Malaria is an ancient disease in India. Known as the ‘king of diseases’, malaria was estimated to cause 75 million cases and 0.8 million deaths annually. In epidemic years, morbidity and mortality used to increase 2–3 times. Ravages of malaria were so rampant and devastating, that the economic growth of the country remained paralysed.

The 1500 MW Nathpa Jhakri Hydroelectric Project was planned on the basis of survey of India Topo sheets of scale of 1:50,000. The survey of the project area and various project components was got done on a scale of 1: 10,000 for the preparation of DPR drawings. Further survey as per requirement of Design Department was also got done to freeze the layout of the project and its components.

Satluj River is a major river of the Indus system and originates from Mansarovar lake in Tibet. The total catchment area of the Satluj upto Bhakra Dam is about 56875 sq km out of which about 36900 sq km lies in Tibet. The total catchment area upto Nathpa dam site is about 49820 sq km.