embankment

An embankment is a raised bank of earth or stone built to contain or divert water, or to support infrastructure such as roads or railways on otherwise low-lying ground. They are commonly used for flood defense, river and coastal protection, and to create stable foundations for transportation routes on reclaimed land.

Construction and design typically involve an impermeable core, often of clay, surrounded by drainage and filtration layers to prevent seepage and internal erosion. The outer faces are shaped into stable slopes, with a crest wide enough to accommodate overlying infrastructure or to allow maintenance access. In many embankments a toe drain, filter layers, and rock or concrete armor may be added to improve stability and protect against scour.

Types and applications vary by purpose. Flood embankments, dikes, or levees are constructed to keep rising water from inundating adjacent land. Embankments also carry highways or railways, elevating transport corridors above floodplains. Depending on site conditions, they may be built with earth, rock-fill, or concrete elements, and may include additional features such as gates, culverts, and pump stations for drainage management.

Maintenance and safety are ongoing concerns. Regular inspections assess seepage, erosion, slope stability, and crest integrity. Maintenance actions include repairing scars from weathering, clearing drainage paths, vegetation management, and reinforcing scour protections at the toe. Failures can arise from overtopping, internal erosion or piping, slope instability, or settlement, often triggered by extreme floods or inadequate maintenance.

In regional terminology, embankments may be referred to as dikes or levees, and their specific design standards reflect local hydrology, climate, and land use.