A tight installation corridor demands easy boardwalk construction

A Trail Source, LLC Project

The problem: Narrow installation space in a wetland

Tim Wegner of Trail Source is no stranger to trail building. As a member of the Professional Trail Builders Association, a criteria-based organization that requires professionalism and experience, he’s installed thousands of miles of mountain biking, hiking, and nature trails. Tim’s experience helped him see the unique problems with the existing trail at the Eloise Butler Wildflower Garden in Minneapolis, Minnesota.

The challenge? Building a boardwalk in a wetland with a narrow installation corridor.“We were replacing a dirt path that had a couple of bridges,” he said. “Since there were several spring-fed areas, the path was always muddy. Users of the path would walk around the muddy areas, making a two foot path nearly six feet wide in some spots.” The solution – an elevated boardwalk – is a tribute to the Cary George Wetland Project and a joint project of The Friends of Eloise Butler Wildflower Garden and The Minneapolis Park and Recreation Board.

Any walkway project must consider installation impacts. This is especially true for installations in sensitive areas like wetlands, as was the challenge for Tim.

“Essentially we were working in a bog,” he explained. “When we needed to drive the pilings in, we’d be standing in water.” However, Tim’s bigger concern was the Minneapolis Park and Recreation Board’s allowance of an eight foot wide installation corridor for a four foot-wide boardwalk. “In order to stay within the constraints of the permit, we knew we couldn’t step more than two feet on either side of the boardwalk in order to put it in.” This presented a unique challenge for planning a sensitive installation.

The solution:

Several boardwalk systems were considered for their durability, aesthetics, and capability of the manufacturer. The chosen product, an almost 300 foot long, continuously curved elevated boardwalk built by Wickcraft Boardwalks, uses a special frame and leg design. Along with its pleasing curved design, it features a narrow frame and post-pile legs. In addition, to add to the beauty of the boardwalk and conserve resources, the decking is made from locally reclaimed treated ash wood from trees affected by Emerald Ash Borer. Tim was able to have the wood milled and shipped to Wickcraft for assembly. The boardwalk is fully ADA compliant.

Tim was able to use locally reclaimed ash wood for the boardwalk.Tim was able to use locally reclaimed ash wood for the boardwalk.
Tim was able to use locally reclaimed ash wood for the boardwalk.
Tim liked the ease of installation the chosen elevated boardwalk offered. “[Installation] is where the Wickcraft boardwalk worked really well for us, because it allowed us to not have to haul in equipment,” he said. “We ran with one single piece of motorized equipment for the install: a gas-powered pile driver.” The ease of installation meant Tim’s team didn’t have to spend their time and effort moving dirt, and they were able to easily avoid significant obstacles like trees.

Not only did the choice of an elevated boardwalk reduce installation impacts, but it also reduced installation headaches for the team. Since the boardwalk’s bolt holes were perfectly lined up, everything went together as it should.

“I can’t say enough about not having to drill it out in the field,” Tim said. “No matter how the frame was flipped, weep holes allowed water to drain out. If you had to drill it out in the field, you’d be removing critical galvanization on the frame and opening it up to rust. This product had to go together perfectly, and it did.”

He also appreciated that the deck boards came preassembled. “Our assembly time was nothing compared to other products we’ve used in the past. With the Wickcraft system, I would say that even though the product cost is more, my cost for installation was significantly less…what I saved in labor cost on site easily makes up for it.”

Tim also needed the boardwalk to meet the community’s expectations. “You gotta realize that when we were working on this project, we had a couple thousand sets of eyes on us…we had to be very careful.” Because of the design of the Wickcraft product, Tim and his team were easily able to stay within the narrow installation corridor.

The results:

“I think we exceeded everyone’s expectations.”Eloise Butler Wildflower Garden
“I think we exceeded everyone’s expectations.”
The elevated boardwalk brings the user up off of the mud so they can comfortably enjoy their surroundings. This also protects the sensitive plants and soils below.

“[The boardwalk] is wide enough that two people can pass each other,” Tim said. “From an environmental standpoint, it prevents people from harming vegetation, walking repeatedly over an area, compressing the soil, and making the water less likely to absorb.” The elevated boardwalk prevents water from pooling in areas where nature never intended and prevents sediment from moving into the spring-fed waterways from the trails.

Of course, it’s not a successful project without the approval of the users. What’d the public think of their new boardwalk? As Tim puts it: “Given the rave reviews of everyone who’s visited, I think we exceeded everyone’s expectations.”

“Nothing in nature is straight…so neither is this boardwalk. It features fluid, continuous movement of design.” – Tim Wegner, Trail Source