As used in this chapter:

    “Arborist” means a person who has met the criteria for certification from the International Society of Arboriculture or American Society of Consulting Arborists, and maintains his or her accreditation.

    “Caliper inch” refers to a manner of expressing the diameter inches of a tree as calculated by measuring the tree’ s circumference and dividing by Pi (approximately 3.14159). Specially calibrated “diameter tapes” or “calipers” are used to determine caliper inches.

    “Dead tree” means a tree is lifeless. Such evidence of lifelessness may include unseasonable lack of foliage, brittle dry branches, or lack of any growth during the growing season.

    “Diameter at breast height or DBH” means the diameter of the trunk at its maximum cross section, measured fifty-four inches (four and one-half feet) above mean ground level at the base of the trunk.

    “Drip line” means an imaginary vertical line extending downward from the outermost tips of a tree’ s branches to the ground.

    “Heritage tree” means any tree listed on the official city of Grass Valley heritage tree list adopted by the city council.

    “Immediate danger of collapse” means that the tree may already be leaning, with the surrounding soil heaving, and/or there is a significant likelihood that the tree will topple or otherwise fail and cause damage before a tree removal permit could be obtained through the nonemergency process. “Immediate danger of collapse” does not include hazardous conditions that can be alleviated by pruning or treatment

    “Person” means any individual or legal entity.

    “Removal” means to cut down a tree, or remove fifty percent or more of the crown, trunk, or root system of a tree; or to damage a tree so as to cause the tree to decline and/or die. Removal includes, but is not limited to, damage inflicted upon a root system by application of toxic substances, operation of equipment and vehicles, storage of materials, change of natural grade due to unapproved excavation or filling, or unapproved alteration of natural physical conditions. Removal does not include normal trimming or pruning of trees when conducted in accordance with the standards established by the International Society of Arboriculture.

    “Significant tree” means a tree having a trunk of eighteen caliper inches or larger in diameter at breast height (DBH).

    “Street tree” means any tree within the public right-of-way. It is the responsibility of the lighting and landscape district (LLD), or if there is not a LLD, the adjoining property owner to maintain such street trees.

    “Tree” means any woody plant having a trunk eight caliper inches or larger in diameter at breast height (DBH). If a tree splits into multiple trunks above ground, but below four and one-half feet, the trunk is measured at its most narrow point beneath the split, and is considered one tree if greater than eight inches DBH. Plants commonly planted as shrubs, including, but not limited to, English laurel, photinia, arborvitae, poison oak, English holly, and English ivy shall not be considered a tree. Trees specifically planted and maintained as a hedge shall also not be considered a tree.

    “Tree account” means an account established by resolution of the council for the receipt of funds to be utilized for future tree purposes, as outlined in the resolution.

    “Tree permit administrator” means the director of public works or his/her designated representative. The tree permit administrator may delegate the assignment of certain development related tree responsibilities in writing to specific community development department staff with the written approval of the community development director.

    “Tree protection zone” means the area reserved around a tree or group of trees in which no grading, access, stockpiling or other construction activity shall occur as determined by the tree permit administrator based on review of the tree and site conditions.

    “Tree removal permit” means written authorization from the city for a tree removal to proceed as described in an application, such authorization having been given in accordance with this chapter. (Ord. 646 § 2 (part), 2005)