Bulkhead (barrier)

A bulkhead is a retaining wall, such as a bulkhead within a ship or a watershed retaining wall. It may also be used in mines to contain flooding.

Coastal bulkheads are most often referred to as seawalls, bulkheading, or riprap revetments. These manmade structures are constructed along shorelines with the purpose of controlling beach erosion. Construction materials commonly used include wood pilings, commercially developed vinyl products, large boulders stacked to form a wall, or a seawall built of concrete or another hard substance.

Coastal property owners typically seek to develop bulkheads in an attempt to slow large landslide erosion caused by wave action.

Lighthouse
The Cape Hatteras lighthouse stands behind a seawall of sandbags that temporarily stabilized the eroding shore; wave action destroyed the seawall soon after it was built.

Studies over recent decades have resulted in public awareness as to potential negative effects that bulkheads may bring to beaches and the interconnected habitat areas of fish, plants, and birds. Many states have enacted laws to protect beaches to allow for future use of the beaches, as well as protect these natural habitats.

Fig 11LG
This example of multiple structures includes a massive seawall and riprap revetment.

Effects

While bulkheads may serve their purpose to slow erosion at a bluff or beachfront, they commonly cause a domino effect of change to the beach profile. The increased wave reflection caused by their presence can result in an increased re-suspension of sand in the water in front of the bulkhead. This can lead to more sand being distributed in the alongshore direction, away from the beach profile. Due to coastal littoral drift, the sand would then instead be distributed toward the ends of the bulkheads, leaving larger gravel and sometimes bedrock in place of the once sandy beach.

Since sand is a natural habitat for several species of fish to lay their eggs and is also the only surface in which eelgrass can take root, these natural processes can no longer take place in this now sand-stripped location. The absence of eelgrass means that the spawning habitat for herring and the protection for juvenile salmon would no longer be present. This new sand-stripped habitat also encourages other species, such as kelp, to move in.

Gallery

NorthPadreIslandfig10LG

Seawall on North Padre Island constructed in the backbeach to protect condominiums from storm waves and beach erosion. Central Texas

USGSseawall-lg

Seawall protecting homes from storm waves and beach erosion. Northwestern Panhandle of Florida

Fig10-large

Hard structures, such as the Galveston seawall, can increase erosion of adjacent beaches.

Seawall-large

Seawall protecting homes from storm waves and beach erosion. Eastern Panhandle of Florida

See also

References

(Soft Shore Protection as an Alternative to Bulkheads—Projects And Monitoring - PDF

External links

Bulkhead

Bulkhead may refer to:

A structural safety device:

Bulkhead (partition), a wall within the hull of a ship, vehicle, or container

Torpedo bulkhead, a type of armor plate or protective covering designed to keep a ship afloat even if the hull is struck by a shell or by a torpedo

Bulkhead (barrier), a retaining wall used as a form of coastal management, akin to a seawall, or as a structural device such as a bulkhead partition

Bulkhead door, an angled door covering the exterior stairwell of a basement

Bulkhead flatcar, a type of rolling stock designed with sturdy end-walls to prevent loads from shifting past the ends of the car

Rear pressure bulkhead, an airtight structural feature of an aircraftOther uses:

Bulkhead (Transformers), the name given to several fictional characters in the Transformers universes

Bulkhead line, a method of coastal demarcation used within a legal system

Bulkhead (stability pattern), a stability pattern used to protect distributed software applications

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