To: Interested Parties

From: Water Resources Branch

RE: July 2004 monthly Water Quality Report

This is the Sabine River Authority Water Quality Report for July 2004. Water quality sampling was performed July 12th through July 15th. Recent weather (previous seven days) in the Sabine River Basin was warm, with daytime high air temperatures from the upper 80s to the mid 90s at Lake Tawakoni and at Lake Fork. Toledo Bend Reservoir and Orange had daytime highs from the mid 80s to the mid 90s. Lows ranged from the low 70s to the mid 70s at Lake Tawakoni and at Lake Fork. Toledo Bend and Orange had lows ranging from the upper 60s to the mid 70s. Lake Tawakoni, Lake Fork, and Toledo Bend were thermally stratified. During the 28 days prior to the July sample run, the Upper Basin received 2.53 and 2.76 inches of rainfall as recorded at Lake Tawakoni and Lake Fork, respectively. During the same time period, Toledo Bend and Orange received 10.30 and 10.35 inches, respectively. The week prior to the sample run, Lake Tawakoni and Lake Fork received no rain. The Lower Basin received a trace.

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

For the July sample run, most water quality parameter measurements at Upper Basin sites were consistent with water of high quality. LT23A and LT23C did not meet the Texas Surface Water Quality Stream Standards (stream standards) numeric criteria for pH. These two sites along with LT23D, LF2, LF3, LF4, SR19 and SR10 also had high levels of dissolved oxygen with greater than 100 percent dissolved oxygen saturation. Chlorophyll a values at LT23A, LT23D and LT23C were above reservoir screening levels. Elevated chlorophyll a levels and high dissolved oxygen with greater than 100 percent dissolved oxygen saturation indicates algal bloom conditions. These conditions may also lead to elevated pH levels. Orthophosphate values at LT23D were above screening levels. No sites exceeded the numeric criteria for the stream standards for E. coli.


Lower Sabine Basin Including Toledo Bend to Morgan Bluff

The July monthly sampling results were indicative of water of high quality at most sites. The area received trace amounts of rainfall during the week prior to sampling. The level of Toledo Bend Reservoir was recorded at 172.14 feet with no discharge from the spillway or the generators at the time of sampling. Stratification was found at all of the lake stations, with pH and dissolved oxygen differences throughout the water column. Anoxic conditions were found at the deepest depths at several stations. Several Toledo Bend sites had greater than 100% saturation of dissolved oxygen and related elevated pH. These factors together usually indicate an algal bloom. The pH at TB6K exceeded stream standards. Dissolved oxygen at station SR2 was below the stream standard.

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. The tidal stations received trace amounts of rainfall during the week prior to the sample run. Most sites in this section of the Basin were slightly stratified, but no anoxic conditions were found at any tidal station. None of the stations recorded salinity values that were greater than 1 ppt. All the parameters measured in the tidal section of the Basin were within the stream standard 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 Friday, December 17, 2004 09:17