I'm playing the current version of SW and I noticed that putting turf by the water on a beach doesn't prevent the tides from flooding over during night. I have to wander if it's working as intended, because as far as I remember I was able to stop the tides before by placing any turf on the shore.
Just to be clear, I did not just place a single piece of turf next to water, I placed a line of a dozen turf pieces covering the shore and yet they kept flooding during night, not only from the sides where there is no turf, but "through" every and each piece of turf placed. Like they don't make any difference.
Additionally, I noticed that if I dig up a piece of turf in, say, jungle biome, that never gets flooded during night, and then place it back or replace it with another turf, that particular tile will henceforth be flooded with tides every time and there is no way to stop it from happening. So yes, looks like a bug.
1. Find beach biome. 2. Place any other turf by the shore. 3. Wait for the night and see if the turf prevents tides. 1. Find any other turfed biome. 2. Dig up a tile of turf and place it back. 3. Wait for the night and see if the tile gets flooded by tides.
A developer has marked this issue as fixed. This means that the issue has been addressed in the current development build and will likely be in the next update.