Which of the following is a sustainable water management practice to reduce pollution?

Implementing rain gardens and green roofs to absorb rainwater is a sustainable water management practice because it enhances the natural water cycle and mitigates pollution. Rain gardens are designed to capture and filter stormwater runoff, allowing it to absorb into the ground rather than flow directly into drainage systems, which can lead to water body pollution. They use native vegetation that thrives in local conditions and can filter pollutants, thus improving water quality.

Green roofs also serve a similar purpose by absorbing rainwater, which reduces runoff and mitigates urban heat, while providing habitat and reducing energy use in buildings. These practices help promote sustainability by managing stormwater naturally, reducing the need for engineered solutions, and minimizing the adverse environmental impacts associated with pollution from runoff.

In contrast, constructing more dams can often lead to ecological disruption and altered water quality downstream, increasing habitat loss for aquatic species. Increasing agricultural runoff generally leads to higher levels of nutrients like nitrogen and phosphorus in water bodies, causing problems such as algal blooms. Utilizing chemical fertilizers and pesticides can contribute to chemical contamination in water sources, resulting in detrimental effects on aquatic ecosystems and human health. Thus, the choice of implementing rain gardens and green roofs aligns with sustainable practices aimed at pollution reduction.