In this study, the development of energy demand in Turkey, the utilization of hydropower potential as well as the problems related to the operation, construction and development phases of hydropower plants have been examined. The number of hydropower plants, their overall installed power (MW), their annual energy production capacity (GWh/yr) and their technical hydropower potential utilization rations have been calculated for the hydropower plants existing in the 25 hydrological basins located in Turkey. The total installed power for hydropower plants under operation for the basins examined in the year 2012 has been calculated as 16,926.80 MW. When the technical hydropower energy potential is taken into account, 28% of hydropower plants are under operation, 27% of them are under construction and 22.4% are under development. In all of the basins, if all of the 1776 projects which are under operation, construction and development are examined, then the total installed power will be 48,298.20 MW, and the annual hydropower production will be 167,333.30 GWh/yr. Hence, as a result, the 77.33% of the technical potential will be utilized. In addition, environmental effects of hydropower plants in the operation and construction phases have been researched.