Water Hyacinth has several deleterious effects. Spreads rapidly over all water, obstructs water flow and water use, interferes with fish and water fowel, reduces water oxygen levels, make water unfit for drinking by humans and livestock, provides ideal breeding sites for mosquitoes. Massive colonies of water hyacinth build up when the plant is introduced into new areas that are conductive for its proliferation or when the natural ecological balance of water bodies is upset due to human activities such as impounding of flowing waters by dams and channeling. Presently, several tropical and geographic range of the plant, are experiencing serious problems of water hyacinth infestations. ACTION Chemical treatment are available, small infestations can be removed by hand. Seeds remain dormant for 15 years so monitoring of pervious infestations is essential to prevent new outbreaks. Water hyacinth can be controlled using chemicals and by manual or mechanical removal. However, the only sustainable solution to water hyacinth is biological control, with the aid of insects used in the  classical biological control strategy, has been successful in reducing water hyacinth infestations in several countries. http://warrior.tubacity.k12.az.us/~man2/winter98/eliza/   http://www.sidney.ars.usda.gov/scientists/nspencer/water_h/     http://www.ifas.ufl.edu/~FAIRSWEB/IPM/ipmfl/v2n4/hyacinth.htm   http://www.sidney.ars.usda.gov/scientists/nspencer/water_h/space_view.htm  http://www.sidney.ars.usda.gov/scientists/nspencer/water_h/consortium.htm