The U.S. Geological Survey's investigations of the water resources of Texas are conducted in cooperation with the Texas Water Development Board, river authorities, cities, counties, U.S. Army Corps of Engineers, Bureau of Reclamation, International Boundary and Water Commission, and others.

Investigations are under the general direction of R.O. Hawkinson, District Chief, Texas District. The address of the Texas District office is 8011 Cameron Road, Austin, TX 78754.

As of September 30, 1993, the surface-water data-collection network of Texas (table 1 at end of the report) included 342 continuous-recording streamflow stations (D), 36 gage-height record only stations (G), 18 crest-stage partial-record stations (C), 62 floodhydrograph partial-record stations (H), 28 low-flow partial-record stations (L), 2 continuous-recording temperature stations (Ml), 12 continuous-recording temperature and conductivity stations (M2), 5 continuous-recording temperature, conductivity, and dissolved oxygen stations (M3), 20 continuous-recording temperature, conductivity, dissolved oxygen, and pH stations (M4), 23 daily chemical-quality stations (Q), 158 periodic chemical-quality stations (Qp), 20 lake surveys for water quality (Qs), and 75 continuous or daily reservoir-content stations (R). Plate 1 shows the location of the stations listed in table 1.

Table 1 shows the station number and name, latitude and longitude, type of station, and the office principally responsible for collection of the data. An 8-digit permanent numerical designation for all gaging stations has been adopted on a nationwide basis; stations are numbered and listed in downstream order. In the downstream direction along the main stem, all stations on a tributary entering between two main-stem stations are listed between them. A similar order is followed in listing stations by first rank, second rank, and other ranks of tributaries. The rank of any tributary with respect to the stream to which it is an immediate tributary is indicated by an indention in the table. Each indention represents one rank. This downstream order and system of indention shows which gaging stations are on tributaries between any two stations on a main stem and the rank of the tributary on which each gaging station is situated.