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# National Water Information System
# 2024/04/24
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# Date Retrieved: USGS Water Data for the Nation Help System
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gw_ref_cd	gw_ref_nm	gw_ref_ds
1s	16s	102s
A	Alluvial fan	Stream deposit of loose rock material where it issues from a narrow mountain valley upon a plain.
B	Playa	Undrained desert basin in which water accumulates and is quickly evaporated.
C	Stream channel	Bed in which a natural stream of water runs.
D	Local depression	An area that has no external surface drainage.
E	Dunes	Mounds and ridges of windblown, or eolian sand.
F	Flat surface	May be part of a larger feature, such as a plateau, plain, or pediment.
G	Flood plain	Smooth land surface adjacent to a river channel that is flooded when the river overflows its banks.
H	Hilltop	Upper part of a hill or ridge above a well-defined break in slope.
K	Sinkhole	Depression that results from the dissolving of soluble rocks and collapse into the solution cavity.
L	Lake or Swamp	Inland lake, swamp, or marsh where the ground may be saturated or water stands above the land surface.
M	Mangrove swamp	Tropical or subtropical marine swamp characterized by abundant mangrove trees.
O	Offshore	Site along a coast or estuary that is continuously submerged.
P	Pediment	Plain of combined erosion and deposition that forms at the foot of a mountain range.
S	Hillside	Sloping side of hill, the area between the hilltop and valley flat.
T	Alluvial terrace	Generally a flat surface, usually parallel to but elevated above a stream valley or coast line.
U	Undulating	Topography is characteristic of areas which have many small depressions and low mounds.
V	Valley flat	Low flat area between the valley walls and bordering a stream channel.
W	Upland draw	Small natural drainageway