Milwaukee-based engineering firm Graef has released a report detailing cost estimates for several of the county’s options to address structural issues at the nearly 50-year-old Mitchell Park horticultural domes.
A full rebuild of each structure’s concrete frame on their existing foundations and a full replacement of all their glass panels would cost about $64 million, the report said. Other options, which include some basic and some extensive repairs to the existing structures, could cost anywhere from $14 million to $54 million.
Graef estimated it would cost between $50 million and $70 million to build a completely new horticultural facility — one that may or may not include dome-shaped structures — at either Mitchell Park or some other site in Milwaukee, should one be selected.
The estimates were based off costs for repairs to, or construction of, similar facilities in cities such as St. Louis, Missouri; Omaha, Nebraska; Des Moines, Iowa; Columbus, Ohio; San Antonio, Texas; Pittsburgh, Pennsylvania; and Madison.
“These cost estimates should be considered as providing a comparative study of the relative costs for each option and should not be used for establishing a budget for actual project implementation,” a statement, written in all capital letters and bold-face font warns toward the end of the report. “Once one or two preferred options are ascertained, space needs analyses and programmatic design are required before a budgetary cost estimate can be developed.”
You can read the report in its entirety here.
From early February through the end of October, construction crews made repairs to the lattice concrete and steel structures of the geodesic horticultural domes. All three domes at the conservatory were closed on Feb. 5, a week after a piece of concrete casting fell from the structure of the Desert Dome.
Crews wrapped thousands of concrete-cast joints that make up the structures to prevent more pieces from falling.
The Show Dome was reopened April 29, the Tropical Dome was reopened on Sept. 26 and the Desert Dome was reopened on Oct. 29.
But the repairs are being viewed by county leaders as a short-term solution.
The closures raised questions about the longevity of the Domes, which County Executive Chris Abele estimated in February may cost between $65 million and $75 million to repair or replace. The steep cost estimate prompted meetings seeking public input on the future of the structures.
At the time, Abele spokesperson Melissa Baldauff blamed their deterioration on what she called an inherited mess of deferred maintenance.
A task force assigned to recommend a long-term plan to the Milwaukee County Board regarding the Mitchell Park horticultural domes met Nov. 30 to discuss financing options.