To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Summary for April 2001. Water quality sampling was performed April 10th through April 11th. The Upper Basin received 2.11-2.53 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 3.95 and 4.77 inches respectively during the 28 days preceding the sample run. Recent daytime temperatures were in the 80's throughout the Basin and lows were mostly in the upper 60's and lower 70's. Temperature and dissolved oxygen profiles indicate Upper Basin reservoirs are beginning thermal stratification and Toledo Bend Reservoir is vertically stratified.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the April sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. Bacteriological counts were within standards at all Upper Basin sites. LT23D at Lake Tawakoni had elevated nitrate/nitrite and LF3 and LF4 at Lake Fork had elevated orthophosphorus. Stream standards do not exist for nitrogen and phosphorus compounds so statewide screening criteria are used for comparison. Lake Fork and Lake Tawakoni reservoirs were partially stratified with mild dissolved oxygen and temperature gradients.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
April 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 profiles exhibited a sharp decrease of oxygen levels at approximately 7 to 10 meters with near anoxic conditions at the bottom. Station TB6S 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 tidal site. Deep-water stations sampled did exhibit thermal stratification but did not show a salt-water wedge. Stations AB7 and CB4 had oxygen readings below stream standards. Higher ammonia levels were recorded at Stations CB4, AB7 and CB1 compared to other sites sampled.
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:
Ø Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
Ø Lower and Tidal Sabine Basin
Cynthia Darbonne, Lower Basin Field Office Coordinator
If above are unavailable
Miles Hall, Environmental Services Assistant Division Manager
Printed Wednesday, June 06, 2001