While attempting to contain the nearly half-dozen blazes threatening the city, Los Angeles firefighters have encountered a major stumbling block: concerns about the city’s water supply.
Wildfires are currently consuming more than 27,000 acres of Los Angeles County. Five people have died, and more than 1,000 structures have been destroyed since the wildfires started. Governor Gavin Newsom told CNN on Wednesday that the county had “depleted all of our resources,” including fire hydrants.
“Those hydrants are designed for two or three fires, possibly one. “And then you have something of this magnitude,” he told Anderson Cooper.
Satellite imagery shows the fires burning only a few miles from Los Angeles’ Pacific Ocean shoreline. How can firefighters run out of water when a large body of water is just down the road?
The short answer is: it’s not that simple.
In theory, seawater could be used to put out a fire. However, its salty components can cause more harm than good, so firefighters generally avoid using it unless absolutely necessary.
Salt is corrosive and can damage metal equipment, including critical components in water dumping planes and fire pumps.
According to Technology.org, salt can reduce the cooling effect of water, making it less effective as a firefighting tool. Salt water also carries a stronger charge than fresh water, making it slightly more dangerous for firefighters.
Firefighters are also concerned about environmental health when using salt water to fight fires. When large amounts of salt water are dumped on a fire, the salt must go somewhere—usually into the ground or washed into nearby bodies of water.
Introducing large amounts of salt into areas with significant vegetation, as one might expect at a wildfire site, is almost always harmful.
Raising soil salinity — the salt content of a region’s soil — makes it more difficult for plants to extract water and nutrients from the soil through osmosis. Salt can also make the soil toxic, inhibit seedling growth, and reduce the soil’s overall permeability (how easily water and nutrients can move through the earth).
Having said that, firefighters do occasionally use salt water to fight fires; they simply have to be cautious and selective about when they do so.
