Erosion and Sediment Pollution Control Program Manual.pdf

Flow Time -----The estimated time required for runoff to travel a specified distance in an anticipated
flow regime, such as overland flow, shallow concentrated, or channel flow).
Flowing Well -----A well that flows under hydrostatic pressure to the surface.
Flume -----1. A pipe or section of pipe used to convey flow across trench or disturbed area. 2. A
constructed channel lined with erosion-resistant materials used to convey water on steep
grades without erosion.
Fluvial Geomorphology (FGM) ----- The study of a stream’s interactions with the local climate,
geology, topography, vegetation, and land use; the study of how a river carves its channel within
its landscape.
Fly Ash -----The solids, ash, cinders, dust, soot, or other partially incinerated material removed from a
gas stream, typically associated with coal-fired electric generating plants.
Footing (Footer) -----The supporting base or ground work of a structure.
Forage -----Unharvested plant material that can be used as feed by domestic animals. It may be
grazed or cut for hay.
Forb -----Any herbaceous flowering plant other than grass or sedge.
Force Main -----A sewer line that is pressurized.
Ford -----A submerged stream crossing where vehicles travel at or near the stream bed.
Forebay -----1. The water behind a dam. 2. A reservoir or pond situated at the point where a channel or
pipe discharges into a sediment basin or detention pond for the purpose of catching sediment
and facilitating maintenance.
Foreshore -----The part of a shore lying between the crest of the berm, or upper limit of wave wash at
high tide, and the ordinary low-water mark, typically traversed by the uprush and backrush of
the waves as the tides rise and fall.
Forest Stewardship Plan -----A written plan that provides an overview of a woodland property in the
context of a landowner’s needs and objectives and serves as a means of communicating
technical information in a concise form that is useful to the landowner.
Forest/Woodland Land Use -----Deciduous, evergreen or mixed forestland; woodlots in suburban or
urban areas.
Forested Wetland -----Wetlands dominated by mature trees.
Foundation Drain -----A pipe or series of pipes designed to collect groundwater from the foundation or
footing of a structure and convey it to a chosen discharge point.
FPS, or fps -----Feet per Second. (Velocity).
Fracture -----A break in rock caused by stresses, or release from stresses.
Fragipan -----A natural subsurface soil horizon with high bulk density compared to the soil column
above it, seemingly cemented when dry but moderately to weakly brittle when moist.
Free Flow -----Flow through or over a structure not affected by submergence or backwater.
Free Water -----Water in soil that is free to move by gravity — in contrast to capillary or hygroscopic
moisture.
Freeboard -----1. The vertical distance between the design maximum water elevation in a BMP and the
top of the berm or embankment. 2. In dams, it is the distance between normal pool elevation
and the top of the dam.
Freeze-Thaw Resistance -----Ability to resist movement and/or degradation caused by cycles of
extreme temperature fluctuations above and below the freezing point.
French Drain -----A drainage device in which a hole or trench is backfilled with sand or gravel —
sometimes with a perforated pipe.
Frequency Curve -----A graphical representation of the frequency of occurrence of specific events,
such as storm events.
Frequency of Storm -----The average period of years that will elapse before another storm of equal
intensity will recur. For example a 10-year storm can be expected to occur once during a 10year
period. Note: This is based on probabilities. Storms with large return periods, such as
100 years, have been known to follow closely after one another.
Friable -----1. Of rock, the characteristic of crumbling naturally or being easily broken, pulverized, or
reduced to powder such as a poorly cemented sandstone. 2. Of soil, the consistency in which
moist soil material crushes easily under gentle to moderate pressure — between thumb and
forefinger — and coheres when pressed together.
363-2134-008 / March 31, 2012 / Page 520