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Water Hyacinth

   

Update: 2011 Treatment Season

The Department of Boating and Waterways (DBW) is committed to working with Delta residents to control water hyacinth. DBW is awaiting an extension on federal permits to continue with its herbicide treatment for water hyacinth. The department’s approved treatment period ended Oct. 15.

This year’s water hyacinth infestation is unusual. High water, continued warm temperatures and a delay in receiving federal approval to start treatment resulted in unprecedented levels of water hyacinth in some areas.

How should I report a water hyacinth sighting?

If you sight water hyacinth, please telephone the Department of Boating and Waterways (DBW) at (888) 326-2822 or send an e-mail to pubinfo@dbw.ca.gov.  Include in your message the address or nearest landmark of the sighting.  If possible, take photographs of the plant.

Facts on Water Hyacinth

• DBW has the authority to control two species of aquatic invasive plants -- Egeria densa and Water Hyacinth -- in the San Joaquin Delta, its tributaries and the marsh (Delta region).
• Both programs are control programs.  The two species are too well established in the Delta region to be eradicated.
• The two programs are required to have permits from the United States Fish and Wildlife Service and the National Marine Fisheries Service (part of National Oceanic and Atmospheric Administration).  These two permits are required by the Endangered Species Act.
• A third permit, from the National Pollutant Discharge Elimination System (NPDES) is required by the Central Valley Regional Water Quality Control Board.
• These permits place restrictions on where DBW can treat the plants; when the programs can start treatments (this varies throughout the Delta region), what levels of chemicals to use and also require an extensive water monitoring program.
• Water hyacinth (Eichhornia crassipes) is a floating plant.  Water hyacinth is often mistaken for the aquatic plants Pennywort and Water Primrose, which DBW cannot treat.
• Required permits restrict when DBW is allowed to treat water hyacinth.  The majority of the Delta region is treated from July 1- Oct. 15.  The program has an April start date in Fresno and Merced counties.
• Every season surveys are done in the Delta region to determine where the hyacinth is located and which areas are in most need of treatment.
• Surveys are also done to determine what agricultural crops are growing near each treatment site.  Certain crops such as grapes have restrictions on DBW herbicide use.
• Water quality sampling is conducted at several of the treatments sites throughout the season to ensure herbicide levels stay within the required limits.
• The floating plant is treated directly and requires only one treatment.  It can be treated, with success throughout the season and down to a single plant.
• The plant is treated with highly diluted concentrations of 2, 4-D or glyphosate depending on the situation, of which both are registered for aquatic use.
• An aquatic adjuvant is used with the herbicides to help increase penetration of the plant surface.  This makes the herbicides more effective which allows less to be used.
• The herbicides are contact herbicides in liquid form and are sprayed directly on the water hyacinth.
• Symptoms can be seen on the plants within days.  Plants turn brown and eventually sink to the bottom.
• Because the plants decompose, care is taken in the amount treated at one time to ensure there is no severe decline in dissolved oxygen in the water.
• Funding for water hyacinth treatment comes from the Harbors and Watercraft Revolving Fund, which receives revenues from boaters’ registration fees and gas taxes.