Water from land to sea due to collapse of a dam,
A lot of things to a lot of creatures in the vicinity or otherwise, a few things to the topography, and very little to the body of water, other than being contaminated by whatever was in the way. Seas are made of water flowing into them.
https :// www . youtube . com/watch?v=sKZUZQytads
https :// www . youtube . com/watch?v=5XupgwBIBCw