ephemeral

1. (biology) Existing for only one day, as with some flowers, insects, and diseases.

2. (geology, of a body of water) Usually dry, but filling with water for brief periods during and after precipitation.Examples: "The graben constitutes a depositional basin and a topographic low, underlain by Cretaceous shales, in which volcanic debris accumulated in ephemeral lakes and streams in Oligocene and early Miocene time."