I’ve been searching for clay and have gathered just about all of it that I can find in the nearby cities.
From what I’ve read there is another way to obtain clay:
[spoiler]My understanding is there is a way to extract it from the shallow water beside rivers.
I’ve tried using a stone shovel to dig into the shallows and the construction menu but there doesn’t seem to be an option to create a clay mound.[/spoiler]
Could someone please point me in the right direction?
As far as I can tell the only option I have in the * construction menu is “Extract Clay”, which requires “clay” to function.
My guess is this is similar to cutting a tree into logs, I just need to find the “tree”.
[spoiler]Is the information I’m reading about “Clay mounds” out of date, can they no longer be created?
With all the radiation hazards I’m encountering continuing the fight without a source of boiled clay is going to prove difficult. X_X
… It isn’t found on a Z-Level under the river is it? I’ve found some swimming equipment but no diving gear yet, so I’m hoping that isn’t the case.[/spoiler]
I remember using the extract clay on shallow water then having to smash the pile that was made to retrieve the actual clay items.
I think you have to find a clay tile, usually near river banks, then extract it. They did change it somewhat recently, but not sure what exactly changed.
Yea, just follow a river bank until you find a tile with a clay deposit (it’s a tile in the shallow water that can be seen right away).
Yes like others have stated here this was changed in a PR. Clay tiles were added and will spawn near rivier banks and very rare to span in other places. You can no longer just obtain them from a hidden tile in shallow water. If your world is pre-change you will need to follow the river enough to have new map generated to get the new tiles.
Short version:
Found it!
(Side note: Apparently clay tiles are removed when you harvest them so I’ll have to hunt around for another one.)
Long version:
[spoiler]Armed with this new information I began an expedition down a nearby river that runs across a large swamp area.
Which apparently is infested with ants and fungal monsters! O_O I’ll have to return when I’m better equipped with incendiary options.
After journeying long enough that my electric vehicle only had about 30% charge, I found it!
A single glorious tile of clay.
Night had fallen but I switched on a heavy flash light and went to work extracting the clay. . .
And that is when the Tank Drone unexpectedly rolled out of the darkness. X_X
(There is a wreckage field in that direction, makes me wonder if the Tank Drone was the cause of it.)
Fortunately most of its initial barrage missed so I had enough time to toss out 5 manhacks and turn off the flashlight.
The drone seemed to change its target to the manhacks and I managed to limp back to my electric car and drag my heavy rail rifle out of the trunk.
With only a few rounds of ammo left and 1 crippled manhack still hanging on somehow, I managed to finally shutdown the Tank Drone (Still not sure how I made it out of that.)
After collecting what was left of the manhacks I again set to work on extracting the clay and final obtained . . . “8” clay! XD
Although that wasn’t nearly the amount of clay I was hoping for, at least the search was suitably epic! ^_^[/spoiler]
Thank you for the help. 
From my experiences with it, yes, you find clay and sand along rivers in single tiles. They don’t always disappear when you harvest, but they do sometimes. So I figure there is some set chance when you harvest it. Honestly, the clay deposits should be larger then this, but I figure it’s in the works.
In terms of realism, this makes very little sense to me. I grew up in the south admittedly, but there was clay everywhere thanks to the high water level and certainly around the river banks once I dug slightly deeper - and this is as a kid with a trowel being bored. It was workable enough that I put it in the sun and made crappy little pots from it.