Recurring Wave Dreams

I post this here because I'm sure I've seen someone posting about something similar in my months of lurking.

I have a friend (no really :p) who is having recurring dreams about giant waves.
Recent examples include her being in a house full of couches with her family which is on the beach facing the ocean. A huge wave comes and destroys the house, cinematically breaking a giant glass window which faces the ocean. Then she is standing on a nearby hill, looking down on the destruction with all her family.

Apparently this started about 2 to 3 years ago and has been consistantly recurring since then. The dreams are not always as described above, they vary but contain the common theme of a giant wave.

I just want to know if anyone has any light to shed on this at all? Why she has these recurringly themed dreams, etc.
I'm sure I saw a post from someone who had recurring dreams about waves before who was saying it was for.. some.. reason but my memory lets me down. >:3

Sidenote: she also just added that she has had many water-themed dreams previously to the beginning of the wave dreams. Apparently when she was younger especially.