After discovering surface cracks and deterioration in the plaza’s concrete in recent weeks, the area near the Main Street Bridge was fenced off to the public due to safety concerns, Watertown City Engineer Jaynellen Holloway said this week.
The plaza, which sits at at the southeast corner of the Main Street Bridge, has been the site of the Santa House. It is also a connecting point to the Riverwalk, and a gathering spot for several events.
Holloway said city officials hired Ayres Associates of Madison to evaluate the plaza’s structure. Ayres Associates is an architectural and engineering services firm specializing in transportation, general civil, geospatial, environmental, and architecture.
She said the firm noted that the walls rimming the plaza at the southeast corner of the bridge are old foundations for a building that once stood there. She said the windows in the lower level facing the river were filled with brick.
“They believe it is likely the lower level of this building was filled with soil and then the surface of the plaza was paved,” Holloway said.
She said Ayres Associates also found the wall was not originally intended to serve as a retaining wall.
“There are steel plates and tie rods visible near the base of the wall,” she said. “These were likely installed to reinforce the wall.”
Ayres also found the foundation wall facing the river has a noticeable bow near the middle of it. The wall protrudes approximately 4 to 6 inches. There is also a depression near the southwest corner of the plaza indicating water is getting into the old foundation and causing erosion of material.
The concrete sidewalk in the plaza is cracked in several places and appears to have settled.
“The sidewalk sounds hollow when it is hit with a hammer in many places,” Holloway said. “This likely indicates there are void spaces under the sidewalk.”
Holloway said Watertown Mayor Emily McFarland and the city’s engineering personnel met with Ayres at the end of their walk through of the area. McFarland decided the plaza should be closed immediately to the public because of safety concerns.
“The plaza will remained closed to the public until such time city officials could put a plan together to correct the concerns found by Ayres Associates,” Holloway said.
The city is currently exploring its options to restore the plaza.
“One option that is off the table is ‘do nothing,’” McFarland said.
Holloway said city officials intend to correct the issues and reopen the plaza as soon as possible. They are currently performing a cost benefit analysis to determine which is most economical, repairing or replacing the plaza structure. Once the option is selected, Watertown officials will work to provide the necessary funding to complete the work.
Holloway said the engineering department is looking to find if there are any grants available to help fund this type of work. She said it’s the city’s hope to complete the work in 2021 and reopen the plaza.
She said the city would like to coordinate the repair of the southeast seawall just south of the plaza on the east end of the Rock River, at the same time, it repairs the plaza structure, but it is unknown if it can be done at this time.
“Ayres Associates performed a walk-through evaluation of the plaza in late September,” Holloway said. “Ayres’ visual observation of the area should not be construed as a complete and exhaustive analysis.”