that breach closures require the quickest possible response to minimize cost. What may start as a
small breach that could easily be plugged by conventional methods can be become a large inlet
requiring million of dollars to fill. Rapid response is supported through effective interagency
coordination. Efficient closure of breaches is facilitated by proper timing of the fill operation. If
possible, seasonal considerations should be made, with closures made during calm, summer
months. If a closure operation is performed during the winter storm season, a temporary wall to
limit losses may be required. Final closure of a breach should be made during time of low tide.
Fills should be made with the largest grain size possible, and a high pumping capacity is required
to overcome the strong current as the breach becomes constricted. Even large breaches can be
overcome by large pumping volumes, provided that filling is accomplished from both sides or a
temporary revetment made on the breach bank opposite the filling operation. Final closure can
be accomplished more efficiently if sand is stockpiled on each breach bank to be pushed into the
breach channel by bulldozer. Breach closures may need to be vegetated to protect against wind
and rain erosion.
Mechanical breaching is typically accomplished by conventional equipment that can operate in
3-4 ft of water. Larger breach cuts may require additional sand removal by a dredge. Artificial
breaching requires careful planning to avoid excessive erosion of both the cut and the shoreline
or to avoid too rapid of a closure by natural processes. The hydrodynamic conditions at a
proposed breach location should be studied to understand the potential tidal prism captured by
the breach, the resulting tidal current velocity, and the longshore sediment transport along the
beach. Artificial breaching should also be timed to ensure adequate water flow in the direction
desired and to avoid premature closure during times of large volume of longshore transport.
ACKNOWLEDGEMENTS: Information on closure operations was provided by Mr. Richard
Mcinerney, U.S. Army Engineer District, New York, for Westhampton Beach; Mr. Robert Parry,
U.S. Army Engineer District, Seattle, for Grays Harbor; and Ms. Heidi Moritiz, U.S. Army
Engineer District, Portland, for Coos Bay.. Photographs for Grays Harbor were supplied by
Mr. Eric Nelson, U.S. Army Engineer District, Seattle. This technical note was reviewed by
Dr. Brian K. Batten, U.S. Army Engineer Research and Development Center, and Ms. Chantal
Donnelly, Lund University, Sweden.
ADDITIONAL INFORMATION: Questions about this technical note can be addressed to
Mr. Ty V. Wamsley (601-634-2099; ) or Dr. Nicholas C.
Kraus (601-634-2016; ). This technical note should be
cited as follows:
Wamsley, T. V. and Kraus, N. C. (2005). "Coastal barrier island breaching,
Part 2: Mechanical breaching and breach closure," ERDC/CHL CHETN IV-__,
U.S. Army Engineer Research and Development Center, Vicksburg, MS.
This technical note was produced under the Coastal Inlets Research Program (CIRP). For
additional information on the CIRP, please consult http://cirp.wes.army.mil/cirp/cirp.html
or contact the Program Manager, Dr. Kraus.
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