FRESHWATER INFLOW PLANNING IN TEXAS 

 Herbert Grubb 

 Texas Department of Water Resources, Austin, Texas 



The Texas bays and estuaries 

 are valuable public resources. 

 They provide habitat for fish, 

 birds, and other living organisms; 

 they contain important archaeolo- 

 gical and historic sites; and they 

 are scenic and recreational assets. 

 In addition, the bays and estuaries 

 attract and support business and 

 human uses; for example they have 

 been modified to provide shipping 

 lanes for Texas' marine commerce, 

 and are used for recreation by 

 thousands of visitors annually. 



Texas has 

 shoreline with 

 most of which 

 row strips of 

 lands . Behind 



almost 400 miles of 

 the Gulf of Mexico, 

 is bordered by nar- 

 sand or barrier is- 

 the islands are lo- 

 cated seven major estuarine systems 

 and several smaller estuarine areas. 

 They are fed by eleven major rivers, 

 ten with headwaters originating 

 within the State. These range from 

 the high precipitation drainage 

 basins of the northeast Texas coast 

 to the arid drainage basins of the 

 southwest Texas coast. Associated 

 with these drainage basins are ap- 

 proximately 2,100 square miles of 

 coastal environments, including 

 more than 1.5 million acres of open- 

 water bay surface area and approx- 

 imately 1.1 million acres of adja- 

 cent marshlands and tidal flats. 



Texas' estuaries are a source 

 of significant quantities of inputs 

 to the State's economy in the form 

 of navigational networks, a natural 

 source of treatment for nutritive 

 wastes, mineral and energy deposits, 

 fisheries, and recreation areas. 



For example, the total Texas harvest- 

 of estuarine-dependent seafoods by 

 commercial and sport fishermen aver- 

 aged about 110 million pounds per 

 year during the 5-year interval from 

 1972 to 1976 (i.e., ^20 million 

 lbs/year of fish and ^ 90 million 

 lbs/year of shellfish). Shipping 

 lanes traverse the entire Texas 

 coastal area, linking Texas' 33 

 ports, including the Brownsville 

 Corpus Christi-Houston-Galveston- 

 Beaumont-Port Arthur energy refining 

 and petrochemical production and 

 shipping complexes to world and 

 national markets. 



Significant proportions of the 

 crude oil and natural gas produced in 

 Texas and sold into national markets 

 are produced in the Texas coastal 

 area and off-shore of the coast. The 

 Texas coastal area also supports 

 major agricultural enterprises rang- 

 ing from tropical fruits and vege- 

 tables to food grains, livestock, and 

 timber. The Texas coastal area has 

 five Standard Metropolitan Statisti- 

 cal Areas (SMSA) in which about 3.8 

 million people or nearly 30 percent 

 of the population of Texas live and 

 work in a highly specialized, 

 technologically advanced industrial 

 society. These SMSAs are linked to 

 the Texas interior through trans- 

 portation and trade and are located 

 near the mouths of rivers which are 

 used throughout their extent as 

 sources of fresh water for municipal, 

 industrial, agricultural, mining, hy- 

 droelectric power, navigation, rec- 

 reation, and other purposes, includ- 

 ing disposal of treated waste ef- 

 fluent. All of these factors must be 



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