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HomeMy WebLinkAboutGateway pptlow,a CiTv GATEWAY Gateway Proje I Tonight's Objectives: • Work Session • Answer Questions asked at the September 17th Work Session and correspondence • Review Staff Recommendations • Answer Additional Questions from Council • Formal Meeting • Outline Staff Recommendations • Provide Opportunity for Public Input • No formal action will be taken tonight GATEWAY IOWA ciTY • • • Questions • Roadway elevations • Flooding issues • Construction • Design considerations / footprint reduction GATEWAY IOWA ciTV Roadway Elevations ■ Is it correct that Dubuque Street has been closed 150 days in the last 20 years due to flooding? Would Dubuque street have been closed only 6 days if the road /bridge were at a 100 + 1 elevation? • Both statements are correct • Does not include closures from local heavy rains ■ Have you assessed any other intermediate flood levels? • Looked at 200 +1 elevation • Approximately 3.4 feet higher than 100 +1 elevation • Updated comparisons for backwater, cost and cross sections in council packet IOWA CITY GATEWAY ]10 ]oo 690 500-year Flood f Foot Flood Level Mayflower Residence Hall 2008 lootl +1 Foot Flood Level 660 Removable Floo0wall 200 - year + l FOOL Flood Level 100- year +1 Foot Flood Level 6]0 No-Build (Existing Grade) 660 650 - 2008 Flood '. 993 Flood 610 630 Dubuque Street @ Maynower Residence Hall a 15 30 60' IOWA CITY GATEWAY �r S Mr +1 FwI Flm L l 3000 FbW-t F. Flw Leval 2_ry rr1 FW F"LeV 1WMr +1FwIFlw L l Nobuiq (Ens0e9 G2tle) � f 3000 FbW 003 Fb Dubuque Street 36.79 o is 30 60- GATEWAY IOWA ciTY Roadway Elevations Why is the use of Hesco barriers in combination with a lower roadway elevation not a reasonable option? • Risk to keep Dubuque Street open with temporary measures • Impacts to traffic during deployment/ removal • Pedestrian / bicycle traffic not possible • Estimated cost of approx. $690,000 to deploy per event • 85% reimbursable for federally declared disaster deployment ATFWAV low,a CiTv Roadway Elevations (i How will water runoff from the east side of Dubuque Street be handled? • Runoff conveyed from east to west to river • Will still use open ditches and cross - culverts • Project will reconstruct and upsize both for better conveyance • Will not be a certified levee when complete Iowa CiTv Flooding issues GATEWAY Can more information be provided on future road closures by various impact levels? ■ Can only look to past events What is the economic impact when Dubuque Street closes? ■ Staff working with Economic Development Division, Summer of Arts and the Chamber of Commerce to try to develop impact of 2008 and 2013 How will the project relate to the Corps operation plan for the Coralville Reservoir? ■ Maximum release of 20,000 cfs could be achieved without impact to elevated Dubuque Street 0 Construction Issues How would cost overruns during construction be paid for? ■ Current estimate includes 20% contingency • Cost overruns paid for by G.O. Bond proceeds • Wastewater project is over 70% complete with 1% change orders Cost clarification between Gateway and No Build options? ■ Cost estimates presented for Gateway options were for construction only and did not include Final Design, Construction Admin and Inspection Fees ■ Trunk sewer not included ■ No Build cost estimate did include the Final Design, Construction Admin and Inspection Fees 0 Design Considerations Travel lanes in the Preferred Alternative are 12' wide. Can this width be reduced and if so, what will the affects be? • This is the standard for Iowa DOT Design Manual, Statewide Urban Design and Specifications, and AASHTO Green Book • Accommodates all vehicles that currently use the corridor • Reducing lane width could lead to an increase in crashes � Design Considerations To increase safety on Dubuque St and Park Rd, would it be better to reduce speed from 35 mph to 25 mph? Would a reduction in lane width result in a reduction in speed? • Currently an Arterial street at 35mph • Speed management will be studied during design • Lane width reduction could lead to reduced speed, but lane width reduction could also lead to increase in crashes ■ 1 -80 /Dubuque is now signal controlled as is Foster /Dubuque 0 Design Considerations Could a pedestrian- activated signal be installed at M ayf I owe r? • Will be considered during final design • Could have positive impact on ped safety and speed control • Other locations with pedestrians crossing in corridor • Would have a negative impact of traffic delay 2Design Considerations The Preferred Alternative recommends wide sidewalks on both sides of Dubuque Street. Can these widths be minimized or perhaps eliminated on the east side? • Purpose and Need to maintain and enhance amenities • Brown to Foster walk was frequent request at public meetings • Reducing widths or eliminating east sidewalk counter to goals • Would reduce walkability of corridor • Iowa River Trail most heavily used in the metro area • North of Kimball, roadway shifted west to reduce impact 0 Design Considerations Can parkway widths be reduced? • Would create winter maintenance issues • Would reduce safety buffer Can the median width be reduced from 0 — 25' to 0 —12'? • South of Kimball — No median proposed • Kimball to Ridge — alignment shifted west • Same as current medians to maintain character of corridor • Provides storage for Cambus and turning vehicles 0 Design Considerations It has been indicated that a right turn lane from southbound Dubuque to westbound Park is warranted by the MPOJC. Why is a new turn lane necessary? • Right turn lane warranted threshold is apx. 300 vehicles /hour • Current traffic is 715 SB right turns on to Park Rd in morning • Right turn lane will increase function and safety • Lane would not impact the wooded bluff � Design Considerations Are dual left turn lanes required on eastbound Park Road? Can we have a shared right and left -turn lane to reduce the width of the new bridge? ■ Dual left needed to obtain acceptable service levels • Will help anticipated growth in Hancher traffic turning NB • Will analyze more closely during final design Is the 3rd lane on Park Road really needed? ■ Recommended by MPOJC in 2008 ■ Part of approved CIP ■ Helps Park Road and Hancher traffic operate at acceptable service levels Design Considerations Are there additional options available for shrinking the horizontal footprint and minimizing impact along the Bella Vista hillside at Dubuque and Park Road? • Retaining walls along east side of sidewalk • Steeper slopes • Tree wells for protecting mature trees • Tree replacement • Native plantings along affected hillside and slope 0 Design Considerations What are the design criteria affecting clear zone and the use of barriers? • Look to Iowa DOT Design Standards for clear zone and barrier requirements • Setback of retaining wall in the Preferred Alternative greater than required clear zone • The top of wall does not require a crash worthy barrier if it is outside the required clear zone • Clear zone will be verified and analyzed in more detail during design IOWA ciTY • - • • GATEWAY • Level of Protection for Dubuque Street • Backwater Reduction Goals • Structural Type of the Bridge 12 Recommendation for Elevation of Dubuque Street Recommended minimum level of protection for Dubuque Street: One foot above the 2008 flood. * Including one day for cleaning, inspection and repair Post Flood of `93 Projects to Consider, All Designed to 100 year + 1' • Rocky Shore Drive /Highway 6 Flood Gate • Riverside Drive Lift Station • South Gilbert /Stevens Drive Flood Gate • Floodplain Map Update Rocky Shore Drive / Highway 6 Flood Gate , shoji 1 . y a 71 M169 2011: . After 2008 we are now implementing a $6.6M upgrade that is part of a 5 project $26.9M collaborative regional effort to protect this area. South Gilbert / Stevens Drive Flood Gate I�: 201 9 After 2008 upgrades to the existing level of protection were investigated, but the estimated cost exceeded funding that was available. Floodplain Map Update 2013 � IJl After 2008 the Floodplain Management Ordinance was 200Q amended to require O protection to 1' above the 500 year event. IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental ConstrulConstructi Construct"Construction Elevation Reduction Improvement Elevation Height of on Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 50Gyr +1' 100yr +1' 20Gyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67M $34.26M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through SOOyr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY • • Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67M $34.26M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M - Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY 0 . Bridge Type Low Steel Backwater Incremental Deck Increment7Estimate i Constr7S34.26 on Construction Elevation Reduction Improvement Elevation Height of on Cost Cost GATEWAY at Idyllwild in Backwater Bridge Dec Estimat Estimate Reduction with with Dubuqt Dubuqueat at S00yr +1' 200yr +r 100yr +1' 3.4" 660.20 Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ` Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67M $34.26M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0" $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0" $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Constructi Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative ' Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M - Arch `• Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Constructs Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M C6 - Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M =.. Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M _ Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch '�� Through 2008 +1' S.2" 0.3" 659.95 11.1" $36.70M $38.47M `• Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0" $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Constructi Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M e6 _ Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M - Through 100yr +1' 3.4" 656.87 $35.99 M $37.58 M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" 36.70M $38.47M _ Arch `� Through SOOyr +1' S.8" 0.6" 661.53 19.0" 36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Constructs Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr+ 1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M - Deck Girder 500yr+ 1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch & _ Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch `• Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck IncrementponCost tructi Construction Construction Elevation Reduction Improvement Elevation Height of ost Cost Cost GATEW AY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M M 6 _ Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M - Deck Girder 500yr +1' 7.0" 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative _ Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99 M $37.58 M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch `• Through SOOyr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Construct! Constructi Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr+ 1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M M6 _ Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative _ Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M C6 - Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0" $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch 2008 +1' S.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch `• Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Constructs Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M - Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch & _ Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch `• Through 500yr +1' 5.8" 0.6" 661.53 19.0" $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Constructs Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M - Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0' $34.20 M $35.01 M $35.34 M $36.65 M EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr +1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M Arch & _ Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch `• Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C - Deck Girder 500yr +1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M 538.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructs Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder SOOyr+ 1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through SOOyr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder 500yr+ 1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63 M $35.01 M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder 500yr+ 1' 7.0' 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder 500yr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 4.9" 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder 500yr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' S.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M ra C Deck Girder 500yr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' S.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' S.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder 500yr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 665.03 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 20Dyr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY s M - Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost G ATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M $38.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA CITY- s M's 16rol Bridge Type Low Steel Backwater Incremental Deck Incremental Constructi Construct! Construction Construction Elevation Reduction Improvement Elevation Height of on Cost on Cost Cost Cost GATEWAY at Idyllwild in Backwater Bridge Deck Estimate Estimate Estimate Estimate Reduction with with with with Dubuque Dubuque Dubuqueat Dubuqueat at at 2008 +1' 500yr +1' 100yr +1' 200yr +1' Deck Girder 100yr +1' 3.4" 660.20 $32.67 M $34.26 M Deck Girder 200yr +1' 6.1" 2.7" 662.52 27.8" $34.63M $35.01M Deck Girder 2008 +1' 6.6" 0.5" 663.45 11.2" $33.41 $35.17M Deck Girder SOOyr+ 1' 7.0" 0.4" 19.0" $34.20 M $35.01 M $35.34 M $36.65 M _ EA Preferred Alternative Deck Arch 100yr +1' 3.6" 659.20 $36.01 M $37.59 M Deck Arch 200yr +1' 4.7" 1.1" 661.52 27.8" $37.96M $38.34M Deck Arch 2008 +1' 5.2" 0.5" 662.45 11.1" $36.71M $38.48M Deck Arch 500yr +1' 5.6" 0.4" 664.03 19.0' $36.94 M $38.33 M $38.66 M $39.98 M Through 100yr +1' 3.4" 656.87 $35.99M $37.58M Arch Through 200yr+ 1' 1.5" 659.02 25.8" $37.93 M 8.31 M -c Arch Through 2008 +1' 5.2" 0.3" 659.95 11.1" $36.70M $38.47M Arch Through 500yr +1' 5.8" 0.6" 661.53 19.0' $36.90 M $38.30 M $38.63 M $39.60 M Arch IOWA ciTY GATEWAY Council Q&A