Loading...
HomeMy WebLinkAbout19 - Design Report - Cottonwood Subdivision - Farmers Canal Culvert FARMERS CANAL CULVERT DESIGN REPORT FOR: COTTONWOOD ROAD IMPROVEMENTS BOZEMAN, MT Prepared By: MADISON ENGINEERING Madison Engineering 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 DULY 2019 FARMERS CANAL CULVERT DESIGN REPORT FOR: COTTONWOOD ROAD IMPROVEMENTS BOZEMAN, MT rn z. - fo."t �G� • tJ ONAt- Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 JULY 2019 COTTONWOOD ROAD IMPROVEMENTS FARMERS CANAL CULVERT REPLACEMENT DESIGN REPORT A. Introduction This report will give an overview of the design of the replacement of the two existing arch reinforced concrete pipe (RCP) culverts with a single box culvert for the Farmers Canal crossing at Cottonwood Road in Bozeman, Montana. In 2007 during the construction of Loyal Gardens Subdivision a double arch RCP culvert was installed at the Farmers Canal crossing under Cottonwood Road to replace a bridge. Since its installation it has proven to be a maintenance problem for the farmers that use the canal. The double arch RCP culvert is being replaced with a single box culvert as required for approval of Phase 2 (south half) of the Cottonwood Road Improvements project. Approval of the culvert replacement design is required by the City of Bozeman and the Farmers Canal Company. B. Original double culvert design summary The original design report for Loyal Gardens Subdivision contains a short description of the design of the original culvert. It references that the representatives from the Farmers Canal indicated that they desired a 72-inch diameter culvert. The calculations provided in the report indicate that capacity was checked for a single 72-inch circular culvert (see Appendix E). However, two 65" x 40" arch culverts were installed, which have an equivalent area to a single 72-inch circular culvert. The reason why a single culvert was designed and a double arch culvert was installed is unknown, but is likely due to the lack of cover required for the installation of a 72-inch diameter culvert under Cottonwood Road at this location. C. Determination of required culvert capacity The Bozeman Design Standards and Specifications Policy, Addendum No. 6, (DSSP)were used as a guide for the box culvert design. However, the DSSP was written to aid engineers to design stormwater runoff culverts not irrigation culverts. The analysis and design of the culvert for the 25-year storm (per DSSP V.C.7.a)was determined to be an invalid method for determining required culvert capacity. The irrigation canal has a head gate at the source (the West Gallatin River) and two 10-foot Parshall flumes located approximately 300 feet downstream from the head gate to control the flow into the canal. In general, the flow in the canal is controlled at the flumes; however, there are a few points upstream from the Cottonwood Road crossing where small creeks flow into the canal according to aerial photos and conversations with the Farmers Canal Company. The following sources were used to determine the required capacity of the culvert: • item 17 (page 10 of 48) from Preliminary Determination to Grant Change to Application to Change Water Right No. 4 1 H 30102910 by Norton Ranch Properties LLC, Norton Ranch Homes LLC and J&D Family LP (see Appendix A), • discussion with the Farmers Canal Company (see Appendix B), • the existing double culvert capacity based on survey data(see Appendix C), • capacity of the Farmers Canal channel approximately 75-feet upstream of the existing double arch culvert (see Appendix Q. • required overflow capacity per DSSP V.C.7.b (see Appendix C) Cottonwood Road Improvements Farmers Canal Culvert Design Report Page 1 of 3 Table 1. Summary of reference capacities for Farmers Canal culvert Reference ReWd capacity Ws) Water rights application 250 Farmers Canal Company 250 Existing double culverts 112 Existing channel upstream 109 Additional overflow capacity 88 The capacity information that was determined to be most useful in sizing the proposed-box culvert is the information provided by the Farmers Canal Company. The design capacity of the proposed box culvert is 250 cubic feet per second (cfs), which is more than twice the capacity of the current double 65" x 40" arch culverts. The canal capacity was also analyzed using Manning's equation by taking an average cross section of the canal assuming a full water depth to the top of the existing 2.34-foot tall canal bank. The cross sections were determined from survey data provided by Alpine Surveying in 2019. r � — Figure 1. Average cross section of canal approximately 75-feet upstream of existing double culvert inlets when water flowing full to top of canal bank. T Figure 2. Section of Farmers Canal immediately upstream from existing double culverts. Photo was taken when canal was not full. Cottonwood Road Improvements Farmers Canal Culvert Design Report Page 2 of 3 D. Culvert analysis and design The slope of the proposed 162-foot long, 3'x10' box culvert is 0.20%. This generally matches the existing slope of the canal. It does not meet the design standard from DSSP V.C.8.c that requires 0.5% slope. The only possible way to meet the 0.5% slope standard would be to maintain the existing inlet elevation and drop the outlet elevation 6-inches, which would necessitate hundreds of linear feet of dredging the downstream canal to provide positive flow eastward. The Federal Highway Administration computer program HY-8 Culvert Hydraulic Analysis was used to analyze the culvert including inlet and outlet control conditions per Bozeman DSSP V.C.8.d. The box culvert is outlet-controlled. At the design culvert discharge flow of 250 cfs, the headwater depth is 3.79- feet, which remains within the limit for headwater depth of 1.5 times the culvert height per DSSP V.C.7.a. See HY-8 analysis reports in Appendix D. The overflow capacity was analyzed using the upstream canal capacity of 109 cfs as the base flow. The overflow capacity was determined per Bozeman DSSP V.C.7.b to be 88 cfs. The combined full canal capacity plus the overflow yields a total of 197 cfs (see Appendix Q. This is less than the design flow of 250 cfs; therefore, capacity in the culvert exists to accommodate overflow per DSSP V.C.7.b. No trash racks are provided for this culvert per Bozeman DSSP V.C.8.b because the Farmers Canal Company has expressed that they do not want them. They have said that trash racks create more of a maintenance problem than they solve. See Appendix B for communication with the Farmers Canal Company. E. Summary Our analysis discovered that the current culverts do not provide the 250 cfs capacity that the Farmers Canal Company desires. The new 3'x10' box culvert provides a culvert discharge of 250 cfs and eliminates the maintenance issues associated with a double culvert. Cottonwood Road Improvements Farmers Canal Culvert Design Report Page 3 of 3 Appendices Table of Contents A. Excerpt from water rights grant change application B. Communication with Farmers Canal Company C. Capacity calculations D. HY-8 Culvert Hydraulics Analysis E. Original double arch culvert design report and calculations (by TD&H engineering) F. Reference materials Appendix A — Excerpt from water rights grant to change application BEFORE THE DEPARTMENT OF NATURAL RESOURCES AND CONSERVATION OF THE STATE OF MONTANA APPLICATION TO CHANGE WATER ) RIGHT NO. 41H 30102910 BY NORTON ) PRELIMINARY DETERMINATION PROPERTIES LLC,NORTON RANCH ) TO GRANT CHANGE HOMES LLC,AND J&D FAMILY LP ) On June 4, 2015, Norton Properties LLC,Norton Ranch Homes LLC, and J&D Family LP(Applicant) submitted Application to Change an Existing Irrigation Water Right No. 41H 30102910 to change Water Right Claim Nos. 41H 30023118,41H 30023119, and 30023120 to the Bozeman Regional Office of the Department of Natural Resources and Conservation (Department or DNRC). The Applicant proposes to retire 26.40 acres of irrigation in order to leave 39.0 acre-feet(AF)of historically consumed water in the West Gallatin River to mitigate depletions caused by pending Provisional Permit No. 41H 30025398, owned by Bostwick Properties Inc. A pre-application meeting for this Application and subsequent Norton-City of Bozeman Change Application 41H 30103245 was held on March 19, 2015. The Department published receipt of the Application on its website. The Application was determined to be correct and complete as of November 11, 2015. An Environmental Assessment for this Application was completed on February 3, 2016. The Department issued a Draft Preliminary Determination to Deny the Application on April 29, 2016. The Applicant submitted an Amendment to the Application on June 7, 2016,to incorporate Water Right Claim Nos. 41H 138898-00, 41H 138899-00,41H 138902-00, and 41H 138903-00 into this Change Application. The Amendment reset statutory timelines for the Application. The Amended Application was determined to be correct and complete as of July 22, 2016. Preliminary Determination to Grant Page 1 of 48 Application to Change Water Right No.41H 30102910 Point of Diversion and Means of Conveyance Subject Water Rights 16. The source of water for the subject place of use has always been the West Gallatin River. Rights 41H 30023118 and 41H 30023119 have always historically been diverted into the Farmer's Canal and conveyed to this place of use. Water right 41H 30023120 served a different place of use and was conveyed through the West Gallatin (Kleinschmidt) Canal until a 1988 change. The goal of this change was to procure more senior water for full season irrigation. This water was conveyed through the Farmer's Canal to the current place of use after the 1988 change authorization approval and subsequent notice of completion. 17. Water was conveyed 7.9 miles in the Farmer's Canal. The Farmer's Canal headgate is located in the SWNWNW of Section 11, T03 S, R04 E. The West Gallatin River is a major source of irrigation water in the Gallatin Valley;typically, a water commissioner is appointed every year to administer water rights. Likewise, the Farmer's Canal is a major irrigation canal in the Valley and employs a ditch rider. Water entering the Farmer's Canal is measured by two 10- foot Parshall flumes, located approximately 300 feet down the ditch from the headgate. In a clarification submitted with the June 7, 2016, Amendment, George Alberda, the current West Gallatin Water Commissioner, and Bill Tatarka,President of the Farmer's Canal Company, estimate the capacity of the Farmer's Canal at approximately 250 CFS. The Department's historical records(Water Resource Survey notes) also indicate a capacity of up to 250 CFS. Records provided by Mr. Alberda and submitted with the Application showed measurements for 2005, 2006, 2007,2009, 2010, 2012, 2013, and 2014 (more records are available upon request, but these last 10 years are sufficiently representative for historic water use analysis, encompassing both wet and dry years); according to those records, Farmer's Canal diversion water was measured at a maximum of 103.425 CFS during those eight years. According to the Department's records, 50 rights are conveyed in the Farmer's Canal. Farmer's Canal conveys approximately 37 CFS of privately held, recorded water rights with a more senior priority date to Fanner's Canal water rights (pre-1883). Farmer's Canal also carries 275 AF of Middle Creek storage water. Farmer's Canal recorded water rights, ranging in priority from 1883 through 1892, account for approximately 234.5 CFS. Preliminary Determination to Grant Page 10 of 48 Application to Change Water Right No.41H 30102910 Appendix B— Correspondence with Farmers Canal Company tims@mad-eng.com From: Dan Triemstra <danbevt@gmail.com> Sent: Wednesday,July 24, 2019 8:01 AM To: tims@mad-eng.com Subject: Re: Famer's canal capacity Tim, Farmers Canal Company Board of Directors is in agreement with a box culvert with a capacity of 250 cfs to be installed at the Cottonwood Road crossing over the canal. Also,we request that no trash rack be installed. Farmers Canal Company of Gallatin County, Dan Triemstra,Secretary On Mon,Jul 22, 2019 at 4:43 PM<tims@mad-eng.com>wrote: Hi Dan, Thanks for chatting today. Please respond to this email verifying that the Canal Company desires the culvert to be designed for 250 cfs. Also, please indicate that the canal company does not want trash racks installed on the box culvert inlet. Thanks, Tim Staub,PE Madison Engineering, LLC 895 Technology Boulevard, Suite 203 Bozeman, MT 59718 406.586.0262 office 406.586.5740 fax tims@mad-eng.com MADISON ENGINEERING 1 Appendix C— Capacity calculations Capacity of existing double arch culverts Q = VA = 9 3 1:4 ,,[S— n Q= cfs n= Manning's roughness coefficient R= Hydraulic Radius(ft) A= Flow area(ft) S= Slope(ft/ft) n= 0.013 (Table 172, Bozeman DSSP) R= 1.01 (Table 4,Hydraulic Capacity of Culverts -American Concrete Pipe Association) A= 14.3 (Table 4,Hydraulic Capacity of Culverts -American Concrete Pipe Association) Soorth= 0.0015 *(existing culvert survey by Alpine Surveying) Slouch= 0.0008 *(existing culvert survey by Alpine Surveying) Q..nh= 64 cfs Qsouth= 48 cfs 04,od,= 112 cfs *Based on survey data,the as-built slope of each culvert is different. Capacity of existing channel upstream of culverts 1. 2 Q= VA = 9 3_ S Q= cfs n= Manning's roughness coefficient R= Hydraulic Radius(ft) [A/P] A= Flow area (ft) S= Slope(ft/ft) n= 0.035 (Manning's n for channels,Chow 1959) P= 25.1 wetted perimeter(existing channel survey by Alpine Surveying) R= 1.96 A/P A= 49.3'(existing channel survey by Alpine Surveying) S= 0.001 (existing channel survey by Alpine Surveying) 4a11aF 109 CfS 'I Overflow capacity calculation Per Bozeman DSSP V.C.7.b Height(ft) 3 Width (ft) 10 %overflow=(110%)*[(20+(A-20)*0.2)/A] A= total area of culvert opening(ft) PO= %overflow PO= 0.81 Determine required overflow capacity O `-�overflow= PO Qcanal PO= %overflow Qcanal= canal capacity, 109 ds ` overflow 88 Cfs The overflow capacity was calculated as a fraction of the upstream canal capacity and not the required 250 ds because the canal cannot carry more than 109 ds; when flowing full.So the additional 88 ds of overflow is added to the canal capacity at full flow to check whether the culvert can handle the canal when it has overtopped its banks. Qtotal,overRow= 197 Cfs The when the canal has overflowed its banks,there is still capacity in the culvert, which was designed for 250 ds. Appendix D— HY-8 Culvert Hydraulics Analysis � R ! o , % { / .t$ ` ! � U I &\ � \ k � ( Q � I [ | � 'A \ || � § . . III sill § f @ @ R Q @ § \ § Goco ) § ( ) \ ) deI, a � :- X < > I� � k 1 � ► r � � � � § _ I 7 � , & 7 � � � a � % � � { � \ \ / k. � .. u uleG d �k k f / c K « » 2 t _� � \ I § 2 ] \ ® K k f I u k 3 § c $ i 2' Z \ \ d � & � . 4C . � t IV / � § � u 2 R o 8 ■ & 7 8 § § o e § G d/ .o � d § u cs Am ■ � � ƒu § k > i <§ § t $ o ! I < k m o cCh f ■ & ! % # � � $ 7 \ \ _ E � cc ® f E 7 $ k rK 6 £ � \ \ � \ ) ° HY-8 Analysis Results Customized Table Culvert Crossing: Farmer's Canal-Cottonwood Crossing Total Culvert Headwater IWet Outlet Normal Critical Outlet Tailwater Discharge Discharge Elevation Control Control Depth(ft) Depth(ft) Depth(ft) Depth(ft) (cfs) (cfs) IN Depth(ft) Depth(ft) 20.00 20.00 4867.26 0.09 10.56 0.08 0.06 10.86 0.86 43.00 43.00 4867.78 0.15 1.08 D.13 0.10 1.38 1.38 66.00 156.00 4868.19 0.20 1.49 0.17 jo.13 1.79 1.79 39.00 89.00 4868.56 D.24 1.86 0.20 10.16 2.16 2.16 112.00 112.00 4868.89 10.28 2.19 0.24 0.18 2.49 2.49 135.00 135.00 4869.19 0.32 2.49 0.26 10.21 :2.79 2.79 158.00 158.00 4869.48 0.35 2.78 0.29 10.23 3.00 3.08 181.00 181.00 4869.75 110.39 3.05 0.32 iD.25 3.00 3.35 204.00 204.00 4870.01 0.42 3.31 0.34 0.27 3.00 3.60 227.00 227.00 4870.25 0.45 3.55 0.36 10.29 :3.00 3.85 250.00 250.00 4870.49 10.48 3.79 0.39 10.31 :3.00 14.09 {fox CUIV4,r, - injej i1vwl elev_ = 'f$66- 7D box CCc '�/P.✓f ou f ie f %nuerf" c l ev. HY-8 Analysis Results Crossing Summary Table Culvert Crossing: Farmer's Canal - Cottonwood Crossing Headwater Elevation Total Discharge (cfs) Box culvert Discharge (Roadway Discharge Iterations (tt) (cfs) (cfs) ,4867.26 20.00 20.00 0.00 1 ,4867.78 43.00 43.00 ).00 1 4868.19 66.00 56.00 0.00 1 4868.56 69.00 39.00 0.00 1 •4868.89 112.00 112.00 0.00 1 4869.19 135.00 135.00 0.00 1 4869.48 158.00 158.00 0.00 1 4869.75 181.00 181.00 0.00 1 4870.01 204.00 204.00 0.00 1 4870.25 227.00 227.00 0.00 1 4870.49 250.00 250.00 0.00 1 4871.45 1350.87 1350.87 13.00 Overt=inq Appendix E— Original double arch culvert design report and calculations (by TD& H Engineering) corresponding culverts that have influenced the direction and quantity of flow of water that drains in the watershed during a major storm event. The total flow that reaches the site is restricted by the 30"culvert (labeled #11)that crosses cottonwood midway through the property and the 42"pipe(labeled#5)that crosses cottonwood just south of Huffine. These two culverts have a combined capacity of 74.8 cfs. The rest of the flow generated in areas labeled 4, 5, 6, 7, and 8 would cross Huffine in culverts located east of Cottonwood during a major storm event. The 74.8 cfs that crosses Cottonwood combines with flows generated in areas labeled 2 and 3 to generate a flow of 106.2 cfs. This flow was analyzed at the 54 inch culvert that conveys Baxter Creek. HY8 was utilized to obtain the 100-year flood elevation of water during the storm. The elevation equaled 4813.37 feet. This projected water elevation was plotted using the contours on the site and the extent of flooding was found. See Appendix-Section 8 for a map of the flooding. The water from area#1 is easily conveyed by culverts 1-3 that are located west of the site. It is seen that the 100-year storm is adequately transferred through the existing culverts throughout the watershed. Only minor flooding is caused during the projected 100-year event which contains itself to a small portion of the ditch running east-west along Huffine Lane and the Baxter Creek channel. There would not be any concern of safety or damage of property and roads during a 100-year flood event. Farmer's Canal There currently is an existing bridge that crosses the Farmer's Canal on Cottonwood. Capacity calculations were conducted on the Farmer's Canal. The ditch can carry 140.24 cfs upstream of the bridge. Representatives of the Farmer's Canal have indicated that they desire a 72"culvert to be installed. A 72"pipe can carry 285 cfs at a d/D of 0.9 and a slope of 0.4%. The City of Bozeman Design Standards require that 140.24 cfs be carried plus overflow capacity that would total 267.5 cfs. Calculations can be seen in Appendix- Section 9. Culvert Calculations Many existing culverts are located throughout the watershed. The culverts that are of importance are: seven under Huffine Lane, two under Cottonwood Road, and one under Stucky Road. See Appendix- Section 6 for a map of the culvert locations and sizes. HY8 was used to analyze the capacity of each culvert and the resulting elevation of water. The culvert's characteristics and the downstream channel characteristics were input into the program. Flows generated by a 25-year storm event were analyzed to see if the culverts have adequate capacity to convey the water. All of the existing culverts are sufficient to convey the 25-year storm. APPENDIX - Section 9 Farmer's Canal Calculations t hydraulic Flow in Circular Pipe usin-. Mannings Equation n = 0.013 d/D - 0.9 Slope = 0.004 Diameter - 72 D Theta R d Hvdra Flow Flow Flow Velocity (ft) Radians (ft) (ft) Radius Area I (cfs) (mad) (fps) 6.00 1 4.996 3.00 5.40 1 1.788 26.803 1 285.64 184.64 10.66 128,206 apm Coy Lckqu�j Stcpe— C)ce k a,59, 1 -Takeo -�c— cqt-��,I(f c� 001 -tc) ConSecvGt►uL tt iLj a ILI uj 1.11 U., mmm to Cl)(n r-u 0 Cl) LApSreckW\ X SE-C�iCkA A- 103, S9 7 tC R _,A 1—7% 71, G-7 Ll - Sct 94 A a. lqq -73 AcJ\ VS A q 6-7S- q ev (OW mi-ilt'r,"A'J'A'A es Tb-S Gavlefalf� 6(fd vebct�� 21�vl ck CA VJR V\E96 CA 4.D a Izr�4,, re ire"v Cal C vL lo4p ov ear qo 1, c 7. o l4.f] , -,\ci ci -r(.OL"j culu Ls oAA Lna V)vi 0('n Appendix F— Reference Materials Table 3 Horizontal Elliptical Concrete Pipe Approximate R Pipe Size Equivalent A Hydraulic Rise x Span Round Area Values of 1.486/nxAxR2J3 (Inch) Diameter (Square Feet) Radius (Inch) (Feet) n =0.012 n=0.013 14 x 23 18 1.8 0.367 116 108 19 x 30 24 3.3 0.490 252 232 22 x 34 27 4.1 0.546 339 313 24 x 38 30 5.1 0.613 456 421 27 x 42 33 6.3 0.686 607 560 29 x 45 36 7.4 0.736 746 686 32 x 49 39 8.8 0.712 948 875 34 x 53 42 10.2 0.875 1156 1067 38 x 60 48 12.9 0.969 1565 1445 43 x 68 54 16.6 1.106 2196 2027 48 x 76 60 20.5 1.229 2910 2689 53 x 83 66 24.8 1.352 3753 3466 58 x 91 72 29.5 1.475 4734 4369 63 x 98 78 34.6 1.598 5856 5406 68 x 106 84 40.1 1.721 7140 6583 72 x 113 90 46.1 1.845 8584 7925 77 x 121 96 52.4 1.967 10187 9403 82 x 128 102 59.2 2.091 11983 11061 87 x 136 108 66.4 2.215 13972 12897 92 x 143 114 74.0 2.310 16153 14910 97 x 151 120 82.0 2.461 18494 17072 106 x 166 132 99.2 2.707 23856 22021 116 x 180 144 118.6 2.968 30338 28004 Table 4 Concrete Arch .• Approximate R Pipe Size Equivalent A Hydraulic Values of 1.486/nxAxRy3 Rise x Span Round Area (Inch) Diameter (Square Feet) Radius (Inch) (Feet) n=0.012 n=0.013 11 x 18 15 1.1 0.25 54 50 131/2 x 22 18 1.6 0.30 91 84 151/2 x 26 21 2.2 0.36 137 127 18 x 281/2 24 2.8 0.45 203 187 221/2 x 353/4 30 4.4 0.56 368 339 265/e x 433/4 36 6.4 0.68 613 566 315/8 x 511/e 42 8.8 0.80 938 866 36 x 581/2 48 11.4 0.90 1315 1214 40 x 65 54 14.3 1.01 1783 1646 45 x 73 60 17.7 1.13 2376 2193 54 x 88 72 25.6 1.35 3867 3569 62 x 102 84 34.6 1.57 5784 5339 72 x 115 90 44.5 1.77 8056 7436 771/4 x 122 96 51.7 1.92 9872 9112 871/8 x 138 108 66.0 2.17 13689 12635 American Concrete Pipe www.concrete-pipe.org info@ concrete-pipUZI y © 0 2009 American Concrete Pipe Association,all rights reserved. I]D 11 (07/0" 7/1YT019 M-wo n Val- 712] lu hl."Js n wig Manning's n for Channels(Chow,_ 195_9). 4 wilh short grass,lave weeds 0.022 0.027 0.033 Type of Channel and Description I Mlnlmum 1 Namet I Maximum b Earth winding and sluggish 1.no vegetation 0.023 0.025 M030 Natural streams-minor streams(lop widlh at floodslage<100 fl) _ 2,grass.some weeds 0.025 (L030 0.033 1.Main Channels _ _ 3.dense weeds or aquatic plants in deep channels 0.030 0,035 0.040 a clean,straight,hill slope,no rips or deep pools 0.025 0.030 0.033 4,earth bottom and rubble sides (L028 a 030 0.035 b unv as show,hug more stones and weeds 0.030 0,035 0,040 5 stony bottom and weedv banks 0.025 0,035 0.040 c clean,winding,some pools and shoals 0.033 0.040 0.045 6.cobble bottom and dean sides 0.030 0.040 0.050 d,same as above,but some weeds and stones 0.035 0.045 0.050 c.Dragline-excavated or dredged e,same as above,lower stages,more ineffective 0.040 0.048 0.055 1.no vegetation 0.025 a028 0.033 slopes and sections 2.light brush on banks 0.035 0.050 0.080 f.same as'd'with more stones 0.045 0.050 0.060 d.Rock cuts rh _slug ,rsechas,weedy dsep_poh0,050 0,070 0 Ow 1.smooth and unfloml 0025 0.035 0.040 wry weedy reaches,deep pools,orfloodwitys 0,075 0.100 0.150 2-jagged and irregular 0.035 0.040 C050 with heavy stand of limber and underbrush e.Channels not maintained,weeds and brush uncut 2.banks submerged In streams,no vegetation In channel,banks usually sleep,trees and brush along 1.dense weeds,high as flow depth banks submerged at high stages 9 p1 0.050 (LOBO 0.120 a bottom:gravels,cobbles,and few boulders ^0,030 0,040 0.050 2.dean bottom,brush on sides 0.040 0.050 0.080 b,bottom:cobbles with large boulders 0.040 0,050 0.070 3.same as above,highesl stage of flow 0-045 2070 0.110 3.Floodplalns 4,dense brush,high stage (LOBO 0.100 0.140 a,Pasture,no brush S.Lined or Constructed Channels 1.short grass 0.025 0,030 0,035 e.Cement 2.high grass 0.030 0,035 0.050 1.neal surface 0.010 0.011 0.013 b.Cultivated areas 2,mortar 0.011 0,013 0.015 1.no crop 0.020 0.030 0.040 b,Wood 2.mature row crops 0.025 0.035 6.045 1,planed,untreated 0.010 0.012 0.014 3.mature field crops 0.030 0 040 0.050 2.planed,creosoted 0.011 Q012 0.015 c.Brush I 3,unplaned %011 M013 0,015 1.scattered brush,heavy weeds 0.035 0.050 Q070 4,plank with battens 0,012 0,015 0.018 2-light brush and trees,in winter 0.035 0.050 0.060 5.lined with roofing paper 0.010 0,014 0.017 3.light brush and trees,In summer 0.040 0.060 0.080 c Concrete 4.medium to dense brush,in winter 0.045 0.070 0,110 1.trowel finish 0.011 0.013 01015 5.medium to dense brush,in summer 0.070 0.100 0.160 2 float finish 0.013 0.015 0,016 d.Trees 3.finished,with gravel on bottom 06015 0.017 0.020 1_dense willows,summer,straight 0.110 0.150 0.200 4.unfinished 0.014 0.017 Q020 2-cleared land with Iree slumps,no sprouts 0.030 0 040 0.050 5.gunite,good section 0.016 0.019 M023 3 sans,as above,but with heavy growth of 0.050 0.060 0000 6-gunite,wavy section (Lola 0.022 0.025 . sprouts 7,on good excavated rock 0.017 0.020 4.heavy stand of timber,a few down bees.In. 0.080 0.100 0.120 !on Wepulsresuvatad rock 0.022 0.027 undergrowth,flood stage below branches d.Concrete bottom float finish with sides of: 5.same as 4.with flood stage reaching branches 0.100 0.120 0.160 1. 1.dressed stone in mortar 0.015 0.017 0.020 Excavated or Dredged Channels 2,random stone in mortar 0.017 0.020 0.024 a.Earth,straight,and un"dorm 9.w11taM rubhk Ittasottry_plaetarod 0.016 0.020 0.024 1,clean,recently completed 0.016 0.018 0.020 4.cement rubble masonry 0.020 0.025 0.030 2.clean,after weathering 0.018 OZ 0.025 5.dry rubble or riprap 0.020 0.030 0.035 3 gravel.pndomt soal0n,dwn O.D22 0.025 0.0.10 - - - .w.mn.ewp.n.rr.'rx1H.l.e Nrbvul�_RMw,aYnNry_n 111klwAar Iq wow.tsl.oraLeJulaeu+r+lerlF%3lielp'9_Mydra�RebrencdMannirgs-n_TebI�1Nn yj M29014 n Values e.Gravel bottom with sides of: 1.formed concrete 0.017 0.020 0.025 2.random stone mortar 0.020 0.023 0.026 3.dry rubble or riprap 0.023 0,033 0.036 I.Brick 1,glazed 0.011 0,013 0.015 2.In cement mortar 0.012 0.015 0.018 g.Masonry 1.cemented rubble 0.017 0-025 0.030 2,dry rubble 0.023 0.032 0.035 h.Dressed ashlar/stone paving 0.013 0.015 0.017 I.!asphalt 1.smooth 0.013 0.013 2.rough 0.016 0.016 j,Vegetal lining 0.030 0.500 wnv.hl orAetlWpmvalerlFXNelpe_HydraulK Relemica'Mannirps_n_Tabkshbn 313