Which one of the following statements is not true for hydropower generated from river dams?

The correct option is Dams encourage sustainable growth.

Explanation and Analysis:

To determine which statement is not true regarding hydropower generated from river dams, let us examine each statement:

1. "Dams encourage sustainable growth." — This statement is not true. While hydropower is a renewable energy source, constructing large river dams often leads to significant environmental degradation, habitat fragmentation, displacement of local communities, and disruption of river ecosystems. Therefore, large-scale dam projects do not fully align with sustainable development principles.

2. "It does not pollute water or air." — This statement is generally true in terms of direct operational emissions. Unlike burning fossil fuels, hydro-electricity generation does not emit air pollutants or directly toxic water contaminants during its operation.

3. "Hydropower facilities can have large environmental impacts." — This statement is true. Building dams alters natural water flow, disrupts aquatic life, floods large forest lands, and affects downstream ecosystems.

4. "Dams displace indigenous people from their river lifelines." — This statement is true. The creation of large reservoirs upstream submerges extensive land areas, displacing human settlements and indigenous communities dependent on the river ecosystem.

Hence, the statement that is not true is that dams encourage sustainable growth.