Greenbelt Program Study Results Now Available from U-M SEAS

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July 9, 2018 - ​A master's group project team at the University of Michigan's School for Environment and Sustainability (SEAS) recently conducted a study of the City of Ann Arbor Greenbelt Program​, which is part of the Open Space and Parkland Preservation Program. Their goal was to measure the “ecological, social and economic outcomes of the City of Ann Arbor Greenbelt Program," according to the Greenbelt Program's director, Ruth Thornton. The study, in its entirety, can be found at

The Greenbelt Program is in place to protect farmland and open space around the city. The Greenbelt Advisory Commission (GAC), which advises the Ann Arbor City Council on Greenbelt-related issues, requested this project with SEAS as a benchmark for the halfway point of the program's total term as determined by the City of Ann Arbor Open Space and Parkland Preservation Millage.​

The research projects completed by teams of U of M students in the SEAS program serve as capstone projects that are part of their graduation requirements for a master's degree. “The city submitted a proposal to the university," explained Thornton, “and we were selected by the students as a project of interest."

Once a project is selected, the students work together with a major advisor and other faculty members with applicable expertise to develop a project proposal and methodology to complete the project. The students started working on the project in February 2017 and presented the results at the May 3, 2018, Greenbelt Advisory Commission meeting.

Project Highlights​​, Findings and Outcomes:

Ecological Impact: The project produced the first program-wide, quantitative inventory of land classification for Greenbelt properties. This land use inventory was then used to model pollutant runoff scenarios, comparing current land use to two alternative future scenarios — agricultural expansion and complete suburban development.

Key Findings: Results indicated that 66 percent of Greenbelt land is agricultural, 24 percent forested, 5 percent is grassland, and another 5 percent is grasslands with scattered trees and wetlands. Pollutant runoff was shown to be greater in both alternative scenarios, suggesting benefits of the Greenbelt Program's impact on water quality.

Social Impact of Program: The study conducted an analysis of the socio-economic effects of the Greenbelt using two approaches: 1) through interviews with Greenbelt landowners to determine how the Greenbelt Program has impacted their farms; and 2) from a survey of 441 Ann Arbor property owners (survey was sent to 1,300 total) to assess perceptions and economic valuation of the Greenbelt by Ann Arbor voters.

Key Findings: The Greenbelt Program 1) promotes social resilience, benefiting the local food system and agricultural businesses; 2) preserves a legacy of farming by maintaining the rural characteristics of the area surrounding Ann Arbor, a highly desirable amenity; and 3) bolsters regional agricultural economics by preserving resources for future generations and supply chain actors.

According to the survey results, support for the program was high among the 441 respondents. Approximately 81 percent of respondents either agreed or strongly agreed with the statement “preserving open space in the Greenbelt is a valuable use of tax dollars." Additionally, approximately 90 percent of respondents either agreed or strongly agreed with the statement “I value having farmers in my community."

The economic value of the program was determined from analysis of survey response data of property owners' willingness to pay for the Greenbelt program.  Conservative estimates show an average willingness to pay of $127 per year at the household level, an amount that exceeds the average cost that households pay in actual millage taxes, resulting in program benefits that greatly outweighs its costs.


This project provided new insight into the ecological, social and economic contributions of the Ann Arbor Greenbelt Program, demonstrating that the Greenbelt Program provides substantial benefits to both residents in Ann Arbor as well as in neighboring communities.

As the millage reaches its halfway point, results from this study can be used to guide future research and public outreach, strengthen regional funding partnerships and shape program development.

“By analyzing data on the economic, social and ecological services of the Greenbelt, the study found that the program is delivering valuable benefits to the residents of Ann Arbor and surrounding communities, including preserving natural areas and farmland around the city, improving water quality and supporting the local farming community," Thornton explained. “From the Greenbelt Program's point of view, these results indicate that Ann Arbor taxpayers still support the program and value the benefits they receive as higher than the cost of the program," she said.

Students and faculty that conducted the evaluation included Patrick Bradley, Sharon Hu, Devin Kinney, Daniel Tanner and Faculty Advisors Dr. Catherine Riseng and Dr. Michael Moore (School for Environment and Sustainability).​

“This project was initially appealing to me because it was local," said Bradley. “The interdisciplinary nature of the project really reflects the curriculum and identity of the School for Environment and Sustainability, and having a project that held closely to that approach was important to me."

“Analyzing the Greenbelt through an ecological, economic and social lens was a unique and challenging experience given the wide variety of methodologies we used, experts we spoke with and results we generated," added Kinney. “This project epitomized the SEAS curriculum in action and helped to develop my own skills in many different areas."

The Greenbelt Program is funded by the Open Space and Parkland Preservation Millage, a 30-year millage approved by Ann Arbor voters in 2003 that also funds the acquisition of parklands for the city's parks system and raises more than $2 million annually.  The millage is expected to generate $80 million over 30 years.  These funds are matched by locally funded programs, landowner donations, and federal grants, including funding from ACEP, a Farm Bill program administered by USDA-NRCS that provides financial assistance to eligible partners for purchasing agricultural conservation easements, with the goal of helping farmers and other producers keep their land in agriculture.

The Greenbelt Program has protected more than 5,200 acres of farmland and open space surrounding the city of Ann Arbor, and has added 98 acres to the city's parks system. The Greenbelt Program protects land by purchasing the development rights on properties within the Greenbelt district, which is made up of portions of eight townships surrounding the city, and by partnering with Washtenaw County and other local partners to purchase natural areas for publicly accessible parks. The city partners with The Conservation Fund, a national nonprofit conservation organization, to help implement the program.

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Contact Information

Ruth Thornton
Greenbelt Program Project Director
734.794.6000, ext. 42798

Ann Arbor has 119,000 residents, spans 28.9 square miles and is frequently recognized as a foremost place to live, learn, work, thrive and visit. To keep up with City of Ann Arbor information, subscribe for email updates, follow us on Twitter or become a city fan on Facebook. The city's mission is to deliver exceptional services that sustain and enhance a vibrant, safe and diverse community.