Hickman Control Point

This investigation is necessary to assess the nature of a resistant layer that extends across the bed of the Mississippi River and its effect on the behavior of the channel upstream.  The resistant layer is located on the Mississippi River between RM 920 and 921 which is downstream of the harbor at Hickman, KY. This layer provides a grade control function on the Mississippi River that has resulted in reported tow groundings during periods of extreme low water.  MVM Operations staff members have discussed removal of part of the layer to maintain the navigation channel. 

There is a concern that lowering the level of the resistant layer may initiate base-level lowering of the channel upstream of Hickman with adverse impacts extending up to Thebes, IL on the Mississippi River and to Olmsted, IL on the Ohio River.  The potential for upstream channel lowering when combined with observed lowering in the channel downstream of Hickman indicate that this reach of the Mississippi River may undergo significant change in the relatively near future.  It is proactive to assess the dynamics of this reach from a geomorphology perspective prior to making any changes in the resistant layer at this location.  There is also a need to consider possible changes up the Mississippi River and Ohio River due to the presence of bedrock across the Mississippi River at Thebes and construction of Olmsted Lock and Dam on the Ohio River.

Principle tasks to be performed during this study include: 

  •  Collect field data to determine the physical characteristics of the resistant material
  •  Evaluate the change in the specific gage record at the Hickman, KY gage
  •  Analyze historic hydrographic surveys to gain an understanding of the local reach dynamics
  •  Review geologic and geomorphologic maps of the area
  •  Collaborate with university staff on seismic survey data obtained through the Hickman reach
  •  Refine geometric detail of an existing sediment transport model (HEC-6T) to capture more localized effects from approximately River Mile 850 on the Lower Mississippi River to Thebes, IL and upstream to Olmsted Lock and Dam on the Ohio River
  •  Perform sediment routings to evaluate the channel bed response over time
  •  Evaluate sediment flux through this reach during the 2011 flood
  •  Analyze historic dredging records, and
  •  Develop a report describing the findings of the investigation.