This chapter briefly deals with the field investigations required to plan a SHP. Field investigations are carried out to collect data and information regarding hydrology, topography, geology, availability of construction materials, infrastructural facilities, muck disposal areas, power evacuation system and environmental impacts. These except hydrology are very briefly described, because details are available for their investigation in Indian Standard codes and manuals which are referred in this chapter. Hydrological data collection and analysis are described in detail in a separate chapter.