To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for May 2003. Water quality sampling was performed May13th through May 15th. Recent weather in the Basin was warming with daytime high air temperatures from the high 70’s to the low 90’s at Lake Tawakoni and at Lake Fork. Toledo Bend Reservoir and Orange had daytime highs from the mid 80’s to the low 90’s. Lows were quite variable, ranging from 56 to 75 at Lake Tawakoni and from 56 to 72 at Lake Fork. Toledo Bend and Orange had lows ranging from the mid 60’s to low 80’s. The Upper Basin received 0.77 and 3.36 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. Lake Tawakoni recorded 0.2 of an inch and Lake Fork recorded 1.7 inches of rain in the week prior to the sample run. Toledo Bend and Orange recorded 0.32 and 0.73 inches respectively during the 28 days preceding the sample run. Deeper reservoir sites were thermally stratified.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the May sample run, most of the parameter’s values seen at the Upper Basin sites were consistent with water of high quality. LT23C, LT23D, LT23A and SR10 had over 100% saturation of dissolved oxygen indicating algal activity. LT23C and LT23D exceeded Chlorophyll a screening criteria confirming algal activity in Lake Tawakoni. SR14 exceeded the numeric criteria for the stream standards for E. coli. Surface water temperatures were between 21.1 and 24.8ºC at river and reservoir sites. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 21.1 and 21.2ºC respectively. Thermal Stratification was evident at deeper reservoir sites.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The May monthly sampling results were indicative of water of high quality at most sites. It had been greater than seven days since the area received a significant amount of rainfall. The level of Toledo Bend Reservoir was recorded at 170.77 feet with no discharge from the spillway or the generator at the time of sampling. Stratification was present at all the lake sites. Anoxic conditions were present at two mid-lake sites. Stations TB6N and TB6M both displayed low dissolved oxygen readings. These stations 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 TB8 also showed a chloride and sulfate results that were higher than normal.
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 It had been greater than seven days since the area received a significant amount of rainfall. Most sites in this section of the Basin showed some signs of stratification with slight oxygen differences throughout the water column. Surface salinities of 2 ppt were found at stations BB1 and SRT1. These stations also recorded salinities of 2 ppt at their deepest depths. 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, July 23, 2003