General Motors Company

Wentzville Assembly Center

Wentzville, Missouri, United States

Certified Gold through 2022

Project Name
Project Type
St. Louis Regional Envirothon
Formal Learning
Northwest Bioswale
Wetlands & Water Bodies
Flint Hill Outdoor Classroom / Native Garden
About the Program
General Motors Company's Wentzville Assembly Center is located in Wentzville, Missouri, about 40 miles west of St. Louis. Managed habitats on and off-site include about 170 acres of wetlands, streams, grassland and a pollinator garden. The team uses these habitats to support wildlife, improve water quality and spread awareness of habitat conservation within the surrounding community. The team also supports the St. Louis Regional Envirothon, which is a problem-solving natural resource education program for high school students.

Practices and Impacts
  • During the Envirothon, teams of students are challenged to hone critical thinking skills and work as a team in the field. They answer written questions and conduct hands-on investigation of state-specific environmental issues in five categories - Soils/Land Use, Aquatic Ecology, Forestry, Wildlife and Current Environmental Issues. In addition to a written test, the teams also present an oral presentation solving a locally appropriate natural resource issue. The project teaches the students about their local habitats, why they are important, and how to help conserve them. All the teams’ results are scored at the end of the day, and the winner of the competition continues to the statewide competition.
  • For the new prairie area, a roadway and adjacent parking availability allows easy access for outdoor classrooms. Clean fill was graded on a previous gravel site and seeded with a prairie pollinator mix.
  • On the 186-acre prairie site, a no-mow zone is maintained and identified as such by signs. The team and partners conduct flora and fauna inventories, monthly wildlife inventories, monthly inspections for land disturbances, revitalizing of decommissioned areas and thinning of invasive woody species. Invasive Bradford pears and bush honeysuckle are cut when noted. Signs are in place forbidding off-road driving. Old railway gates at the fenced facility are open to allow access to wildlife.
  • Monitoring in 2017 showed six native plant species, three invasive plant species and seven wildlife species. In 2018, there were nine native plant species, four invasive plant species and nine wildlife species. The 2019 inventory indicated the presence of nine native plant species, five invasive plant species and nine wildlife species. Monitoring also shows that milkweed originally planted in 2014 is thriving. 
  • The team has created and maintained a native bioswale from a drainage ditch that was once filled with cattails. It concentrates and conveys stormwater runoff while removing debris and pollution.
  • The bioswale project seeks to provide shelter, food and space for a variety of native species, while specializing in plants that remove pollutants from stormwater. Progress is measured by conducting quarterly flora and fauna inventories and conducting monthly visual inspections.
  • After the soils were tested, the bioswale was seeded with swamp milkweed, common milkweed, ironweed, purple coneflower, stiff goldenrod, boneset, prairie dock, ox eye sunflower and rattlesnake master.
  • In 2019, the team inventoried 14 native plant species, four invasive plant species, and six wildlife species. This inventory signaled a higher proportion of native plants in the bioswale.  
  • The Flint Hill Elementary project team and GM volunteers scouted the school’s outdoor area and chose an outdoor classroom location for its good soil, sloped formation that could serve as an amphitheater and its proximity to the native prairieland.
  • Student planted 2,500 native plant specimens and converted 200 square feet of previously impervious grass space to native habitat space. School leaders also completed a master plan to convert a large space to outdoor student seating and native plant trails. This outdoor learning area will have gardening space in raised beds and a wildflower garden.
  • All students first complete planting in reused milk containers, and then transfer them to the outdoor classroom. The team conducts quarterly plant inventories of the outdoor classroom. Monitoring shows five native plants have germinated and taken root.