Sindh lies between the two monsoons — the southwest monsoon from the Indian Ocean and the northeast or retreating monsoon, deflected towards it by the Himalayan mountains — and escapes the influence of both. The average rainfall in Sindh is per year. The region's scarcity of rainfall is compensated by the inundation of the Indus twice a year, caused by the spring and summer melting of Himalayan snow and by rainfall in the monsoon season. These natural patterns have recently changed somewhat with the construction of dams and barrages on the Indus River. Parts of southeastern Sindh receive rainfall of up to and some cities have received very heavy rainfall on occasion. In 2005, Hyderabad received in just 11 hours.