To: Interested Parties

From: Water Resources Branch

RE: June 2006 monthly Water Quality Report

This is the Sabine River Authority Water Quality Report for June 2006. Water quality sampling was performed June 5th through June 8th. Recent weather (previous seven days) in the Sabine River Basin was warm, with daytime highs in the mid 80s to low 90s at Lake Tawakoni and at Lake Fork. Toledo Bend Reservoir and Orange had daytime highs from the upper 70s to the low 90s. Lows ranged from the mid 60s to low 70s at Lake Tawakoni and at Lake Fork. Toledo Bend and Orange had lows ranging from the low 60s to the low 70s. During the 28 days prior to the sample run, the Upper Basin received 0.8 and 0.99 inches of rainfall as recorded at Lake Tawakoni and at Lake Fork, respectively. Lake Tawakoni received 0.72 inches of rain and Lake Fork received 0.58 inches of rain the week preceding the sample run. Toledo Bend and Orange received 1.13 and 5.67 inches of precipitation during the 28 days prior to the sample run.

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

Water quality parameter measurements at the Upper Basin sites were consistent with water of high quality for the June sample run. The level of Lake Fork was recorded at 400.34 feet msl with 18 cfs releases and the level of Lake Tawakoni was recorded at 431.33 feet msl with 6 cfs releases at the time of sampling. Stations SR22 and SR21 fell below the stream standards numeric criteria for dissolved oxygen. Lower dissolved oxygen levels may occur in the early morning hours with low stream flows, warmer temperatures and with the decomposition of organic material. Stations LT23C, LF3 and LF4 exceeded 100 percent saturation for dissolved oxygen. Stations LT23A, LF4, SR22, and SR19 exceeded the recommended screening criteria for chlorophyll a. High chlorophyll a levels in conjunction with dissolved oxygen saturation values exceeding 100% often indicate algal bloom conditions. Algal blooms normally occur in the warmer summer months and form when nutrients in waters are exposed to high temperatures, sunlight, and calm water conditions. Station LT23D slightly exceeded the recommended screening criteria for ortho-phosphate. Station SR11 exceeded the stream standards for sulfate. All reservoir and stream sites were within the stream standards numeric criteria for E. coli.


Lower Sabine Basin Including Toledo Bend to Morgan Bluff

The June monthly sampling results were indicative of water of high quality at most sites. The area received 1.51 inches of rainfall during sampling. The level of Toledo Bend Reservoir was recorded at 167.71 feet with 204 cfs discharge at the time of sampling. Most reservoir stations were stratified with dissolved oxygen and temperature differences throughout the water column. No anoxic conditions were found at any lake station. The stream standards numeric criteria for pH was exceeded at station TB6R, and dissolved oxygen percent saturation results over 105% were recorded at stations TB6LN, TB6R, and TB6A. An algal bloom at each of these open water sites is a possible cause of the high percent saturation results. Algal blooms normally occur in the warmer summer months and form when nutrients in waters are exposed to high temperatures, sunlight, and calm water conditions.

Tidal Section of the Sabine Basin below Morgan Bluff

Most sites sampled in the tidal portion of the Sabine Basin had values that are consistent with water of high quality. Tidal stations received 0.13 inches of rainfall in the seven days prior to the sample event. Surface salinities were found at all but the two most northern of the tidal stations. The largest salinity value, 12 ppt, was found at the deepest depths of stations SRT1C, SRT1B, and SRT1. All parameters measured fell within the stream standards numeric criteria.

 

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
Terry Wilson, Upper Basin Field Office Coordinator
903-878-2420 (twilson@sra.dst.tx.us)

      Lower and Tidal Sabine Basin
Jerry Wiegreffe, Lower Basin Field Office Coordinator
409-746-3284 (jwiegreffe@sra.dst.tx.us)

      If above are unavailable
John Payne, Special Projects Administrator
409-746-2192 (jpayne@sra.dst.tx.us)
or
Miles Hall, Resource Management/ Project Development Division Manager
409-746-2192 (mhall@sra.dst.tx.us)

 

Printed Wednesday, September 27, 2006 at 13:14