To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for October 2002. Water quality sampling was performed October 8th through October 10th. Recent weather in the Basin was mild with daytime high air temperatures in the low 90s at Lake Tawakoni and Lake Fork, and ranging from the upper 70s to the low 90s at Toledo Bend Reservoir and Orange. Lows were mostly in the 60s and 70s at night throughout the Basin. The Upper Basin received 1.78 – 1.27 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. Toledo Bend and Orange received 5.29 and 9.50 inches respectively during the 28 days preceding the sample run. Reservoir profiles indicated a mixed water column in Lake Tawakoni and weak stratification in Lake Fork and Toledo Bend reservoirs.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the October sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. The most recent significant rain was 0.44 inches at Lake Tawakoni and 0.94 inches at Lake Fork one day prior to the sample date. Surface water temperatures were between 19.4 and 24.1ºC at river and reservoir sites. LF20, SR22, SR19, SR17, SR15, and SR14 exceeded the numeric criteria for the stream standards for E. coli. A leaking wastewater main was discovered and repaired as a result of unusually elevated E. coli values seen at SR15 and SR14. This repair was noted in the September 2002 report. Recent rainfall probably accounts for elevated E. coli values at other sites. Chlorides at SR11 were slightly elevated above screening levels. The stream standards for chlorides are for annual averages. Screening levels have been established to be used as a guide for monthly values. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 23.9 and 23.9ºC respectively. Bottom temperatures at the same sites were 23.9 and 18.5ºC respectively. Lake Tawakoni was mixed, but Lake Fork is still weakly stratified at the deepest site near the dam.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The October monthly sampling results were indicative of water of high quality at most sites. The area received a significant amount of rainfall on the first day of the sample run. The level of Toledo Bend Reservoir was recorded at 166 feet with no discharge from the spillway gates or the generator at the time of sampling. All lake sites showed some stratification, but only the deepwater stations showed anoxic conditions at the deepest depths. Stations TB6N, TB8, TB6J, and TB6M had oxygen levels that were below the stream standard. These stations are located in headwater areas of small coves and do not represent the conditions of the main body of the reservoir. Stations located in the main body of the reservoir showed no impact from the water quality conditions indicated in the backwater areas. Station BA4 had a sulfate result that was above the stream standard. Chloride results were found to be above the stream standard at station TN6N, and the E. coli level at TB6N was also above the stream standard.
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 at most sites. The area received heavy rains the week around the sample event. Around four inches of rain was recorded for the two days prior to and the day of sampling. Similar temperatures were found throughout the water column at most sites, but the oxygen levels showed some stratification. No anoxic conditions were found. Surface salinities were found at all but one of the tidal stations with station ICW1 recording 3 ppt, BB1 having 6 ppt and SRT1 with 4 ppt. The highest salinity value was found at station SRT1 with 13 ppt at a depth of 9.6 meters. Station BB1 also recorded a dissolved oxygen result that was lower than the stream standard, and bacterial results were high at all of the tidal stations due to the large amounts of rainfall the area received.
This Report and additional data for these monitoring stations are available on our World Wide Web site (www.sra.dst.tx.us). If you have any questions or comments concerning this report, please contact:
Ø Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
Ø Lower and Tidal Sabine Basin
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
Printed Friday, January 17, 2003