Reopening Minneapolis' Witch's Hat Tower to the public — and potentially making it available for large events like weddings — will likely cost the city at least $350,000, according to a new assessment of the long-closed landmark.

The 110-year-old Witch's Hat Tower, officially the Prospect Park Water Tower, was last open to the public for a "Doors Open" event in 2019. That's when a step in the narrow steel staircase coiling up to the observation deck broke beneath visitors' feet, forcing organizers to evacuate the building, said Susan Larson-Fleming, who was the archivist with the Hennepin History Museum until 2017. No one was allowed inside for four years while graffiti accrued around the tower's base and a heavily reinforced iron door kept would-be urban explorers at bay.

Now, neighborhood organizations say it's time to get the historic water tower the repairs it needs to reopen, and the city has a clearer picture of how much that could cost.

In May, Minneapolis sent a structural engineer from KLJ Engineering up into the tower to conduct a basic structural assessment. KLJ delivered its initial findings last month, which included estimated costs for a slate of options and the recommendation that the city employ a building science and forensics firm for deeper investigation.

KLJ's Drew Andersen found the tower in fair condition considering it was built in 1913. But there were a few visible problems including concrete deterioration, rebar corrosion and staircase connections that had rotated out of alignment and were no longer providing support.

"We're not surprised we're hearing that there are serious deficiencies," said Joe Ring, president of the Friends of Tower Hill Park, who is anxious to know when repairs will be ordered. "We're kind of dumbfounded because it doesn't seem to be moving forward."

The Friends and the Prospect Park neighborhood association volunteered to staff the tower on the occasions it was open in the past. Now, Ring says the neighborhood groups want the city — which owns the tower — and the Park Board — which owns the surrounding parkland — to work together to restore and maintain the site, which has a National Register of Historic Places designation.

The city asked KLJ to estimate costs for three paths forward: keeping the tower closed, retrofitting it for limited access to the historical tower observation deck or opening it to larger public events like weddings. The options range from $50,000 for localized repairs to $350,000 for limited scope renovation to $1.3 million for complex rehab.

The most expensive option would make the Witch's Tower far more accessible than in years past. Typically, the tower was open just a few hours of the year during the Pratt Community School's ice cream social attracted significant crowds hoping to glimpse its sweeping view of the city.

"If people wanted to get up to the tower, you had to wait in a line that kind of wrapped around the park and then down the street to University Avenue, it was so long," said Larson-Fleming.

That was the case when the tower was last accessible, for Doors Open 2019. While only 80 people could be inside the tower at any time, nearly 5,000 people climbed it over the two-day event, said Lynn Von Korff of the Prospect Park Association.

Council Member Robin Wonsley, whose ward includes Prospect Park, said the city is working to propose to the Park Board an agreement around shared maintenance responsibilities. Ideally, the tower would be restored to the point that it could be open to the public for more days of the year than it was before, she said.

"We want to make this a very special gathering space that can be part of a more regular experience in the lives of our residents who value this park and value the structure so deeply," she said. "It doesn't have to just be a one-time thing. Let's figure out how to make that happen."

Correction: A previous version of this story misidentified Susan Larson-Fleming.