS·.6 "6 (31 O·(ell.ft,.on,-.5 2 0''tldl") .5 5 Te ••••ell'll (Zl or l!)prQ'.'f .....,••"n'to IC."t I)I '''.'' _.-_.--. iii'.'tf'.I'~'lftcllft.'IH"'.Utrou,..4 D ...Q .c••••.0''....n.01 .iH"•..,.,.4 . .1 .4 01- .S .5 .30 .35 35 II 10 7 8 9 - ..... to- ~ lo.t.... ~ F"§ ~ al .... 0 to- %: <:) 1M % .... -HEADWATER DEPTH FOR BOX CULVERTS WITH I NLET CONTROL 3-52 110 10,000 CHART 2 II'',000 EXAMPLE (I)(3) 158 6,000 0-41 lIoc'"13.5 'Nt) Q-'ao cto i". -144 5,000 132 4,000 U·"-5. IfJIlQ D ,Nt 3,000 II)a.s I •• 120 4. 2,000 [2)1.1 7.4-loe 131 t.t 7.1' I 'D i.'Nt 3. -91 1,000 3. ~800 -84 600 //2:- 500 / 12 400 /2. '"w 300 ,,,,V :c ~~Q 1.5 ~/ ~10 200 /1.5 §/' 54 g / l-ea::/101 100 IU 48 /'~>80 ...I /'ell::c ~ Co)""42 %60 l- ~4.1.0 II.en 50 w 0 Q H;SCALE ENTRANCE Q ea::40 TYPE ea::l.0 IU 36 .... l-30 ~.9 .-IU III Sq,.,.M,••1111 e :I 33 II.U••l1 :s .9 ell: Q Q 20 121 Gro........4 ••tlt C( "... 30 h.od.ol!%.!.8 ~131 Groo..I.d .8 27 projoctill' 10 24 8 .7 r'" .7 .1- 6 To utI Icol.IZI ..i3l P"lOcl 21 5 II ..iu.'oll,r•.col.(II.till. 4 u••itrol,II';IICIiIl.d Ii...'"rou,1I ......o olld Q 1C01 ...Of ,....II n 3 ,lIl1otr.'o'. .6 .6 II .6 2-15 .5 .5 1.0 .5 r .... 12 HEAOWATER SCALES 2113 j:l£VISEO MAY 1964 3-53 HEADWATER DEPTH FOR CONCRETE PIPE CULVERTS WITH INLET CONTROL CHART 3 -151.'1I 3000 EXAMPLE Sil.'18·,4"Q.sao ~..(2) 138.11 2000.....~.HW('''')4.0 '121.71 (II 2.1 11.& (Il 2.2 1.1 3.0113.72 (S)2.S '.2 ·0",'_ IOe.8.--·".83 -2.0-'--- ·91.,.400 -""~'-,-CIt 00 -1.5 IAI .3.53 Q ::c -....Q .-1.5-:z:!-z ""1i a 48 ...-To u".0..«II.,())en IAI CIt ......"'..i""II".lI:~Q. i:88.43 •100 tfW........_.......•g .,.......4 diecll.....0 ..A !eo ,.i....'..e.ICIII.Ill.\.0 1.0 C en 1.0>-,,_I'••lIll Ie'"(I):2080a31260".jft'~..j_••I,r.lI:.9 .9•..........11_Oft ........e •••1M .9 0 Clt '0 (21 _'51.l- ll:! '3.34 e 40 ••~::c ::c .8-Q :-30 I- 4'.32 en Q.•Q ... Z Q .7 .7:20 .1 45.29 III: CIt "WID ... ~-ENTRANCE !C...42121 SCALE TYPE •N t- in Q .8 10 (II ............,,,e... 38 124 8 110••••11 % lal G,__.._ 8 ~"',",I .5 5 lSI Q,.".'''d 5 ~4 lIt.joel,,,, 30al9 .3 .4 .4 4 2 8 1 •0 ~1.0 _1 &3.14 HEADWATER DEPTH FOR OVAL CONCRETE PIPE CULVERTS LONG AXIS HORIZONTAL WITH INLET CONTROL ~IUIII""~llUalC IlOAOI JAN.1M3 3-54 - CHART 4 .44.4 (2)(3) 6 (I)6 5 5 6 4 5 4 4 3 3_ :5 z--2 1.5 -'.5 \AI !!! II: I'- 0 en 2 1.0II:1.0 \AI 1.0... !9 9 9 2:.8 "..... \AI Q C .7 7 iii ., ~~ Q .6 C \AI 2: 5 .5 ENTRANCE TYPE GI ,........... ;t . .':I,ec t ••, EXAMPLE •D i.I••• "Wf"'" Si..:3.",10' 00100 ef. I--I~ CD t I I I I . o I l til I I IS a II)10 '00 13)1.1 10.S III S"11 "11 13) 121 T ,.12).,III .....sf,..,llt . '"....."a"._••,.. .f "'",.CIt . I.i"'.,,Ie II,. ,._I"'"IUf.[I' I.oj.el 11.".."••11,I.M""''''.lIt •.,It.,,ea6e 121,'(31. 2000 3000 5000 4000 HEADWATER DEPTH FOR OVAL CONCRETE PIPE CULVERTS LONG AXIS VERTICAL WITH INLET CONTROl. Z 100 80 60 50 40 30 HW!O 20 SCALE 1.0 10 8, 5 4 1000 lOa 600 500 400 300.----ZOo 14_21 19130 ,.,1151 871136 771'ZI 72 I 113 ,e1106 63_,. 58_,. CII \AI 531832:g !" !"./ ----CII ,/I'- ,/U ----!,/ -----38.60 ~ \AI '"C-34 _53 c \AI 2: !!ucCII •3Z _4'a z:2'.4'!! W 27.42N in 24138 ..... .... - - 3-55 CHART 5 '.5 .5 2. ,,, 1.0 .9 .~ ,8 .a ,7 .7 .6 .9 1.0 2. --~ (I) 6. (2) (3) 15.6. 5.:___6. 4.--- ~ 4. 3 .4. 3. 3. _.-'.-S"'" //'-; /~:: lita:: W I- W ~' el Q z :z:: ~ Q. W Q HEADWATER OEPT~FOR C.M.PI PE CULVERTS WITH INLET CONTROL EXAMPLE HW'HW T (h.fl III ..I '.4 IZl Z.I 1.3 131 2.2 I.' '0 i"t ••• D.3.j"d..13.D f ••" Q...ct. TG •••lui.eZI G'(3)D'.'OC~ "'o,u:.,.teU,'.ICOI.P),'''en u••,tt.j,",'.'.'''14 Ii".'"..a''q''' o G-ful Q ,c.I••~.r 'tJllt"01 ilh"t'Gftl•. HW SCA ..E ENTRANCE .,. 0 TYPE ..... I- el (I)"'dideaU ~.8Q (21 ""p.'ofd 'A r::.:Infat ...Cl W fa Ita".:z:: IJl Pr-ajl't,nt .7 lOOT 10,000 use e.ooo t56 6,000 ~.OOO 144 4,000 132 I 3,0002 120 ~ III 2.000~ Cloe........c 96 !1,000 ~ U 800::I•..60084'" I ~oo 400 72 , I 300 1 lit lI.200eoC,) ~ 54 § w -100 ..;- <:) 80/"41 a::ce .:z:: 42 .........:;; .,/Q /' 36 33 30 27 10 8 -24 6 5 21 4 3 18 2 115 1.0 12 lit W.:z:: C,) ~ ! § I-a::w>~ ~ C,) lI. 0 a::w I- W ~ el 0 II u 0a.« Qz«,. ,n - .- .....3-56 CHART 6 .55 (I) 4I"'(2)-....-_.-;..-.-_.{3l . 3 ~4 ~3 -f-e I ~I ~I.S 1.5 ~1.5· -'------ a 1.0 ~1.0 1.0!.~..••111en .9_ II:.1...~.1 0 en ••2 II:.7 ~.7 .w ~ z .7- z: ~....1 .1-••1M Q .1 II: i Q C ~.5\AI I-.5 .5z: ~...4 .4 .'5 '.'s HEADWATER DEPTH FOR C.M.PIPE -ARCH CULVERTS WIT H I NLET CONTROL EHT"ANCE TYPE NW-N_ T I"'" 1.10 1.0 1.11 ••1 1.11 I •• MI'er".............. ""..'1.. .EXAMPLE SIze:51".II' 0"10." lit IttI. 1-1-1rn Itt IleMWIf Itt 100 5,000 .,000 5,000 1,000 100 100 500 400 300 1,000 10 • I 5 '",.-_I,lit"151 ....1.' I ....1••'..1,It ttl,,tIM _t",I,M I tIlr . o '"0 H'IN,",ner .. I .III."..... 1.0 •• •ll'-Id••-.- 9'·1"iI "-5" 1'-1".4'·r 1'·r.Ir·.- ,.-I'" IS-.'.' II'.tS' .7'·0"•5'·1" -1Men••a Zen- J ••.1 ..AClDtTIONAL _UI ItOr Dt.....IONED Alii LIITID III '''.ICATOR'.eATALGe - 3-57 CHART ", 3.0 .52 .52 3.8 •••• 10 A • 11"11,1,'...... ......100· •t t t 1.'••*1TYltI 0.041 o.lMS 0.04'o oas • o.ou 0.'"0.04'G'I.I -Q•2.0 % Z.O; IE ~.. ~"5:I 1.5 c 2S ! % t-lL ~ Q III:.....c "01.0 !cw %.S ,1l,,11!!=-'----------••0 .J .1 .7 tlO..,., i f. 158 ro-114. '151 120-loa 9. a4 7Z CIt 1M %g !60 !! S 54 CIt-.....g III: 4'!1M ~-:2 g g w ~41 e:t~ III:% 1M &oJ..3.en1M2Sr-:Ic 33Ci ----sO-Z1 24 ~ 21 ~II 15 I;..HEADWATER DEPTH FOR CIRCULAR PIPE CULVERTS WITH BEVELLED RING INLET CONTROL 3-58 .... I i 3.4.3.11 Outlet -Control Nomographs Charts 8 through 14 Instruction for Use Outlet control nomographs solve equation 2,paragraph 3.4.3.5,for head H when the culvert barrel flows full for its entire length.They are also used to determine head H for some part-full flow conditions with outlet control.These nomographs do not give a complete solution for finding headwater HW,since they only give H 1.n equation 3,HW ==H+h -LS o •r-0 !(See discussion for 3.4.3.5 Culverts Flowing with Outlet Control)• 1.To determine head H for a given culvert and discharge Q. a.Locate appropriate nomograph for type of culvert selected.Find k e for entrance type in Table 3.4.4. b.Begin nomograph solution by locating starting point on length scale.To locate the proper starting point on the length scales follow instructions below: (1)If the n value of the nomograph corresponds to that of the culvert being used,select the length curve for the proper ..... ..... k e and length. see (2) locate the starting point at the g1.ven culvert If a k e curve 1.S not shown for the selected k e , below.If the n value for the culvert selected -i 30222/3 841218 (2) differs from that of the nomograph,see (3)below. For the n of the nomograph and a k e intermediate between the scales given,connect the g1.ven length on adjacent scales by a straight line and select a point on this line spaced between the two scales in proportion to the k e values. 3-59 (3)For a different roughness coefficient nl than that of the chart n,use the length scales shown with an adjusted length L l •calculated by the formula 2 L l =L[~]See instruction 2 for n values. Using a straightedge,connect cu1vert barre 1 and mark the c. line."See instruction 3 point on length scale to size of point of crossing on the Uturning below for size considerations for - 2. rectangular box culvert. d.pivot the straightedge on this point on the turning line and connect given discharge rate.Read head in feet on the head (H) scale.For values beyond the limit of the chart scales,find H by solving equation 2. Values of n for commonly used culvert materials. Concrete .- r ! - - 30222/3 841218 Pipe 0.012 Boxes 0.012 3-60 Corrugated Metal Small Medium large Corrugations Corrugations Corrugations (2 2/3"x 1/2")(3"x 1")(6"x 2") Unpaved 0.024 0.027 Varies* 25%paved 0.021 0.023 0.026 Fully paved 0.012 0.012 0.012 *Variation in n with diameter shown on charts.The various n values ...... ~ r have been incorporated into the nomographs and no adjustment for culvert length is required as instructed in lb (3)• 3.To use the box culvert nomograph,chart 8,for full-flow for other than square boxes. a.Compute cross-sectional area of the rectanglar box. b.Connect proper point (see instruction 1)on length scale to barrel area*and mark point on turning line. - ..... c.pivot the straightedge on this point on the turning line and connect given discharge rate.Read head in feet on the'head (H) scale • *The area scale on the nomograph is calculated for barrel cross-sections with span B twice the height D;its close correspondence with area of squart boxes assures it may be used for all sections intermediate between square and B =20 or B =1/20.For other box pr6portions use equation 2 for more accurate results. 30222/3 841218 3-61 --J 1 ]J J 1 1 1 I -1 1 I l ~ l, ii f til ~ l' ! DISCHARGE (Q)IN eFt ill i 111"";"1"""1 i!·'·S'I ••·!..,···,····.····.····,'1'.',"'1'1""1'1111,1111''''1 II "'··0 ~:;~:;::~OO-~:;~~l!:30 ~~~S ,0 000000 0 008o0 0 0,t DIMENSION Of SQUARE lOX IN FEET 0"''''- -N':",:.."'.~.III~;:M .,N M tot M •X M M X ac _ _ N ill COl "'..'"•~.1II0 lit I I I 1'1 I'IIL--JI,'Ii', ,I I iii i 'I iii I i iii 'I iii I r I r-- ""'IP .0-N""''''••0~,0 0 0 0 0 0 0\+.,"~REA OF RECTANGULAR 10)(IN SQU~RE FEET 'U.IIII1.Lilli---------- ."Ii I Ii iiI'1'1 iii Ii'ii'Ii I Ii II I""I "T 'I '--I,-I ,-,0 I N 0 ........lot N fiia G1Uo"o o ::J: J> :0 -f Q) IIi' h Ii II~;JI.... • •-c 1!I i~:'I ...~t.,r "4 II I &.. •fi~r .......• ••.0 .0.0 \t ct '" So ,.. +-., ~ ~~ ~ 4..'" "'b .',,~ \I"!\ "'1 \ •HEAD IH)IN FEET \\ \\ \\\,\ \~~V. ;·b~~~'I. \...\~OO \"0.\o \lrCb \~OO \ oozo::u .....ITI '-t X:J~ITIITI II zm » °GlOOoX..... -.....0 I\)CO:U r-Cr-r-<ITI :0 -ten w I Q\ N -: CHART 9 ,..OUtllt CIO_ItO'..iII••"._,COM..,t."\II tI, ...411c14 c","'''oc .. a 6 10 .4 8 ,5 6 -:i o-~--_!"0 7!Z!!!!!&',-==I j ~~~~i()",,,,,~~!O!~...-;..;i!'+-;;;;)'ll"~--::~"""':S~--_;L~'---,SlOp.0-~7IT"" SUIMEItGlO OUT~ET C~vEItT 'I.OW'NG 'U~~"W.M."o-I..S. 27 21 134 24 120 108 36 33 72 66 60 ,42 2000 1000 BOO 600 500 400 300 2CO II) 1.0. U ~II) l&I-X :!u100Z l&I ~;<:)«8 - C .:l%... U SO Q::II) Q l&I 50 I- """40 2 <II: Q 30 20 - ..... 18 20 ,·10 15 8 6 5 i2 -4 HEAD FOR CONCRETE PIPE CULVERTS FLOWING FULL n .0.0 12 3-63 ,"'" 2000 CHART 10 6 4 0.4 0.5 06 0.1 0.8 0.9 1.0 .,00---..-.. -~O --1 8 9 10 f •·o~.,0 f•'0.~ ......".,c ,...."'....~._lOW., ...........Cl 1ft ..,...,p ..,.1141.... '¥'f 7 D......"".;;,."""""II'!~le:M....i:~L__(_~~_~__....~,j ft.=- $>0"~o-~r"", SU,,,UGlO OUTLlT CUf"y(ItT 'lDW.IltG 'ULI. MW ........-l..Se ---- D ""Ie".Gr. or I tl R-O'l.,,,ro' '"_'oUott...r ,1"0"",e'ftef."f.'1 0"".".,tlc.1 "'OTE ---- ,315187 3'.24 4512~ 421121 n143. 151.97 121.17 113.12 106." 98.f3 91158 IIhU r6 .... '013'--$3.~"it 32 1000 100 600 500 40O 300 200 enw fit ::..Co) Co)! !!a ~•.!C.2 --_\AI III 100 !I!1::1 1ICII: C 110 •::zucen~Q 10 en-SO W Nen40 30 20 ..... P""" 23114 10 II 6.....5 1I.l1II~OF 'U'I.IG 1l0AOS ""'''.1'13 20 HEAD FOR OVAL CONCRETE PIPE CULVERTS LONG AXIS HORIZONTAL OR VERTICAL FLOWING FULL n-0.012 3-64 -I - CHART II 2000 ...I \TH .....t 'V'a "'.1000 i ..--..I ft..Sa•::., ::I ~VJK...VJiii'W!;;c ~~100 ..510'.S.-.6 SU_"G1D oun.n eIA.Y(IIT 'l.QW'"G 'Ul.. 100 120 14.........-L5. 500 10e ,.,hi....CN.................4.ee.........w.1;1,.8..till....--.ct.............'II.......,",Oc.d...-"00 9'LO 300 84 f'qii.. ;j>.,0 200 12 0:4~<~~o~lSI .. IA.I 2 60 .,Q""'...'<... lAI ""'"... '4 \.,~! 100 In A ....--3w~Q~\\~% %...-.0 U CI !42 ~.\~~c /''''.IA.I 4 80 !% '0 -/-1.0°!0-36 /\ 40 II:33 ./'..'\'!lOQ ·6 OoU !AI _____-!!.AM"l~~..\ . ,---I- 30 WI 30..c.-t.'--~~.o~taQ'8C211"'"a 20 10 24 21 ~oo to I a 8 20 r-'.15, 4 11 -3 Z HEAD FOR....STANDARD C.M.FjPE CULVERTS FLOWING FULL "'.111 CI''WltC 1106111 .....,n a 0.024 3-65 CHART 12 4 3 2 - 4 5 6 ~....1........8 ~.9 %-10- '¥'f I HWt I !~~""G",~...,.,,,,~..,~bRilIICC---~Sj-a/l-.-:"So-_----'''~~ SUeMllIGt:D OUTI.ET CULvERT FlDWllIIG FULL -liIW ...".1\0--1..50 6 ,.,_rlef era.....,f'U.CDMO'II'....by _.....d_ro.1I III '110 d ,,,IlI'OC.IIu,. 7 8 -9 10 '"'Z III i !....~.. 29"Xtrf 3ft'X22" 25·XIft' -11.1 In 20 ii JC Z cla. In .... N iii 10 9 8 7 6 5 4 3 300 .... "II: C % ~ In 2i 200 ..... 100 r-90 80 70 60 2 HEAD FOR STANDARD C.M.PIPE-ARCH CULVERTS FLOWING FULL n=0.024 3-66 CHART 13 '"'"eooo 4000 :E..:::_5::: 5000 SUIIIIRGED OUT"CT CUl.VEltT 'UlWIIlG 'U...._.".-.-..s. 180 ,.....Iet c_...--...e_t.HW .., 'M __I _111M ill ,...._....._. 2000 Ie.2 144.,... X 152u ~3 1000~120 C!,p,+..p (~...... I 114 ~,,~.....Cl <;)"'So,...800 •101 ... III 100 II:.pO <,...!u ...102 ~e...I.....xi!2 9.~I 6•..Q 0 Q 90 ""cw•~'If:P T w .... ,~..~T'L'8II:!·c 2 ~~9:J:11u0 .--------'"Z Q ••~..~~10 is 500 ~~2-- I "·13.•~--0'tj:) 68 200 Lao .s .00 \-,.Ie .....~i ~\.'r,.!~ ~~)- ~.:l0 20 .- 100 eo 0....It S'O_OUI T'0_0520 10'0.0:511 IS'0.0:501 30 40 50 HEAD FOR STRUCTURAL PLATE CORR.METAL PIPE CULVERTS FLOWING FULL n·0.0328 TO 0.0302 ..... 3-67 ,.... '"'"' 3000 2000 CHART 14 sua.IIRD OUTLET CULI/EIIT 'LO'lIIING 'ULL HWo H ......l.SO ~OIl''''cr ••R RDI .uII"'..'....c."'!IU'.HW '" ..........ncriHd 1ft ,ft.dU...."roc._" I &.6 I 10.1 61.4.6 1000 ... 800 w III........ ~ &00 % In ~...II: U ~OO C•i!III •IL 0 400 ~ I ~... ~0 IZ:-C III %300 ~U II:!!--Q Z f lit 200 -III !:::!en 1~3 I 9.2 12.9.8.3 11.4.1.2 1.0.5.I Si,. 6.1 I .... I.'IS.' II."I 1.Z 16.1110.' O.ouy 0.0321 a.031S a.0301 I % Io C III % 2 ! 6 8 9 10 100 50 IIUIIIAU 0'~l.IC 1I0AOS ,jAN.I~ 3-68 HEAD FOR STRUCTURAL PLATE CORRUGATED META L PIPE ARCH CULVERTS 18 IN.CORNER RADIUS FLOWING FULL nil 0.0327 TO 0.0306 20 r...........--- ----~ ---- ,.,,-I ~ ~~I I j - I ~....CRITICAL DEPTH -~_-L--1__I , i/REcr"-N6WLAR SE.C710N /f I I I I'I --+----j !.-4-- I : - -- 5 ..=u.3 z-~2 "0 oo 10 20 40 CHART 15 50 ~ 16 ,"""I !;Ie I j I ; !114 i i !j : I 1 I I 1 I :i :!I ,"I.I 13r-IIZ ..,:1 I ~ I Z 10 ~ ~9 8 7 j !; !I I i I i, I i 1 i j , \i i i ,I,I, i ii I " I ' I I :,i I ~ I 6 A ~: )I !S ) 4 SO 100 ISO -NOTE;de C.1NNOT EXCEEO D lIultUU f)II PUIlL'C ~"()S ......19113 3-69 ZSO 300 3S0 ..- - 3..... 2 fj1'!lilIlII! .- CHART 16 ~iI ~3.~I •(I'I ~I i de CANNOT EXCEED TOP OF PI PE I ,.J.rt/fZtJ Il.~ 1-t·O'DIA. I 10 20 30 40 '0 60 OtSCHARGE-Q-CFS 70 so 90 100 6 r---r--,---,..-or-!,",,",,!"-"'T",-"""'--"--'!-""'-,r---r--,--!-r--r-!"""T'-""""--""-'Si:'~:I I I )I :___ 300200100 !~~:Ii'l~ ,l---+--+--+--+---t--+-:~"""'''V''~-+-I---+--+--r--±::;:OO~O=:;''-r---t--+---j7~....r-l/~~I I I~I I ~r--l-+-+-:~~~~f'l"9V-t-il-t--iI ~~A~~~~~;-9-'+_I,-+'-"++-t-tl---i 6 ~~u 4 ~~F"!!t:/7'i !I!'U ;.S'i I I i I I ~ a.1-_1--h/~h0~·~'+-~_+--+_+---t'_+-~~dC CANNOT EXCEED TOP OF PIPE ..~ w 3 V""l'.,'I j'I I I 1---+--1~a. Q I /"~6'I Iii i i!UI -'i/4"!,;'I i I I I,I ~--r--0 c(.I'4'"OIA.;I I I i I ~~2 0.....400 ~~O 600 100 600 900 1000 ~ DISCHARGE -Q -CFS ....~~ ~,~ 14 r--......-or---~"""T'--......,.-----r--,..........,...--...,..-.,...--~--r-...,...-.., 4 Olo--.....;..~........=-""---I--.......----.......~2..0~00..,............--_......--'-...,.........--I._.......----.......-40.-l00 DISCHARGE -Q -CFS CRITICAL DE PTH CIRCULAR PIPE _-i--....:dC CANNOT EXCEED TOP OF P.;.;IPE"="_-l I BUREAU OF PliSLI·:"CAOS JAN.iS64 +--+-....,..."'7"'?_",...~--r-~;_-L-......~f-~'----.--i-......;.....--1 i-~.__---:..-~---+-__i---l ;I 1--.....;..-.;...--+-..,~'7'f.>-'--i--+--!--.L-~'-+--+--+---+-+--+--+-""'--1~-+---1 r--'---------+-!-'--........-----......._- I Z ~--+--+--I--+--I--+---+----+----- i 10 1-----------+----.+---i--+---i-~~?_"~- ..- - 3-70 ~ [ I .... 3.4 3.0 .... CHART 17 i ..,~/ 2.0 1--I--Io-+--+~---lV~iofV~oF--+---II...--+--+--+--+--+-+--+-i!-1-+-"'1"'1--1 A~V :__ ~~V de CANNOT EXCEED TOP OF PIPE t-!_ /,~~/!I,: 180 I I 160140 45·s29"I I I 38"s _2!',-a'-.+--+---+-+--+---i~+--+_+--+----II_-+--+_j---+---+-';'--i f I I i ·sI4·i:I I f I,~I........r---IiI.-~,.........r i I i ,I I 20 40.60 80 100 120 OISCHARGE-Q-CFS ,, I I.i .i I i I !i!I I 'i I~~!_VI !-!to-- i I I ---'~~!!---l--t-""--I--i---l--+-+--+-......,j.,...r;iojICo--+:"....e:;j..---r--------+----i--~- j 'I ~~~~!I I!i-'-:-r-'---- I ~~vy i !:" "~V/'./"'I I I . " I ~V ....",i '::I I I " I---'!I V //......'I de CANNe-":{CEEO TOP OF "'~E -----.~07/,i I.._---+I 1---.;1_....1_---1 :3 ~:;/::!I.i .I ::i ,h 10'1 15 1 '\97i I -7""--~-r-t-.-.+-r-+.-'-~v i !::I I!'I 2 .106~~~~~7 j!!;.i";I .I ~'+-"I'-+--~-t--+-+--T --t---ir---+---+-+---+----i-..-~"----.....-_.91·.51:!I I,I .76".148"SCI's 38"I,i IIlI====~~~-i.._L..l_-L_L..L-L_L....L..-l_L...L---L_L...L__l o 100 ZOO 300 400 ~OO 600 700 800 900 1000 OISCHARGE-Q -CFS 6 ~ 5 ~ 4 - BUREAU OF pt;aLiC ROADS ,jAN 1964 CRITICAL DEPTH OVAL CONCRETE PI PE LONG AXIS HORrZONTAL 3-71 CHART 18 i J::.:;;; ----....-::~~i ~c:;-.,......-i Ik::::::=-t-.-::;...-VI""!~~ -----~~~"...I IIIII ~~V --f- A ~j I I I I ~~"=:::"'3.""I l'.IdeCANNOTEXCEEDTOPOFp'PElIi3.·....i I I -T-- 29".45·:1:24·.38" I !I I14'1123··Hi--; I I -L.!I pJ-.=j !I I L-~100 .-;....-I I 1 I l V I-"""I I I ~,.....----I i--!~V ..........~........I .I I:i --I,.......-'i : .......~~~V io""'" j -+-:; I :,......- J.-t---+--I ~~7-"""-1 II!I I ' , ~-97·.15'·I +f'"C'H~T.~~~~TOF,°"1/77·.12'·III //"'-"68'.106·I~;3'.91.I 48·.76" I I I I 1 ' ,38'·1&0"I i -i-i"ti-I -- - .... 4 2 8 6 2 20 40 60.80 100 120 D'SCHARGE-Q-CFS 140 160 180 200 100 200 300 400 500 600 DISCHARGE-0-CFS 700 800 900 looe -I BUREAU OF PU8LIC ROADS JAN.1964 3-72 CRlTlCAL DE PTH OVAL CONC RETE PI FE' LONG AXIS VERTICAL -CHART 19 ,.50 , ~--+--- .-----,-~--- ____-'1---'--0 -~_ (Ie CANNOT EXCEED TOP OF i='li='E ........---_....-. I 20 30 40 OISCHARGE-Q-CFS .'.t . .+--7!~+--'_..~-------........----------,.~--- -_..-,...._-----_..__..--- ---+-"-'!.....--t--.-t-"--------.. -.....-----~-.-..-----~--~____t' ..._-_.---.;..-:..-. --------------..-._~.-""1--- 1-......._._--4-+-......--,.-;-....7f"-'-"I-:L-...:..,.,e.-------.-__----l--+-i-............;..~--'---___4 1---i-~iAI""-'=~!.2X--~----.~-.-----------------'---1 I--"-'!-"tl-------·.-------,--------~--..- Ie -- 2 0 t-.--------~..."".'_7I_..,.,.---------- 2.0 1.8 ~1.6 11.1 11.1...,1.4~.. I % )0- 1.2A. 11.1 Q... C 1.0 Co) )0- cr: Co)as 0.6 04 0 3.4 32 3.0 %:22 I- C1. 10.1 Q ....I ~/6 I-1.4 IX Co)l.2 .-----+-fiV2!..~ 10 I--...o....;-t,i&'£:.1,-::.::,~=-----___.,.-~--_-...;...------------- O.S~--t-A.. 06 r-..-'-__......:....,j__..;.-._...,j,---:._~~----I o 20 40 60 80 100 120 140 160 leO 200 220 240 DISCHARGE -Q -CFS - .- ..... BUREAU OF i='USlIC ROADS JAN.1964 CRfTICAL DEPTH STANDARD C.M.PI PE -ARCH 3-73 CHART 20 --I"""~,'A""" ~..- -'~L,..-'....! ~~~""/....I ~~.",./ ,....; /~Y J'~i ....~"~V V I 1/~./l/,j '//",, /V ./.",, V //""/V V """I I I VV!.r V ; I , /V:/.r de CANNOT EXCEED TOP OF PIPE I I ; A/,/A'I !I i F//.k9-~a 6'·5"I F "=:8'·r·~:9:I i I:r-O"a;-I".I--0'-1"a 4'-•iI! ! I I I II ~...4 w W Ito.....I g "II I:z:... IL 3w ~Q -'Cu i= I"""Gi:u 2 ....I o 100 200 300 400 DISCHARGf-Q-CFS 500 9,......,..-...-_..,..---_-..,.-_-t""--.-...----r-..,.-..,..--,-..,..._-,....-r--r....~ 1---+-_+-1---1--"--.---;---;--+--1-.---.-~_--i-+--+--+' I 1--+--+-N-~4'"--+---+--+-oi--+--+---'IdeCA!'INOT EXCEED TOP OF PIPE ,~! z'-'""""''""-~_I....:-__'_-Io-__--....:...---I.-..i--......--L.-I.-..i--...L..--L._I.-.J--l-......;..---J o 400 600 800 2000 ... ~11---+--+-l--+--+-;.-......-O'-oi--+--+---..,..4il~~~,....c:;;-..;...-+-~--~ ~ '.."II. :z:61-+-:--+-...,....--;--+--t'..,9~~""'..,...a...___.,._"O'--l-__-..;..._c....r---r---i--__I... IL ~"! Q 5 I---l---i--;-------~~~"'-Il"'";".oor;~---_----l-.----r---'------! ...J-e U -.-.----~-:-+-~r--I t::41-..........,.-_*"-7'''7'''~+-+-......-+---.......~----r---i___i_--i----'-....~a:u - 8UREAU OF PU!k'C ROADS .IAN.'964 CRITICAL DE PTH STRUCTURAL PLATE C.M.PIPE-ARCH 18 INCH CORN!A RAOIUS 3-74 3.4.3.12 Performance Curves.The principal disadvantage in using nomographs for the selection of culvert sizes is that it requires the trial and error method described in the text.Some engineers who limit their selection to a relatively small number of types of culverts would find it advantageous to prepare performance curves such as shown in Figure 3.4.12. These curves are applicable through a range of headwaters and discharges for a length and type of culvert.Usually charts with length intervals of 25 to 50 feet are satisfactory for design purposes. Figure 3.4.12 is plotted from the data shown in the following tabulations. These data were obtained from the nomographs contained ~n the text. (Computer programs are available from the Bureau of Public Roads for making these computatios).The first tabulation is for the inlet-control curve on Figure 3.4.12,and the second tabulation is for the outlet-control curves. Data for Inlet-Control Curve HW .Q....HW X 4 D (Read)*D-.5 21 c.f.s.2.0 'ft. .6 29 2.4 .7 37 2.8 .8 46 3.2 .9 56 3.6 1.0 65 4.0 F"'"1.1 74 4.4 1.3 90 5.2 1.5 102 6.0 1.7 112 6.8 2.0 12-6 8.0 2.5 145 10.a 3.0 165 12.0 *(Read from Chart 5 (page 3-56)Projecting Inlet (3)) 30222/3 841218 3-75 DATA FOR OUTLET-CONTROL CURVES Q d C dc +D H HW for Various So 2 ~ (Assume)Chart 16 (Compute)Chart 11 0%.5%1%1.5%2.0% ** 20 cfs 1.3 ft.2.6 ft..2 ft.2.8 ft.- 40 1.9 3.0 .8 3.8 2.8 1.8 .8 60 2.3 3.2 1.9 5.1 4.1 3.1 2.1 1.1 80 2.7 3.4 3.3 6.7 5.7 4.7 3.7 2.7 100 3.1 3.6 5.2 8.8 7.8 6.8 5.8 4.8 120 3.3 3.6 7.5 11.1 10.1 9.1 8.1 7.1 140 3.5 3.8 10.2 14.0 13.0 12.0 11.0 10.0 160 3.7 3.8 13.6 17 .4 16.4 15.4 14.4 13.4 ~ HW =H +h -L5 where h o =dc +D 0 0 2 **(Read from Chart 11-or by Equation 2) The curves plotted apply only to the type and length of culvert shown. Culverts placed on grades steeper than about 2.5 percent will operate on the inlet control curve for the headwater-discharge range of this plot.If a free outfall condition does not exist a correction for tailwater should be made as instructed in Step 3b,3.4.3.9 Procedure for Selection of Culvert Size • .... 30222/3 841218 3-76 HYDRAULlC PERFORMANCE CURVES FOR 48-tNCH C.M.PIPE CULVERT WITH PROJECTING INLET :rY//V I:I ~O •I I I '~O';oVJ I /'......0//lvji~1 I ~/I VI IJ ~/It 1/' I JV/lJ'I !, l/;I/il !I I. I lt~I' .' LIMIT V ~/i' .750:31 ; LL.,....k e =0.9I..../I I ~/n =.024 lENGTH ~200 tt. 1/--iNLET CONTROL -OUTLET CONTROL I NO TAILWATER I/210HW:O+(I+K.J.lf29oa20406080100120140 160 180 200 DISCHARGE (0)CFS 12 ....I I -10 -9 ...,:8-u.-~7 ~-O::sLLJ...,-~50 <t LLJ :I:4 3 2 Figure 3.4.l2 3-77 ..... r I - .... PROJECT;/42 a DESIGNER:L..o.~ DATE:2-/8-64 HYDROLOGIC AND CHANNEL INFORMATION SKETCH STATION:;,2./+I. I EL•..LLL ~A:t=~7 -lQ1=/60 t:.fou Q~o TWI =.$.0 •--*------J' EL./••f TW Q2 =TWZ =So·.0/Y, EL.99 f tL='.O'e 41-MEAN STREAM VELOCITY =8 %.uoc. MAX.STREAM VELOCITY =/0 'lS6C, HEADWATER COMPUTATION Cl) CULVERT z ...>-::; DESCRIPTION INLET CONT.OUTLET CONTROL HW:::H +ho -LSo ..I~1I.It: Q SIZE i::l:..IU COST COMMENTS...0 II de dc+D I-~..1 (ENTRANCE TYPEI HW Ke H TW ho LS o HW ~01&1 0 >2 u c.,p (<"/7:).-...-H¥J MoSS no;.." ~_I(/60,S."tS&7.0 '-S''-7"ry 48"..~~N_N'''h"/"0 48 z.z.S P.O .S 85 ~.7 3.8 3.8 /.0 //.///.//3.Z 1"7'''.$40' It /"'0 ...S 4.1 3."~.I .3 4&//.0 ?OS 7.8 /1.1 ~.....1_,,.,'1 -~de. $4 /.S("?t:J .5.~e tfJ.IIt".c._,.,.,.(c:., /60 48..z.3S"9.4-4.7 ~3.8 '3.4 /4;~c Ho-v II."h..s,.It:I,.-N'ttlwf .S 3.7 ~.8 /.0 7.$'"1".,..,$4-" ,. ~NvV DC.I'/60 540"/.~?Z ,S ~·9 3.6 4-.1 3 4./Lt:J 6.0 7.z./4.7 ~...~;,~:o&'.....c .,.c.,..rIe (}::;.,.) il'60 48 /.9S 7.8 4.0 :J.7 ~.B .3 :J.B /'0 ~.8 7.8 I'4.Cl ~NIN"011:: <i-~e eltd .ND~·Z v,/.""9;' SUMMARY a RECOMMENDATIONS: THE SElECTIOK OF A 54 1 CMP WITH HEADWAll Will KEEP THE HEADWATER BELOW THE AHW WITH A MINIMUM OUTLET VELOCITY.A 481 CONCRETE PIPE WITH 8ROOVE EDiED EKTRAKCE 6IVES EQUAl KW AKD SllBHTlY HIBHER OUTLET VELOCITY.PROTECT 101\OF OUTlET CHAKKEl MI6HT 8E NECESSARY I N SOME lOCATIONS• 3-78 .... I .... ..... I'- ! ..... .... PROJECT:z·4-6 (ij DESIGNER:,J.1'9.P: DATE:2-/8-64 HYDROLOGIC AND CHANNEL INFORMATION SKETCH.STATION:6~2/ El.1/4 -f ,/~.l-AHW=~ °1 =/80 cf,6.u ~S"TWI =.;s$'-L-___ EL/.~/TW..!:£Oz=Z2S'c.';".:=Q.s-D TWZ =4.0 So·...:..E§7- EL9D?tl.=..itl2..R' MEAN STREAM VELOCITY =/oy~ .MAX .STREAM VELOCITY =/4 jI~c. HEADWATER COM PUTATION Gz ...~CULVERT 3~INLET corn OUTLET CONTROL HW=H +he>-lSo ..,!: DESCRIPTION Q SIZE ~:I:...IU COST COMMENTS...0 II de+D :;)...1 (ENTRANCE TYPE I HW I<e H de TW ho LSo HW S 0'" 0 2 U > C/ICCIILA-.t:Mt=III..,.., 60·~1,..,.,..l _II.,,-$;~NW''-":0.J.IHr.ISc:J /.s ?s Da ,c.~".:1- "180 S4"z.z.a,.9 9.1 3.9 4.&3.S 4.2 IDoD 5.9 9.9 ,,,., HlN'-+.,~"/0'1'",,ZZS .54"3.1S'/4.Z.·9 IS:3 4.2-4.4 4.0 4-.4 /~o 9.7 14.z..I'f.Q ~so -7"'ry6c" II /110 6D ..I.GI ?ss ·9 S:9 "·9 4.4 3.S 4.4 ID.D 0.3 Toss 111.7 ".9 4.2-4.0 4.~3.9"2ZS 60 2.1 .10.$9.3 4.6 /1),0 ID.S 17.S" SUMMARY a RECOMMENDATIONs: OUTLET VELOCITIES ARE ABOUT THE SAME FOR EACH SIZE,INDICATING CHANGE IN SIZE HAS LITTLE EFFECT.SIZE SELECTED {50 OR 54.IHCH)DEPENDS ON DESlun's CUflDENCE 111 fLOOD ESTIMATE AND DAMAllE INCURRED If A LARIER FLOOD SHOULD OCCUR.NOTE THAT TW MUST 8E GREATER THAN 10.l' faR OUTLET CONTROL TO laVERN 'OR THE 5.·PIPE fLOWl1I 180 CfS•ACCURATE DETERMINATION 0'TW DEPTHS 18 UNNECES8ARY IN MOST CASES. 3-79 I"'" r .- .... .... PROJECT:Z 8S-Z.DESIGNER:~.19.H. DATE:2·.15-64 HYDROLOGIC AND CHANNEL INFORMATION SKETCH , STATION:3/4 'r/O EL.!!L. A:J=£E-'L ~J..0,=l~ff!__e{4.=QZ$'TW,=$.0 ,-*---;----°2 =TWZ =EL901 So·...:..!!.£Yo EL.aJ t TW 3.0' L =400' MEAN STREAM VELOCITY::;tz'lsec. MAX.STREAM VELOCITY=.IS Y.sec:. HEADWATER COM PUTATION e CULVERT z 1-)-:::i DESCRIPTION INLET CONT.OUTLET CONTROL HW=H +he -LSo ...13:lII!:: Q SIZE gJ:.....,COST COMMENTS1-0 ~de de+D ;:).... (ENTRANCE TYPE)HW I<e H TW ho LSo HW ~OUI D >Z u C,."p (&;"1':)-,......'N"",h.·~;, AJ«·I'.~flJ IZD $"4"I.U -S':6 "-:rry 60" ".7 i 4.9 :#IItr.'"_...c,./&0 60 .91 4.9 2.$3.0 4.0 3.0 4.0 10.iI »I~~c..vrr -r7 ._~ C _P I!Irclt 7a H "'8 Ie c"....A:'~."oA4.·k,../20 .,..../'Z4 4.".7 '.4 2.4-~.o :S.O 3.0 1(J.o 4.6 I tt:.,/",e..r t:.,.cr.fa 8.K 4'"~~.5(7-Wow./.20 .'/'2;'4.9 .4 Z.t:J 3./3.$3.0 ~.S 1••0 ~4.9 ~ C."e""f..0".I "0 .",~f<;r:I ..d P,4,J·'120 ;,sIt ~$I 4.8 .2 2.9 2,·7 2.9 .5.0 .s.o .10.0 \I"4.8 ..C__h C,'r .~~I" ~_r,.d ~/20 $4-/oN S.O .Z 1.7 3./3.8 3.0 5.8 /O.d S:o ,.. ~I~ SUMMARY a RECOMMENDATIONS: IN-PLACE COST,AYAILABILITY,LOCATION,COVER REQUIREMENTS,ETC.,SHOULD BE CONSID'fRED BY THE DESIGNER IN SELECTING CULVERT.CMPIPE 'ARCH CULYERTS DR CONCRETE OVAL PIPES HIGHT BE A SOLUTION WHERE COVER IS LIMITED • 3-80 ..... - - - - 3.4.4 Bridges 3.4.4.1 General.This paragraph will present the design criteria appli- cable to the locating of the bridge abutments and substructure,which may constrict the waterway,to insure hydraulic conditions for safe a structure and the efficient passage of fish in watercourses that have been classified Type A or B.The criteria for fish presented in Table 3.2.1 and a depth of flow 50%greater than that specified in 3.2.2 Inadequate Water Depth shall be required during the two year flood. The criteria for design discharge determination shall be in accordance with the applicable portions of 3.3 Drainage Structure Design Criteria.The watercourse bed stability at the critical section should be investigated by either of the methods indicated in 3.4.2.1 Permissible Velocity Method or 3.4.2.2 Tractive Force Method. 3.4.4.2 Hydraulics of Constrictions in Watercourses.When an area con- striction is introduced to an otherwise uniform.friction-controlled prismatic channel of mild slope,a backwater profile is developed upstream from the constriction (Kindsvater,Carter,and Tracy 1953).Please refer to Figure 3.4.13. 30222/3 841218 3-81 -~I(O}--.....B D(-~y""..._, T ....,..,...~ (1)b (2)(3ICCb {4} 1 -....-L........-:::-Live stream bollndal'1 ..... ,- t ~ddY zone .....I (al Datum Chan".,bOttO", ':~'''''tJ",~Ii~'~ht,~n""",,,,,_Note:horizontal scale distorted (b) ..... .- Backwater profile Normal profile k'".I'll, h~~,... ~ ha~llt '"j""'Y4=Y hon=htll r h....h,1I Channel bottom {uro slope"/, Datum..... (e) i' Figure 3.4.13.Definition of flow through constriction.(a)Plan; (b)elevation;(c)elevation,adapted '1<)assunption of zero friction loss. 3-82 The upstream end point of the backwater curve is assumed to be at section O. Near the constriction at section 1,the centrail body of water begins to accelerate.An adequate approximation for the location of Section 1 may be taken at a point one opening width b from the center of the opening. At the constriction,the flow is rapidly va.ried,characterized by marked acceleration in directions both normal and parallel to the streamlines.The longitudinal water surface drops rapidly in this region.Within the con- striction,the live stream contracts to a width somewhat less than the nominal width of the opening,and the spaces between the live stream and the constriction boundaries are separation zones occupied by eddying water.As the water passes through the contraction,the contracted stream reaches a minimum width at Section 2,which corresponds to the vena contracta in an orifice flow.After the vena contracta,thj~live stream begins to expand until it reaches downstream Section 4,where the uniform-flow regime is reestablished in the full-width channel.Between Sections 3 and 4,the flow ~s gradually varied.Over the whole reach from Sections 0 to 4 encompassed by the backwater effect of the constriction"the total energy loss is the same as that for uniform flow. The equation for the discharge through the constricted Section 3 is Eq.1: Q =CA3 [2g (Ah - h + f 1/2 .... Where: A3 =area water prism at Section 3 VI =average water velocity at Section 1 hf =hydraulic ~~iction loss between Sections 1 and 3 C =is an overall coefficient of discharge bh =Difference in depth of flow between sections 1 and 3 30222/3 841218 3-83 - The overall coefficient of discharge C is calculated by first determining the C',the coefficient of discharge standard value which is a function of the physical type of abutment configuration along the flow Ii nes of the constriction.,The types are shown in Figure 3.4.14.The coefficient C'are dependent upon two factors;"m"the percent ,of channel contraction and L/b the ratio of the width of the abutment parallE!1 to flow and the width of the constricted opening. The value of m may be calculated by: Eq.2: m ==[1 -]100% - where K refers to the conveyance capacity - Eq.3: K =1.486 r 2 /3 A n ..... ..... ,~ - and subscripts,I,rand c refer to the Sections to the left of,to the right of,and the constricted section • The overall coefficient of discharge C is now determined by adjusting C'for the effects ot secondary variable by multiplying C'by the appropriate cor- rection factors k. A listing of these corrections follows: k F ==a coefficient that adjusts C'for the influence of a nonstandard value of F k~==a coefficient that adjusts C'for the influence of angularity of flow 30222/3 841218 '3-84 ..... 0- - ..... -lzcF- TYPE I Type I opening,vertical embankment,vertical abutment TYPE II Type II opening,embankment and abutment slope. ~~~-------.j"---TYPE m oA.-_ Type III opening,embankment .and abutment slope/ _____-~lL-------- Type IV opening,embankment Silope and vertical abutment with wing walls. Figure 3.4.14 Constriction Types 3-85 wing walls k x =a coefficient distances x/b k y =a coefficient - - ..... ..... - ke =a coefficient that adjusts C'for the influence of angle of wing walls k e =a coefficient that adjusts C'for the influence of eccentricity of constriction kj =a coefficient that adjusts C'for the influence of piers and piles k r =a coefficient that adjusts C'for the influence caused by round- ing entrance corner of abutment for vertical-faced constrictions k t =a coefficient that adjusts C'for the influence of submergence of bridge members kw =a coefficient that adjusts C'for the influence of length of that adjusts C'for the influence of the ratio of (See Fig.3.4.l9C and Fig.3.4.20C) that adjusts for the influence of ratio of depth of water width to opening;Ya +Yb/2b (See Fig.3.4.18B) The CI values and the correct ion factors can be obtai ned from the Figures 3.4.15 to 3.4.23 at the end of this Section. It 1S possible that certain combinations of the empirical coefficients applied to C'may yield a value of C greater than 1.O.In such cases, however,a value of C =1.0 should be used. Referring to Figure 3.4.13 in designing bridge opening for the maximum dis- charge we are concerned with backwater profi.le or the surcharge above the normal profile and the depression in the normal profile at Section 3.The interest in the former is to see whether overtopping of the banks occurs and the latter to determine water velocity at Sec:tion 3.By adjusting Eq.1 we obtain a relationship forAh. 30222/3 841218 3-86 J )]I O'·-~-l )-~J Key to Tables C·and k Values for Each Constriction Type TABLE 3.4.5 cOw -1::-0 I-'N NN ....N 00- W Type C'k F k,kG k e k. J k r k t k w k x k Y Type I 3.4.15 3.4.15B 3.4.16 3.4.23 3.4.23 3.4.15 3.4.23 3.4.15 A B D A C,D C B A,B&C Type II 3.4.17 3.4.17 3.4.23 3.4.23 3.4.23 3.4.18 88=1:1 A C A C,D B B Type II 3.4.18 3.4.18 3.4.23 3.4.23 3.4.23 3.4.18 88=2:1 A C A C,D B B w I 00 Type III 3.4.19 3.4.19 3.4.23 3.4.23 3.4.23 3.4.19.... 88=1:1 A B A C,D B C Type III 3.4.20 3.4.20 3.4.23 3.4.23 3.4.23 3.4.20 88=2:1 A B A C,D B C Type IV 3.4.21 3.4.21 3.4.21 3.4.23 3.4.23 3.4.23 88=1:1 A B C A C,D B Type IV 3.4.22 3.4.22 3.4.22 3.4.22 3.4.23 3.4.23 3.4.23 88=2:1 A C B D A C,D B 88 =8ideslope -~ Eq.4 2 h -.YL- 2 C 2 g 1.S the friction loss between Section.s 1 and 3 and may be calcu- h F =b (Q)2 +L ( Q )2 1Kl K3 K3 where;b =the distance section 1 1.S upstream of the constriction,generally equal to the breadth of the constriction L =the length of the constriction Kl &K3 =are the total conveyances of Sections 1 and 3 respectively where h F lated by: Eq.5 ..... ..... - In Figure 3.4.13 the increase hl*in water surface from the normal stage to the backwater stage at Section 1 is known as the backwater of the constric- tion.The distance h is the difference in water-surface elevation between Sections 1 and 3.The ratio hl*/h is called the backwater ratio,which is known to be a function of the channel roughness,percentage of channel con- traction,-and constriction geometry.A laboratory investigation (Tracy and Carter 1955)was made on the backwater effect due to vertical-faced constrictions with square-edged abutments.Data plotted in Figure 3.4.24 indicates the relationship among backwater ratio,Manning's 0.,and contrac- tion ratio m.It can be seen that the channel roughness is relatively unimportant as a factor in determining the backwater ratio.In fact,the limit of change in the backwater ratio due to roughness is practically reached at an 0.of about 0.050.The previously cited laboratory investiga- tion also reveals that the influence of cross··sectional shape on backwater ratio is included in the contraction ratio. 30222/3 841218 3-88 - .... The backwater ratio in Figure 3.4.24 is for constriction of basic type,that is,for a vertical-faced constriction with square abutments.The backwater ratio for other types of constriction may be obtained by multiplying the backwater ratio by an adjustment factor k a •This factor has been found to be a function of the contraction ratio m and the ratio C/C b .aS1C Cb .and C are,respectively,the discharge coefficients for theaS1C basic type and for other types of constriction that can be determined by the method described in the preceding text.The value of Cb .can beaS1C obtained directly from Figure 3.4.15 a and b..Based on experimental data, the relationship among k a ,m,and C/C .is shown in Figurebas1c 3.4.25. 3.4.4.3 Procedure for Design of Bridge Waterw~.The first step is to list design data.Drainage Structure Design Data Sheet 1 is provided for this. (See 7-page sample calculation following Fig.3.4.25 at the end of this section)• a.Design discharge Q in cfs,for required periods (i.e.Q50 or QlOO etc.) ..... b.Establish constriction type (1,II III or IV),breadth of constriction, length of constriction and the constriction centerline relative prin- cipal channel water prism.In watercourses with fish,Type A or B (see 1.2 Scope)it is preferable that the abutments or piers fall outside of the two year flood channel.This will ,ilvoid the need to undertake an analysis for the two year flood • During the field investigation the watercourse~should be surveyed at Section 1 (a distance upstream of the proposed constriction equal to the breadth of the constriction)and Section 3 (at the downstream end of the constriction), refer to 3.4.2 Waterways.The field investigation should also determine Manning's n,the slope between Section 1 and 3,and the substrate classifi- cation for permissible velocities or tractive force calculations. 30222/3 841218 3-89 c.Determine a rating curve for the reach between Sections 1 and 3 using the average of the areas and hydraulic radii for several depths includ- ing the design flood depth. ..... d.Calculate the conveyances K for Section I and the constricted channel at Section 3 and the ratio L/b (embankme1llt and constriction breadths)• e.Calculate m (channel constraction)from conveyances K (Eq.2)with m and L/b go to figure for constriction type (Figures 3.4.14 to 3.4.22) to determine C'the coefficient of di"schiarge (standard value). f.Determine if the constriction type or location require any modification to C'i.e.C1 x k ,kF etc.=C.SeE~Table 3.4.5 for figure loca- tionfor modification factors. x kF =Cbasic is used with C determined·in f.In Figure to obtain k a • k a times hl'''~/h will give the corrected3.4.25 h1*/h)• With nand m given enter Figure 3.4.24 to determine hl*/h.(If the constriction under investigation is not Type I a C 1 and kF are deter- mined for the m,L/b and the Froude"number in Figure 3.4.15 a and b. The C' g. ..... h.With the value hl*/h estimate h (Trial starts 0.9 x 'VI A])2-1- .A3 2g and calculate h1* ....i.Calculate trial A3 using depth of flow calculated 1n c less ( h -h1*) which is Y3' j.Using Eq.5 and 4 and correcting C value in Eq.4 for Froude number kF calculate h,if value agrees with that assumed in h,the solution is reached.If not repeat h,i and j with a new estimate of h • .... 30222/3 841218 3-90 - ..... .... k. 1. When solution is reached check V3 velocity per tractive force or per- missible velocity criteria,if satisfactory or close to satisfactory a analysis at the lo-year flood may not be necessary. For fish watercourses where the two-year flood water prism is con- stricted,perform analysis a thru j to dletermine that velocity V3 does not exceed requirements stipulated in Table 3.2.1. 30222/3 841218 3-91 COMPUTATION 0 ..PEAK DISCBAllGJ:.AT CONTllACTlONS --.--~----,~I~=~ TYPE II 1.00 J I 10.to a I~C j OAO.i.. j !0.70 ] -0 - "............. ...1 -1-"-r-. r...•.·1-'-.,-._1"- ---,,,...............--+0 f-o,.0..••I --"0 i·O 10 ~~~~~....-ef _ A.au.c""'!tor ~oerflcl_at diaclulrp 10 100 '.lor-~I'""T""'T""T""T""'T""T""T'"T""'l""''"T'""T''''I'""T"''T''''''T''''1·-r'"T'"~I'''''T'''''T''''''T'''''T--r''T'"T'''''l''''''"T'""T''''T'''''T""'I::oII k,1.0llt-H-+-+-++++-H-H-HH-H-+-+-+++±::l--t""Fl--f-'H-H-+-+-++-H-H o 0.10 QZO lUG 0.40 0.50 o.~,.'r ......_....-j~ a.V~at d18cbarp coefflci_with ,.......cIe alllllbe1' 0.10 - I. i-t:••!'l6 Oft~=:[C ..... u.~~.I •.... I-. 1.10 ,..... ~ !t.OI ~.-o 0.AlI Cl.04 ODI O.lll 0.10 0.12i.II....--.~II......_ef . C.V..._at dilIclIarI.cOIUlci.at with _~ 0.14 Figure 3.4.15.--Type 1 opening,vE!rtical embankment,vertical abutment. 3-92 DISCHAllGZ-COU'FICIENT CURVES oo....io.. ~ ; I I ~ L-bo _.._.f-~--,.---f- ~~/- C. i- f I-f- -1\I- I-r- l- I , ~I!;.... - - .f- ! ~..... . j-, I I., ,, .. I , I I I +-, I ,,,I ,, ,I ~ , H-I I f-t4 :I, 1-1- f-!~........I f-..+..-, t "i' ; ~:, ~ ......... - ~ ~ Figure 3.4.16.--kw and k t curves for vertical embankment ment of TYpe I opening see figure 3.4.23. . ~ abut- ..!..••g .5... 0"9 and g ....•i !-·1- I I '\ ~~~l~t ~/ ..a ~ ! H I 0 -lJ-{§i ! 1 .• ! !3 - ....3-93 COMPUTATION Or'PEAlC DISCHARGE AT CONTRACTIONS .... """'I I .... I 1.00 •.~ !!i 0.10 "•'u ---I !~!,.I t lill II·I t·-t-I',....~-~....._....":--h .~.~.-_.---I f4-+-~..~~..:::::-:::. , I .t 4ft·f-·......kJ.............~~~_...'t !'I :·,I ;j '::-':lo."~r::-.s:-.-:-......'.~.--~~-r--~....~:~'oIrj;,,; '"""'"-!'..~....;....t.~~.."-rI---~ _. -·I ..~~I"'-i ---5-~...~•1"'~ I ~-:.I"•." ~51.......1Ii_;---1------_.-.,..5J.J--,.I ~1 ~,i I I ;,!I ..-~~.ctE~·...04 ---+-:F·GZIO G7 ••1.00 r-:-.,j i i I I :)I I f I~.o j.0.L-'~._._..--7-r -J,..',--...._.-.-:-.i I, I '+,"I·i •~+'i-J-j !, 100 100' '0 90 10 10 ~~~R ~ ••'.re...·.f all.....a.....II .. A.Sue c~ror coefficient 0(~barle ~~~10 ~ .....,c...III ~coM,..ti... 8.Variatieln ot dUicbarp coefficient with Ya'Jb ..alio --zD"" zo zo 10 10 -\?-0.20 ........._.. I I iii-.,...'-r-t-!-,:.++-1-!f.1 !I~"""'"-,I !~_.I i ro-r-~H-.'I :--...i"'o_~:.-.~-'-.:""0.07" _..-f !r-r-+--'-.05 I..-.. 03 I ..~.,:1 L j I f .I "r I ~'-..j....,.-..-m-TilT_. I 1 !i I i i, 1.00 0.100 F- ! r ! 1.00 clIe 90.0 1110 -IQO .-if'I !.l-...-r ,.........I ,I.'1 ) iol !I H-M ,t·~J~V i~t ·t .'.';..- i -1"'.1'!A t •.-Ii,...I·I~..:;: ,'----!-....;-1"'---;-.,X ~l i.•..j..-• ..I, ~!!!"!'Lt-;;.L ..i...i..l-.1 ~....;....l...,i.. -"7-+-'J1 -,....-..,-......f---...... """i --,--.---. 1\t-.-~............·-t ..t.I ~- 1-'--'1 ..--...'!'_1-l r-rr-r .ttl i I !t t1'"'t""1-.-0 10 ZO 30 ~~10 10 10 ••Pti,e:_of ca....CCIII.roetl •• C......ietlon 0(clittchar,.coelticiiDt wtth ......Larity Figure 3.4.17 .-Type II opening,embankment slope 1 to I,vertical abutment.See figure 3.4.23. ..... I 3-94 [I"'" I I DISCHARGE-COEFFICIEl'fT CUllVES TYPED 10090~~~»~M••Pw......__I _"'M· A.Bu.curv.for coeffici.etlt 01 di.chal'p 20o ...,.....'"'",......I..."';0..10..,I I 1""...jO;,...,..~O1"".........Q!o "'"I I ~ I-"SIn...MIIlllIl_...10..I ""'.....I ,, \tk.o.ao ~L.l!'1"".... ••1.00 1"'"...,............I ,i '.41 ..0.7 ••0"....--r.-- """10..1... I-~.o .. I .0 ....1-1-++- h-t-t.i I I i i I \.00 010 o I f!"'"I d I I~ 'I J ! 'a-•<oJ-u 100~ "-Ill,.0.20_ ~~»~N••...._.............._tIM B.Vuial:l_01 cUacharlOl coefficient w1th Ya'Yb ratio 2iI 20 ~.--. I ~....I I , i""'+oo..i 1"-"'-,, I ....1....~. I a ........1<'1.3 I I -;i-r+ 0 \0 1.00 uo 1070$ti ~.....,••II _....cot.ut. C.Vulallao 01 dbchar...coefficient with ...."larity 0 ..a-- I ....Y I ~l.o I .... Z j 1-... 1.0-..... I ""I I j,.oo J..- l,...o 1-1-1-t..-~I- "'"I ..- l<"------"- --r.;1-1\I- :...l-.-t-•... 0 \0 ID 50 40 ;;f: l.tl 0.10 0.10 r I Figure 3.4.18.--Type II opening,embankment and abutment slope 2 to 1, vertical abutment.See figure 3.4.23. 3-95 COMPUTATION OF PEAK DISCHAIlOZ AT CONTRACTIONS _.~~._____...l--TYPE m ..J.-_ ....."""J'•;0..;...10... r"."'"r"'oo ...... "'",- '"'-i., ",i-I", 1"00.--~!"'oo~ """'FO ~! !"'oo ;._.r....,....c_l_ r"'oo~.- 1-1-1-~... , I ;, ; ~, ,rr. 1-1' 1-....~, I--1M -,~., 1-....""~I---......-- ..-I.....L tel I-;~~- I ~1-1-~...r-1-------"",100-100-1\I-~1-tt t t"1 r-rrrrl-/0-1--.. -...f-l-- 010 1.00 o .~~~~ ';'0'--of _c ••'••ctl•• B.v...lat~01 dlacbu'l.coeffici.nt with Cl'llarity ~ I f->-1->--r:-~1-, ..-!Jl..1----~lr 1--f-"'110 -l-"'.A"~,,I~1--"",I.ol~ .. II--:I"I-I-~rr ~..',~ ~;;..~fa'I-i- II 1-1..-"""...:,............-l-I..-°T..--, 1-1-;...--,'I f-t-" 100_I I.llD I. LID o.GI 0.04 Q.CMI QOI 1110t-Il-of ...__of .,.... C.V...IaU_01 diachu'l._Ieleat with 1rllUo b 0.11 OJ. .....Figure 3.4.19.--Type III opening,embankment and abutment slope 1 to 1• See figure 3.4.23. 3-96 DISCHAROE-COEFFICIElfT CURVES 10.90 i ,i C f 0.80 :.... 1..I 0.70 J r r 1.00 ~-~l+:.: ]';lit":..m:....r·· I I ;I-i ,, I"-J"H...-. I ,. .r...~""!"-... r .!I I I I -i- '---'~-~r'l"'r-.~~4._.L....-'-....,....::'"-:"I , l'OS ..~~....1....I ..--r+i~_..--""....i 1""0 ,,...........~r...~.,..,.......;.~I I."""~ ._. ,,!'"-':-.....-....;: i ,'-I No..;;:;:~~..-~_. ~-p I ,:~,No ~0.6l-I I"t'-~~::....-n .....~Ft1~~--._. St.......-'""t••I 1-1 j .,~-+..~I '--dOl "0.1 t.0.7 "0'l-f .i !I I ftl.-,~ iiIT -l :1=~..tOO to , i I, ·1 ..; I ;I --:~.o ,'0 1-.+I .i .,.:['r !-t ..-':--j'I r I ~i :,' ..... 10 20 ~~~~~...J<Ir_of __"••11., A.a-Clll'ft ror coefl1cienl of l1iacllar.. 80 to 100 80~~~~~~......._If _O_Ofl. B.v...iatiDn of eIi,char.e coefficient witb anc"larity 10 .1'l-_-.---10'"'/,"V.....J ,.A' ~.......J<'.A'"I.-c...I I ,I ;I I ioo".....,I I I _i I t Io-o~\;1--'j ,~-4+r-I ,-i I I ,,,~~ I I i --1---'-- l-I --rr j.ool--~i I-1\-~~.Il-Ioo'~.... I-5".--~1-....i-L-,I ,.00 0.1'0 0 0.10 ..... - 1.00to~IIIlIC:"'U-=o.o!I~...l....I-.l.-::QI.:-.I0:J-.I...I...l.~o.l:-::l!I:J-.I...I...l.~QI::20-1-I...l...l.o.-:U=-..l-......~*t-I..lo~Q3!I-t .......".Ie 1I~.III ..-. c.V...latiOll of dl..h ......coeffjci_wilh "ratio b Figure 3.4.20.--Type III opening t embankment and abutment slope 2 to 1. See figure 3.4.23. 3-97 COMPUTATION OF PZAK DJSCHAJlQ£AT CONTRACTIONS - ..... _~_--~~r'--_ 100eoM150~~M.......-",---A......c .......far coeffici.nt of lilac_•• 1010 ... I --.........~"""r : '!'-"""I......I""I"".....;.-1-1-;,--l.-r -'-'-l- I I I I 1""1"-""':--L "'"I'---,1.00'~,..-r---,I I I"",o.lSOb-"""--,._1:: ~,,:I"Ionl ; S1_........;----I ....,."'"'-I 'I" ,.OJ ..0.5 ..~-:I I r j ,,,!>ft.r---;.....,..---~+., ;;;a'a ..-I I I ---1--- ,·0.1 leG?joO .!, ; "1.00 I0 .. !. .0.10t ! 1.00 -'I(;i i 0.10 .;• '; ~ !o.1O 1.. ~ 0.1 o ,.... ,- i I 10 ·t-~--l--o--.:....----- ~-----1\ ..+..,l..-..... I V .....I I ,~ '.-.r' ZO 30 150 30 ~.........ef _ •__11ee B.V.nu_•.,d1IIchar••coeffici.ftl willi ......laI'ity 06. lOO .. I QIO ~ Q.IO 4 - 0.100 10 ;.- I, .... I I I I I ,I -~0-I I '+-r-H::4~t ~-L H-t ~-r-~-+T·t.~I ~_-r-+-:;r'"":: ---1iilL t-;i I I'k'~ I i .....,'......-:"T i ',:;';'-~'-L~ft '''--':t--"'""__, .....,....r -r : :~........-r-3 '..;.... ~-I , ~~....-I , I I ;I ,.. 1.1 1.10 LO 1.0030•~~.~~"........,-"'-C.V.....U_of dIac.......caeff1ci.nt willi wUll-w.u ....Le K. Figure 3.4.21.-Type IV opening,embankment slope 1 to 1,vertical abutment with wing walls.See figure 3.4.23. 3-98 ,.- ! DISCHAlt,GE-COD'FI(:IEhT CUIlVJ:S -- 10010403010111........III~-..... A.BaM Clll'ft rrw c __aI dUclUu'p 0"'&t-:::t.I-......... ,..... ... I.0----,-t·o.,.o.t ..~;~~--..,..a.so '.10-I i Q.O ·~.O i .0 - .-..00 , 0 to 30 1.0 0.10 i ::0.70j .'.. 1.00 OM 0.10 ..'- Z , , 'fl __t__--- -1\ 0.70 0 10 m »~~10.._"'--e.V_aI dUcIUu'p clMft'lcWId wUII _1arI1)' 70 10 1.10 k,.1.00 I ~ I I..- 0.»Q40 Q50 0.10 0.70 ,.,...-.-....r.ln: C.VU'lMIa aI <ll8cbu'p cMfflcwld _till ,..-de _r ll.IO - 1.10 .--rnr-_r-•"1 --L.1lL-~o ,... . r Figure 3.4.22.--Type IV opening,embankment slope 2 to 1.vertical abutment with wing walls.See figure 3.4.23. 3-99 COMPUTATION OF.PE,AIC DISCHARGE AT CONTRACTIONS o.tO0 0.1 0.2 0.3 0.4 .·Ic~'",..... A.Vuiatiaa 01 diKharC.coefficient _illl .cc.ntricity i.~~7a......-- •1,... '"_.·.w __10ft 31 - N I ;""'ooi, I ;r-.. I ,;, r-.. ,oaoo a.OS OJO 0.15 0.20 0.25 0.30 ~-a".,.UIiltIII....ftCI ,.,iD B.V...iation or di.char..coefflci.nt "illl d.I....01 .llb.......I.nc.of b ..idl. 1.00 +~••~!1.0-Tra·'. 1.00 100to1102030~~80 M "'-""ClfII at ......C....'etl•• C.V...iation 01'diecharI.coefflcl.nt _itll ......0(b ..idle pile. WWdPILES •• •j'~..• •• t?Wd@ ~t·O.......... ~o·l:-J:;-:;;.-r r/Io~~-I-"""l'--"----~.v ;;;l-I /,y,::.a.1Q JI 1/,;-~I ,I '1.I +.+t-f '/~I -- :"[~.*."",-'r +t-o •-I i~'--++.., -r-0.l1li800. "a ~.- k'''05QI.: '0030~~80 ~80 to"'-"e-Il fA c__.,,_,octl. D.V...iati....ofodi.char..coefficient .illl ...ea of bridge pier. ~PIERS -IEZZZZa j •.!Lcz:z::zz:z:a &. ~ '0 I ~tI I .... """'-1);, 1.00 o.s5 ZO Figure 3.4.23.--Types I-IV openings,ke , k t ,and kj curves. 3-100 ..- 1.00 o.eo ~Iai 0.60.. t_0.40 J 0.20 ----m-eo-160---- ~~-_140--_...--I "..~1 20--- ~----.10 I--~-0.00o 0.010 0.020 0.030 0.040 0.050 0.060 0.070 Manning's an" Figure 3.4.24.The effect of channel roughness on the backwater ratio for basic-type constrictions.(Tracy and Carter 1955 ) 1.21.1 C/Cbasic 0_'73I'"...........,;:~r--'73 ...'73 \"~i'-..k m:ao "-ro-..-I r-....I Ix \t:D:::..m=60_ \\.....'52-'48- t'...'47 1 I 8 ~52-_'52 1\'52 \'52 '"...........~:40-7 ~6 I I Legend _ ~o m=80 6 x m=60 ~-m=40- "m:20 v m=as ......, !.'r'2~I indicated 5 '27 ~0- 1.0 0. O. I. o. O. - Figure 3.4.25.The effect of constriction on the backwater ratio. 3-101 .- -~ FILE NO./h53-/03 DATE 8/2sj&=4 -PAGE I--OF --Z PAGES Sire /~ve.sh9';;;1nO~0".;;1 d 5~c/?o/)/ IAlZAffI;CO SUBJECT,$,-J /2.00/t//-s,/vnc'lh",A2ve yo Y SUS/TNA JOINT VENTURE COMPUTED ..5,f?CHECKED C c:. - - - "I.~',V-/8 "'01 ~ /.0 L:::\~":: ~')'.I.75"'1~',7':TJJ';7tv1~.--3~8"""--1C.--J"1 ~..48 1 .....I?-::::0.035 ..5 -=-c:J.oo/:< ch;?'7/J€/c.::J#?'7/,/O$e'd'ar:'Yr:2v'e/s F co."61€s ks.s r~2"7 c"/'/dr:;;JA'7e~er - - - - ..... , ~hrco(/rse ChS.5/H£c/,;:;o5 77/2~6;-ov!?ff" );,jI ~.5C67/e O€~/?n q /60yr /%a d qe>D =~~20 ch QIC =/200 qz =Z50 e;=3~:20 Q "';./ZCJO a 22.50 Susitna Hydroelectric Project Drainage Structure Design Data Sheet Location:Township TJ2 N Secti on _.:oo:3;......=O~_ Range gee_ /,'1 0 ~o 12 /.....11 A /Meridi an (:)A...;J LJ (V Project Feature:(project access road,material site access road,etc.) Station:/200 ~?h.2P1 (:)/,/?!ver Y Jd/lc.ha,? "Type Water Course CD B C User Fish Group (8 &Conly) Drainage Area:_c_o_~~o::..-_acres I ®III IV Q2:2 SO cfs Qdesign:3J~'2 Q cfs Frequency of Qdes i gn :50 years Watercourse Area for Q2:/!()ffl C,ft2 Gradient O.00/::(ft/ft Watercourse depth of flow for Q2:.2:.IS ft -Classify channel substate:/h:?/c;?n/bc2/?/amouafo;;;~€5! ~:;:> 7'dV<:E:/s /ocog,.6ks /t&.55 //5:7/7 c::'//?cAcs Channel configuration:Braided Meandering ~aig~ Other (describe)&...:::::...:.Y":-:.:t::..::ck~)7;:Z·J;i.1?__•_ Culvert Type:Other br-/d9€U,..!('/};ce/J/er PIG".. .t , Size:tA./Ih~;-c./}:7nntPl 3&15574:/ 50 1 Slope:2?;'Y2t;.:J5 ,-/(/61"ftlft Length:_ft. V,Q2:ft/sec V,Qdesign:t?~~ft/sec HW/D,Q2:%HW/D,Qdesign:% Attest,ed t~bY~_~:;;:r/~ Fisheries Biologist sa SUBJEC1'~"'_L;."S~J2oa'FILE No/~5'3-/tJ3 .V.~JlJd~I/o'?_VIEr Y DATE ft/zS/§=4 SUSITNA JOINT VENTURE COMPUTED 5"If CHECKED C C PAGE ..3 OF -.2 PAGES LJ~.$/?,'7 /~b~St!Fd'(;)'7 7r"~W CeJA.f-rrlt::.f/on GcNf1 55 -==~S-.'/w~/J,38'p~rltVeeh ~"e o;/$~~~..$ ~r/~?~~,,//A:;'tYte :J CttF-Arr;?/.conC,.~;t1tF=/?/€;-'" $t/,P;It?DrT /sNrA/&k SE.€o'.;7sA O(,J/hh~on ~ct1o;?.3 (!),.rrhnte=P.:Jj'£/. -;.r;-7/271 ]/tJO LL'/0;217~• - - ":.0.032. -7t 27 &, L -::3~75 (S"~e h~",,~:i.9./.9 c..))(;:J!7S /b ~~B L-~-:::e /.0 m ::(i -k,.}/dl/' /<;"/ -=3a.::J % C /~?//l~?paA7/Jo~/;"..S5=Y.S://:--0-'1 h9vr~.s 3,~/:9 :::In d"3,~,':2 0 ·- ....~IIA8CO SUSITNA JOINT VENTURE SUBJEC'<5(:j'-"C~:s"S~/:200 ' U/s _u".,~hr;""&-er Y COMPUTED S&CHECKED Cc. FIL.E NO./~53-/CJ3 DATE~S/9# PAGE 4....OF .1 PAGES S5 :=/:/ 55::2:/ J::~.L ~/()Y-~S~ Ay ~B ~/O')(/.s)/O' =(!J.03 ~,4'''-0'''1 h"3·~2:3 h,.I"?~3l:J,9 .,oJ'::O.0;3 ~:•.:71$9 ~I('Inl-er,Ro/:7T£d pOW?/lis.3.9.I;;c 3"0'3.~'20e, ~,..~~::.I d')f ,::;.7 S-...",.{)I I 01'"~r b ~D --~-.""3 ~ S 5 -:/.'/.I ,S'!I S.s &'2 f I J.x /./7'--t..,,-I'03 ~x 1./0 C &C/~·~,)t z'923 (:96!f))(/'/W ::/.1.:')"4 >~0 t/s~~tJ ¢:'~~0 r- !, - .- ! .... - ~N.4. '*e N.A. ~/JrA. ~NA.'.As /\(A. .,f;y~s h?~~2 '3 ~r /1.t A. L')(.y~s nJ6.3.~.19 c ~/0//J~t.c;4f'et "X."'7. 3."T'.:10 C ./ Ijm~IIASC8 SUSITNA JOINT VENTURE SUBJECT slre::J~c;,.C5S/P1?/2od FILE No./.Cs:3-/03 (//5 Ju"ch~Y).RJvt!'r Y DATE '8/2s/B-4- COMPUTED --S /f CHECKED C C PAGE 5"OF ..2-PAGES (s-;-~,~) S/n C if?C t:)tJ?$r,./ch t:J ~/5 /7"r 7f',P1!!!'T dd.l~r"..,/;?~C~:;.nd~fr()~h93,?:/S4f/3 hr /n~:3t:J.9 I %~~i> A C~'C#.93Y h",Cld'~/YO._--=Q=--.-:::::::~?C Z 0A;f;y~~((1-9--//.-.s;-(l-=OV";:-IO-=)-:J]/n::=:=:.'2=(.=IO:::='~, =:~.:3 i' 43 ~=(J.!77S C C~/ -CJ.93C;-(O.97S )O.:J 5J'C.~~r- !:a.9/5 .- r ~=0.77 h~~n?"3.~/.24 w~rA n z:4(J'32 r'1t'?%:-3a 9 h7dJ h ==(J,~.9 h'?A h C D~n.d"=.J!A"(..l~)=(J.rr~1d.77) =eJ.377 .- ,- -. ,.... , SUSITNA JOINT VENTURE SUBJECT$k£:;J ""1 CrJ!}$s/"f /200 I Vb Jvn~;f6~~I/I!G;-Y COMPUTED 51?CHECKED c C FILE No.LC53-/03 DATE WS/'?¢ PAGE .k...-OF -2 PAGES SUSITNA JOINT VENTURE SUBJECT ~3~e;.-"SS'17 /2t7()/ Vhf J V#"1CnO",!jl/er Y COMPUTED 51(CHECKED C C FILE No/~53 -/0.3 DATE 9/2sL~¢­ PAGE LOF 7.PAGES ~#frr,n7 /0 ~~'liF:J.0/./.3 ~(;~;C#'4/~h,.~/hc r r ..... ..... - ;""df~CI"?{2V1"'.2?~}:7r 54:-~;?tf;1")y :J~2 (/--(1~,/-f:9'b7?/~5"J)~673 1 -~39 /0-~L C~/~('.Ih*o'7.f,?;'-C?~ REFERENCES REFERENCES 1.Alaska Department of Fish and Game.1981.Proposed Habitat Regulations. 2.Alaska Deptartment of Transportation and Public Facilities.Hydraulic Manual.pp.1-32 -3.American Iron and Steel Institute.1983.Handbook of Steel &Highway Construction Products.3rd Edition p.164. 4.Anderson J A.J A.Paintal, Procedures for Riprap-Lined University of Minnesota. J.Davenport.1970.Tentative Design Channels.National Highway Research Board. ...... -, 5. 6. Bossy,H.G.August 1961.Hydraulics of Conventional Highway Culverts. Presented at Tenth National Conference of the American Society of Civil Engineers. California Department of Public Works,Division of Highways.1963. Planning Manual of Instructions.Part 7,Design. ..... ..... .- -~ 7.Chow J Ven Te.1959.Open Channel Hydraulics.New York. 8.Corps of Engineers.1944.Hydraulic Tables.Washington,D.C. 9.Fan,Chia Hwa.1947.Hydraulic Engineering.Chinese Society of Hydraulic Engineers,Vol.15,No.1.pp.71-79.Nanking. 10.Freethey,G.W.,D.R.Sculley.1980.Water Resources of the Cook Inlet Basin,Alaska.U.S.Geological Survey. 11.French,J.L.1955.Hydraulic Characteristics of Commonly Used Pipe Entrances.National Bureau of Standards.Report No.4444. 12.Johnson,P.R.,C.W.Hartmann.1969.Environmental Atlas of Alaska • Institute of Arctic ,Environmental Engineering and Institute of Water Resources.University of Alaska. 13.Kindsvater,C.E.,R.W.Carter,H.J.Tracy.1953.Computation of Peak Discharge at Contractions.U.S.Geological Survey Circular No.284. 14.King,H.W.1954.Handbook of Hydraulics.New York. 15.Kirpich,P.Z.1940.Civil Engineering.Vol.10,No.6.p.362. 16.Kirpich,P.Z.,G.R.Williams.1969.Hydrology,Section 1;pp.1-~6 in: c.V.Davis and K.E.Sorenson,eds,"Handbook of Applied Hydraulics", 3rd ed.New York. 17.Lane,E.W.1937.Design of Stable Channels in Erodible Material.pp. 123-142 in:"Transactions of the American Society of Civil Engineers," Vol.102-.- 30222/REF 840201 4-1 ~ 18. ...... 19. 20. 2l. !""" 22. pq [ Lauman.J.E.1976.Salmonids Passage at Stream-Road Crossings:A Report with Department Standards for Passage of Salmonids.Oregon Department of Fish and Wildlife.Portland • Manning.R.1891.pp.161-207 in:"Transactions of the Institute of Civil Engineers of Ireland.nyol.20.Dublin. Mulvaney,T.J.1851.p.18 in:"Transactions of the Institute of Civil Engineers of Ireland."Yolo 4,pt.2.Dublin. National Weather Service.1972.Mean Annual Precipitation.Inches;Mean Annual Snowfall,Inches.Map,Alaska. Tracy,B.J.,R.W.Carter.1955.Backwater Effects of Open Channel Constrictions.pp.955-1006 in:"Transactions of the American Society of Civil Engineers,"Yolo 120-.- 23.u.S.Department of Agriculture.Forest Service.Roadway Drainage Guide for Installing Culverts to Accomodate Fish.Alaska Region Report No. 42. 24. 25. 26. -27. 28. 29. u.S.Department of Commerce,Bureau of Public Roads.1961.Design Charts for Open Channel Flow.Washington.D.C. u.S.Department of Commerce,Bureau of Public Roads.1965.Hydraulic Engineering Circular No.5. u.S.Department of Commerce,Bureau of Public Roads.1965.Hydraulic Engineering Circular No.10. u.s.Department of the Interior.Bureau of Reclamation.1957.Hydraulic and Excavation Tables.Washington,D.C. u.S.Department of the Interior,Bureau of Reclamation.1977.Design of Small Dams.Washington,D.C. u.S.Department of the Interior.Geological Survey.1964.Magnitude and Frequency of Floods in Alaska South of the Yukon River.U.S. Geological Survey Circular No.493. - ..... 30.u.S.Department of the Interior.Geological Water Resources Data for Alaska,Water Year Division,Anchorage. Survey. 1983. 1984 (annual). Water Resources 30222/REF 840201 4-2 APPENDIX A ~-...~-----~_._._-•._._._._----~.._-------------._._- 1""'1 I .... - -- - r APPENDIX A PROJECT DRAWINGS A-l --FIGURE A1 ...."""ss_ CONSTRUc:TDt ROAD PE......1fT aTE ROAD UTl\.lOOlI NOIEC'BooH"A"... 1C&Ll:y ""'"I!lPO Pm' Cllletl-1000 FElTI LEGEND WAUNA.DAM .ND RESERVOiR ,tf!I' lUITNA HYDIlOELECTRIC PROJECT ALASKA POWER AUTHORITY --I ! ) ~Wllt.-'"Ll~\,')'/(')~ ,f"\J~'>----.(/-J./~"~~~ L9CATlOI!MAP 1CoILI:0 4 _ •IIK.IS (I INC'"•4 MILEI) e ~ ~I f~l-S45kY#~'~~TU"'",SS"'"llttU10GOLDCRUKA- ~l I~f1/P/ ~{II'-',.,-- ~~~~j1i~~~~~~~~~r-f~-~y7 ~~ MIo.lM~ "UILOOO .MI.ao.ooo ,,,.-.000 ,--"']"'1 ~""'i I "1 '}.,~1 ]r "']I ----1 ...-)) f Iii :n ,J ill .... ".-It --FIOURE All CI MOl •10 IIL£II l-'~1- \UtlI81T 1-' PROPOSED TRANSMISSION CORRIDOR_..... ALASKA POWER AUTHORITY SU8ITNA HYDROELECTRIC PROJECT Ic...r ,to 40 "ILEI LEGEND --<!>--_"'''0 _IIEO HI_A. ---IICCI$UIY MWEO UNDlYIDlD HIGH." -.----.•tECClHDNtY 8MVn HletNIIy -IWlRQlD_._-...... •_.-T"RANSUlSSION CORRIDOit ~ '0~·~~···-1_· G t i ;, "i "/ .../'. ~rC- w.)~r/~toil~~,1/+//. 01 J )J 1 o '0 oJ 1 n ~/- ~., -..r-.'....-.r-"'t ---I ·····1 1 J 1 ---11 )1 1-~]1 J h---?J -r::1--"1'-/\1 °VI LL.--"/'//~~f\0,}-~_/l ~()J1.)J r?)U r-~:;j <-~7-J,f f1-~Sr'---c....__~~/1/(I l/L (r Cl o . '01'.',1 /,,[)(JL?I'--....:::..ooo~/-..'~..._.....?\~-"2._ --~"''''''''4 \d?.-/~.-...--...\...~.:::__/~ILEGEND J-PRoP.S••""". •••••.PR.DPQSEb RAILROAD .............EXI$TI NG R"ILROj,O _EXIS'!!...~_ ---~-----_.._-----I ~.-PRQPOSlD ~-;41.1 I TRMSMISSIOH LI"E HIOlftfAY _C'''I ..k'''~DA"Y~LINE ALASKA POWER AUTHORITY 1---S~U~SI·rN~HYO~LECrRlc PROJEcc=r----I WATANA DAM AND RSIERYOIA PROJECT PLAN WATANA a DEVIL CANYON DEVELOPMENTS V';,\\\'IM:i -';0 ..--- FIGURE 1\3 "..-, !t APPENDIX B - APPENDIX B RAINFALL FREQUENCY DATA FOR ALASKA B-1 .... .... ..... i l~--+----- ~L_-+-_ -~.5 J.OJ !.:'-1----------:: I .;--l~ .~;; i ~.1I• i !I ~._~._-_..~~~.-1-----I I' I ·-J------i-----i-----£ I ~:2"~ I 1----r-'i ---r-i ~I iii I !:!I'n~I.14-------------~------._.i! ~I -Ioc,a:: a:: ~kL--t~--=---+--_4t_'~T~~t_.0=...-.--..-...- . ...-:-~-• ll--l---t-,- i~---,. ~ Ill:oc""" I ~i N !.----I~.5 I 3i ~ -. ":I .. • I "':'IL._-------,:.: I ... ~ ...... ~ II'" 1,- al w Q; -'-"---'1''S :l 52 ""' .... ..... !r;rG7~~~./I I./ / I < !r--+---~< ..J < I ~ iiiw 6 ~ ..:I..:I ! 1IC '"Z<a::==0 ! =0< ~. 1ft ~ "';.. -! .=.'---L------+------t----!i-:."k ~;l; ~. :J---J:....-..-----+-----+--o-.31' ~I l J~:I -4--~~:L.r--l--+-+--+-+-+-+--j~tL-I---l--::r-+--+--f--+---:i-:;-r;;- ;; 5 ~ l----J.--~----..J..-'--A-:'+--,.'--~-f:h L~l--;-~------l ~ i z :c II: !I~~ 2 ~- •! < :Ill: u:l < ..I < £ J I ¥-- .... i - ,.... -- ...... \ ,.... <:.:: III------4----~ < . :I - I!j i i i ~ II T4- k i :"" "1 ;':.':I .,-I J..~~ .t ,--, .-1 is r.l=I t) ~,,! I i l :!c :-I Z :i II: a:=2 °.- J ,II: F'"-: t: 51 ~ .5 ,F'"=~.; ,;...,,;.. c.., I.'". • 1 lZl-i\w ~~_.:S; i i tJ .._§~0 i Ii:!.l!.... j ~r~ l .! I ~Q F'"~·I •_0 £ ..,£·:I ;,= <~.:.l:i111'1 ~'~-<,. ..l ;'.< ~.; £.]~---I. :::tlv::; r t k - .... -! T < ~onL__+:; < - APPENDIX c - - - APPENDIX C TRACTIVE FORCE METHOD OF CHANNEL DESIGN USING MOST EFFICIENT SECTION In a trapezoidal channel the hydraulic radius,Rt is equal to the flow area, At divided by the wetted perimeter WP R =A/WP Y ~+z l)l/J~R = +(z 2 + L When using the tractive force method the value of the roughness coefficient,n,can be related to the characteristic grain size t dch (feet)(Ref.8),using the equation 1/6 n =0.0395 (dch) 2.Determine the size of material to be us~l in the channel,dch,the roughness coefficient.n,the angle of repose e t the side slope z = tan e t the permissible tractive force on the bottom t Tb and the, perm sible tractive force on the sides t Ts • 3.Estimate the slope of the channel.S.between the end points of the channel F t 4.Determine the design discharge t Qd 5.Compute the optimum ratio of bottom widt1b.t b t to depth,y (Ref.3). b =2 [(z2 +1)1/2 -z]y 6.Compute the ratio of the hydraulic radius to y 30222/3 841218 R Y = C-l - 7.Compute the ratio of the area to y2 A b -2 -+ZY==Y 8.Solving Mannings equation and the equation for permissible tractive force R To ==(62.4 Y S ) Y K, Ts Where:K == "'"" Tb (j2) ( R 2/3) and Q ==~S 1/2 x 1.49 x y 8/3 , n ,... 30222/3 841218 C-2 - Let To =Tb =Critical tractive force solving for y: - ""'" "I 2 9.Compute b and A 1/3 3/13 ..... 10.After a channel has been designed for Qd.check other fishery requirement flows such as Q2'QI0 and minimum flow requirements to see that constraints on fish passing criterL!such as velocity,headwater, and depth are not violated.Alter design as appropriate to meet these standards and recheck design flow capacity and tractive force, criteria • 30222/3 841218 C-3