Chronic Flooding

• WWizards of the Coast2012-10-01
  Official Ruling
  Chronic Flooding becoming attached to a tapped land won’t cause its ability to immediately trigger. That land must go from untapped to tapped.
• WWizards of the Coast2012-10-01
  Official Ruling
  Chronic Flooding’s ability will trigger whenever the enchanted land becomes tapped for any reason, not just because its controller taps it for mana.

Rulings via Scryfall