Sabine River Authority of Texas

To: Interested Parties

From: Environmental Services division

RE: november 1999 Water Quality Monitoring Report

This is the Sabine River Authority Water Quality Summary for November 1999. Water quality sampling was performed November 2 through November 4. Daytime high air temperatures during the seven days prior to the sampling dates were mostly in the low 80's . However, a cool front and about an inch of rain two days prior to the sample run dropped maximum temperatures to the low 60ís. Nighttime lows after the cool front were around 50 degrees. Dry weather prevailed during the twenty days since the October sample run. The 1inch rainfall two days prior to this sample run changed flows only slightly at most USGS gauging stations, but flow at station 0802900 at Hwy149 below Longview increased from 89 cfs to 208 cfs.

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

For the November sample run, most of the water quality values seen at the Upper Basin sites were consistent with water of high quality. The most recent rainfall was a 1 inch rain two days prior to sampling. Lake Tawakoni recorded 2.12 inches of rain since October 1st (33 days previous) and Lake Fork recorded 1.91 inches during the same period. Water temperature and dissolved oxygen profiles were similar from surface to bottom at Lake Tawakoni and Lake Fork indicating complete mixing, with no thermal stratification. Strong winds and cooler temperatures during the two days prior to sampling probably caused the complete lake turnover. Water quality parameters were within stream standards at all Upper Basin reservoir sites and only one Upper Basin river site exceeded standards for one parameter. SR17 exceeded the maximum pH (8.5) with a pH of 8.96. SR11 and SR10 had elevated conductivity, total alkalinity, and total hardness. These values may elevate during low flow conditions, but these values are still higher than normal for these two sites. The Secchi disk visibility (water clarity) was also higher than normal and turbidity was low, indicating few suspended solids.

Lower Sabine Basin Including Toledo Bend to Morgan Bluff

Samples taken during the November WQM sampling were indicative of high quality water at most sites. Toledo Bend Reservoir sites exhibited conditions associated with a late fall algae bloom: deep Secchi disk depths and supersaturated oxygen levels. Deep-water stations of the reservoir were well mixed, having no thermal stratification. Station TB6N, located below a municipal wastewater treatment plant, had higher conductivity, chloride, sulfate, and fecal coliform results. Station TB6N also had very low dissolved oxygen levels comparable to other sites. Station BA4, located below a paper mill, had higher conductivity readings. Station BCC1 had elevated fecal coliform levels, which can be contributed to rainfall less than a week previous to sampling event.

Tidal Section of the Sabine Basin below Morgan Bluff

Water samples indicative of high quality were collected from the tidal portion of the Sabine Basin. A definite salt-water wedge was detected as far north as the I10 Bridge. An outgoing tide was observed at the time of sampling. Deep-water profiles were well mixed and exhibited no thermal stratification.

 

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:

 

Printed Friday, June 09, 2000