In 2011, Carlisle/Wortman Associates (CWA) assisted Ann Arbor Township in creating a Tree and Woodland Resource Preservation Ordinance. Since then, CWA assisted with two updates to the ordinance in 2017, and again in 2025.

The Tree and Woodland Protection Ordinance is based on the community’s ecological preservation values outlined in the Township’s Master Plan. 

The ordinance emphasizes the environmental benefits trees and woodlands provide, including stormwater filtering and sequestration, stream flow mitigation, streambank preservation, water quality improvements, habitat for terrestrial and aquatic wildlife, and other ecological functions for the community. The ordinance also acknowledges the aesthetic benefits of woodlands and trees, the value woodlands and trees add to properties, and the recreational opportunities they provide. 

The ordinance provides approaches to land development that help preserve significant trees and woodlands, such as locating development in areas of the site that were previously cleared, installing tree wells and retaining walls, and maintaining grades within the dripline of trees that are intended to remain.

The ordinance provides various alternatives to tree replacement on site, such as using the tree replacement “budget” to conduct other environmentally beneficial activities on site like invasive plant removal, prescribed burn, streambank stabilization, and other ecologically based projects.