By Mr Carlos J Lazo (USACE)May 29, 2011
VICKSBURG, Miss. - As a result of the recent flooding along the Mississippi River, millions of gallons of water have been diverted into lakes, reservoirs and other bodies of water including Eagle Lake near Vicksburg, Miss.
With the introduction of additional flood waters, Eagle Lake’s water quality was affected but to an extent still unknown by the U.S. Army Corps of Engineers Vicksburg District who is monitoring the lake.
“We’re monitoring the influence of how the water is affecting the different tributaries,” said Brian Johnson, an environmental engineer with the Vicksburg District, “Specifically in the upper Yazoo basin.”
These tributaries are small rivers and creeks that flow directly into the Mississippi River.
“At a later date we can go back and summarize all this information and create an environmental assessment,” said Johnson.
The information is collected by taking water profiles. A profile involves taking a water-quality sonde " an instrument that measures different items within the water including dissolved oxygen, conductivity, turbidity, pH levels and temperate " and annotating the differences found in each item at various depths. Each sonde is calibrated at the district before being taken out to the field to ensure accurate readings at the various locations, said Johnson.
Johnson collected the changes in these items throughout Eagle Lake to ensure accurate readings of how the flood waters are mixing throughout the lake.
Water samples are also collected, said Johnson, and are sent to labs for further testing. These compliment the information collected with the water profiles.
“You can’t do everything on location,” Johnson said. “Some tests take days.”
These tests can reveal important information about the water quality that can directly affect the aquatic habitat.
“We’re testing for several things,” Johnson said.
This includes the organic content that can directly influence the oxygen content, as well as the amount of nutrients and sediments found throughout the lake.
Using a depth sampler, Johnson pulled water samples within the top meter of the surface throughout Eagle Lake.
Along with Eagle Lake, the Vicksburg District continues to catalogue water conditions within its area of operations that may be influential to the Mississippi River.
It’s too early to tell if any affects exist do to the increase in water caused to the various bodies of water and the aquatic habitat within them. Once the water has receded to pre-flood depths, the Corps will conduct more readings and create an environmental assessment to identify any changes.