Water Quantity

CHAPTER ONE

"When the well's dry, we know the worth of water."
Benjamin Franklin

Please note that all the graphics from the print version of the Almanac have not been included in the Online format due to size and bandwidth limitations.

Texas Environmental Almanac, Chapter 1, Water Quantity, Page 1

• Geographical variations cause large disparities in available water supplies, from water shortages in arid West Texas to abundant supplies in the eastern portion of the state.

• A growing population and industrial base will continue to increase pressure on existing supplies and generate demand for development of additional water delivery facilities such as reservoirs.

• Reliance on groundwater is facing serious limitations in many areas of the state due to overpumping and water quality problems.

• Even though all water forms part of the same hydrological cycle, the Texas institutional structure for managing water quantity and protecting water quality is divided among several state and local government agencies charged with implementing a convoluted set of statutes and court decisions.

TEXAS AGENCIES WITH MAJOR WATER RESOURCE RESPONSIBILITIES
Texas Water Development Board		Texas Natural Resource Conservation Commision
Water quantity planning Grants and loans for wastewater protection ans surface water treatment and water supply facilities		Water use permitting Water quality inventory and monitoring Wastewater discharge permits Water quality standards Enforce Clean Water Act, Safe Drinking Water Act and Texas Water Code Overall responsibility for water quality (other agencies share responsibility)
Texas Department of Agriculture	Texas General Land Office	Texas Parks and Wildlife Department	Texas Railroad Commission	Texas State Soil and Water Conservation Board and Local Soil Conservation Districts
Responsibility for regulating agricultural chemicals	Management of coastal areas Oil spill clean-ups	Review of water use and wastewater discharge permits to ensure protection of aquatic habitats, parks and endangered species	Water quality aspects of oil and gas exploration and production	Authority over many aspects of agricultural and silvicultural non-point source pollution
River Authorities		Groundwater Conservation Districts		Local Governments
Manage water supply reservoirs and act in conjuntion with state and local governments to monitor and protect water quality		Collect information on groundwater use and quality in district Some limited authority to regulate pumping and protect water quality		Limited authority to protect water quality through ordinances, enforcement such as sewer discharge ordinances

HOW MUCH WATER IN TEXAS?

Texas receives about 366 million acre-feet of rain annually. In the period from 1940 to 1970, surface runoff varied from 23 to 57 million acre-feet per year. Average annual flow is about 49 million acre-feet.(1) Levels of precipitation and run-off vary greatly across the state. In the eastern portion, precipitation averages 56 inches per year; in West Texas, annual rainfall is only about eight inches.(2) This rainfall feeds 191,228 miles of streams and rivers contained in 15 major river basins and eight coastal basins, 5,700 inland reservoirs which comprise over 3 million square acres, nearly a million square miles of bays, almost 8 million acres of wetlands and vast underground storage areas known as aquifers.(3)

Texas has only one natural lake - Caddo Lake in East Texas. The other 5,700 lakes have been constructed by humans.(4) About 97 percent of the surface water consumed by Texas is drawn from 191 reservoirs that each hold more than 5,000 acre-feet of water.(5) Approximately 11 million acre-feet of surface water are available for human use at Texas major reservoirs. At present, the state uses only about 65 percent of this dependable yield.

One acre-foot is equal to 325,851 gallons - an area about the size of a football field covered with one foot of water.

Texas Water Development Board, Texas Water Facts, (4) .

Texas also has an estimated 3 to 4 billion acre-feet of groundwater stored in nine major aquifers and 20 minor aquifers, underground natural rock formations which hold groundwater. However, only about 10 percent of this groundwater is recoverable using traditional technology.(6)

In addition to these available groundwaters, each year about 5.3 million acre-feet of annual rainfall recharges the state's aquifers. In 1990, the 8.9 million acre-feet of water pumped from underground exceeded natural recharge - the downward replenishing flow of rainfall through the soil to the aquifer.(7) The Texas Water Development Board projects that by 2040, the state will decrease its groundwater use to about 5.7 million acre-feet of groundwater.(8)

WHO USES THE WATER?

Texans pump, push, pull, consume and discharge water for all kinds of uses. Statewide, demands for water totaled about 15.8 million acre-feet in 1990, with groundwater use equaling about 56 percent of total use.(9) Water use in Texas can be divided into six major categories. Irrigation, municipal use and manufacturing together accounted for nearly 95 percent of all water consumed in 1990. Steam-electric-power generation, livestock watering and mining together accounted for 5 percent of consumption in 1990.(10)

WATER OWNERSHIP IN TEXAS

Despite their interrelatedness in the hydrological cycle, groundwater and surface water are treated differently in Texas.(11)Surface water bodies are the property of the state but the right to use surface water for specific purposes such as irrigation or mining is a private property right. Today, these "water rights" are regulated by the Texas Natural Resource Conservation Commission. Groundwater is privately owned: it belongs to the owner of the land above it and the owners may pump all the water they can from beneath their land regardless of the impact to nearby landowners.(12)

EIGHTEENTH AND NINETEENTH CENTURY WATER LAW

The history of water regulation in Texas began with the Spanish settlers in Texas. Spanish water law required specific authorization to use water. The Spanish (and later Mexican) type of water law evolved into the "prior appropriation" doctrine which holds that water "rights" are separate and apart from the rights of land ownership, much like oil and mineral rights are today separate from land ownership.(13) However, in the 1800s Anglo-American settlers in Texas introduced English common law for claiming the use of water. This water law establishes the right of use based upon ownership of land. The owner of land adjacent to a river had the right to fish that river or divert water for irrigation, or otherwise make use of it. These property-based water rights are legally referred to as "riparian" rights, after a Latin word that means pertaining to the bank or shore of a river or lake. Groundwater was likewise attached to the property above it; landowners were free to pump whatever they could from wells dug on their property.

Texas Environmental Almanac, Chapter 1, Water Quantity, Page 1

Please send questions, comments, or problems with this page to ltarver@mail.utexas.edu..