In front of the First Presbyterian Church at Chicago and Lake. (RoundTable photo)

The City of Evanston’s Forestry Division, as well as private tree and landscape companies, continue to deal with the aftermath of a powerful wind and rainstorm on Aug. 10.

According to Michael Callahan, the City’s Arborist and Forestry Supervisor, 11 City trees were uprooted due to the high winds, and an additional 20 City trees needed removal due to extensive damage.

Strong winds appear to have been the culprits for the demise of otherwise healthy trees that were blown over, he said.

On Brown south of Colfax (RoundTable photo)

The largest uprooted tree was a 54″ diameter American elm that was 100 years old. The oldest tree that had to be removed to date was a 150-year-old bur oak.

Two trees which fell on houses had to be removed. The City does not yet know exactly how many hanging branches and other hazards were taken care of, or how many still need trimming or removal.

The City’s 311 staff and the Evanston Police Department telecommunicators worked overtime to field several thousand storm-related inquiries, with over 600 requests for tree damage services.

Forestry staff continue to evaluate those calls to determine which reports relate to City trees and which are on private property. Staff must also determine which are duplicate reports.

A tree falls on a neighbor’s property on Hinman (RoundTable photo)

When tree damage occurs on a private property, or on a neighbor’s property, it is up to those building owners to work together with their insurance companies to address the tree work. The Forestry Division recommends that private tree owners seek advice and service from companies that have accredited Certified Arborists on staff.

Callahan explained that Forestry staff evaluate tree risk based on the International Society of Arboriculture Tree Risk Assessment protocols. The City has four employees certified for this type of evaluation.

“Rot, tree vigor, hollows, poor structure, and many other factors” are evaluated to determine the risk a particular tree poses.

“An alive and green tree does not necessarily mean a tree is safe; all trees pose some level of risk,” he added.

Ellen Galland has had an architectural practice in Evanston since 1983. For more than 20 years, she has written articles for the RoundTable, including the column “Ask An Architect" and "The Green Column"...