Old River Control Complex Sedimentation Investigation
ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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This report documents an investigation of sediment diversions at the Old River Control Complex ORCC conducted for the U. S. Army Engineer District, New Orleans. The investigation was conducted via a combination of field data collection and laboratory analysis, geomorphic assessments, and numerical modeling. The objectives were to determine current rates of sediment diversion, evaluate potential impacts on the stability of the Mississippi River, and identify options to increase sediment diversion rates. As operated since the early 1990s, sediment diversion at the ORCC probably is less efficient than required to maintain channel stability in the Mississippi River downstream of the ORCC. While there is clear evidence of significant channel aggradation in the vicinity of the ORCC, the impacts of ORCC operations on regional sedimentation remain uncertain. Operational alternatives were analyzed that potentially could increase the long-term sediment diversion efficiency at the ORCC. In particular, the investigation found, via a synthesis of field investigations and numerical modeling, that while the auxiliary control structure is the most efficient at diverting bed material from the Mississippi River, the low sill structure is more efficient at delivering bed material to the outfall channel leading to the Atchafalaya River.
- Hydrology, Limnology and Potamology