Physicochemical conditions and benthic macroinvertebrates were studied in Village Creek, a southeast Texas clean water stream. Physicochemical conditions varied seasonally, downstream and with discharge. A total of 143 taxa of macrobenthos were collected and the number at each station ranged from 44 to 98. Diversity was determined by Shannon's index (d). Station d values for individual collections ranged from zero to 4.50. Annual d values ranged from 3.21 to 4.93. The large number of taxa and high d values obtained in this unstable sand substrate environment may have been due to high discharge, carrying many taxa from small tributaries and other diverse habitats in the drainage basin. The concept of high diversity-high environmental stability was contradicted and high d values occurred during maximum discharge and stream scouring. Lowest d values occurred after return to near normal discharge conditions. The Village Creek drainage basin lies within the region of southeast Texas known as the Big Thicket. This area once stretched over 3.5 million acres (1,416,450 ha) and has great biological diversity. Species of the Appalachians, the coastal plains, open woodlands, and the everglades are found in this region (Correll 1971). The Congressional Act of October 1974! (Public Law 93-439) established the Big Thicket National Preserve and stated the purpose as follows: "in order to assure the preservation, conservation, and the protection of the natural, scenic, and recreational values of a significant portion of the Big Thicket area .. ." Village Creek, a natural stream, is one of the most essential streams included in the preserve and four of the eight preserve units are within its drainage basin. Little research has been done on Village Creek. Tatum and Commander (1971 ) conducted a preliminary water quality study in March and May, 1971. The present study involved the determination of physicochemical conditions and diversity of macrobenthos from six stations for an entire year. Results of this study will serve as baseline data 263 This content downloaded from 207.46.13.117 on Sun, 23 Oct 2016 04:32:06 UTC All use subject to http://about.jstor.org/terms on effects of basin development and increased recreational use in the preserve. STUDY AREA AND STATIONS. The Village Creek drainage basin is located in the east Texas counties of Hardin, Tyler, and Polk. The basin has an axial length of 125 km and an average width of 35.7 km. Village Creek flows southeasterly and drains an area of 2,883 km2 into the Neches River. Utilizing Horton's (1945) stream order classification system as modified by Strahler (1957), Village Creek is a 5th order drainage system. The formations exposed by the basin are of the Tertiary and Quaternary periods and range in age from Miocene to Recent. The substrate consists of sand with pockets of gravel, clay, and silt (Darton et al. 1937). The average gradient is 0.38 m/km.