Boat dock bumper cars

I live on Lake Travis in Austin, TX. We are currently in a huge drought and the lake is about 50 feet below full. We only have about four feet of water at our house and the lake is dry just past our house. A couple of weeks ago we received a huge amount of rain in a couple of hours. This produced some fairly bad localized flooding. We noticed the lake had turned into a pretty swift river with all kinds of crap starting to float down. Then the boat docks started to appear. We had seven docks, a party barge, and a sailboat end up in back of our house. We drove around and found a floating house that had broken free and traveled about a quarter mile away. We counted at least 30 docks that had torn free due to the rising water and washed down the lake. One owner we talked to said his dock had traveled almost a mile. We've only lived here for about a year but this is one of the crazier things I've seen.