I have already read the wiki. I tried experimenting with the cave in method, but it can't get it to work.
It requires a wall of soil above the aquifer. Also, you need to respect the edges of the "soil" after it lodges itself on the ground. This method basically substitutes aquifer soil with non-aquifer soil.
Hint: if you want to avoid getting wounded dwarves (which is wise given how long it takes them to heal), embark along with you 3+ stones, make them into mechanism, and support the soil layer you're going to collapse with a support. This way you can use that to bring it down from a safe distance
Some alternatives:
- Permafreeze maps: just dig out a big hole in the open, and channel through the ice
- Non-permafreeze: same, but wall out the edges of the hole, lest everything comes down on your head in summer.
- Pump method: use pumps to move water from your "prospecting" aquifer site (through which you intend to drill) to auxiliary aquifer holes, then build walls along the free, waterless edge. Use this array to progressively enlargen your "prospecting" aquifer. The idea is to eventually build a wall inside an aquifer pond, as the water only spawns from aquifer-tagged natural walls. This is easier to fix if digging through stone, as you can smooth it out to prevent water leakae, instead of building artificial walls.
-Legendary miner method: they can dig fast enough to channel down before the digging place gets full. Now, obviously, this doesn't really give you a realiable access beyond the aquifer, but if you tunnel into a cave, you can use this as part of an one-way transporting method into the underworld for some daring pioneers
- Volcanos are surrounded by non-aquifer tiles. You might be able to dig down through those