Ladakh was once covered by an extensive lake system, the vestiges of which still
exist on its south-east plateaus of Rupshu and Chushul - in drainage basins
with evocative names like Tso-moriri, Tsokar, and grandest of all, Pangong-tso.
Occasionally, some stray monsoon clouds do find their
way over the Himalaya, and lately this seems to be
happening with increasing frequency. Drass, Zanskar and the Suru Valley on the
Himalayas northern flank receive heavy snow in winter; this feeds the glaciers
whose melt water, carried down by streams, irrigates the fields in summer.