Ashe Juniper Contribution to Water Table Issues in Texas

Ashe Junipers have the dubious distinction of being a serious deterrent to ground water sources in the Edward’s Plateau region of Texas. This is a major issue and has been given an increased level of attention by federal and state land management agencies. As has been stated, the average adult ashe juniper consumes 32 gallons of water per day. When taken into the context of over 8.6 million acres in Texas being inhabited by this thirsty plant, the problem can be seen for the drain it creates on the state. Water is one of the growing issues in Texas. For a state that has a rising population and only moderate rainfall (approximately 32 inches per year in the Hill Country of Texas), the issues of conservation and water management will become more difficult. 

The Texas Water Development Board (TWDB) published in a 1997 report to the Legislature their observations about a statewide water plan. “Water, more than any other natural resource, will determine Texas’ future... it is our most precious resource and [our] basic economic commodity. It is distinct from other natural resources and has no substitute.”

Furthermore, there are thousands of acres in Texas covered with heavy water users in the form of brushy vegetation, which includes mountain cedar. The TWDB, using data developed by the Natural Resources Conservation Service (NRCS) and the U.S. Department of Agriculture (USDA), estimates that this brushy vegetation uses about 10 million acre-feet of water every year, which is equal to about 67% of what Texans consume.

Due to a myriad of poor soil conservation practices, the reduction of naturally occurring fires, and devastating droughts of the 1930s, 1950s and 1980s, the state’s grasslands have retreated giving way to brushy vegetation. The result has been the proliferation of water consuming brush plants and a reduction of beneficial hardwoods and grasses.

Many Texans are trying to decide what they can do to improve the water table on their land. One rancher, Mr. Kelly Prehn, has studied the problem and has developed techniques to deal with the water issues caused by an abundance of mountain cedar and other brushy plants. The method, The Prehn Method, is an innovative way to obtain more water for ranches, farms, rural development areas, weekend country homes, or even one’s own backyard. 

This has become a very serious problem in Texas. In a January 29, 2005 article in Austin American-Statesman titled “State remakes West Texas land”, the reporter states that “San Angelo-The oldest ranchers in these parts say the only trees here a half-century ago on the grassy savannah were the pecans and the live oaks that thirsted by the banks of creeks and rivers. Those creeks are long dry, and the trees that fed upon them are parched and rotted. It was the enormous appetite of the mesquite and cedar that exhausted the land of water, that crowded out the prairie grass and eventually starved the competition.” “If something isn’t done, this whole region is moving into desert.” says Fred Teagarden, a senior hydrologist at the Upper Colorado River Authority. “The reason we’re so zealous is because it’s a matter of survival.”

Leon River Restoration Project

“Historically Central Texas grassland ecosystems consisted of lush grasses growing in a deep fertile soil profile. Poor management of grassland ecosystems has resulted in loss of native vegetation, invasion by undesirable plant species and loss of the soil profile. The tall deeply rooted warm season grasses that once dominated Central Texas grassland ecosystems included Big Bluestem, Little Bluestem, Indian Grass, Eastern Gamma Grass, Switch Grass and other species. These desirable grass species have been replaced by invading woody species such as ashe juniper that have negative impacts on soils, native vegetation, and water quality and water quantity. Restoration of these valuable rangelands will improve grazing, habitat for native wild life, and will improve water quality and quantity for future residents” as stated in Monitoring Program to Evaluate Water Quality Impacts of Vegetation Restoration in the Leon River Watershed, a web site authored by Texas A&M University staff.

The goal of the Leon River Restoration Project participants is “is to restore the productivity of native rangelands and habitat for native wildlife and to ultimately improve water quality and quantity in the Leon River Watershed. To accomplish these goals, the CTCA (Central Texas Cattleman’s Association) [with cooperation of Texas Department of Agriculture] is proposing the removal of non-native woody species that are invading rangelands and destroying productivity. Rangeland in Coryell and Hamilton Counties will be selected for revegetation using maps created by Blackland Research and Extension Center and overhead imagery to assist in final site selection prior to ground truthing and clearing of ashe juniper from selected sites in cooperation with landowners. Through vegetation management, this project will quantify the potential water supply increase for Central Texas urban and rural residents while improving the grazing quality with the reducing of ashe juniper on rangelands.”

Updates to this project will be provided at this web site.