Miami Beach brings in Stantec to decide whether the 5th Street pedestrian bridge can be built

Miami Beach has lined up the engineering firm Stantec to answer whether the long-planned pedestrian bridge over 5th Street near Alton Road can be built at all, after the developer responsible for it told the city the job is impossible because of high-voltage power lines buried under the site, according to a city memo for the Nov. 9 meeting of the commission’s Public Safety and Neighborhood Quality of Life Committee.

Stantec estimates its study will take nine to 12 months, or four to six if a fix turns up early, the memo says. The city first asked Kimley-Horn, which had peer-reviewed the bridge design, but that firm declined, citing potential conflicts of interest. The city has finished negotiating with Stantec and is issuing a purchase order to start.

Power lines 30 feet down

The bridge is being designed and built by TCH 500 Alton LLC under a development agreement tied to the 500 Alton project, with the city’s share capped at $10 million from the 2018 general obligation bond and about $3 million more from a Florida Inland Navigation District grant, according to the memos. While drilling test piles, the contractor hit an unmapped Florida Power & Light duct bank about 30 feet down that serves most of the South of Fifth neighborhood.

In an Aug. 21 letter to the city manager and city attorney, the developer’s lawyers said their geotechnical engineer and an outside peer reviewer both concluded that neither the current design nor a third redesign is viable, because the safety buffers around the lines leave no room for the footings. The letter says moving the lines, which it calls the main pathway for power to reach Miami Beach, isn’t feasible either, so the only workable route is to drop the bridge and build a bay-walk alternative. The developer has paused work while it waits for the city’s direction.

The city’s schedule still shows the bridge finished in fall 2027, but the memo says that date doesn’t account for the study or any redesign.

The over-water option

A second memo on the same agenda sizes up that alternative: a bay walk running about 300 feet out into the bay to reach enough headroom to pass under the MacArthur Causeway, about 700 feet long in all. Based on costs in the recent 1250 West Ave. agreement, the city puts it at $24.5 million to $28 million. It would need seagrass and coral surveys, state, federal and county permits that the memo says would likely take years, FDOT and possibly Coast Guard approval, and extra federal review because the queen conch is now listed as threatened. It isn’t known whether the grant could be moved to that project.

The committee meets at 9 a.m. Monday, Nov. 9, in the City Hall commission chambers and on Zoom (webinar ID 878 3335 2956). The memos are for discussion; no vote is scheduled.