Water hyacinth chokes Kathirikkai Vaical

The weed flourishes because of stagnating water and absence of underground drains

As summer advances, Tiruchi’s inner-city waterbodies are choking up with water hyacinth, the freshwater weed that is the bane of urban landscapes all over the world.

The aquatic invaders can be seen in full bloom on the Rettai and Kathirikkai canals, along with solid waste generated by the commercial and residential buildings along the Vayalur to Nachikurichi stretch.

“This weed grows in stagnant water, and tends to spread across the surface through vegetative propagation like grass.,” Anand Gideon, Associate professor and Head, Department of Botany, Bishop Heber College (BHC), told The Hindu.

BHC is situated close to the canal banks and has been collaborating with Citizens for Uyyakondan (CFU), a civic platform that works with government departments to rehabilitate the historic water channel.

The tendency of the weed to block sunlight absorption and oxygen levels in water affects the aquatic ecosystem, by killing the fish population. It also ferments quickly, creating mats of rotting plant material on the waterway’s bed. This leads to increased flooding in rivers and canals.

The lack of a comprehensive underground drainage system in the area has allowed many buildings to directly channel waste water into the canal, which civic activists say could be a major reason for the water hyacinth’s prolific growth here.

“The weed doesn’t seem to grow in pure water or pure sewage, but only at the confluence points. Completing the underground drainage work by the Corporation is essential to get rid of the weed,” said Manoj Dharmar of CFU.