Groundwater Hydrology of Springs

Engineering, Theory, Management and Sustainability

Neven Kresic, Zoran Stevanovic, Neven Kresic, Zoran Stevanovic

• Verlag: Butterworth-Heinemann
• Jahr: 2009
• ISBN:
  9780080949451
• Thema: Naturwissenschaften
• Thema: Hydrologie

Groundwater Hydrology of Water Resource Series - Water is an essential environmental resource and one that needs to be properly managed. As the world places more emphasis on sustainable water supplies, the demand for expertise in hydrology and water resources continues to increase. This series is intended for professional engineers, who seek a firm foundation in hydrology and an ability to apply this knowledge to solve problems in water resource management. Future books in the series are: Groudwater Hydrology of Springs (2009), Groudwater Hydrology of River Basins (2009), Groudwater Hydrology of Aquifers (2010), and Groudwater Hydrology of Wetlands (2010).

First utilized as a primary source of drinking water in the ancient world, springs continue to supply many of the world's cities with water. In recent years their long-term sustainability is under pressure due to an increased demand from groundwater users. Edited by two world-renowned hydrologists, Groundwater Hydrology of Springs: Theory, Management, and Sustainability will provide civil and environmental engineers with a comprehensive reference for managing and sustaining the water quality of Springs. With contributions from experts from around the world, this book cover many of the world's largest springs, providing a unique global perspective on how engineers around the world are utilizing engineering principles for coping with problems such as: mismanagement, overexploitation and their impacts both water quantity and quality. The book will be divided into two parts: part one will explain the theory and principles of hydrology as they apply to Springs while part two will provide a rare look into the engineering practices used to manage some of the most important Springs from around the world.

• Description of the spring and the aquifer feeding it
• Latest groundwater and contaminant transport models
• Description of sources of aquifer use
• Understanding of contamination and/or possible contamination
• A plan for management and sustainability

Chapter 1. Sustainability and management of springs

Neven. Kresic

MACTEC Engineering and Consulting, Inc., Ashburn, Virginia

1.1. Introduction

The following excerpts from the anthological work by Gunnar Brune, Major and Historical Springs of Texas, published in 1975 by the Texas Water Development Board, are applicable to historical significance of springs around the world and their subsequent demise, caused first by ignorance and unrestricted land use and then by the overwhelming pressure of population growth and inadequate regulations:

Springs were vital to the survival of Texas' earliest inhabitants, over 30,000 years ago. At an archeological site near Lewisville in Denton County, radiocarbon analysis has dated the remains of these early new-world men at 37,000+ years old, including crude sculptures, spears, and spear throwers (Newcomb, 1961). These early Americans always made their campgrounds near water, whether it was a spring, spring-fed stream, a river, or a lake. Bedrock mortars or rock mills were worn into the rock by the Indians as they ground stool, acorns, and other nuts, mesquite beans and grain. These mortars can still be seen at many Texas springs. It is also noteworthy that the Pueblo Indians of west Texas used spring water for irrigation of crops long before the arrival of the Europeans (Taylor, 1902 and Hutson, 1898).

Because the springs were so vital to the life of both the Indians and the white man, it is not surprising that many battles were fought over their possession. In 1650 when Spanish explorers first visited Big Spring in Howard County, they found the Comanche and Pawnee Indians fighting for its possession. When a network of forts was strung across Texas, they were, in nearly all cases, located near springs in order to have a reliable supply of pure water. Later the covered-wagon and stagecoach routes came to rely heavily upon springs. For example, the “Camino Real” or King's Highway, completed by the Spanish colonists about 1697 from Natchitoches, Louisiana, to San Antonio and Mexico, passed 13 major Texas springs and many more minor ones. Most of the springs in West Texas are very small in comparison to those in central and east Texas, because of the very low rainfall and recharge. Nevertheless, they often meant the difference between life and death to the early pioneers.

Nearly all of the larger springs were used for water power by the early settlers. At least 61 were used in this way. Gritsmills, flour mills, sawmills, cotton gins, and later electric generating plants were powered by the flow of spring water.

In the late 1800's, many medicinal or health spas sprang up around the more mineralized springs. At least 25 springs, chiefly in east Texas, were believed to be beneficial in curing various ailments. Most of these waters are high in sulfate, chloride, iron, and manganese.

Many of the early settlements relied entirely on spring water. At least 200 towns were named for the springs at which they were located. About 40 still are shown on the official Texas State Highway Map, but many of the springs have dried up.

Throughout the long period during which various Indian tribes occupied Texas, spring flow remained unchanged except as affected by wet and dry climatic cycles. At the time of Columbus' epic voyages Texas abounded with springs which acted as natural spillways to release the excess storage of underground reservoirs. Early explorers described them as gushing forth in great volume and numbers. The very early accounts usually describe not springs but “fountains”. This is an indication of the tremendous force with which these springs spouted forth before they were altered by modern man. As an example, less than 100 years ago Big Boiling Spring, one of the Salado Springs (Bell County) was still described as a fountain rising 5 feet high. Such natural fountains ceased to exist in Texas many years ago.

Probably the first effect upon ground-water tables and spring flow was the result of deforestation by the early white settlers. Deforested land was placed in cultivation or pasture. The deep open structure of the forest soils was altered as the organic matter was consumed and the soils became more impervious. Heavy grazing by introduced stock animals was probably especially harmful. Soon the soils were so compacted that they could take in only a small fraction of the recharge which they formerly conveyed to the underground reservoir.

This reduction of recharge affected larger areas as more and more land was placed in pasture. However, the effect upon water tables and spring flow was probably relatively small in comparison with later developments. In the middle 1800's deep wells began to be drilled. It was found that flowing wells could be brought in nearly everywhere. The “Lunatic Asylum” well in Austin, drilled to the basal Trinity Sands, threw water 40 feet high. Water from a well south of San Antonio reaching the Edwards Limestone rose 84 feet above the surface of the ground (Hill and Vaughn, 1898). Nothing could have had a more disastrous effect upon spring flows than the release of these tremendous artesian pressures through flowing wells. Most of these wells were allowed to flow continuously, wasting great quantities of water, until the piezometric heads were exhausted and the wells stopped flowing.

Although the effects of flowing wells upon spring flow were severe, there was more to come. When the wells ceased flowing, pumping began. Ground-water levels were systematically drawn down, as much as 700 feet in some areas. At first pumping for municipal and industrial use was primarily responsible. In recent years tremendous quantities of ground water have been withdrawn for irrigation, amounting to about 80 percent of the total ground water used in Texas. As a result, some streams which were formerly “gaining” streams, receiving additional water from streambed seeps and springs, are now “losing”, and many streams have ceased flowing. Thousands of small springs have dried up, and the larger springs have generally suffered a decrease in flow.

Natural spring waters if taken at their source are considered to be ground water and no permit is required for their use. Once they issue forth and flow in watercourse, however, they become public surface waters. As such, a permit from the Texas Water Rights Commission is required for their use.

A spring is normally a spillway for an underground reservoir. This reservoir may be overlain by land belonging to a number of owners. If the landowners other than the spring owner choose to pump ground water heavily, lowering the water table and causing the spring to cease flowing, the spring owner has no recourse in the courts to prevent them.

An example is Comanche Springs at Fort Stockton (Pecos County). These artesian springs, issuing from a Comanchean limestone ground-water reservoir, formerly flowed as much as 66 ft³/s, and served the Comanche and other Indians for uncounted thousands of years. From 1875 on the springs were the basis for an irrigation district which supplied water to 6,200 acres of cropland. Heavy pumping of the aquifer lowered the water table so that the spring discharge began to fall off in May 1947 (U.S. Bureau of Reclamation, 1956). The irrigation district sought an injunction in 1954 to restrain pumping which interfered with the normal flow of Comanche Springs. The injunction was denied by the courts, and the springs ceased to flow in March 1961.

Figure 1-1 is a historic hydrograph of the Comanche Springs, based on flow measurements by the United States Geological Survey (U.S. Geological Survey, 2008), showing the cyclic influence of the aquifer pumping and the final drying up of the springs. Similar examples of a catastrophic influence of aquifer pumping on springs are numerous both in the United States and around the world (Figure 1-2). Since the environmental regulations and water resource governance vary in different states and different countries, so do actions to prevent or mitigate such negative impacts of groundwater withdrawals. For example, most states in the United States have some form of required permitting for large water users, including protection of seniority rights, as illustrated by the following excerpts from a news article (Barker, 2007):

Water experts, state officials and the businesspeople and farmers at the heart of Idaho's most heated water dispute are entering their third week of testimony in a case that could dictate how the state uses one of its most precious resources in the future. The hearing is slow, plodding and arcane as attorneys for fish farmers, groundwater-pumping irrigators and the state cross-examine hydrologists about spring flows or state officials about the papers they have filed. To settle the disputes, though, officials and judges will have to resolve several points on which the water users disagree. The consequences of the decision could be massive.

At stake is whether the state shuts off the pumps that bring water to thousands of acres of farmland, factories and towns across central and eastern Idaho...