During the summer, glacier melt waters flood the lake, sometimes overflowing it. In fall and winter the lake disappears,
becoming a mudflat with scattered pools of water connected by a stream. The Maligne River pours into the lake from
the south and drains out through sinkholes in the bottom. The water then streams through a cave system formed
in the slightly soluble limestone rock, surfacing again in the area of Maligne Canyon 16 kilometers downstream.

Source: http://www.pc.gc.ca/pn-np/ab/jasper/visit/visit25_e.asp