To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Summary for June 2001. Water quality sampling was performed June 12th through June 13th. The Upper Basin received 1.27 - 1.94 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 6.58 and 4.43 inches respectively during the 28 days preceding the sample run. Recent daytime high temperatures were in the 80's and 90's throughout the Basin and lows were mostly in the 60's and 70's. All sites on Toledo Bend Reservoir were thermally stratified and Lake Tawakoni and Lake Fork were stratified at deep-water sites and less so at shallower sites. All three reservoirs showed signs of algal bloom conditions.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the June sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. Two Lake Fork Reservoir sites exceeded standards for pH. High algal activity often causes a pH increase and data for percent saturation of dissolved oxygen indicates these two sites, and other Upper Basin reservoir sites, had high algal activity. At SR14, the bacteriological count exceeded standards and the nitrate/nitrite level exceeded screening criteria. Lake Fork reservoir had full thermal stratification near 9 meters at LF2. There was no specific depth of stratification at LF3 where temperature and dissolved oxygen gradually increased uniformly from bottom to surface. LF4 was stratified at about 10 meters. Lake Tawakoni was fully stratified near 12 meters at LT23A and weakly stratified between 3 and 4 meters at the two upper-lake sites.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
June WQM sampling results were indicative of water of high quality at most sites. Toledo Bend Reservoir was slightly below normal pool level at the time samples were taken. All stations sampled on the reservoir exhibited thermal stratification. Anoxic conditions were also observed at the deep-water stations. Stations TB6N, TB6, and SR2 had oxygen readings that were below stream standards. Stations TB6J, TB6K, and TB6H had pH values that were above stream standards, while stations BCC1 and SR2 had pH values below stream standards. The high pH values that were found at several lake sites were accompanied by high oxygen readings that point to an algal bloom on the reservoir at the time of sampling.
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. Salinity was only detected at Stations AB2 and CB1. A salinity reading of only 3 ppt was detected at a depth of 6.1 meters at Station CB1. Deep-water stations sampled were only slightly thermally stratified and did not show a definite saltwater wedge. Stations AB7 and CB4 had oxygen readings below stream standards. Stations SR1 and SRT2 had pH readings that were below stream standards.
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
Cynthia Darbonne, Lower Basin Field Office Coordinator
If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
Printed Tuesday, August 21, 2001