Making sure that your basement is waterproof is important. Water can cause all kinds of damage when it gets into your basement or your foundation. It can cause your foundation to crack and settle, which can cause all kinds of damage to your house. Another issue with water seeping into your basement is that it can cause mold and mildew. The mold can be hidden, which means you can't deal with it until it becomes such a problem that it affects your family's health or until it finally grows up somewhere visible.