No, he's not plowing water. During a storm like the one we just had the
ocean throws rocks the size of basketballs (and bigger) onto the roads.
They plow to ensure emergency vehicles can pass.

Here's an image of a truck plowing rocks ....

https://tinyurl.com/ya8k828v


and here's one a couple of seconds later as he disappears:

https://tinyurl.com/yafaot6p