To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for December 2002. Water quality sampling was performed December 10th through December 12th. Recent weather in the Basin was cool with daytime high air temperatures from the 40’s to the 50’s at Lake Tawakoni and Lake Fork, and ranging from 40’s to the 60’s at Toledo Bend Reservoir and Orange. Lows were mostly in the 20’s and 30’s at Lake Tawakoni and Lake Fork, 20’s through 40’s at Toledo Bend, and 30’s through 40’s in Orange. The Upper Basin received 3.04 – 2.14 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. All but a few 100ths of an inch was during the previous seven days. Toledo Bend and Orange recorded 3.82 and 10.71 inches respectively during the 28 days preceding the sample run. Reservoir profiles indicated complete mixing of the water column in Lake Tawakoni, Lake Fork and Toledo Bend reservoirs.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the December sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. The most recent significant rain was 0.33 inches at Lake Tawakoni and 0.30 inches at Lake Fork within 24 hours of sampling. Lake Tawakoni and Lake Fork recorded an additional 0.5 to 1 inch of rain the previous day. SR22 was significantly influenced by locally heavy rainfall and resulting runoff. This site exceeded numeric criteria for the stream standards for E. coli, and had elevated turbidity and total organic carbon. Field notes indicated this site had high flow, a lot of flotsam, and appeared very muddy. The next site downstream, SR21, appeared normal and had not yet been impacted by runoff from upstream. SR21, SR19, SR15, and SR14 also exceeded the numeric criteria for the stream standards for E. coli. Surface water temperatures were between 7.1 and 10.6ºC at river and reservoir sites. LT23A and LT23D at Lake Tawakoni were slightly over 100% saturated with oxygen indicating a possible moderate algal growth. The nitrate/nitrite level at LF2 exceeded reservoir screening criteria. No stream standards exist for nitrate/nitrite, so screening values are used as a guide. Chloride levels at SR16 exceeded river/stream screening criteria. Stream Standards for Chloride are for annual averages. Screening criteria are used as warning limits. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 9.75 and 10.6ºC respectively.
Bottom temperatures at the same sites were essentially the same as their surface temperatures. Lake Tawakoni and Lake Fork were completely mixed.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The December monthly sampling results were indicative of water of high quality at most sites. The area received heavy rainfall five days prior to the sample run. During that rain event the area received just over three inches of rain over two days. The level of Toledo Bend Reservoir was recorded at 168.36 feet with no gates discharging from the spillway, but the powerhouse was generating at the time of sampling. All lake sites were very well mixed with similar readings throughout the water column at all sites. Several sites displayed high bacterial results, but this is not uncommon following a large rain event like the areas recently experienced. The sites with high results were TB6N, TB6J, TB6F, BA4, BCC1, and SR2.
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. The area received very heavy rains seven days prior to the sample event. The southern sections of the area received around four inches of rain during a two-day period, but some sites in northern Orange County received up to seven inches over the same two days. Most sites in this section of the Basin were well mixed with only slight oxygen differences throughout the water column. No recordable salinities were found at any site at any depth. All of the tidal stations had high bacterial results, which could be directly related to the very heavy rains the area received.
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
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
Printed Tuesday, February 25, 2003