Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: may 2001 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for May 2001. Water quality sampling was performed May 8th through May 10th. The Upper Basin received 1.59 - 1.86 inches of rainfall during the 28days since the previous sample run, as recorded at Lake Tawakoni and Lake Fork respectively. Toledo Bend and Orange received 1.63 and 2.66 inches respectively during the 28 days preceding the sample run. Daytime high temperatures were in the 80's throughout the Basin and lows were mostly in the mid 60's. Temperature and dissolved oxygen profiles indicate the reservoirs are beginning summertime thermal stratification conditions.

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. Bacteriological counts exceeded standards at all Upper Basin river sites. This isn't unusual with recent rainfall runoff, as was the case this month. Fecal streptococcus was also elevated at these sites indicating sources were probably natural. The three Lake Fork sites had over 100% saturation of dissolved oxygen and elevated chlorophyll a at two of these sites as evidence of high algal photosynthetic activity. Lake Fork reservoir had weak thermal stratification at LF2 near the dam and strong stratification at LF3 and LF4. Lake Tawakoni was weakly stratified at LT23A near the dam and not thermally stratified at the two upper-lake sites.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

May WQM sampling results were indicative of water of high quality at most sites. Toledo Bend Reservoir was slightly below pool level at the time samples were taken. Deep-water stations sampled on the reservoir exhibited thermal stratification. Deep-water stations exhibited near-anoxic conditions at the bottom. Station TNH01 had a level of fecal coliform above stream standards. Station TB6M had an oxygen reading that was below stream standards.

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 not detected at any site except Station SRT1. A salinity reading of only 5 ppt was detected at a depth of 10.4 meters at Station SRT1. Deep-water stations sampled did exhibit thermal stratification but did not show a definite salt-water wedge. Stations AB7 and CB4 had oxygen readings below stream standards.



This Report and additional data for these monitoring stations are available on our World Wide Web site ( If you have any questions or comments concerning this report, please contact:


       Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
903-878-2420 (

       Lower and Tidal Sabine Basin
Cynthia Darbonne, Lower Basin Field Office Coordinator
409-746-3284 (

       If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
409-746-2192 (


Printed Thursday, July 26, 2001