The accumulation of (beach) sediment, deposited by natural fluid flow processes.
May be either natural or artificial. Natural accretion is the buildup of land, solely by the action of the forces of nature, on a beach by deposition of water- or airborne material. Artificial accretion is a similar buildup of land by reason of an act of man, such as the accretion formed by a GROIN, BREAKWATER, or beach fill deposited by mechanical means.
Derived from the Latin “accrescere” which means to grow or increase, it is the gradual and imperceptible addition of soil or other material by the natural processes of water-borne sedimentation or by the action of currents against shores and banks. Accretion is the washing up of sand, silt or soil so as to form firm ground, called alluvion. In common practice the terms alluvion and accretion have been used almost interchangeably. Usually, however, alluvion means the deposit itself while accretion usually denotes the act.
The act of growing to a thing; usually applied to the gradual and imperceptible accumulation of land by natural causes, as out of the sea or a river. Accretion of land is of two kinds: By alluvion, i.e., by the washing up of sand or soil, so as to form firm ground; or by reliction, as when the sea shrinks below the usual water-mark. The term “alluvion” is applied to deposit itself, while “accretion” denotes the act. However, the terms are frequently used synonymously. Land uncovered by gradual subsidence of water is not an “accretion” but a “reliction.”
Accretion has been defined 16 different ways in documents like Glossary of Coastal Terminology, Meteorology Terminology, Glossary of Coastal Terminology, and 7 more.