The Nakdong river basin, which supplies drinking water to the Busan Metropolitan City, the second largest city in the Republic of Korea, became heavily polluted from the growth of an upstream textile industry. Research revealed that downstream water treatment costs exceded upstream water protection costs, prompting authorities to focus on protecting and treating wastewater at source.
The Songhua River Basin is the third largest river basin in the People’s Republic of China. Almost the entire northeast of the country lies within this basin. The Songhua is also one of the China’s four most polluted rivers, suffering until recently from untreated urban wastewater, industrial wastewater and agricultural non-point sources.
Laguna Lake, the fourth-largest lake in Southeast Asia, lies in the provinces of Rizal and Laguna. Increased development within the basin has caused water quality to decline steeply.