When you have heavy rain where you live, there is a lot of water coming down on your roof. There are certain spots on your home that are more prone to leaks, and these are protected by something called kickout flashing. Kickout flashing is designed to direct water away from places where your roof and wall intersect, since these areas could let water inside of your home, leading to water damage.
The problem is, not all homeowners know what the purpose of kickout flashing is, and since it might look unsightly, they have removed it. If this is the case with your home, you should remedy the situation, preferably before the next rainfall. If your kickout flashing is damaged, you should also replace it.
Considering the cost of remediating water damage, you should definitely take every step necessary to keep your home waterproof, and kickout flashing is an important part of this.