Agenda - Parks and Recreation Commission - 02/12/2015

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Mississippi Skyway Preliminary Engineering Report SRF Consulting Group, Inc. was engaged to assess the feasibility of constructing a grade separated crossing over TH10 and Riverdale Drive. The study included the following objectives: Identify potential locations for a new pedestrian bridge crossing of TH 10 and Riverdale Drive. Conduct preliminary analysis of alignments and profiles for further consideration in future design phases. Identify impacts to adjacent private and public lands for possible Right -of -Way (ROW) easements and acquisitions. Identify impacts to existing utilities. Outline potential structure types and aesthetic options for consideration. Provide an outline of future tasks to continue to move the project forward in compliance with anticipated funding requirements. Review possible additional site development options for the surrounding site to facilitate pedestrian and bicycle connections to the approach areas. Throughout the process, multiple alignments were considered (see Appendix B & Appendix J). With assistance from the City, the preferred alignment selected was a straight alignment from the Ramsey Northstar Station over TH 10 and Riverdale Drive with a circular helix approach ramp on the south side of Riverdale Drive. Wayfinding and bridge aesthetics were also taken into consideration. The proposed bridge aesthetics take their cue from the surrounding civic architecture including City Hall, the municipal parking ramp, and the Northstar Ramsey Station. Undoubtedly, MnDOT, local stakeholders and the greater community will have an interest in the visual quality of the structure. Further input from stakeholders will help ensure that the bridge will be an attractive and distinctive civic landmark that reflects community values. Preferred Pedestrian Bridge Concept D Seven different structure types were considered as feasible options for the pedestrian bridge. The City has identified Bridge Concept D in Appendix E as the preferred option, which includes dual bowstring truss center spans with concrete girder side spans. Preferred Bridge Concept D is described as follows: Visual emphasis is at the center of the bridge at the arcing trusses. The new bridge will be distinct from the existing enclosed skyway but will complement its appearance. Center trusses and vertical piers are the dominant architectural features. A center pier is required in the TH10 median. Decorative railing enclosure creates an "open" experience on the deck without a roof. Estimated Project Costs and Funding Sources A preliminary estimate of project costs has been developed based on the proposed pedestrian bridge options presented in this report. The preferred bridge concept costs are estimated at $5.1 million to $5.6 million. These costs are based on 2015 dollars and include a 10% contingency and an estimated 20% for engineering and construction administration cost. In 2014, the National Parks Service (NPS) awarded the City a grant for construction related activity for the Mississippi Skyway pedestrian bridge. The "MISSISSIPPI RIVER SKYWAY BRIDGE - MISSISSIPPI NATIONAL RIVER AND RECREATION AREA (MISS)" grant provides total program funding of $490,000 with a grant availability sun -set date in 2017. The City is considering multiple additional funding options and partners for the final design considerations and construction of the proposed pedestrian bridge facility. This report has conservatively assumed the use of typical Federal funding sources for purposes of estimating total project costs. Note that multiple Federal funding sources are available, and each may present a different set of specific project criteria. Next Steps The Mississippi Skyway pedestrian bridge project will likely require a Cooperative Construction Agreement between the City and MnDOT. An Environmental Review Summary has been prepared (see Appendix H) to identify existing resources within the vicinity of the Mississippi Skyway project. An environmental review document will be needed to meet requirements of the National Environmental Policy Act. The type of document will be determined when funding is identified based on coordination with funding partners and federal agencies. The construction of the bridge is anticipated to be a Categorical Exclusion (Type II document; no significant environmental impacts are anticipated.) Right -of -Way: Easements can be negotiated at this time and should be prepared to satisfy Federal real estate acquisition statutes and regulations. Utility coordination may begin with impacted utilities so that utility owners can begin to determine the extent of the impact and the preliminary resolution, whether it be modification or relocation. MnDOT coordination may continue. A MnDOT State/Federal Aid project coordinator will need to be assigned for determining the State/Federal processes to be followed and for review of preliminary and final construction documents. iii Mississippi Skyway Over TH10 Preliminary Engineering Report December 2014