Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: july 2001 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for July 2001. Water quality sampling was performed July 10th through July 11th. The Upper Basin received 4.76 - 4.18 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 6.28 and 3.65 inches respectively during the 28 days preceding the sample run. Recent daytime high temperatures were in the 90's throughout the Basin and lows were in the 70's. Toledo Bend, Lake Fork, and Lake Tawakoni were all thermally stratified. Samples were taken at all sites for total and dissolved metals in water, and sediment samples were collected at selected sites. Data for metals will be made available at a later date pending completion of laboratory analyses.

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

For the July sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. Four Upper Basin sites had over 100% saturation of dissolved oxygen, indicating algal bloom conditions. At SR14, the bacteriological count exceeded stream standards. This site also exceeded the standard in June and SRA is exploring possible sources. Lake Fork Reservoir was thermally stratified but there was no specific break point at LF2. Temperature and dissolved oxygen gradually increased uniformly from bottom to surface. Lake Fork sites LF3 and LF4 had a distinct thermocline between five and six meters. The thermocline at LT23A, near the dam at Lake Tawakoni, was between six and seven meters. The upper-lake sites are shallower and were less strongly stratified.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

July 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. All stations sampled on the reservoir exhibited thermal stratification. Anoxic conditions were also observed at all lake stations at the deepest depths. Stations TB6N, TB6, TNH01, and TB6M had oxygen readings that were below stream standards. Stations TB6J, and TB6K had pH values that were above stream standards. The high pH values that were found at TB6J and TB6K were accompanied by high oxygen readings that point to an algal bloom their area of 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 detected at the surface only at Station BB1. Station SRT1 had a salinity reading of 6 ppt at a depth of 10.1 meters, but was <1 ppt at the surface. Deep-water stations sampled were only slightly thermally stratified and only Station SRT1 showed a saltwater wedge. Stations AB7 and CB4 had oxygen readings below stream standards. Station CB1 had a fecal coliform result that was above 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:

 

       Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
903-878-2420 (sraubfo@yahoo.com)

       Lower and Tidal Sabine Basin
Cynthia Darbonne, Lower Basin Field Office Coordinator
409-746-3284 (darbonne@sra.dst.tx.us)

       If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
409-746-2192 (mhall@sra.dst.tx.us)

 

Printed Wednesday, September 26, 2001