To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for August 2003. Water quality sampling was performed August 12th through August 14th. Recent weather in the basin was hot with daytime high air temperatures from the low 90’s to the 100’s at Lake Tawakoni and at Lake Fork. Toledo Bend Reservoir and Orange had daytime highs from the upper 70’s to the upper 90’s. Lows ranged from 72 to 77 at Lake Tawakoni and from 71 to 76 at Lake Fork. Toledo Bend and Orange had lows ranging from the upper 60’s to the upper 70’s. The Upper Basin received 2.1 and 1.37 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork, respectively. Lake Tawakoni recorded 0.31 inches and Lake Fork recorded 0.5 inches of rain in the week prior to the sample run. Toledo Bend and Orange recorded 3.44 and 3.25 inches, respectively, during the 28 days preceding the sample run. Reservoir sites were thermally stratified.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the August sample run, most of the parameter values seen at the Upper Basin sites were consistent with water of high quality. LT23D did not meet the numeric criteria for the stream standards for dissolved oxygen. SR14, SR11 and SR10 exceeded the numeric criteria for the stream standards for E. coli. Surface water temperatures were between 24.4 and 27.8ºC at river and reservoir sites. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 27.8 and 27.2ºC, respectively. Thermal stratification was evident at reservoir sites.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The August monthly sampling results were indicative of water of high quality at most sites. The area received a significant amount of rainfall during the sample run. During the day prior to the sample run and the two days when sampling occurred, the lake area received just over three inches of rain. The level of Toledo Bend Reservoir was recorded at 169.08 feet with no discharge from the spillway or the generator at the time of sampling. Stratification was present, at least slightly, at all the lake sites. Anoxic conditions were only present at the deepest stations. Stations TB6N, TB6M, TB6L, TB6K, TB8 and TB6 displayed low dissolved oxygen readings. Stations TB6N, TB6M, TB6L, and TB6K are located in headwater areas of small coves and do not represent the conditions of the main body of the reservoir. Stations in the main body of the reservoir showed no impact from the water quality conditions indicated in the backwater areas. Station TB6 is located in the discharge canal below the generator and low oxygen readings are not uncommon the generator is not operating,. Sites further down on the river showed no affects of the oxygen readings in the canal. Station TB6N also had a high bacterial reading, but again, the main lake stations showed no affect from this result.
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 heavy amount of rainfall just before sampling. In the two days prior to sampling the area received close to three inches of rain. Most sites in this section of the Basin showed some signs of stratification with slight oxygen differences throughout the water column. No anoxic conditions were found at any of the tidal stations. Surface salinities were found at all but the northern most station. The surface salinities ranged from 4 ppt at station ICW1 to 6 ppt at station BB1. The highest salinity, 14 ppt and 15 ppt, were found at stations SRT2 and SRT1 at their deepest depths. Station SRT1 had a bacterial count above the stream standard, but it could have been caused by runoff from the heavy rains the area received. There were also dredging barges located in this section of the lower river while sampling occurred.
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
Terry Wilson, Upper Basin Field Office Coordinator
Ø Lower and Tidal Sabine Basin
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are unavailable
John Payne, Special Projects Administrator
Miles Hall, Resource Management/ Project Development Division Manager
Printed Tuesday, October 07, 2003