8 TIMBER OF THE EDWARDS PLATEAU OF TEXAS. 



was adopted after the Revolution, whole regions were reduced from 

 fertile farms and vine^-ards to barren wastes, and that within recent 

 years the policy has been pursued of reclaiming these lands by rees- 

 tablishing the forest covering, though at an enormous expense. Some 

 of the same conditions and possibilities exist in the region which we 

 are to consider in this bulletin. 



THE EDWARDS PLATEAU AS A SOURCE OF WATER SUPPLY. 



The water supply furnished by the rainfall of the Edwards Plateau 

 is important not only for its own area, but especially for the coast 

 plain lying to the southeast and south of it. The plateau is a vast 

 receiving or catchment area for water, the major portion of which is 

 given up to the plain, either immediately, in the form of destructive 

 floods, or gradually, in the form of steadily flowing or intermittent 

 streams or artesian water. The great Rio Grande Plain from the 

 Colorado to the Rio Grande is a level, irrigable area, whose richness 

 of soil and mildness of climate mark it as one of the endlessly 

 resourceful and productive regions of the country, if only it can get 

 water enough. Its relation to the interior highlands of the Edwards 

 Plateau (see relief map. frontispiece) is therefore one of extreme 

 importance. While no pretension is here made to such a treatment 

 of this subject as would fall to a hydrographic engineer, it is never- 

 theless possible to point out how the forest growth of the plateau 

 affects the supply of water, and how through its agency the suj^ply 

 may be improved. 



DESCRIPTION OF THE REGION. 



The Edwards Plateau is the southernmost province of the Great 

 Plains region, which comes to an abrupt termination in the escarp- 

 ment known as the Bal cones escarpment — a line of clifis formed by a 

 gigantic downthrow or faulting. These cliff's constitute the front 

 line of the hill region one sees so clearly marked from Austin to San 

 Antonio, and thence westward to Del Rio. Strictly speaking, the 

 plateau is arbitrarily bounded by the canyon of the Pecos River on 

 the west, and on the northeast by the escarpment overlooking the 

 central denuded area (the Granite country, etc.): but in this bulletin 

 the discussion includes as well all of the adjacent area of the Central 

 Denuded Region and the rougher eroded and timbered parts of the 

 Grand Prairie from the Colorado northward, since they have the same 

 relation to water supply as the more limited plateau proper. 



According to Hill-' the Edwards Plateau proper includes all of 

 Crockett. Valverde. Edwards, Sutton, Schleicher. Kimble. Kerr, 



''^Hill and Yaughan. The Edwards Plateau and Rio Grande Plain (p. 205), 

 Eighteenth Ann. Rpt. U. S. Geological Survey, Part II. 



