What Is a Bulkhead? Definition, Purpose and Types

The word "bulkhead" comes up in listings, inspection reports, permit applications and contractor quotes, often without explanation. On a waterfront property it refers to one thing: the wall that separates the yard from the water and keeps one from becoming part of the other.

This page gives a working definition, explains what bulkheads are built to do, and outlines the main structural types. For the full picture, start with the complete guide to bulkhead walls.

A working definition

Agency definitions agree on the essentials.

• The Virginia Institute of Marine Science (VIMS) defines a bulkhead as "a vertical structure that acts as a retaining wall usually constructed parallel to a shoreline."
• Maryland's shore erosion guidelines describe a vertical structure of wood, stone, concrete, plastic or similar material "designed to retain land or to prevent land from wave damage."
• The U.S. Army Corps of Engineers (USACE) design manual states that a bulkhead is "primarily intended to retain or prevent sliding of the land," with protection from waves of secondary importance.

Put simply, a bulkhead is a retaining wall that stands in or at the edge of the water. The soil behind it is usually higher than the bottom in front of it, and the wall holds that difference in place.

What bulkheads are built to do

USACE guidance identifies several uses.

1. Retain soil at the shoreline. This is the core function. The wall keeps the upland from sliding or slumping into the water.
2. Provide water depth at the shore. USACE notes that bulkheads are required where some depth of water is needed directly at the shore, such as for boaters. This is why canal communities and marinas rely on them.
3. Stabilize low eroding banks and bluff toes. A bulkhead can retain soil at the toe of a bank or protect the toe from undercutting.
4. Hold fill. Bulkheads are used for reclamation projects, where fill is placed seaward of the existing shore.

FEMA adds that bulkheads provide protection against low to moderate wave action. They are not built for heavy surf. FEMA states plainly that bulkheads "are not suitable for ocean shorelines."

Where you find them

Bulkheads are common on sheltered water: residential canals, tidal creeks, rivers, protected bays, lakes and harbors. North Carolina's Division of Coastal Management describes the bulkhead as the most commonly used stabilization method on the state's estuarine shorelines.

On exposed ocean coasts, engineers generally turn to more massive seawalls, sloped revetments or other measures. Our guide to bulkhead vs. seawall explains where one ends and the other begins.

The main structural types

Bulkheads differ in how they resist the soil behind them. USACE and FEMA describe them as cantilevered, anchored, or gravity structures, and the USACE property owner's guide adds post-supported walls as a common lower-height form.

Sheet pile walls are made of interlocking or tightly spaced sheets driven into the ground. The USACE owner's guide lists steel, aluminum and timber sheeting, and later guidance adds vinyl and fiberglass. How each type carries load is explained in how bulkhead walls work.

What a bulkhead does not do

Bulkheads have limits that owners should understand before relying on one.

• They protect only what is behind them. The USACE owner's guide states that bulkheads offer no protection to adjacent areas up and down the coast or to the fronting beach.
• They can increase scour in front. Vertical faces reflect wave energy. USACE notes this can erode the bottom or beach in front of the wall.
• They do not guarantee a stable bluff. If a bulkhead is placed at the toe of a steep, failing bluff, the bluff above can still slide and push the wall toward the water.
• Their ends are weak points. VIMS describes return walls as end sections that tie the bulkhead into the upland to keep it from being flanked as the shoreline retreats on either side.

These limits are one reason some states now encourage alternatives. Maryland's guidelines state that it is generally against state policy to authorize new bulkheads. See riprap and living shorelines for other approaches.

Materials at a glance

FEMA lists wood, steel, stone, vinyl and concrete as bulkhead materials. North Carolina adds fiberglass, and Maryland lists aluminum. Each has different strengths and failure modes, from marine borers in timber to corrosion in steel. Compare them in our materials guides on timber, steel, vinyl, concrete and composite sheet piling, or use the material explorer.

Why permits come up

Because bulkheads sit at or below the water line, building, replacing or extending one commonly involves federal, state and local review. Requirements vary by location and project scope. The bulkhead permit guide explains the agencies that typically take part.

Getting to know your own wall

If you own a bulkhead, a few facts are worth recording: its material, approximate height, whether it is anchored, what lies in front of the toe, and its approximate age. The inspection checklist gives you a structured way to record them. The bulkhead components explained guide will help you name what you see.