Culvert vs. Outfall — What's the Difference?

A culvert is a structure that allows water to flow under a road, railroad, trail, or similar obstruction from one side to the other. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material.

An outfall is the discharge point of a waste stream into a body of water; alternatively it may be the outlet of a river, drain or a sewer where it discharges into the sea, a lake or ocean. In the United States, industrial facilities that discharge storm water which was exposed to industrial activities at the site are required to have a multi-sector general permit.

A tunnel carrying a stream or open drain under a road or railway.

The place where a sewer, drain, or stream discharges.

Channel (a stream or drain) through a culvert

To burst forth, as upon an enemy; make a sally.

A sewer or drain crossing under a road or embankment.

(obsolete) A sudden eruption of troops from a fortified place; sally.

The part of a road or embankment that passes over such a sewer or drain.

(dialectal) A quarrel; a falling out.

The channel or conduit for such a sewer or drain.

The point or place of discharge of a river, drain, culvert, sewer, etc.; mouth; embouchure.

A channel crossing under a road or railway for the draining of water.

The mouth of a river; the lower end of a water course; the open end of a drain, culvert, etc., where the discharge occurs.

To channel (a stream of water) through a culvert.

A quarrel; a falling out.

A transverse drain or waterway of masonry under a road, railroad, canal, etc.; a small bridge.

The outlet of a river or drain or other source of water

A transverse and totally enclosed drain under a road or railway