What are utilities?
For the guidelines listed here, utilities comprise those companies and government agencies responsible for operating and maintaining essential service infrastructure within the State of Michigan. These include systems such as the electric transmission and distribution systems, pipelines, roadways and transportation facilities, railroads, communication lines and facilities, and hiking and biking trails. In almost all cases, these systems are extensive in size and have a long linear footprint in the landscape.
Why do utilities trim or remove trees?
Utilities trim or remove trees to provide for the safe use of the infrastructure by the public and utility workers, as well as providing a reliable system upon which we all depend for our daily livelihood. Because this work is required to keep these systems operating safely and reliably or to effect repairs to damage caused by storms or other catastrophic events, delaying work is often not possible or practical. However, Michigan utilities and their vegetation management contractors also have an interest in protecting the property of their customers and the state’s natural resources. To reduce the probability of spreading oak wilt during utility tree pruning and tree removal operations, the following practices are recommended.
General Utility Guidelines for Management of Oak Wilt Disease:
1. Climbing spikes should only be used on oak trees that are going to be cut down. Do not use climbing spikes on oak trees that are going to be trimmed.
2. Stumps of oak trees cut down should be treated with an approved herbicide or painted with a latex paint or tree wound dressing immediately after making the final flush cut.
Specific Timeframe Guidelines:
October 16th – March 14th
During this timeframe, oak trees may be trimmed or cut down without the need for painting of cuts or stumps with latex paint or tree wound dressing. Utilities should attempt to schedule their routine maintenance work in areas of higher oak wilt occurrence during this time of year.
March 15th – April 14th and July 16th – October 15th
These periods are collectively referred to as the “Lessor Risk” period when the risk of transmitting oak wilt is very low. Whenever practical during this timeframe, oak trees in developed landscape areas may be trimmed or cut down. However, cuts should be painted with latex paint or tree wound dressing and stumps treated with herbicide or painted to prevent the possible transmission of oak wilt spores. In forested areas and undeveloped landscapes, painting of cuts is only recommended in known areas of high oak wilt occurrence or at sites that presently have oak wilt in nearby trees.
Boom type mechanical trimmers are widely used to increase worker safety and for areas without satisfactory access to aerial lift buckets. It is not practical to paint cuts when using boom-type mechanical trimmers. Therefore, utilities should attempt to use mechanical trimmers in undeveloped and forested areas during this time of year.
April 15th – July 15th
Most overland transmission of oak wilt occurs during this timeframe, although the likelihood is very low unless oak wilt is present nearby. Whenever practical during this timeframe, trimming wounds on oak trees should be painted with latex paint or tree wound dressing and stumps of oak trees cut down should be treated with herbicide or painted to prevent the possible transmission of oak wilt spores.
It is not practical to paint cuts when using boom type mechanical trimmers. During this period, boom type mechanical trimmers should be limited to saw head type trimmers that leave flush cuts. Boom trimmers with flail type cutters should not be utilized during this time of year and utilities should attempt to avoid areas with high oak wilt occurrence during this time of year.
Utilities often respond to emergency conditions to restore service of the utility or to prevent injury or death to the public, first responders, or utility workers. Typical emergency situations result from weather events that interrupt service or present hazards to people using the utility infrastructure such as a tree falling across a road or a tree falling on electric power lines. During these events, the first priority of the utility is to alleviate hazards to the public and to restore the utility service to its customers or the public. As such, treatment of wounds to oak trees is not practical and the aforementioned guidelines do not apply to work performed for emergency operations.
For resources on oak wilt management, CLICK HERE.