Long-term violation of exterior modification

I recently started working with a community of 44 condo units that are 10 years old. In 2005, a unit applied to extend their deck into some of their backyard grass with some concrete 12x12 pavers. After they were approved, they put in a 2ft. raised deck instead of pavers. Now, two years later, the current board and I have noticed the mistake/violation and it will soon be a issue. My question is: How have others handled this and what recomendations do you have for dealing with this situation?

What will soon cause this to be an issue? Just curious? Is it causing a problem of some sort?

The HOA could remove the structure if the owner refuses later if it is causing damage to the common property. Did it change the lay of the land and causes flooding to another area that previously didn't suffer from any? Those are issues that need to be addressed when considering such structures. It also may be the reason to give the owner that they must modify.