paving:
Covering of stones on a channel bed or bank (used with
reference to natural covering).
peaked stone dike:
Riprap placed parallel to the toe of a streambank (at the
natural angle of repose of the stone) to prevent erosion of the
toe and induce sediment deposition behind the dike.
perennial stream:
A stream or reach of a stream that flows continuously for all or
most of the year.
phreatic line:
The upper boundary of the seepage water surface landward of
a streambank.
pile:
An elongated member, usually made of timber, concrete, or
steel, that serves as a structural component of a river-training
structure.
pile dike:
A type of permeable structure for the protection of banks
against caving; consists of a cluster of piles driven into the
stream, braced and lashed together.
piping:
Removal of soil material through subsurface flow of seepage
water that develops channels or "pipes" within the soil bank.
point bar:
An alluvial deposit of sand or gravel lacking permanent vegetal
cover occurring in a channel at the inside of a meander loop,
usually somewhat downstream from the apex of the loop.
poised stream:
A stream which, as a whole, maintains its slope, depths, and
channel dimensions without any noticeable raising or lowering
of its bed (stable stream). Such condition may be temporary
from a geological point of view, but for practical engineering
purposes, the stream may be considered stable.
probable maximum flood:
A very rare flood discharge value computed by
hydrometeorological methods, usually in connection with major
hydraulic structures.
quarry-run stone:
Stone as received from a quarry without regard to gradation
requirements.
railbank protection:
A type of countermeasure composed of rock-filled wire fabric
supported by steel rails or posts driven into streambed.
rapid drawdown:
Lowering the water against a bank more quickly than the bank
can drain without becoming unstable.
reach:
A segment of stream length that is arbitrarily bounded for
purposes of study.
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