To: Interested Parties
From: Water Resources Branch
This is the Sabine River Authority Water Quality Report for October 2005. Water quality sampling was performed October 10th through October 13th, approximately two weeks after the landfall of Hurricane Rita. Hurricane Rita struck the Gulf Coast of Texas near the Louisiana border in the early morning hours of September 24. Hurricane force winds persisted as the storm moved north through East Texas and degraded to a tropical storm near San Augustine, Texas. Although the storm had been downgraded from a category 5 to a category 3, it still brought high winds and rains throughout the coastal region. A total of 6.54 inches of rainfall were recorded near Orange and thousands of trees were uprooted or broken off and leaves were shredded from their branches. The Lower Basin had not received more than a trace of rain in the preceding weeks. After the hurricane, water quality impacts were seen as a result of the shredded green leaves and limbs that were blown into local water bodies. Anoxic conditions (dissolved oxygen < 1 mg/L) and dead fish were documented in the Lower Sabine River from Highway 12 in Deweyville, Texas, down to the Intracoastal Waterway. Fish kills were also reported in the lower rivers, bayous, and estuaries from Calcasieu Lake in Louisiana, Sabine Lake and east Galveston Bay. The storm surge was much smaller than originally anticipated, but higher than normal tides persisted after the storm. Tidal monitoring data in this report show signs of lingering impacts from the massive amount of organic material that was deposited in water during the storm. Data from non-tidal sites during this sampling period does not indicate persisting water quality impacts, however the damage to the forested areas and disturbed soils may have very long lasting effects on water quality. Recent weather (seven days prior to the October sample run) in the Sabine River Basin was warm, with daytime highs in the low 90s at Lake Tawakoni and at Lake Fork. Toledo Bend Reservoir and Orange had daytime highs from the mid 90s to the high 90s. Lows ranged from the mid 40s to low 70s at Lake Tawakoni and at Lake Fork. Toledo Bend and Orange had lows ranging from the low 50s to the low 70s. The waters of Lake Tawakoni were mixed and only the deepest waters of Lake Fork were thermally stratified. During the 28 days prior to the sample run, the Upper Basin received 1.52 and 1.95 inches of rainfall as recorded at Lake Tawakoni and at Lake Fork, respectively. Lake Tawakoni received 0.04 inches of rain and Lake Fork received no rainfall the week preceding the sample run. Toledo Bend received 4.39 inches of precipitation during the 28 days prior to the sample run and Orange received 6.54 inches of rain.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
Most water quality parameter measurements at the Upper Basin sites were consistent with water of high quality for the October sample run. The level of Lake Fork was recorded at 399.82 feet msl with 64 cfs releases and the level of Lake Tawakoni was recorded at 431.65 feet msl with 6 cfs releases at the time of sampling. Station LF3 exceeded 100 percent saturation for dissolved oxygen. Stations LT23A, LF3, LF4, and SR22 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. Station SR21 exceeded the stream standards numeric criteria for chloride. A natural salt deposit near Grand Saline, Texas, is the probable source of elevated chloride.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The October monthly sampling results were indicative of water of high quality at most sites. The area received no measurable rainfall the week prior or during sampling. The level of Toledo Bend Reservoir was recorded at 163.49 feet msl with 204 cfs discharge at the time of sampling. Most reservoir stations were only slightly stratified with dissolved oxygen and temperature differences throughout the water column. No anoxic conditions were found at any of the lake stations. Station TB7A had a lower than normal dissolved oxygen result. Stations TB6LN and TB6H recorded chlorophyll a results and station TB6R recorded a dissolved oxygen percent saturation that were each above the recommended screening criteria. Although this area did receive damage from Hurricane Rita, the impact to water quality was minimal and is expected to have a relatively short duration.
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, with the exception of low dissolved oxygen readings recorded at one station. Dissolved oxygen data indicates lingering impacts from the organic material deposited in the watershed during Hurricane Rita approximately two weeks prior to sampling. Clean-up operations may produce some localized problems with water quality, but long-term effects from damage to the watershed may be experienced fro many years. The tidal stations received 0.12 inches of rainfall in the seven days prior to the sample event. All stations in this section of the Basin showed stratification, and anoxic conditions were found at several of the deeper stations. Surface salinities were found at all but the northernmost Tidal station. The largest salinity value, 16 ppt, was found at Station BB1 at the surface to a depth of 4.5 meters. In addition to the low dissolved oxygen readings that were found throughout this section of the Basin, stations ICW1 and BB1 also recorded high bacterial counts.
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:
Terry Wilson, Upper Basin Field Office Coordinator
Lower and Tidal Sabine Basin
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are
John Payne, Special Projects Administrator
Miles Hall, Resource Management/ Project Development Division Manager
Printed Thursday, April 13, 2006 at 15:36