hydroelectric reservoirs

Hydroelectric dams are discharging too much emissions?
Once upon a time, hydropower was the first choice and superior to thermoelectricity and other forms of power because of its low cost, high performance and ... friendly environment.
Hydroelectricity discharges one billion tons of CO2 into the atmosphere every year
Dams and reservoirs that supply water for hydroelectricity are a huge source of greenhouse gases.