The water will be affected when something slides into the water or if there is a large vertical slip strike under the water.

During the 1812 earthquake, the river flowed north for 3 days. That occurred because the area, now known as "Reelfoot Lake", suddenly sank, and it took the river 3 days to fill what is now the lake.

The Tsunami of 2004 was caused by a massive vertical slip strike under the Indian Ocean.
The best luck is what you make yourself!