March 18, 2008

In an effort to preserve urban forest tree canopy, the Knoxville Utilities Board (KUB) has established the following guidelines for use by its foresters in evaluating and designating "special status" trees. Trees so designated will be exempted from ground-to-sky pruning, subject to the following standards.

Definition

Special status designation may be granted to mature trees having the following characteristics:

• Diameter larger than thirty inches at breast height

• Native, hardwood species

• Canopy tree - providing the uppermost level of canopy in the area

• Located in an urban area (outside the urban area, special status will be considered at the customer's request. in advance of pruning)

Special status designation may not be granted to trees with the following characteristics:

• Signs of decay, cracks or unhealthy canopy

• Presence of codominant (forked) trunks and embedded bark or multi-stem trunks . Inadequate trunk taper or basal flare

• Hazardous degree of lean or poor tree architecture in general

• Signs of root problems

• Moderate or high hazard rating

Pruning Standards

Once a tree has been designated by KUB as a special status tree, KUB will not require ground-to-skY pruning on that tree, and will allow some canopy to remain overhanging the power lines. However, the following standards will continue to apply:

• KUB will continue to prune trees above, below, and to the sides of lines for a minimum of ten feet of clearance for distribution lines and a minimum of twenty-five feet of clearance for transmission lines, using the lateral pruning method.

• All dead, diseased, and weak limbs, and limbs with weak attachments (Le., branches with narrow angles of attachment and embedded/included bark) overhanging the lines will be removed, whether or not they are within the required clearance zone (10-25 feet).

• If limbs overhanging the electric lines can be removed by pruning small diameter limbs without a significant impact on the aesthetics or health of the tree, overhang will be removed in order to prevent more substantial overhang in the future.

KUB reserves the right to re-evaluate special status trees in subsequent pruning cycles, and also reserves the right to negotiate additional overhang trimming or removal of special status trees with customers who request it.

In all cases, KUB's primary objectives will be to ensure the safety of the public and utility workers and to provide reliable electric service to all its customers.