Visual error when digging in water

Hey guys, it’s me again playing with water and getting fun results.

I’m getting an interaction with water having strange fully lit backfaces visible after mining in the water under the water level. Also water doesn’t fill spots mined out. (can’t make my pond bigger)

Steps to reproduce:

  1. click mine tunnel and select and area under and out of the water to mine
  2. watch your townspeople dig it out
  3. Water doesn’t fill the hole properly, causing backfacing issues

Expected Results: Water to fill the hole forever.

Actual Results: water tries to fill the parts, gets messed up.

Actually loading the game it shows the water level has dropped in the pond I was excavating. Some visual planes exist where the old water level used to be (these are also fully lit)


Save file: Dropbox -

Release - 729 (x64)
No mods

Sys info