Why can't the well be backfilled?

Because geomantic omen is exquisite, a well is wealth. Never fill it, but seal it.

If the well is backfilled, it will violate the taboo of geomantic omen, so it is best to know the local geomantic custom.

Well, mainly used for the construction of groundwater. It can be a combination of vertical, inclined and different directions, but it is generally vertical and can be used for water intake, drainage and water injection.