When water slowly crosses their roots, they act as a biological and mechanical filter, converting toxins to harmless chemicals, and removing particulate matter. In places like the southern United States, where the plant has been known to overpopulate in public water systems, it is generally illegal to sell or own the plant. Water gardeners who keep the plant are urged to be responsible when disposing of it. Never allow it to enter public waters, and compost or destroy the excess plants you take from your pond. Mechanical means have been partially effective in eradicating the plant, but when it is thick, it can kill the engines of weed eating ships.
Chemical controls threaten other plant and animal life in the area.
The most effective methods of controlling water hyacinths are the introduction of certain moths and weevils that feed on the plant. So far the natural method has worked best. It is hoped that the introduction of these bugs won't eventually affect the balance in the area beyond what is intended. A number of uses have been found for the plant. Among these uses, its leaves can be made into cloth and crafts items, and it can be fed to livestock.