Rangeland Watersheds
The
majority of the water for Texans comes from a land resource called
rangeland, the state’s largest watershed. Rangelands
comprise sixty percent or ninety million acres of Texas land. Rangelands
consist
of grasslands, shrublands, marsh areas, deserts,
and woodlands which are not used for commercial timber production.
Rangelands support livestock production as well as provide habitat for
native wildlife, but their most important function to Texans is
as the State’s watershed.
The
precipitation that falls on Texas rangeland is a major source of
surface flow and aquifer recharge. The majority of rivers and streams
in Texas originate or flow through rangeland. As precipitation is the
ultimate source of all fresh water, it has many destinations.
In
an average rainfall year, it is estimated that forty-two percent
of the
precipitation falling on Texas is evaporated directly back into the
atmosphere. An additional forty-seven percent is lost or used through
transpiration (for plant growth). Only a little over one percent
of the annual precipitation recharges aquifers and the remaining
ten percent
runs off to become stream flow.
Thus,
precipitation that is currently captured directly for human use as
fresh water in aquifers
and surface water represents only a small proportion of the annual
precipitation received, but management of the rangeland vegetation
can redirect these percentages and is very critical to sustaining
ample water for Texans.
The management of rangelands can have major impacts on the water available
in Texas. Rangeland in a state of good health will provide Texans with
a high quality water source, promote infiltration for ground water
recharge, filter overland flow of water, provide forage for livestock
production, and provide wildlife habitat.
Rangeland that is in an unhealthy state will have increased runoff
with high nutrient and sediment content, and will not maintain as much
soil moisture which is needed for the production of native plants required
by domestic livestock and native wildlife.
Related Resources
Harvesting
Rainwater for Wildlife
Providing
enough water can be a problem when grazing livestock on rangeland.
Authors explain how rainwater capture is done and give specific examples
on how to determine the amount that you need.
Rainwater
Harvesting: Livestock
Providing
enough water can be a problem when grazing livestock on rangeland.
Authors explain how rainwater capture
is done and give specific examples on how to determine the amount that
you need.