Alluvion

Alluvion refers to the gradual accumulation of sediment or soil at the banks of a river or watercourse, which leads to an increase in land area. This process can result in the legal ownership of new land being conferred to the adjacent landowner, as the alluvion is considered a natural extension of their property.

The term originates from Latin 'alluvio' meaning 'to wash against,' reflecting the natural process that occurs alongside fluvial bodies. Historically, legal frameworks regarding alluvion have developed in response to the common law principles governing land ownership and boundary rights.

In modern law, the principle of alluvion is most relevant in property disputes regarding riparian rights, where landowners alongside rivers and streams claim ownership over newly formed land created by deposited materials. Courts often reaffirm these principles in determining property rights when changes to land boundaries occur due to natural processes.

• A farmer whose land borders a river receives additional land after a flood deposits soil and sediment at the riverbank.
• A landowner challenges a neighboring property claim following the natural shifting of a river's course, resulting in the formation of new land.

• United States v. 1,140.74 Acres of Land, 1993