Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: june 2000 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for June 2000. Water quality sampling was performed June 13 through June15. Daytime high air temperatures during the seven days prior to the sampling dates were in the 80s in the Upper Basin and in the 80s and 90s in the Lower Basin. Nighttime lows in the Upper Basin ranged from 59 to 72 degrees. Low temperatures in the Lower Basin were in the 60s and 70s. Several recent rainfall events were recorded prior to and during the sample run.

Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni

For the June sample run, most of the water quality values seen at the Upper Basin sites were consistent with water of high quality. LF2 on Lake Fork Reservoir was the only site that appeared to be thermally stratified. However, all of the reservoir sites had a significant dissolved oxygen gradient with low D.O. near the bottom and gradual increase toward the surface. Several sites had over 100% saturation of oxygen, indicating high algal activity. LT23C and LT23D were 141% and 131% saturated respectively. Ammonia and orthophosphates exceeded nutrient screening criteria at LF7. SR21 on the river main stem had elevated conductivity, ammonia, and chloride. Elevated conductivity and chloride values at this site are usually caused by rainwater runoff from natural salt deposits in the Grand Saline Creek watershed upstream.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

June WQM sampling results were indicative of high water quality at most sites. Toledo Bend Reservoir was near pool level during this sampling event. Profiles taken at deep-water stations on the reservoir exhibited thermal stratification with near-anoxic conditions near the bottom. Stations TB6N, TB6I, TB6M, and TB6L had oxygen readings below stream standards. These stations are predominantly shallow sites with large amounts of both emergent and floating aquatic vegetation. Station BA4 had higher sulfate, nitrite/nitrate levels, and conductivity readings compared to other stations. This station is sampled from a bayou that receives discharge from a paper mill.

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. All values measured were within stream standards criteria. Salinity was detected at all tidal stations. The greatest salinity measured occurred at SRT2 with a reading of 12 ppt at 9.2 meters depth. A salt-water wedge was also detected at tidal stations.



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
409-746-3284 (



Printed Monday, September 18, 2000