There is a mod that claims to fix this bug:

https://mods.factorio.com/mod/FixOldLandfill

Feels like this should be built into the game so old landfill tiles get updated when loading an old save

TL;DR
Should be able to undo the action of placing landfill, this should revert the tile back into water. I am NOT suggesting the ability to create water anywhere, just revert to water that existed previously.

What ?
The action of placing Landfill should be able to be undone. Either through ...

Please let us undo landfill! It's too easy to make permanent mistakes with landfill and blueprints.

Since 0.17.10 Landfill is now a separate tile, differentiated from grass-1.

We should be able to undo landfill but not just create water where it wasn't there before.

As of 0.17.10 Landfill is now a separate tile, differentiated from grass-1. So it should be able to be undone or dug up please!

https://wiki.factorio.com/Version_histo ... .0#0.17.10

Now that we have an awesome rail planner, can we please also get a belt/pipe planner too?

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