South Side Red River Bridge Corridor Study Phase III Preliminary Geotechnical Study Phase IV New Alignment Alternatives Evaluation

Study Review Committee (SRC) Members Jack Cousins - Clay County Engineer Tim Magnusson - Clay County Planner Brian Gibson - Transportation Analyst, F-M Metro COG Richard Lane - Traffic Engineer, Fargo Cindy Gray - Senior Planner, Fargo Bob Bright - Executive Director, F-M Metro COG Mark Bittner - City Engineer, Fargo

Project Timeline Spring 1998 – Initiated Study July 1998 – Public Meeting #1 September 1998 – Public Meeting #2 December 1998 – Joint Planning Commission Meeting January 1999 – Neighborhood Rebuttal March 1999 – Phase I Final Report 2000 – Initiated Phase II Supplemental Study and Neighborhood Response 2000 – Completed Land Use Analysis for Study Area May 2001 – Neighborhood Response May 2001 – Phase II Report June 2001 – Joint Planning Commission Meeting Initiated Phase III Geotechnical Study January Phase III Geotechnical Study Report February Initiated Phase IV Study Report March Phase IV Study Report

Overall Study Goals & Objectives w Preserve a corridor between 52nd Avenue S. and 88th Avenue S. that will be needed years from now. w Decision will allow the City of Fargo, Clay County, Cass County, and the City of Moorhead to do long range planning for one type of corridor or the other. w Decision will allow the affected residents to do their own long range planning.

Phase I Study Results w Technical evaluations of 11 alignment alternatives. w 70th Avenue S. and 76th Avenue S. were both feasible and met study objectives. w The Forest River Neighborhood Preservation Committee prepared a detailed review of the Phase I Report. w This feedback resulted in a response document and the development of the Phase II Supplemental Report.

Phase II Study Results w Added a new alternative: The combined 70th/76th Avenue S. alternative. w Sub-Alternative A for the 76th Avenue S. Alternative was selected to minimize both the impacts of the arterial upon the neighborhood and the impacts of the neighborhood streets upon the arterial. w All three alignment alternatives feasible.

Final Three Alternatives

Criteria System Continuity and Route Direction Interchange Spacing Land Use Planning Traffic Operations Mainline Length Length of Supporting Roads Residential Acquisitions Neighborhood Severance Homes Adjacent to New Roadways Farmland Severance Cost 70th Avenue S. Alternative No direct connections 1.5 miles Introduces.5 mile arterial spacing Optimal 6.2 miles 0 feet None 8 Greater $22.2 million 76th/70th Avenue S. Alternative Direct connection to the west 2 miles Introduces.5 mile arterial spacing Indirect travel route 6.4 miles 0 feet None 8 Greater $22.7 million 76th Avenue S. Alternative A Direct connections to the west and east 2 miles Consistent with 1 mile arterial planning Add’l full accesses 6.2 miles 3,600 feet 10 Minimized 14 Least $23.5 million Phase II Technical Comparison of Final Three Alternatives

Phase III Study Goals & Objectives w Determine the geotechnical feasibility of crossing the Red River at 70th and 76th Avenues. w Refine alignment alternatives and bridge lengths based upon study findings. w Update Cost Estimates based upon study findings.

Soil Stability Analysis w Soil borings provided a cross-section of soils near the crossing locations of 70th and 76th Avenues w Analysis resulted in top of riverbank setback requirements at 70th and 76th crossing locations and approach embankments. w Additionally, river bed rip-rap is required at the crossing location and adjacent to the approach embankments of the 76th Avenue Alternative.

Soil Stability Analysis Results w 70th Avenue Setbacks: –30 feet from elev. 905 on west riverbank –0 feet on east riverbank w 76th Avenue Setbacks: –120 feet from elev. 905 on west riverbank –140 feet from elev. 902 on east riverbank –60 feet from elev. 905 on west approach embankment (from oxbow to the north) –220 feet from elev. 902 on east approach embankment (from oxbow to the north) w Additional geotechnical analysis recommended at final bridge location

Geotechnical Considerations

Backwater Effects w A preliminary backwater (flooding) analysis was conducted at each river crossing location using a draft HEC-RAS (Hydraulic Engineering Center River Analysis System) model developed by Houston Engineering. w With the recommended setbacks, neither crossing alternative will affect the hydraulic capacity of the river channel.

Bridge Adjustments w All bridges aligned to cross on a tangent w 70th Avenue: 1,170-foot bridge length w 76th Avenue: 1,200-foot bridge length, 2 300’x10’x10’ Box Culverts to cross County Ditch 32

Alignment Adjustments & Impacts w No change under the 70th Avenue Alternative. w No change under the 76th/70th Avenue Alternative. w Significant changes under the 76th Avenue Alternative due to abutment and approach embankment setbacks.

Phase III Conclusions & Recommendations w Applying the required setbacks and rip-rap, both the 70th and 76th Avenue crossings are technically feasible. w Hydraulic capacity of the Red River channel can be maintained with the proposed bridge abutment setbacks and bridge profile. w An additional bridge crossing location south of the 76th Avenue Alternative should be considered in a fourth phase of the study. w The Phase IV study will identify this new alternative(s) to be evaluated alongside the current alternatives, for the purpose of selecting a preferred alternative.

Phase IV Study Goals & Objectives w Identify new alternatives to ease impacts and reduce construction costs. w Evaluate new alternatives against the three previous alternatives. w Update Cost Estimates based upon study findings. w Select a preferred alignment alternative.

70th Avenue Alternative

76th/70th Avenue Alternative

76th Avenue Alternative

New South 76th Avenue Alternative (Dismissed)

New “Jogged” South 76th Avenue Alternative

New “Jogged” 76th/70th Avenue Alternative

FEMA Flood Buyout Properties w The 76th Avenue, “Jogged” South 76th Avenue and “Jogged” 76th/70th Avenue alternatives require the use of lots purchased with FEMA Hazard Mitigation Grant Program (HMGP) funds. w If the preferred alternative uses any HMGP buyout lots, FEMA would want to investigate the environmental consequences of the alignment versus other alignments. w Approval of use would be subject to environmental review. Reimbursement of funds is unlikely.

Comparative Cost Estimate

Phase IV Conclusions & Recommendations w All five of the bridge location and corridor alignment alternatives are technically feasible. w With the exception of the original 76 th Avenue Alternative, all other alternatives have similar costs. w The “jogged” alignments are less desirable for an arterial roadway serving east-west trips. w Each alternative results in different pros and cons as they relate to residential impacts, route continuity, traffic operations and cost. w Elected officials should weigh these factors in the selection of a preferred alternative.

Next Steps w Who should complete this??