Riverside Drive/CSAH 20

Brainerd, MN

Improvements to Crow Wing County CSAH 20 have been completed in five phases over the past eight years. The project culminated in a challenging segment perched on a bluff known locally as Ahren’s Hill overlooking Gilbert Lake. The 0.9 miles of improvements addressed significant safety issues, stormwater runoff, and poor roadbed subgrade and foundation, thus maintaining a regionally significant roadway.

The roadway hugs the bluff as it rises up from Gilbert Lake. Providing safe passage while minimizing environmental impact was imperative, from both a public and an engineering perspective. WSN and Gale-Tec Engineering combined talents to design a roadway and a 2,950-foot-long vegetative-faced reinforced soil slope (RSS) that addressed the project’s considerable challenges as well as the client’s needs.

The Ahren’s Hill RSS is believed to be one of the largest vegetative-faced geosynthetic reinforced walls in the Midwest, in terms of area and length. Plantings grew quickly in its rich, organic material, creating a grand “Chia Wall,” so to speak. The CSAH 20 Ahren’s Hill improvements and vegetative-faced RSS successfully employed intricate engineering techniques to accommodate public attitudes toward maintaining a regionally significant roadway. As a result, the lake has been protected from excessive erosion, users have a safer roadway on which to travel, and the view from the lake remains beautiful.




  • 7 Wonders of Engineering - Minnesota Society of Professional Engineers
  • Grand Award - American Council of Engineering Companies in Minnesota