To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Summary for April 2002. Water quality sampling was performed April 16th through April 18th. Recent weather was mild. The Upper Basin received 5.93 – 5.94 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 4.73 and 4.52 inches respectively during the 28 days preceding the sample run. At Lake Tawakoni, Lake Fork, and Toledo Bend Reservoir, daytime high air temperatures during the most recent seven days prior to the sample run were in the 70’s and 80’s and nighttime lows in the 50’s and 60’s. Orange weather was a little warmer with highs in the 80’s and lows in the 60’s and 70’s. Reservoir profiles indicated incomplete mixing of the water column as evidenced by gradual decrease in temperature and dissolved oxygen from surface to bottom. Many of the river sites were influenced by flow from reservoir releases.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the April sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. The most recent rain was 0.76 inch at Lake Tawakoni and 0.1 inch at Lake Fork three days prior to the first sample date. Surface water temperatures were between 15 and 21C. E. coli approached the single-grab stream standard limit at BS18. Nitrate/nitrite exceeded screening guidelines at LT23D and LT23A. LT23D also had high turbidity. Surface temperatures at Lake Fork and Lake Tawakoni were about three degrees warmer than bottom temperatures. The temperature gradient was minor and only LF3 had a significant thermocline at seven meters.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The April monthly sampling results were indicative of water of high quality at most sites. The last significant rainfall occurred about eight days prier to the sampling event. The level of Toledo Bend Reservoir was recorded at 172.5 feet with some discharge through all eleven of the spillway gates at the time of sampling. One unit was running at the powerhouse during the sample event. All lake sites were thermally stratified. The deep-water stations did show some low oxygen levels at the deepest depths, but no anoxic conditions were found. All field readings taken were within the stream standards for this section of the Basin.
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. All sites showed some slight differences in the oxygen levels as the depths increased, but all sites were well mixed with respect to temperature. The only salinity was recorded at station BB1, with a value of 2 ppt at the surface and at a depth of 5.1 meters. The bacterial levels at sites SRT1 and SRT2 were above the stream standard.
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:
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 Thursday, June 20, 2002