Dredging Research Program (DRP)

Passage of the Water Resources Development Act of 1986 changed a long period of Corps dredging activities that consisted primarily of maintaining existing waterways and harbors. That legislation authorized major deepening and widening of existing navigation projects. Implementation of an applied research and development (R&D) program to meet demands of ever-changing conditions, and generation of significant technology to be adopted by all dredging interests, would be a means of reducing the cost of dredging the nation's waterways and harbors. A 7-year, $35-million Dredging Research Program was initiated at Waterways Experiment Station (WES) in 1988 and successfully concluded in 1994, achieving all major goals established by field users during the program development process.

The DRP's major objectives were development of equipment, instrumentation, software, and operational monitoring and management procedures to significantly enhance the Corps' dredging activities. The DRP's purpose was to reduce the cost of dredging to a minimum consistent with Corps mission requirements and environmental responsibility. The program consisted of five technical areas from which distinct products could be developed, and where annual and one-time direct and indirect benefits could be quantified. These five technical areas were (1) analysis of dredged material disposal in open water, (2) material properties related to navigation and dredging, (3) dredge plant equipment and equipment processes, (4) vessel positioning, survey controls, and dredge monitoring systems, and (5) management of dredging projects.

Results summarized by technical area:

Technical Area 1, Analysis of Dredged Material Disposal in Open Water:

• Developed understanding of boundary-layer properties of both cohesive and noncohesive sediments
• Developed instrumentation for monitoring suspended-sediment plumes and for determining resuspension from disposal mounds
• Formulated and verified short-and long-term numerical models for determining fate of material disposed in open water
• Improved field techniques for collecting long-term data pertaining to movement of nearshore berms designed as feeder beach material or wave attenuation devices

  Technical Area 2, Material Properties Related to Navigation and Dredging:

• Developed descriptors of bottom sediments to be dredged
• Devised new drilling parameter recorder technology
• Designed and field-tested a methodology for surveying navigation channels containing fluid mud
• Developed acoustic impedance techniques for performing rapid measurements of characteristics of consolidated sediments

  Technical Area 3, Dredge Plant Equipment and Equipment Processes:

• Developed new technologies and enhanced existing dredge systems to achieve economic hopper dredge load during dredging operations
• Improved eductors
• Developed a single-point mooring system for direct pumpout of hopper dredges onto beaches
• Enhanced technology for dredge production and process monitoring
• Modified designs for hopper-dredge dragheads to increase production

  Technical Area 4, Vessel Positioning, Survey Controls, and Dredge Monitoring Systems:

• Addressed the need for reporting offshore onsite water levels
• Enhanced a vessel-heave system for dredging purposes
• Developed real-time, on-the-fly Global Positioning System (GPS) navigation for surveying and dredging
• Evaluated dredge production meters
• Developed the operational aspects of a silent inspector for monitoring contract hopper dredges

  Technical Area 5, Management of Dredging Projects:

• Developed a framework for comprehensive site management of the open-water placement and monitoring of dredged sediments
• Designed criteria for level-bottom capping and contained aquatic disposal of contaminated dredged materials
• Provided engineering design guidance for nearshore berms constructed of clean sediments

The DRP concentrated primarily on the physical aspects of handling dredged material. It became apparent during the conduct of the program that significant and substantial uncertainties pertaining to the chemistry and biology of dredged material should be pursued by a formally structured R&D program. This understanding resulted in the development and beginning of the Dredging Operations and Environmental Research (DOER) Program at WES in October 1996.

Summary reports online

Web Date: July 13, 2001