Council hears concepts, technical risks for reuse of old power plant on the Cedar River

City of Waverly officials on Feb. 3 heard a detailed presentation from Slingshot Architecture and partner engineers about possible reuses of the former power plant on the Cedar River and about the structural repairs the building would require.

The consultants presented concept layouts that mix river‑facing restaurant space, multipurpose event areas and small retail or co‑working spaces, plus site ideas such as patios, a small lawn amphitheater and improved trail connections. Slingshot said mixed uses are more likely to attract a development partner than a single large tenant.

Why this matters: the building projects a prominent downtown presence and sits immediately adjacent to the river and to City Hall. The council and consultants framed the work as a multi‑year, public‑private effort that will require stabilization of river‑facing walls and careful permitting because of river hydraulics and protected species.

Consultants described the structural issues and next steps. Slingshot and its structural partner said the north wall of the turbine/penstock area shows the worst concrete deterioration and that any stabilization will likely require either a cofferdam/build‑out or a wall that “sandwiches” the existing wall so it does not collapse under construction loads. The team called for additional geotechnical borings and hydraulic analyses before any major work. They flagged karst geology (underground caverns) near the site as a risk that could change foundation options from ordinary sheet pile walls to more complicated solutions.

The presentation also covered regulatory and permitting steps the city should expect. The team said the U.S. Army Corps of Engineers (Clean Water Act Section 404 process), U.S. Fish and Wildlife Service, Iowa DNR and FEMA flood‑map reviews will likely weigh in on river work; consultants reported that endangered mussels have been found in the river and that federal permitting will address ecological impacts and mitigation.

Costs and timing presented to the council were preliminary. Consultants offered a broad stabilization cost range based on early assumptions — a sheet‑pile or similar approach could be roughly $1.5 million to $2 million in initial estimates but said conditions might allow lower‑cost options once borings and options are fully developed. The team said a targeted geotechnical program will narrow costs; a barge‑mounted drilling mobilization was estimated at roughly $100,000, and the full borings + geotech scope was discussed in the transcript as likely to be in the low hundreds of thousands of dollars. The consultant and staff recommended the city fund borings and hydraulic work first to reduce technical uncertainty.

Council direction and follow‑up: council members pressed the consultants on the risk that repairs could increase flood heights and on permitting timelines. Consultants said a hydraulic analysis would test that risk and that small map revisions are a possible outcome if the project slightly changes effective flood elevations.

By informal consensus the council asked staff to move forward with the next technical phase — geotechnical borings and related engineering — and accepted a staff recommendation to budget a study package set not to exceed $300,000 for the investigative work (mobilization, borings, geotechnical analysis and preliminary structural options). The transcript records this as a council consensus rather than a formal roll‑call vote; staff said final contract terms and a phased plan would return to council for formal authorization.

Consultants emphasized that the city’s role would focus on preparing and stabilizing the exterior and site to make the building attractive to a future private developer, not on delivering the interior program. They recommended pursuing available grant funding and historic‑tax‑credit pathways where eligible, and noted similar projects in other Iowa communities that combined federal/state grants with private investment.

The consultants said they expect to deliver the investigative scope and a refined cost range within weeks after clarifying the geotechnical scope; they estimated the remedial and redevelopment work would likely be a multi‑year effort if the council chooses to proceed.

What happens next: staff will bring a proposed scope and cost estimate for the geotechnical and hydraulic work back to council for formal authorization and contracting. Consultants said that if borings and hydraulic analysis show workable conditions, the project would then move into phased stabilization and permitting steps designed to make the building marketable to private developers.

Ending note: the council’s discussion repeatedly emphasized balancing the building’s historic and economic potential against the sizeable upfront stabilization costs and the risk of spending public funds without a private development partner. The city directed staff to sharpen the technical estimate, pursue third‑party grant options and return with a formal contract and timeline for the investigative work.