Alaska Department of Fish and Game
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Definition of Terms
- Anadromous Fish
"Anadromous Fish" means a fish or fish species that spends portions of its life cycle in both fresh and salt waters, entering fresh water from the sea to spawn and includes the anadromous forms of pacific trouts and salmon of the genus Oncorhynchus (rainbow and cuththroat trout, and Chinook, coho, sockeye, chum, and pink salmon), Arctic char, Dolly Varden, sheefish, smelts, lamprey, whitefish, and sturgeon.
"Banks" means the portion of the stream channel cross section that restricts the lateral movement of water at normal bank-full levels. Often exhibiting a distinct break in slope from the stream bottom.
"Bed" means the substrate, bounded by the stream banks, over or through which the water column flows.
- Braided Channels
"Braided Channels" means the intertwined branches or secondary channels of a river or stream and characterized by the separation and rejoining of two or more channels separated by bars or islands.
- Mean high water
"Mean high water" means a tidal datum used in referring to tidelands or the tidally affected portion of a stream, that is equal to the average of all high tides over a 19-year Metonic cycle, as established by the National Oceanic and Atmospheric Administration.
- Mean lower low water
"Mean lower low water" means a tidal datum used in referring to tidelands or the tidally affected portion of a stream, that is equal to the average of the two low tides of each day over a 19-year Metonic cycle, as established by the National Oceanic and Atmospheric Administration.
- Ordinary High Water Mark
Ordinary High Water Graphic * (PDF 2,291 kB) "Portion of the bed(s) and banks, up to the ordinary high water mark (OHW)" means
- (A) in the non-tidal portion of a river, lake or strea: the portion of the bed(s) and banks up to which the presence and action of the non-tidal water is so common and usual, and so long continued in all ordinary years, as to leave a natural line or "mark" impressed on the bank or shore as indicated by erosion, shelving, changes in soil characteristics, destruction of terrestrial vegetation, or other distinctive physical characteristics;
- (B)in a braided river, lake, or stream: the area delimited by the natural line or "mark," as defined in Part A above, impressed on the bank or shore of the outside margin of the most distant channels; or
- (C) in the tidally influenced portion of a river, lake, or stream: the portion of the bed(s)
and banks below the
- OHW as described in A or B above, or
- mean high water elevation; whichever is higher at the project site.
- Riparian Vegetation
"Riparian Vegetation" s the plant life that occurs adjacent to a waterway and functions to buffer (or protect) the water body. Riparian buffers [Riparian Management Zone (RMZ)] perform a range of functions: trap/remove sediment from runoff; stabilize stream bans and reduce channel erosion; trap/remove phosphorus, nitrogen and other nutrients that can lead to eutrophication of aquatic ecosystems; trap/remove other contaminants such as pesticides; store flood waters, thereby decreasing damage to property; maintain habitat for fish and other aquatic organisms by moderating water temperatures and providing woody debris; provide habitat for terrestrial organisms; improve the aesthetics of stream corridors (which can increase property values); offer recreational and educational opportunities (based on Schueler 1995a, Malanson 1993).