It was a Fire Whacker something like a broom. I had to keep using it to hit the fires, there is stamina drain and if you stay around the fire too long, you can catch fight too. Luckily I upgraded my stamina, therefore i am able to fight the fire for a longer period. It does looks very tiring and if it is IRL I doubt I will able to put out a forest fire with it. I also frantically pluck out the surrounding fiber around the ground so the fire would not spread. Luckily the game is very responsive and plucking the fiber is done quickly. As far as I've played, there's no well system, I've only unlock rain catchers which doesnt have the option to pull water to douse the fire.

I had watch streams of how the fire can burn down the base and I already put the campfire outside. Perhaps thats the reason why it took to the last of my playing time then to catch fire.