Bureau of Reclamation Banner
Lower Colorado Region
Boulder City, Nev.
Media Contact:
Jack Simes
928-343-8334

Released On: March 22, 2006

Spray Program to Control Invasive Weed to Begin in Palo Verde on April 1
On April 1, the U.S. Fish and Wildlife Service will begin applying aquatic pesticides in the Palo Verde Irrigation District's outfall drain. This spraying program will start in the drain from the Palo Verde area to the California side of Walter's Camp and up to the confluence with the Colorado River.

This program, which is scheduled to continue through October 2006, is part of a comprehensive multi-agency effort to control the infestation of giant salvinia in the Lower Colorado River and associated backwaters. Giant salvinia (Salvinia molesta) is a highly invasive non-native aquatic weed that can damage irrigation systems and waterways. The spray program was implemented to avoid proliferation of the weed downstream.

The pesticides being used for the program include diquat dibromide (Reward), glyphosate [N-(phosphonomethyl) glycine, isopropylamine salt] (Rodeo), and copper carbonate (CuCO3) (Clearigate). According to manufacturer's label, humans and domestic animals should not drink or swim in water treated with diquat or glyphosate for one day after treatment. Copper herbicides have no use restrictions or precautions.

Giant salvinia, described as "the world's worst weed," is an aquatic fern from Brazil which was discovered by biologists in the lower Colorado River in the summer of 1999. The plant is very invasive; under the right conditions, it multiplies rapidly, threatening recreation use of infected waters, fishing areas, irrigation water delivery, hydropower production, endangered species, and sensitive habitats.

The Bureau of Reclamation is leading the effort to control and eradicate this plant from the Colorado River. The Lower Colorado River Giant Salvinia Task Force also includes the Bureau of Land Management, U.S. Fish and Wildlife Service, Arizona Game and Fish Department, California Department of Fish and Game, and other state and local entities; a complete listing can be found on the Task Force's web site at http://lcrsalvinia.org/salviniahome.asp.

# # #
Reclamation is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits. Visit our website at www.usbr.gov.