By the second half of the 20th century, rapid industrialization and urbanization had severely degraded water quality in the Kallang Basin. The Kallang River was devoid of aquatic life and considered ecologically dead.
The basin of the Gagas River, a fragile spring-fed river in northern India, has seen major changes over the past few decades. Dwindling tree cover has led to a marked reduction in water flows. River fish no longer form part of the local diet, and agricultural production has declined.