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Urban Forestry EAB Management Plan (River Falls)

The Situation

The city of River Falls is home to a high population of ash trees, many of which are considered high value. They experienced their first identified EAB case July 1, 2019. Ash tree mortality is near 100% within approximately 1-2 decades after EAB introduction, and tree decline and mortality becomes exponentially higher after approximately 5-7 years from identification in a specific location. River Falls needed a response plan, so Eocene was brought in to conduct an assessment and develop the response plan, including a solution to the insect infestation and eminent loss of a significant portion of the tree population. Ten issues were uncovered that required action on, after surveying trees on public and private lands, trees in maintained and natural areas, tree removal and replacement options, communication and resources, and EAB treatment options.

Our Solution

Eocene developed a response plan as a comprehensive assessment of the city’s ash trees, along with an evaluation of their levels of EAB infestation, overall health condition, and characterization of their growing sites. Following the assessment, Eocene posed three elements as a solution to the infestation and eminent loss of a significant portion of the tree population, all with the goal to attack the pest early on. The response plan proposed a means to confront EAB on the community’s terms, rather than do nothing and let the insect continue devastating the tree population.

Elements of Response Plan

  1. Update the tree inventory which found that ash trees comprised 25% of the total 8,000 public trees within the city’s canopy.
  2. Conduct survey and develop detection strategy by examining signs and symptoms of EAB.
  3. Introduce ash tree management policy, noting action steps for treatment, removal and replacement of specific trees within the canopy.

Project Scope

With an overall goal to determine tree suitability for protective treatment against EAB, four steps were developed:

  1. Project Kickoff
  2. Implement project with kickoff meetings with community tree board and city staff in the field to explain project and calibrate the inventory methods.
  3. Field Assessment to Gauge EAB Infestation Level
  4. Conduct a field assessment of approximately 1,400 ash trees to determine the EAB infestation level and overall condition rating as customized to the needs of the city and recorded in the city’s ArcGIS software.
  5. Next Steps Recommendation Report
  6. Develop and submit a final report with recommendations on how to manage the city’s ash tree population.
  7. Individualized Maintenance Recommendations
  8. Create a spreadsheet with individual ash tree maintenance recommendations.

The City of River Falls’ Urban Forestry Department has a mission to preserve and perpetuate one of the community’s most valuable natural resources and assets – its municipal forest of trees on public property. This includes trees on boulevards, parks and other city properties.

  • The city of River Falls’ urban forest had a high population of ash trees, including a substantial number of high value ash trees covering their tree canopy.
  • The city was experiencing a building cases of emerald ash borer (EAB) and required consultation on next steps in managing the infestation.  
  • Eocene Environmental Group completed an assessment of the ash trees, evaluating their levels of EAB infestation, overall health condition, and characterization of their growing sites.
  • After the data collection, Eocene analyzed the information gathered in the assessment and prioritized ash trees for removal or retention and treatment in a comprehensive management plan.

Eocene created a comprehensive management response plan and proposed three ash tree retention and removal options, following the development of the response plan and the assessment and evaluation.


square miles surveyed


ash trees assessed and inventoried


trees proposed for removal

Learn More About the Eocene Environmental Group Team/

Eocene has an experienced and passionate team of biologists, archaeologists, environmental planners, foresters, arborists, agronomists, animal scientists, sustainability risk specialists, software developers and engineers. Check out the “Our People” page to learn more about our team.

Our People