In architecture

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

, a starling (or sterling) or, more commonly, cutwater is a defensive bulwark, usually built with pilings or brick

Brick

A brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.-History:...

s, surrounding the supports (or pier

Pier

A pier is a raised structure, including bridge and building supports and walkways, over water, typically supported by widely spread piles or pillars...

s) of a bridge

Bridge

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

 or similar construction. Starlings are shaped to ease the flow of the water around the bridge, reducing the damage caused by erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

or collisions with flood-borne debris, and may also form an important part of the structure of the bridge, spreading the weight of the piers. So the cutwaters make the current of water less forceful.

One problem caused by starlings is the accumulation of river debris, mud and other objects against the starlings, potentially hindering the flow.