Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: may 2000 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for May 2000.  Water quality sampling was performed May 9 through May11.  Daytime high air temperatures during the seven days prior to the sampling dates were in the 70s and 80s in the Upper Basin and in the 80s in the Lower Basin.  Nighttime lows in the Upper Basin ranged from 50 to 71 degrees. Low temperatures in the Lower Basin ranged from 62 to 73 degrees.  The most recent rainfall event was recorded on May 4th after several other recent significant rain events.

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

For the May sample run, most of the water quality values seen at the Upper Basin sites were consistent with water of high quality. Water temperature and dissolved oxygen values at Lake Tawakoni were very similar throughout the water column with no significant thermal stratification.  LF2 on Lake Fork Reservoir was the only site that appeared to be thermally stratified.  It was weakly stratified between seven and eight meters.  LT23D on Lake Tawakoni was unusually muddy, possibly due to strong winds as recorded on field notes.  This site had a secchi depth of 0.17 m and turbidity of 80.1 NTU.  River sites were normal with the exception of elevated ammonia at SR14.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

May WQM sampling results were indicative of high water quality at most sites. The level of the reservoir was near pool level during sampling due to heavy rains the previous week. Profiles taken at deep-water stations on the reservoir exhibited thermal stratification with near anoxic conditions at the deepest depths. Station TB6N had fecal and strepococcus counts above stream standards. Station TB6N is sampled from a bayou that receives discharge from a wastewater treatment plant. Low oxygen readings were recorded at sites TB6, TB6I, and TB6M. These low levels of dissolved oxygen could be attributed to the decomposition of recently flooded vegetation. Station BA4 had higher sulfate and nitrite/nitrate levels compared to other stations sampled during this time. Station BA4 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. Heavy rains the week previous to sampling caused the river to have a flushing event. This accounts for above average flow and no discernible salinity readings at tidal stations. A salt-water wedge was not detected at the deepest profile taken nor was there any thermal stratification observed.



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