Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: February 2000 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for February 2000. Water quality sampling was performed February 15 through February 17. Daytime high air temperatures during the seven days prior to the sampling dates were mostly in the 60s and 70s in the Upper Basin and in the 70s in the Lower Basin. Nighttime lows in the Upper Basin were in the 30s and 40s. Low temperatures in the Lower Basin have been mostly in the 50s and 60s. Dry conditions prevailed throughout the Basin and water quality was not affected by recent runoff events. The Lower Basin received from 0.16 inches of rainfall at Toledo Bend, to 0.38 inches in Orange, nine days prior to the sample run. The most recent precipitation upstream of Toledo Bend Reservoir was recorded 18 days prior to the sample run on January 28 when most of the in the Upper Basin received about an inch of sleet and snow.

Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni

For the February sample run, most of the water quality values seen at the Upper Basin sites were consistent with water of high quality. The most recent precipitation was 1-2 inches of sleet and snow over most of the Upper Basin 18 days prior to sampling. Water temperature and dissolved oxygen profiles were similar from surface to bottom at Lake Tawakoni and Lake Fork indicating complete mixing, with no significant thermal stratification. Several sites on the river and one reservoir site (LF3) had dissolved oxygen values in excess of 100%, likely indicating algal activity is still fairly high. However, dissolved oxygen values in excess of 100% can sometimes be due to rapid warming of a water body. High chlorophyll a levels were seen at LT23A, LF7, and LF2. Mild temperatures were present during the sampling event but several days of sub-freezing weather with icy precipitation were encountered during the last week of January. Ammonia was slightly over screening criteria at SR14 and chlorides were at the upper limit of stream standards at SR14 and above stream standards at SR11.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

February WQM sampling results were indicative of high water quality at most sites. Profiles taken at deep-water stations on the reservoir exhibited thermal stratification. Higher conductivity readings, total alkalinity, and chloride levels were observed at Station TB6N. TB6N is located downstream from a municipal wastewater treatment plant. Higher conductivity readings and sulfate levels were observed at Station BA4. Station BA4 is sampled from a bayou that receives discharge from a paper mill.

Tidal Section of the Sabine Basin below Morgan Bluff

Stations sampled in the tidal portion of the Sabine Basin had values that were consistent with water of high quality. All values measured were within stream standards criteria. Salinity was detected at all four tidal stations: SRT1, SRT2, BB1 and ICW1. The greatest salinity readings were observed at the deepest depths at Stations SRT1 and SRT2. A salt-water wedge was not observed at tidal sites; profile readings taken were well mixed.


This Report and additional data for these monitoring stations are available on our World Wide Web site ( If you have any questions or comments concerning this report, please contact:


      Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
903-878-2420 (

      Lower and Tidal Sabine Basin
Cynthia Darbonne, Lower Basin Field Office Coordinator
409-746-3284 (

      If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
409-746-3284 (



Printed Tuesday, September 12, 2000