No-work zones (NWZ)

The purpose of a no-work zone is to protect workers from tree hazards in situations where the danger tree or parts thereof have not been removed 

When the decision has been made to retain a valuable wildlife tree that has been assessed as dangerous to workers, a no-work zone must be clearly identified and marked on site. The no-work zone must include all the area on the ground that could be reached by any dislodged portion of the tree.

No-work zones will take into account the nature of the hazard and the lean of the tree.

On steep ground, the no-work zone will be extended downhill to protect workers.

No-work zones can be adjusted in size depending on the size of surrounding live timber (e.g., a small tree surrounded by much larger trees that shield the adjacent area have a NWZ radius less than 1.5 defect lengths.

A kickback area should be included for semicircular no-work zones. The size and shape of this area is determined by tree lean, condition, and form (branching).

See the Wildlife/Danger Tree Assessor's Course (No-Work Zones (NWZ) for detailed information.