Accession Number:

ADA156635

Title:

Effects of Depth on Dredging Frequency. Report 3. Evaluation of Advance Maintenance Projects.

Descriptive Note:

Technical rept. 1978-1982,

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS

Personal Author(s):

Report Date:

1985-04-01

Pagination or Media Count:

47.0

Abstract:

Overall costs of maintaining authorized or required project depths in the navigation channels and harbors of the United States by dredging have increased dramatically during the last decade. To reduce these costs by extending the interval between maintenance dredging operations--and to provide full project dimensions for a greater period of time--advance maintenance is performed at critical shoaling areas of many navigation projects. Advance maintenance is dredging done beyond the existing authorized depth of a project to provide a predetermined amount of catchment capacity below design depth. It is exclusive of the allowable dredging tolerance usually 1 to 2 ft common to most dredging operations which compensates for inaccuracies inherent to the practice. This report, examined and evaluated the effectiveness of advance maintenance dredging in producing desired results for six selected navigation channel segments. These segments are Shipyard River, S.C., Coos Bay, Oreg., and three reaches of the Columbia River, Oreg.-Wash. This was accomplished by comparing shoaling rates and distributions and dredging frequencies resulting from maintenance operations on these projects which included advance maintenance with other which did not. Results indicated that advance maintenance was beneficial in some, but not all, cases and that it should be evaluated on a case-by-case basis.

Subject Categories:

  • Hydrology, Limnology and Potamology
  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE