Hydroelectricity is the best source of generating electricity in India from the viewpoint of sustainable development.

1. Renewable Energy Source:
- Hydroelectricity is a renewable energy source as it relies on the water cycle, which is continuously replenished by rainfall and snowmelt. This ensures a sustainable and long-term supply of electricity.

2. Environmentally Friendly:
- Hydroelectric power plants do not produce greenhouse gas emissions or air pollutants, unlike coal-fired power plants that contribute to air pollution and climate change.
- Hydroelectricity does not release harmful pollutants into the atmosphere, which helps in improving air quality and reducing the impact on human health.

3. Water Resource Management:
- Hydroelectric power plants require the construction of dams or reservoirs, which can help in managing water resources effectively.
- The reservoirs created by dams can be used for irrigation, drinking water supply, and flood control, thus providing multiple benefits to society.

4. Contribution to Grid Stability:
- Hydroelectric power plants provide a stable and reliable source of electricity, which is crucial for maintaining the stability of the power grid.
- The ability to quickly respond to changes in electricity demand makes hydroelectricity an important asset for grid operators.

5. Job Creation and Economic Development:
- The development of hydroelectric power plants creates job opportunities in construction, operation, and maintenance.
- It also stimulates economic growth by attracting investments in the power sector and supporting local industries.

6. Diversification of Energy Mix:
- India heavily relies on coal for electricity generation, which has adverse environmental and health impacts.
- By promoting hydroelectricity, India can diversify its energy mix and reduce its dependence on fossil fuels, contributing to a cleaner and more sustainable energy future.

In conclusion, hydroelectricity is the best source of generating electricity in India considering its renewable nature, environmental friendliness, water resource management, contribution to grid stability, job creation, economic development, and diversification of the energy mix. Investing in hydroelectric power plants will not only meet the growing energy demand but also support sustainable development goals in the country.