Keystone Park closed after engineering report finds safety concerns

By Willis Patenaude | Times-Register

The optimism over the renewed possibilities for the rehabilitation of Keystone Park came to a sudden end last week, when City Council was forced to close the patio area on the lower level, as well as 20-feet behind the wall and all hopes of any project to revitalize the park after it was used for a staging area during the Keystone Bridge rehab, have been replaced by an orange fence and an uncertain future. 

The closure comes on the heels of a structural evaluation report, which was recommended by Main Street Iowa (MSI) after they submitted a design concept proposal back in May of 2024, which was supposed to provide ideas on how to “activate and enhance underutilized spaces” which would improve the historic park. During that field inspection, it was noted that the stone retaining wall showed signs of deterioration and possible bowing, and as a result, MSI recommended having a structural engineer inspect the wall before moving forward with any restoration projects. 

The final report, which arrived about a month early, details the observational assessment conducted on November 8th by MSA Professional Services Inc. (MSA). At the request of the City of Elkader, MSA performed a site visit to review the condition of the retaining wall, as well as the stairway and decorative railings, which were also cited as being in need of some repair by the MSI report. With City administrator Jennifer Cowsert, MSA did a “limited visual assessment” of necessary structural elements, without the benefit of design drawings for the retaining wall, which given the fact that the wall was originally built in the late 1800’s, locating them is an unlikely enterprise. 

Regardless, MSA went ahead with the assessment, using a sounding hammer to check for hollow-sounding areas, which would indicate structural concerns. While the stones that were tested were “found to be sound,” the report did indicate some hollow pockets existed in all three areas where concrete block masonry was observed. Those three sections used to be windows in the basement of three buildings that previously stood on the plot, but were demolished in 1977. 

The issue however, is that no one knows if the masonry infill is the same thickness as the wall or what is exactly laying underneath the ground of the park, leaving the report to conclude, that “at least some of the masonry block sections were left hollow as opposed to being filled with grout.” 

The other area of concern in the report is the wall tilt, which was measured at various heights and lengths along the wall. According to the report, the wall tilt varied from 0” per foot height of the wall on the east side and up to 1.5” on the west side of the wall. The wall tilt measured was listed as “significant” in the report, and MSA could not state whether the wall was stable or if it was still moving, creating “safety concerns.” The wall was also showing signs of tilt at the location of the pillars, not just between them. 

The pillars, the report noted, were only installed on the west side of the wall, where the largest amount to tilt was observed, leading MSA to conclude that the tilt began prior to the pillars being installed and that the pillars were installed to prevent further tilting, though how effective the pillars were, is “not clear.” Additionally, the eastern-most pillar also had “noticeable tilt.” 

What is notable about the wall tilt is that this report isn’t the first time it has been noticed on the wall. According to Cowsert, wall tilt was also noticed as far back as 2008, and after the flood, a monitor was put on the wall, where it remained for the next few years, until the monitor disappeared. Cowsert did not know what happened to the monitor, but she did state that during that period, the wall “moved a little bit,” but it “wasn’t enough to be alarming.” After the disappearance of the previous monitor, at least over ten years ago, and with wall tilt being observed, no further measures were made to monitor the wall.  

During the Council meeting as the vote to close the park was being discussed, Frank Phippin, a member of the Park Board, disagreed with the notion that the park needed to be closed. Even though the Park Board was given a copy of the MSA report, Phippin wanted the Park Board to have the opportunity to actually speak with the MSA engineer before any decision about the park was made. He also stated he didn’t believe the threat of collapse was “imminent” or “quite as serious,” as it was made out to be, expressed reluctance to “take any action to close part of it down,” and wanted to get more information before moving forward. 

Council however, did not concur, with Councilmember Randy Henning immediately pointing out that irrespective of what Phippin or the Park Board wanted, the closure and that the wall could collapse, was already “on paper.” The discussion digressed, but Phippin remained adamant that he did not agree with the assessment or at least, did not agree with any closure until the Park Board was able to meet with the engineer. However, Cowsert noted the dangers in waiting and that if something happened in the interim with the wall, the city would be “way liable,” and in the end, it wasn’t Phippin’s place to “question the engineer.” 

While Council understood Phippin’s position, Councilmember Deb Schmidt commented that when Council has a “recommendation from an engineer” that they have to “do what’s best for the community” and in this case, doing what’s best was closing sections of Keystone Park down and they did so with a unanimous vote.

The foreseeable future for Keystone Park, based on the MSA report, is one that will see it closed for at least a year, while monitoring the wall for further movement and according to the report, any wall movement over 1/4” from the initial measured position could indicate potential wall failure. The wall monitoring is estimated to cost $21,000 over that time and puts on hold all MSI proposals, railing replacements, and additional loads being added to the wall. 

The other, larger problem is the actual wall repair, because regardless of the wall tilt, MSA does not believe it can be repaired due a number of factors, including the determination that helical tiebacks, a possible solution which would tie the wall back into the soil beneath the park, is not feasible because a 2008 geotechnical report indicated that the soil behind the wall consisted of mostly silty sands, which are not “conducive to receiving tiebacks.” The process would require excavation of the wall to verify the wall’s thickness and the soil behind it would need to be replaced. As such, this option was not recommended by MSA.

What MSA did recommended was a wall replacement, which they considered the “most viable option,” where the wall is completely replaced with a concrete retaining wall or a concrete retaining wall with a stacked stone façade to resemble the original wall. The report ruled out an option of simply replacing it with another stacked stonewall due to unknowns like materials, equipment, labor expertise, and potential cost. 

According to MSA’s estimates, a concrete wall replacement will cost $440,000, while the version with the stone façade would be around $580,000, but as Henning pointed out at the meeting, that when it “comes time to do it, the cost of it is going to double [and] and fall in the same line as the Bridge did as far as cost.” Mayor Josh Pope shared Henning’s concern, while Councilmember Tony Hauber expressed concern over a potential lack of bids for the project, leaving the city with just one, costly option. 

Whatever the cost will end up being, as of now, Council has made no decision on how that cost would be covered, though Cowsert did indicate they would seek out possible grants and fundraise for it, but until then, the lower level and 20-feet back from the wall of Keystone Park will remain closed, ending another rehabilitation project before it starts.