Ephemeral Catchments [EC] (playas, pools, tinajas, kettles, and tanks) are bodies of standing water formed in depressions, basins or in streams. A playa is an internally drained lake found in a sandy, salty, or muddy flat floor of an arid basin, usually occupied by shallow water only after prolonged heavy precipitation. A pool is formed in a small depression found in a marsh or on a floodplain. A tinaja is a pool in a seasonal stream that may support a flora upon desiccation. A kettle is formed in a depression by melting ice blocks deposited in glacial drift or in the outwash plain. A tank is an artificial pond built to hold water for livestock and wildlife (sometimes fish) that contain water for short and irregular periods of time, usually after a heavy precipitation.