As the population increases so does the demand for water. Our reliance on water for agriculture and household use has been very prevalent during the severe drought across the state this year.
Texas has more than 191,000 miles of rivers and almost 2 million acres of lakes. The state's rangelands play an important role in the quality of the water we depend on.
Rangelands, grasslands, shrub lands, marshes, deserts and woodlands account for about 60 percent of Texas' land. These rangelands support livestock production as well as habitat for native wildlife, but most importantly they serve as the state's watershed.
Most of Texas' water supply comes from captured surface sources such as lakes and ponds or is pumped from underground aquifers, both are dependent on precipitation that falls on rangeland so that recharging can take place. These areas have an impact on the quantity and quality of water on which we depend.
It is estimated that in an average year:
• about 42 percent of rainfall evaporates into the atmosphere,
• 47 percent is lost through plant transpiration,
• 1 percent recharges the aquifers, and
• 10 percent runs downstream.
Rangeland influences the amount of water that evaporates, infiltrates and runs off. Researchers have found that with 60 percent ground cover, runoff can be kept to 5 percent, thus protecting water quality. Ground vegetation filters sediment particles in which pesticides, nutrients and other pollutants bind to, therefore increasing water quality.
As human populations grow so do the number of homes and roads to reach them, reducing the amount of land available to absorb precious rainfall and limiting nature's filtering system and avenues to recharge our aquifers. Fortunately, because of the efforts of our forefathers, there are millions of acres of rangeland protected from development and misuse. But is it really enough to sustain us with the quality of life we've become accustomed to - or will we need to act soon to save our precious resources?
EDDIE BAGGS, extension agent with the Texas AgriLife Extension office in Denton County, can be reached at 940-349-2880.