CTH D Buffalo Lake Causeway Reconstruction Project
2026 Engineering Excellence Best of State
Entering Firm: KL Engineering Inc.
Client: Marquette County Highway Department
The CTH D Buffalo Lake Causeway posed a significant challenge for decades. This low-lying causeway flooded during high-water events, repeatedly closing the only direct route across Buffalo Lake. Each closure forced users onto hour-long detours, while unstable soils and differential settlement continued to undermine the roadway even after a rehabilitation attempt.
Engineers innovated to build on weak soils and restore reliable access across Buffalo Lake.
KL Engineering started by reviewing all possible solutions. Standard reconstruction methods proved unworkable or too expensive. The team explored lightweight alternatives and ultimately identified an unconventional but effective solution – to use wood chips as lightweight fill. Drawing from successful precedents elsewhere, engineers confirmed that when buried and encapsulated below the waterline, wood chips remain stable for the life of the roadway. This became the first project in Wisconsin to use the material in this manner.
“This innovative, creative, and cost-effective approach allowed engineers to overcome extreme soil challenges without resorting to prohibitively expensive alternatives, while delivering a resilient, elevated corridor that now provides uninterrupted access for the community.”
- Awards Judge Matt Dapp
Crews placed 1,500 truckloads of wood chips to rebuild the causeway, raising it above historic flood levels and replacing failing culverts with durable pipes. The project also delivered fishing platforms, bike lanes and improved access to Buffalo Lake.
Completed on time and within budget, the reconstructed causeway provides reliable, year-round connectivity and stands as a proof of concept for sustainable, cost-effective infrastructure on challenging soils.