Workings, mines and the water table
Coal and iron mines advance through timber-supported stairways; a working whose face is below the water table fills with water, and a town that has never lost one does not know to look.
A mine is a timber-supported stair driven into a hill, one navigable level per column, and every extension costs timber. Digging overburden yields the material actually removed, never imaginary ore, and the miners’ sets, handrails and head frame are drawn at the 1/32 m scale in the native viewer.
The one thing a mine has to get right has nothing to do with the ore: the water table. hydrology.rs gives a level for every column below which the ground is full of water. It follows the land, but far more gently than the land does; under a hill thirty courses above the river it sits about a third of the way up, so a working on the hillside has room and a working on the flood plain has almost none. A lake standing on top of a column raises it to the lake’s surface, and a saturated year raises it a little everywhere.
A working whose face is below the table fills with water: the stair is impassable, nobody works the face, and the chronicle says so. Nobody can pump it out before the engines; from the industrial era the town pumps drowned workings out for a fee. A town that has never lost one does not know to look, and after the first it stops driving below the table, which is why the first century of mining on a wet site is shorter than the second. The failure the model is built around is a working that was dry when it was dug and is not any more: a wet decade, or a new lake filling upstream of it.
In the code: crates/sim/src/city/mining.rs crates/sim/src/city/quarry.rs crates/sim/src/hydrology.rs