Intensive Survey of Dickinson Bayou Above Tidal. Segment 1104, May 6-7, 1985.

An intensive survey of Dickinson Bayou above tidal (Segment 1104) was conducted May 6-7, 1985. This segment is located in Galveston County, and its length is 11.7 Km (7.3 mi). Major land usage is for irrigated crop production (rice) and pastureland. Hydrological modifications consist of irrigation supply canals and return flow ditches. This survey was not conducted during low-flow, steady-state conditions because irrigation tailwaters were entering the bayou during the study period. Nine mainstream stations, five tributaries, one wastewater discharge, one irrigation return flow and one irrigation supply canal were sampled during this survey. Several individual dissolved oxygen measurements were below the 5.0 mg/L segment criterion. Ortho- and total phosphorus concentrations were elevated throughout most of the segment. Inorganic nitrogen and organic constituents were elevated in the lower half of the bayou. Mainstream flow rates rangeed from 1.36 ft3/s (0.039 m3/s) at the upstream station to 7.36 ft3/s (0.209 m3/s) at the downstream station. Tributary inflow accounted for 5.97 ft3/s (0.169 m3/s). Overall average width of the segment was 12.8 ft (3.9 m), and the range was from 4.9 ft (1.5 m) to 36.1 ft (11.0m). Stream velocities were relatively slow, ranging from 0.477 ft/s (0.145 m/s) to 0.282 ft/s (0.086 m/s). Fecal coliform counts were all well below the segment criterion of 2000/100 mL).