Here is why California can’t use ocean water to help fight the wildfires

Salt water can wreck a fire, but it can also wreck equipment and vegetation as well

Fire officials in Los Angeles have run into a serious snag while trying to contain the nearly half-dozen blazes threatening the city - questions about the water supply.

Wildfires currently cover 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 began. Governor Gavin Newsom told CNN on Wednesday that the county had "depleted all of our resources," and that fire hydrants were completely tapped.

"Those hydrants are typical for two or three fires, maybe one fire. And then you have something at this scale," he told Anderson Cooper.

Satellite imagery of the fires shows them burning only miles away from L.A.'s Pacific Ocean shoreline. How could firefighters run out of water when there's a massive body of it just down the road?

The simple answer is: it's not that simple.

A firefighter waters down a home after the Eaton Fire burns in Altadena, California. Some have questioned if ocean water can be used to battle the blazes (AP)

Sea water, in theory, could be used to help a fire. But, its salty components can do more harm than good, which is why firefighters typically avoid using it unless absolutely necessary.

Salt is corrosive, and it can damage metal equipment, including critical equipment in water dumping planes and fire pumps.

According to Technology.org, salt can also reduce the cooling effect of water, meaning salt water can be less efficient as a firefighting tool. Salt water also carries a charge better than fresh water, making it slightly more dangerous for firefighters.

Environmental health is also a concern for fire officials considering the use of salt water for battling blazes. When salt water is dumped in large quantities on a fire, that salt has to go somewhere — typically, into the ground, or it's washed into nearby bodies of water.

Introducing large quantities of salt to areas with significant vegetation — as one might expect at the site of a wildfire — is almost always detrimental.

Raising soil salinity — the salt content of an area's soil — makes it harder for plants to draw water and nutrients from the soil via osmosis. Salt can also make the soil toxic, hamper seedling growth and harm the general permeability — how easily water and nutrients can move through the earth — of the soil.

All of that said, firefighters do sometimes use salt water to fight fires; they just have to be careful and selective about when to employ those methods.