To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for March 2003. Water quality sampling was performed March 11th through March 13th. Recent weather in the Basin was cool with daytime high air temperatures from the 40’s to the 70’s at Lake Tawakoni, and the 50’s to the 70’s at Lake Fork, Toledo Bend Reservoir and in Orange. Lows were quite variable, ranging from 26 to 42 at Lake Tawakoni and 30’s and 40’s at Lake Fork, 40’s and 50’s at Toledo Bend and Orange. The Upper Basin received 4.80 and 3.33 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. All but a few 100ths of an inch were more than seven days prior to the sample run. Toledo Bend and Orange recorded 7.43 and 8.41 inches respectively during the 28 days preceding the sample run. Reservoir profiles indicated onset of thermal stratification but very weak, with one or two degrees of difference in temperature from surface to bottom.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the March sample run, most of the parameter’s values seen at the Upper Basin sites were consistent with water of high quality. Lake Tawakoni and Lake Fork recorded only a few hundredths of an inch of rainfall during the seven days prior to sampling. All six reservoir sites on Lake Tawakoni and Lake Fork had over 100% saturation of dissolved oxygen, indicating possible high algal activity. LT23D and LT23A exceeded screening guidelines for nitrate/nitrite. All Upper Basin sites were within the numeric criteria for the stream standards for E. coli. Surface water temperatures were between 9.28 and 15.2ºC at river and reservoir sites. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 9.28 and 10.1ºC respectively. Bottom temperatures at the same sites were 1-2 degrees cooler than their surface temperatures, indicating the onset of weak thermal stratification.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The March monthly sampling results were indicative of water of high quality at most sites. The area received rainfall on the second day of sampling, but the last heavy rainfall was seven days prior to the sample run. The level of Toledo Bend Reservoir was recorded at 172.0 feet with seven gates discharging from the spillway and the generator was operating at the time of sampling. All lake sites were beginning to become stratified, which could be seen in the temperature and oxygen readings. Station TB6A had a bacterial result above the stream standard. This reading is most likely a result of the rainfall in the area while sampling. The station was also not sampled in its normal location because of the rough conditions on the lake. The samples were taken from the embankment above the generator.
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 a significant amount of rainfall seven days prior to the sample event. Most sites in this section of the Basin showed some signs of stratification with slight oxygen differences throughout the water column. No salinities were found at any of the tidal stations. All results from the tidal stations were within the stream standards for this section of the Basin.
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, Resource Management/ Project Development Division Manager
Printed Wednesday, June 04, 2003