Bank Protection Revetment, or other armor protecting a bank of a stream from erosion,
includes devices used to deflect the forces of erosion away from the bank.
Bank An elongated deposit of alluvium within a channel or across its mouth.
Barrier A low dam or rack built to control flow of debris
Base Flood The flood or tide having a 1 percent chance of being exceeded in any given
year (100- year flood). The "base flood" is commonly used as the "standard flood" in Federal
flood insurance studies. (see Regulatory Flood).
Base Floodplain The area subject to flooding by the base flood.
Base Flow The flow contribution to a creek by groundwater. During dry periods, base
flow constitutes the majority of stream flow.
,Basin (1) The surface area tributary to a stream or lake. (2) Space above or below ground
capable of retaining or detaining water or debris.
Bay An indentation of bank or shore, including erosional cuts and slipouts, not
necessarily large.
Beach The zone of sedimentary material that extends landward from the low water line to
the place where there is marked change in material or form, or to the line of permanent
vegetation (usually the effective limit of storm waves).
Bed The earth below any body of water, limited laterally by bank or shore.
Bed load Sediment that moves by rolling, sliding, or skipping along the bed and is
essentially in contact with the stream bed
Bedding The foundation under a drainage structure.
Beneficial Uses As referred to in the State Water Quality Standards, beneficial uses are
activities that range from recreational to agricultural uses, depending on the source of the water.
,Berm (1) A bench or terrace between two slopes. (2) A nearly horizontal part of the beach
or backshore formed at the high water line by waves depositing material.
Best Management Practices (1) A measure that is implemented to protect water quality
and reduce the potential for pollution associated with stormwater runoff. (2) Any program,
technology, process, siting criteria, operating method, measure, or device that controls, prevents,
removes, or reduces pollution
Block Precast prismatic unit for riprap structure
Bluff A high, steep bank composed of erodible materials.
Boil Turbulent break in a water surface by upwelling
Boom Floating log or similar element designed to dampen surface waves or control the
movement of drift
, Bore A transient solitary wave in a narrow or converging channel advancing with a steep
turbulent front; product of flash floods or in-coming tides.
Boulder Largest rock transported by a stream or rolled in the surf; arbitrarily heavier than
12 kg and larger than 200 mm
Braided Stream A stream in which flow is divided at normal stage by small islands. This
type of stream has the aspect of a single large channel with which there are subordinate channels
Breaker A wave meeting a shore, reef, sandbar, or rock and collapsing.
Breakwater A fixed or floating structure that protects a shore area, harbor, anchorage, or
basin by intercepting waves.
Bulkhead A steep or vertical structure placed on a bank, bluff, or embankment to retain or
prevent sliding of the land and protect the inland area against damage.
Bulking The increase in volume of flow due to air entrainment, debris, bedload, or
suspended sediment.