As a result of Thailand’s rapid economic, technological, industrial, and social development as well as population increase, the country’s natural resources have depleted drastically. This was coupled with misuse of natural resource evidently leading to the problem of environmental deterioration, especially in big cities.An important environment problem is water pollution caused by discharge of water from factories, hospitals, hotels, stores, markets, communities as well as households, directly into ditches or public canals. Since the water did not undergo any treatment before being discharged, it then became polluted and the problem of environmental degradation had worsened. Inevitably, the situation had affected the well-being of many Thais.His Majesty King Bhumibol Adulyadej was highly concerned about the sufferings and, on many occasions, traveled to inspect the water pollution problems at various locations in and outside of Bangkok, including its peripheral areas. During those visits, His Majesty granted several initiatives to solve the water pollution.From 1984 to 1987, His Majesty had suggested the use of good quality water to dilute polluted water, resulting in the term Good Water Chases Bad, as well as the use of water hyacinth and aquatic plants as natural water filters. These approaches proved to be able to alleviate the problem, yet further attempts remained essential to manage the water pollution in Thailand which had become more increasingly critical since 1988.