berms

A berm is an artificial ridge or raised barrier, typically consisting of earth or other aggregate material, that forms a linear feature in the landscape. Berms can also occur naturally as raised banks, but the term is most often used for man-made structures such as the raised edges alongside roads, railways, and waterways.

Coastal, river, and flood-control berms are designed to absorb wave energy, reduce erosion, and provide temporary storage of floodwaters. In urban and infrastructure projects, berms separate traffic from shoulders, aid drainage, and help control runoff around roads, railways, airports, and industrial sites. In agricultural settings, berms can act as irrigation basins or drainage barriers, helping manage moisture and guide surface water.

In landscape design, berms are used to create height variation, screen unsightly views, and improve drainage and soil conditions around planted areas. They may be simple mounds or part of more complex site grading. Berms can also play a role in environmental restoration and stormwater management by directing or slowing runoff and promoting infiltration.

Construction and design involve placing and compacting material to form a stable mound, often with drainage and erosion-control layers and, in some cases, vegetation to reduce surface erosion. Materials range from soil and sand to rock, concrete, or recycled fill. The specific geometry and materials depend on purpose, climate, and site conditions.

Maintenance is important to prevent erosion, settlement, or breach during heavy rainfall, snowmelt, or seismic events. Improperly designed or maintained berms can alter local hydrology, harm habitats, or fail structurally, requiring monitoring and corrective measures.