A temporary control line established by spraying water or fire-retardant foam onto unburned fuels. It is used to halt the spread of low-intensity fires or to serve as a secure anchor point for starting a burnout operation. Because the water evaporates, a wetline is only effective for a short duration and must usually be backed up by a mineral soil handline.
Heard on the job
Engine 4 is putting down a wetline along the dirt road so we can fire off it and secure the flank.
Insider tip
Never trust a wetline to hold a fire overnight; once the sun comes up and the relative humidity drops, the fuel will dry out and the fire can creep right across it.
Also heard as
- wet line
Do not mix it up with
- Blackline: A wetline uses water to temporarily stop fire, while a blackline uses pre-burned ground to permanently remove fuel.