Hydraulic Report. County Road 595 Bridge over Dead River. Prepared By AECOM Brian A. Hintsala, P.E

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1 Prepared for: Prepared by: Marquette County Road Commission AECOM Ishpeming, MI Marquette, MI December 9, 2011 Hydraulic Report County Road 595 Bridge over Dead River Prepared By AECOM Brian A. Hintsala, P.E

2 AECOM i Contents 1.0 Introduction Method of Analysis Variables and Coefficients Starting Point Discussion Conclusion... 2 List of Appendices Appendix A HEC-RAS Computations Appendix B Profile Sheets Appendix C Topographic Map HEC-RAS River Sections Appendix D Bridge Plans Appendix E Cross Sections Appendix F Damage Waivers Appendix G Flow Rates Appendix H Site Photographs Appendix I USGS Topographical Map and River Gradient Calculations

3 AECOM Introduction This hydraulic report is being prepared for the Marquette County Road Commission concerning the proposed County Road 595 crossing of the Dead River. The site is located in Section 11 of T49N, R29W, Quad Map Name Bulldog Lake (Lat /Long ) in Champion Township, Marquette County. Multiple road alignments were investigated. The chosen alignment crosses the river at the site of an existing bridge. The existing bridge is both structurally and geometrically inadequate for the projected road traffic and requires replacement. 2.0 Method of Analysis The hydraulic analysis was performed using the HEC-RAS River Analysis System computer program, Version developed by the U.S. Army Corps of Engineers Hydraulic Engineering Center. The steady flow data for the flood events were obtained from the Michigan Department of Environmental Quality (MDEQ). 3.0 Variables and Coefficients The river sections near the bridge use an expansion coefficient of 0.30 and contraction coefficient of 0.50 which are suitable for a typical bridge per Table 3.3 of the HEC-RAS Hydraulic Reference Manual. The Manning s n-values for friction loss were selected using Table 3.1 of the HEC-RAS Hydraulic Reference Manual. The main channel is fairly uniform with some weeds so a value of was chosen. Upstream of the bridge the overbank areas are swampy with light brush so a value of was chosen. Downstream of the bridge the overbanks are covered with heavy brush so a value of was chosen. Representative photographs of the site are included in Appendix H. 4.0 Starting Point The starting point of the analysis was a surveyed river section about 210 feet downstream of the proposed road. This location was chosen because it was far enough downstream to be outside of the influence of the proposed bridge. The starting water surface elevation was calculated by HEC-RAS using the slope-conveyance method. An average channel slope of was estimated from a USGS quadrangle map and used for the normal depth boundary condition. The calculations are included in Appendix I. 5.0 Discussion Downstream of the bridge, the main channel of the Dead River is well defined and conveys the majority of the flow up to and including the 100-year flood event. Upstream, the main channel width is more variable and the floodplain becomes much wider. At the 100-year flood event, the majority of the flow is carried by the overbank floodplain. The river gradient is relatively flat and the flow regime is sub-critical for all flood events. The existing bridge has a 13 foot wide timber deck which is supported by longitudinal steel beams. The beams span 17 feet between the abutments which are stone filled timber cribs. The proposed bridge will be placed directly over the location of the existing bridge (after is removed).

4 AECOM 2 The proposed bridge is a pre-cast concrete, three-sided culvert (ConSpan) with a span of 24 feet. Since the culvert is a buried structure, the normal road section is continued over the bridge. The concrete footings will be placed on the natural soils at the site and will be protected from scour by driven steel sheet piling. The restored stream banks will be treated with heavy riprap which is sized and placed in accordance with the Michigan Department of Transportation 2003 Standard Specifications for Construction. The river cross sections are placed in HEC-RAS at the distances measured along the center line of the channel. In some cases the surveyed sections on each side of the bridge were adjusted up or downstream as required to model the bridge using the standard bridge/culvert input section of HEC- RAS. This is required because the actual location of the bridge was not known when the survey was performed. The final positions of the sections are shown in the plan view in Appendix C. The ConSpan three-sided arch can be modeled either as a culvert or as bridge in HEC-RAS. For this project, it was modeled as a bridge to better represent the natural stream channel. In addition, since HEC-RAS does not perform scour calculations for culverts, modeling the ConSpan as a bridge allowed scour calculations using HEC-RAS. The existing road approaches on each side of the bridge cut off a large portion of the overbank flow during the higher flow events. Ineffective flow areas were included in the overbank portions of the cross sections upstream and downstream of the bridge as suggested in chapter 5 of the HEC-RAS Hydraulic Reference Manual. The proposed bridge has a larger span to alleviate existing bridge encroachment on the main channel. This reduces the water velocity at the bridge as well as the water elevation upstream. Table 1 on the following page summarizes the key model results for two configurations: 1. The existing 17 span bridge. 2. The proposed 24 span bridge. 6.0 Conclusion Analysis results indicate that the proposed bridge decreases water surface elevations and channel velocities for all of the flow events compared to the existing bridge.

5 Hydraulic Comparison of Various Bridge Options 3 County Road 595 Bridge Design Dead River 4/1/2010 Table 1 HEC-RAS Analysis Results Velocity in Channel at Bridge River Station 2.8 Flow thru Bridge Water Surface Elevation at Upstream Face of Bridge River Station 3 Energy Gradient Elev at Upstream Face of Bridge River Station 3 Energy Gradient Elevation at 260' Upstream of Bridge River Station 5 (ft/sec) (cfs) (feet) (feet) (feet) Model Configuration 100 Year 10 Year 100 Year 100 Year 200 Year 100 Year 100 Year (550 cfs) (220 cfs) (550 cfs) (550 cfs) (700 cfs) (550 cfs) Change (550 cfs) Change Existing Bridge Proposed Bridge

6 AECOM Appendix A HEC-RAS Computations

7 AECOM Computations The HEC-RAS data files are included in a separate electronic folder named: HEC-RAS_Dead River.zip In order to provide a brief summary of the analysis results, a Profile Output Table for the existing and proposed conditions are included on the following pages.

8 HEC-RAS Plan: Existing River: Dead Reach: Dead Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) Dead 5 10 Year Dead 5 50 Year Dead Year Dead Year Dead 4 10 Year Dead 4 50 Year Dead Year Dead Year Dead 3 10 Year Dead 3 50 Year Dead Year Dead Year Dead 2.8 BR U 10 Year Dead 2.8 BR U 50 Year Dead 2.8 BR U 100 Year Dead 2.8 BR U 200 Year Dead 2.8 BR D 10 Year Dead 2.8 BR D 50 Year Dead 2.8 BR D 100 Year Dead 2.8 BR D 200 Year Dead 2 10 Year Dead 2 50 Year Dead Year Dead Year Dead 1 10 Year Dead 1 50 Year Dead Year Dead Year

9 HEC-RAS Plan: Conspan Brdg River: Dead Reach: Dead Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) Dead 5 10 Year Dead 5 50 Year Dead Year Dead Year Dead 4 10 Year Dead 4 50 Year Dead Year Dead Year Dead 3 10 Year Dead 3 50 Year Dead Year Dead Year Dead 2.8 BR U 10 Year Dead 2.8 BR U 50 Year Dead 2.8 BR U 100 Year Dead 2.8 BR U 200 Year Dead 2.8 BR D 10 Year Dead 2.8 BR D 50 Year Dead 2.8 BR D 100 Year Dead 2.8 BR D 200 Year Dead 2 10 Year Dead 2 50 Year Dead Year Dead Year Dead 1 10 Year Dead 1 50 Year Dead Year Dead Year

10 AECOM Appendix B Profile Sheets

11 Dead River Crossing Plan: Existing Bridge 4/3/2010 Dead Dead Legend EG 200 Year WS 200 Year EG 100 Year WS 100 Year EG 50 Year WS 50 Year EG 10 Year Crit 200 Year WS 10 Year Crit 100 Year Elevation (ft) 1555 Crit 50 Year Crit 10 Year Ground Main Channel Distance (ft)

12 Dead River Crossing Plan: Conspan as a Bridge 3/31/2010 Dead Dead Legend EG 200 Year WS 200 Year EG 100 Year WS 100 Year EG 50 Year WS 50 Year EG 10 Year Crit 200 Year WS 10 Year Crit 100 Year Elevation (ft) 1555 Crit 50 Year Crit 10 Year Ground Main Channel Distance (ft)

13 AECOM Appendix C Topographic Map HEC-RAS River Sections

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15 AECOM Appendix D Bridge Plans

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18 AECOM Appendix E Cross Sections

19 AECOM Cross Section Cross sections are included for the existing condition and the proposed bridge condition.

20 AECOM Existing Channel Condition

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27 AECOM Proposed Bridge Condition

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34 AECOM Appendix F Damage Waivers

35 AECOM No Damage Waivers Required

36 AECOM Appendix G Flow Rates

37 DEQ - Flood Frequency Discharges Page 1 of 1 12/6/2011 Joint Permit Application DEQ Home CIWPIS Online Services Permits Programs Site Map Contact DEQ Flood Discharge Request Record /6/2011 Home Water Management Lowflows Discharge Requests Watersheds Map Discharge Information Watercourse: DEAD RIVER Location: Trail 5 Drainage Area: 8.63 mi 2 Basin Name: 45 - Dead Contributing Area: 8.63 mi 2 County: Marquette Tn/Rng/Sec: 49N29W/11 Township: Champion Latitude: Quad Name: Bulldog Lake Longitude: Quad ID: D11NW Requested By: Sheila Meier (DEQ-LWM- Received Date: 11/23/2011 Ishpeming) Request Type: Trans. - County Issued Date: 12/5/2011 File Number: Reference Number: Discharge Frequencies: Volume Frequencies: 10%: 220 cfs 2%: 440 cfs 1%: 550 cfs 1%: 1100 acre-ft 0.5%: 700 cfs 0.5%: 1400 acre-ft 0.2%: 950 cfs Access to the Flood Flow Database is provided as a service to allow you to check the status of your flood flow requests or to view discharges from previous requests for preliminary design purposes. The discharges values are only valid for the original requestor and for one year after the original request date. To obtain discharge information from the Hydrologic Studies Program, a flood flow discharge request form may be submitted electronically to the DEQ. A written or response to your request will be returned to you and must accompany your permit application. Michigan.gov Home DEQ_Home Online Services Permits Programs Site Map Contact_DEQ State Web Sites Privacy Policy Link Policy Accessibility Policy Security Policy Copyright 2011 State of Michigan

38 AECOM Appendix H Photos

39 County Road 595 over the Dead River.DOC Existing Bridge Looking North Looking Upstream from Existing Bridge

40 County Road 595 over the Dead River.DOC Looking Upstream from Existing Bridge Looking Upstream from Existing Bridge

41 County Road 595 over the Dead River.DOC Looking Downstream from Existing Bridge

42 AECOM Appendix I USGS Topographical Map and River Gradient Calculations Map includes portions of Quadrangle maps: Bulldog Lake Silver Lake Basin

43 087 55' 0.00" W ' 0.00" W ' 0.00" W ' 0.00" N ' 0.00" N ' 0.00" N ' 0.00" N ' 0.00" N ' 0.00" N 475 Proposed bridge location CR 595/Dead Riv. 5m Intv. 5m Diff or 16.4' = 16.4/13,110 = or 0.13% 4 W ' 0.00" W ' 0.00" W Copyright (C) 1999, Maptech, Inc ' 0.00" W