Chronic Flooding

Enchantment — Aura

Enchant land
Whenever enchanted land becomes tapped, its controller mills three cards.

2012-10-01:
Chronic Flooding’s ability will trigger whenever the enchanted land becomes tapped for any reason, not just because its controller taps it for mana.
2012-10-01:
Chronic Flooding becoming attached to a tapped land won’t cause its ability to immediately trigger. That land must go from untapped to tapped.