As mskwik put it...
The guild well can be built at guild level 17. It comes in 5 levels with construction levels needed starting at 15. This is not an unlimited source of water, it will run out eventually, how quickly depends on the level, each level higher roughly doubles the time it will last.
The build process starts like any other building, it will take a small amount of wood and stone to get started, amounts depending on level. At that point it will not be complete but will open as a work spot, to complete it you will have to work there digging the rest out. This requires level 10 mining to do and will show a fuzzy status like the greenhouses.
Edit by Rudilyn: While digging our well, I received a random drop of 1 stone block.
When complete it will take a short amount of time to fill and then show as a working spot where you can fill bottles like at the fountain. It will show the amount of water left available at that point and will function until empty at which point it can be demolished (not going to do that automatically so people don't have to wonder where it went).
Guild Well
(guild level 17 needed)
| Level | Level Req. | Water Capacity | Lumber Req. | Stone Blocks Req. |
| 1 | 15 | 5,000 | 200 | 200 |
| 2 | 25 | 10,000 | 200 | 400 |
| 3 | 35 | 20,000 | 200 | 800 |
| 4 | 45 | 50,000 | 200 | 1,500 |
| 5 | 55 | 100,000 | 200 | 3,000 |
*The amount of water in the Well can be up to 10% more or less.
