Plastic thing under bumper torn up

I was taking my roommate to pick up her car when I hit a patch of black ice and went into a ditch. Thankfully no one was hurt and when I got out to inspect, it didn't look as though there was any damage to the car. After a more thorough inspection, I found that the plastic thing that was behind my front bumper by the front left tire was all torn up and keeps pressing against the tire randomly.

My question is two parts: One, is this causing damage to my tire and two: how much would it be to get it repaired?