Reservoir Sediment Studies in Kansas

Science Center Objects

An understanding of the quantity and quality of sediment deposited in a reservoir is necessary for effective reservoir and basin management. Sedimentation affects the useful life of a reservoir for such important purposes as flood control, water supply, and recreation. Sediment quality is an important environmental concern because sediment may act as a sink for various water-quality constituents and as a source of constituents to the overlying water column and biota. An analysis of reservoir bottom sediments can provide historical information on sediment deposition as well as magnitudes and trends for water-quality constituents that are associated with sediment such as phosphorus, trace elements, and some pesticides. Such information can be used to document and understand the effects of various natural and human factors on reservoir conditions.

Reservoir sediment investigations conducted by the U.S. Geological Survey since 1995 have been completed with specific objectives being to:

  • Estimate total sediment volume and mass 
  • Estimate annual sediment deposition and yield from the basin
  • Determine the occurrence and trends of constituents
  • Estimate annual constituent loads and yields from the basin
  • Assess sediment quality
  • Assess how reservoir conditions have changed over time and identify possible issues of concern
  • Provide a baseline for future assessments
  • Methods used include bathymetric surveying, bottom-sediment coring, chemical analysis, and statistical analysis
Map of Kansas reservoirs
A map of Kansas reservoirs. The reservoirs in pink have sediment studies on them either in the past or ongoing. (Public domain.)

 

  • Bottom-sediment concentrations of arsenic, chromium, and nickel greater than the threshold-effects guidelines for adverse biological effects in aquatic organisms are typical for reservoirs in eastern Kansas (Juracek, 2003, 2004, 2008, 2010, 2011; Juracek and Mau, 2002) and may be indicative of natural contributions from soils and bedrock.
  • Adverse effects of historical human activity on reservoir conditions is clearly documented in reservoir bottom sediments. Examples include the use of copper sulfate to control algal blooms in a reservoir (Juracek, 2004), historical lead and zinc mining and smelting in the basin (Juracek, 2006, 2007; Juracek and Becker, 2009), the use of leaded gasoline (Juracek, 2004; Juracek and Ziegler, 2006), and pesticide usage in the basin (Juracek and Mau, 2002).
  • Biological indicators preserved in the bottom sediment, such as diatoms and cyanobacteria, can be used to assess the current and historical trophic condition of lakes (Juracek, 2008, 2011, 2015).