A bridge abutment having a fill slope on the streamward side.
The term originally referred to the "spill-through" of fill at an
open abutment but is now applied to any abutment having such
A pier or abutment footing that transfers load directly to the
A permeable or impermeable linear structure that projects into
a channel from the bank to alter flow direction, induce
deposition, or reduce flow velocity along the bank.
See guide bank.
A condition of a channel when, though it may change slightly at
different times of the year as the result of varying conditions of
flow and sediment charge, there is no appreciable change from
year to year; that is, accretion balances erosion over the years.
A condition that exists when a stream has a bed slope and
cross section which allows its channel to transport the water
and sediment delivered from the upstream watershed without
aggradation, degradation, or bank erosion (a graded stream).
Water-surface elevation of a stream with respect to a reference
Natural cobbles, boulders, or rock dumped or placed as
protection against erosion.
A body of water that may range in size from a large river to a
small rill flowing in a channel. By extension, the term is
sometimes applied to a natural channel or drainage course
formed by flowing water whether it is occupied by water or not.
Removal of soil particles or a mass of particles from a bank
surface due primarily to water action. Other factors such as
weathering, ice and debris abrasion, chemical reactions, and
land use changes may also directly or indirectly lead to bank
Sudden collapse of a bank due to an unstable condition such
as removal of material at the toe of the bank by scour.
Any technique used to prevent erosion or failure of a
The quantity of sediment passing through a stream cross
section above the bed layer in a unit of time suspended by the
turbulence of flow (suspended load).