Sabine River Authority of Texas

Date: 6/29/99

To: Interested Parties

From: Environmental Services

RE: April 1999 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Report for April 1999. Water quality sampling was performed April 13 through April 15. Weather during April can be characterized warm and dry throughout most of the Basin. Toledo Bend received the most rain (7.11 inches) and the coastal area of the Basin received the least. Evaporation values were greater than rainfall at all three lakes. Due to failure of laboratory equipment values for ammonia, orthophosphate, total hardness and total alkalinity were not obtained.


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

All of the parameter's values seen in the Upper Basin sites are consistent with water of high quality. The temperature and dissolved oxygen profiles showed some signs the reservoir sites are beginning to thermally stratify with the onset of warmer weather. The sites LF3 and LT23D showed the strongest thermal stratification, both between four and five meters. The three sites on Lake Fork were very clear with secchi depths up to 1.88meters. This clarity will probably decrease in coming months when algal density will increase with warmer temperatures and higher light intensity. Fecal coliform bacteria numbers were low at most upper basin sites. SR21 had the highest numbers with 192 cfu/100mls which is just under the state stream standard for fecal coliform bacteria.



Lower Sabine Basin Including Toledo Bend to Morgan Bluff

Values measured during the April WQM were indicative of water with high quality and were within normal range for this time of year. Stations TB6N, TB6I, TB6M, and TB6L had low dissolved oxygen values, these value were below stream standard spring time dissolved oxygen criteria. These criteria were established to protect fish spawning. Station BA4 had an elevated fecal streptococcus value but a fecal coliform value in normal range. This combination indicates that fecal contamination is form animal sources. Station BA4 also had an elevated turbidity value. This value along with the elevated coliform value is most likely related to runoff. Dissolved Oxygen and temperature values at most Lake sites on Toledo Bend decreased with depth. However, these values do not demonstrate a firm stratification.


Tidal Section of the Sabine Basin below Morgan Bluff

Values for stations in the tidal portion of the Sabine Basin were also consistent with waters of high quality. No values measured in this area were outside of stream standard criteria. Despite the lack of rainfall all values for salinity were less than 1 ppt. This is most likely due to the amount of water being released form Toledo Bend.



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: