Part II: The First Aquifer LevelTime to start digging very, very carefully. Now that all four pumps are running you should see something like this on the first aquifer level:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
ooooo~ooo
ooooooooo
o~oo.oooo
ooo.X.ooo
oooo.oo~o
ooooooooo
ooo~ooooo
ooooooooo
The squares I've marked as being open space may show flickering water from time to time, but as long as the pumps are running above, should stay at 1/7 - 2/7 depth, and shouldn't interrupt your miners while they're working. The first step in mining through this aquifer level is to channel 8 tiles away around the work area, like this:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
ooooo~ooo
oooHHoooo
o~oo.oHoo
ooH.X.Hoo
ooHo.oo~o
ooooHHooo
ooo~ooooo
ooooooooo
Once that's done, you can safely mine out the 4 diagonal tiles adjacent to the stairs:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
ooooo~ooo
oooHHoooo
o~o...Hoo
ooH.X.Hoo
ooH...o~o
ooooHHooo
ooo~ooooo
ooooooooo
And channel out 4 more tiles, extending the trenches you've already dug like so...
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
ooooo~ooo
ooHHHoHoo
o~o...Hoo
ooH.X.Hoo
ooH...o~o
ooHoHHHoo
ooo~ooooo
ooooooooo
Now this next part seems to be the mildly dangerous one. One at a time, digg out the remaining tiles bordering the central stairs area and immediately channel out the square behind each, the square below where each pump drains. With these squares cut away you'll get a fairly blinding wash of mist, but you'll have finished making this level of the aquifer water tight. At this point you should have:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
oooooHooo
ooHHH.Hoo
oH....Hoo
ooH.X.Hoo
ooH....Ho
ooH.HHHoo
oooHooooo
ooooooooo
With the aquifer level now watertight, the cleared space around the stairs should begin drying slowly. Now that the pumps are no longer needed, dismantle the 4 pumps adjacent to the stairs above, as well as the horizontal axles between them, and cut a single channel at the end of the axle leading to the waterwheel (where the light square on the screw pump was prior to dismantling it). Place a gear assembly over this channel and you should end up with something like this:
.........
.........
.H<@H....
.HWWW....
...|.....
...|.H...
...|.....
.H.*H....
...HXH...
....H..H.
.........
...H.....
.........
If you have no stone whatsoever you can use a screw pump instead of a gear assembly, in either case you may have to floor over one of the channels adjacent to the stairs to give your dwarves a place to work. If you are using a screw pump to transfer power, be careful placing it, if it's in the same position as the original pump but reversed in direction, you'll flood the level below. If it's in the same position but reversed
and you've floored over the tile at it's exit, it will begin flooding the level ABOVE the aquifer. The safest position is to place it at the end of the axle, running in the same direction, with no open input or output, preventing it from doing anything but transferring power to the pumps below.
.........
.........
.H<@H....
.HWWW....
...|.....
...|.H...
...|.....
.H.@H....
...VXH...
....H..H.
.........
...H.....
.........
On the first aquifer level, begin by walling off the 12 channeled tiles nearest the stairs, like so:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
oooooHooo
oo###.#oo
oH....#oo
oo#.X.#oo
oo#....Ho
oo#.###oo
oooHooooo
ooooooooo
Next, cut 4 channels adjacent to the stairs, north, south, east and west, and rebuild 4 screw pumps in the same positions as they were originally in on the level above:
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
oooooHooo
oo###^#oo
oH<@H@#oo
oo#HXH#oo
oo#@H@>Ho
oo#v###oo
oooHooooo
ooooooooo
At this point, only one of the pumps should be running, so build 3 horizontal axles connecting the other pumps, again, in the same positions as you used previously.
ooooooooo
ooooooooo
o~oo~oooo
o~~~~oooo
ooooooooo
oooooHooo
oo###^#oo
oH<@-@#oo
oo#|XH#oo
oo#@-@>Ho
oo#v###oo
oooHooooo
ooooooooo
Congrats, you're ready to move on to the next aquifer level now. Cut a set of stairs down into the next level and you should have the following on each level:
Above Aquifer 1 Aquifer 2
......... ooooooooo ooooooooo
......... ooooooooo ooooooooo
.H<@H.... o~oo~oooo ooooooooo
.HWWW.... o~~~~oooo ooooooooo
...|..... ooooooooo ooooooooo
...|.H... oooooHooo ooooo~ooo
...|..... oo###^#oo oo~~~o~oo
.H.*H.... oH<@-@#oo o~oo.o~oo
...HXH... oo#|XH#oo oo~.X.~oo
....H..H. oo#@-@>Ho oo~o.oo~o
......... oo#v###oo oo~o~~~oo
...H..... oooHooooo ooo~ooooo
......... ooooooooo ooooooooo
More to come in Part III: Deeper Aquifer Levels...