Introduction
Water is a vital resource needed for life. As populations continue to grow, the availability of
fresh water is of concern, especially for regions such as the Texas Lower Rio Grande Valley.
This region is one of the fastest-growing metropolitan areas in the United States (U.S. Census
Bureau 2000). As such, growing demands for water have placed pressure on city leaders to find
alternative ways to conserve existing water supplies. One such method currently under
examination is through the control of an invasive species, Arundo donax.
Arundo donax (a.k.a. giant reed) is a large, bamboo-like plant that grows 20-30 feet tall
and consumes large quantities of water, as much as 528 gallons per square meter (Bell 1997).
Giant reed thrives in the Mediterranean climate of the Rio Grande, and without any native
control, the plant has invaded several thousand acres of the Rio Grande riparian area. This
invasion is not only consuming large amounts of water, but since the plant has grown to such a
high density, the Border Patrol has experienced safety and security problems, as infrared sensors
cannot detect any heat beneath the plant canopy (Goolsby 2007).
In an effort to control giant reed and alleviate Border Patrol and water-demand concerns,
the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) is
investigating four insects for biological control of Arundo donax (Goolsby 2008). This paper
examines the economic implications for the Texas Lower Rio Grande Valley of using these
biological control agents, including (a) a base analysis of the water saved being applied to
agriculture irrigation due to the reduction of Arundo donax, (b) a benefit-cost analysis, and (c) an
economic impact analysis for the region.