Noahs Ark Retaining Wall  Project of Distinction 



Noah’s Ark, the largest outdoor park in the United States, is located on 70 acres in the heart of Wisconsin Dells. The owner of this family-fun waterpark asked Holtz Builders to help resolve a deteriorating existing concrete retaining wall near the Kahuna Wave pool. This project included the removal and replacement of over 5500 square feet of concrete expanding over 173 linear feet, temporary removal of two pavilions to be reused later, replaced both ornamental and wood fencing, added a new cast wall using form liners and wall rubbing to 2200 square feet, and installed new asphalt to the area removed for concrete footings and walls. In-depth structural calculations were done by structural engineers to ensure wall stability.    

A job of this magnitude, completed in the coldest months of the year, doesn’t go without its challenges. In February, all exterior work had to be stopped for eight days due to safety concerns because of heavy snowfall, freezing rain, sub-zero temperatures, and high wind gusts. To mitigate the delays, Holtz Builders set up a heated work area so subcontractors could continue to make progress on other areas of the project. Holtz builders then set up a ground thaw machine in order to ensure that the frost would not be an issue when the work started back up. Other safety measures included de-icing as needed and putting down salt. The schedule was revised and communication with the owner and sub-contractors was essential to keep the project moving efficiently. 

Another challenge within this project was in the electrical scope of work. In removing the concrete retaining wall, it required cutting the wall in two different locations. During that process, an unforeseen 3” electric line was severed at grade under the concrete. The electrician was notified immediately to unhook the suspected wires from the panel. In addition, during a walkthrough, it was discovered that both junction boxes used as pull points for the circuits were not safe to be used any longer due to the harsh conditions at a waterpark.  After approval of a submittal for new conductors, a new 3R outdoor rated box attached to the wall with new fittings for the conduit secured to the box was installed. Material demand and shortage caused a drastic fluctuation in wire, PVC, and steel prices. The supplier would only guarantee prices for five working days, but with open communication and diligent work, Holtz Builders was able to effectively replace the damaged wire and update the junction boxes for exterior conditions. 

Another challenge was that the excavator hit bedrock when digging for footers. Holtz Builders hired a structural engineer for the project to ensure that the wall met all local and state building codes.  These calculations, done on Enercalc, detailed all of the rebar needed for wall stability by taking into account the resistance to underground lateral pressure imposed by soil and water. The solution was to drill the rebar into the bedrock. All the rebar was accurately measured to be 18” on center and passed field inspection.    

Decorative concrete form liners were attached to the wood framing system to mimic stone on the inside of the wall panels to act as a mold for the concrete to be formed against. This added detailed texture makes for an impressive welcome feature for all guests to enjoy as they enter the waterpark. A wall of this magnitude needed to be completed in segments.  

For safety, the installation of 152 linear feet of decorative Montage Plus 3-Rail Classic ornamental iron fence was anchored with titan anchors on top of the wall to match the existing fencing onsite. This steel fence system provides the elegant look of wrought iron, without rusting. It included heavier posts, rails, and pickets that will withstand the seasonal shifts in weather and temperature of living in Wisconsin.

Despite weather setbacks, electrical miscues, and solid bedrock, Holtz Builders was able to set the foundation for an amazing, grandiose retaining wall that acts as an entryway feature to the largest waterpark in America.  With 44% of the work being self-performed, Holtz Builders was able to complete the project on time through clearly defined roles and responsibilities for every subcontractor and company worker.