It is the reality that hydro projects are life line for any country , to fill the gaps of power generation you cant rely on small hydro projects . You need bigger dams and hydro power for that like Mangla , terbella etc . It is a must for the country . Even if it is built now by a new investment by any financial institution it will cost somewhere arround Rs 7-8 / kwthr because investment is quite huge . You can judge and calculate yourself that Bhasha requires 12 billion USD and would produce 4500 Mwatts . You can calculate unit price yourself , but once the debt debt servicing ends then its a party time for a country . It must be a top most priority for any govt to go for it .
But you country cannot rely on hydro power only , it is simply not sustainable . In our country the 65% rain falls in 30 percent time of the year i.e june , july , august . Rest 70 percent of the time is dry and you cannot produce peak loads with hydro powers dams . Some times in winters the Terbella produces just 10 percent of its installed capacity . Therefore to run a country you need coal power / nuclear / alternative energy / furnace oil plants. Coal is a good cheaper solution along with nuclear power .
For imported coal usage it is a curse , India is using its coal in Rajisthan coal power plants very succesfully. Ironically we had gas in our country so we didnt work on coal and bio mass however indians mastered the coal and bio mass technology . Many Indian companies built their own power plants based on coal and biomass and uses their own coal . We can use the imported coal but we must design our power plants with the provisions so that those could run on local coal too . We must use local coal in our coal power plants too . We would not be needing foreign exchange reserves to procure coal anymore .