Often our guests on the Mekhala cruise are curious about the numerous patches of water plant floating in the Chao Phraya River and wonder what its impact is on the river’s ecosystem.

water hyacinth Mekhala chao phraya river
Water hyacinth floating on the riverbank

The plant is actually water hyacinth.  It is native to South America and was introduced into Thailand from Indonesia in 1901, during the reign of King Rama V. The story goes that a palace official was impressed by the plant’s beautiful flowers and brought it back to Thailand to grow in the garden of one of the royal palaces.  Later floodwater inundated the palace grounds, causing the water hyacinth to spread to the waterways of Bangkok and to neighboring cities.  Since the plant reproduces very quickly, it soon covered a large body of water in the rivers and canals. It impeded water flow, blocked sunlight from reaching native aquatic plants, and starved the water of oxygen, often killing fish and turtles.  It became a big problem and successive governments tried to find a way of controlling it.  Some locals used the plant in new food recipes.  Some used it as animal fodder, and some sought to discover its medicinal properties.

water hyacinth Mekhala chao phraya river II
Water hyacinth in front of a house

A royal project, initiated by King Bhumibol, the current king, offered a solution by using water hyacinth as part of a natural water treatment. The project is implemented in a man-made lake where wastewater from industrial activities was dumped. The method, which is called oxidation pond, is designed to treat waste water through the interaction of sunlight, bacteria, and water hyacinth.

Another brilliant way of controlling this invasive plant species, however, is to use it to make flip-flops, handbags, baskets and various kinds of furniture.  In fact, nowadays, we find products made from water hyacinth everywhere, from high-end designer furniture stores to small souvenir shops.

water hyacinth basket