ダム穴あな

noun

bell-mouth spillway; morning glory spillway; glory hole spillway

Colloquial term for a bell-mouth spillway used in dams. The English gloss 'glory hole spillway' is a technical term and may be unfamiliar to general learners.

• ダム穴あなは、貯ちょ水すい池ちの水すい位いが上あがりすぎたときに水みずを逃にがすための設せつ備びだ。

  A bell-mouth spillway is a facility for releasing water when the reservoir level gets too high.

• あのダムのダム穴あなは、上うえから見みると大おおきな渦うずを巻まいている。

  The bell-mouth spillway of that dam creates a large whirlpool when viewed from above.