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RIVER BLESSING
The Nurturing Role of the Blanco River in this Community
By Jean Williams and Dee Ann Story
The Blanco River
Water flowing in the Blanco River, Cypress Creek, and innumerable small seasonal creeks over time carved the land features of the Wimberley area. Water from wells, springs, and streams supplied the community needs for water generously, in most times, with a water source of excellent quality.
Our water, and related land resources are our heritage, a source of delight for the people who live and visit here, but a question mark for the future. How we approach that future will measure the community’s will to live within the limits of our resources.
In celebrating the River, we must be mindful that the beauty and purity of its water rest in our hands alone.
History of the River
One of the several streams in Texas known as “Blanco,” the Blanco River of the Hill Country supposedly was named by the Marquis de Aguayo expedition, a Spanish force of some 500 men who, along with 4,000 horses and other livestock, crossed the River en route from northern Mexico to east Texas to reoccupy territory seized by the French in 1719.
Beginning many millennia before these Spaniards passed through the area, the Blanco was home to Indians drawn to its banks by the abundance of water, shade, firewood, concentrations of edible plants, and other valuable resources linked to the River. Never well described by the early Spanish explorers and displaced by Apaches, Comanches, Tonkawas, and other immigrant Indians who moved into the area, these native peoples are known mainly from the archeological remains they left at their seasonal camps along the River and its tributaries.
Permanent settlement in the Blanco Basin came late. The saw and gristmill marking the beginning of Wimberley was built in c. 1848. Blanco, Twin Sisters, and Fischer trace their origins to the early 1850s, while the beginning of Kyle dates to 1880. Much of the watershed remains sparsely settled ranch land. The main exception is the Wimberley area, which has experienced great growth in population and development since 1947 when it consisted of a post office, nine businesses, a consolidated school, and 175 persons.
Physical Characteristics of the River
The Blanco is a major element in the drainage system contributing the Guadalupe River Basin. It rises in Kendall County and flows eastward and slightly southward for about 87 miles where it joins the San Marcos River thence into the Guadalupe River and ultimately into the Gulf of Mexico. Total drainage area of the Blanco is about 400 square miles from which the River is fed by springs emerging from fractured and cavernous limestones and by a number of small creeks and surface runoff. The quality of water flowing in the Blanco is generally good to excellent.
One of the River’s larger tributaries is Cypress Creek, another significant part of the Wimberley water ambience. Cypress Creek emerges from Jacob’s Well, a famous and fascinating historical landmark.
The Blanco throughout its length is beautiful and free flowing, tumbling over streambeds and between limestone cliffs. It primarily serves small communities, agricultural needs, and enormously popular recreational and aesthetic demands of Central Texas people.
The watershed is relatively short and steep, and with sheer slopes and shallow soils. These characteristics combined with intense thunderstorms moving off the Edwards Plateau cause flooding that is particularly severe when high rainfall follows a period of drought. Records kept by the U.S. Geological Survey since 1924 of River flows at Ranch Road 12 show a maximum flow of 113,000 cubic feet* per second in May 1929 and minimum flow of 0.6 cubic feet per second in August 1956. A far lesser flood on June 6, 1985 produced a maximum flood flow of only 44,200 cubic feet per second. An eyewitness to this flood recalls that she saw a three-bedroom mobile home float downstream and crash into trees just above the crossing near 7A Ranch.
The Blanco River Basin has a fragile relationship between the water and the land.
Ground Water in the Area and its Relationship to the River
Less spectacular but equally vital to the Wimberley community are the ground waters supplied to the community by the Wimberley Water Supply Corporation, a number of small public water purveyors, and private wells. Water from wells in this area is drawn from limestone. The major water-bearing layers important to Wimberley are the Glen Rose and Travis Peak formations.
Water is stored in these limestone formations in caverns and cracks. It is replenished by rainfall and water flowing over areas where the formations come to the surface, and further by leakage between formations. The ground and surface water system of the Blanco River Basin not only supplies our water needs but also helps to replenish water stored in the vital Edwards Aquifer. In the period 1934 to 1985, the Blanco River system contributed about 36,700 acre feet** of water annually to the Edwards. Total annual recharge to the Edwards Aquifer from all contributing river systems is a little more than 600,000 acre-feet annually.
* One cubic foot per second equals 449 gallons per minute.
** One acre foot of water is the volume of water necessary to cover one acre to a depth of one foot.
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