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
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
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
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:
Terry Wilson, Upper Basin Field Office Coordinator
Lower and Tidal
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are
John Payne, Special Projects Administrator
Miles Hall, Resource Management/ Project Development