WATERSHED RELATED TERMS AS COMPILED OR DEFINED BY THE

 NITROGEN AND PHOSPHORUS DELIVERY FROM SMALL WATERSHEDS TO
2010-NH-Watershed-Managers_Roundtable-notes
ARIZONA WATERSHED MAP FY 2022 TITLE OF PROJECT LOCATION

BOOKS ABOUT SALMON & WATERSHEDS (MOSTLY FOR KIDS) COMPILED
DATA EVALUATIONDOCUMENTATION FORM NAME OF WATERSHED NAME OF ORGANIZATIONTRIBE
DESIGN AND DEVELOPMENT OF SOFTWARE FOR TRAINING THE WATERSHED

Watershed An area of land that drains water to a common outlet

Watershed Related Terms

As Compiled Or Defined By The DNR Lake Watershed Delineation Project

December 2006



Watershed. An area of land that drains water to a common outlet.

- Can be called a basin, catchment, contributing area or a geographic management units

- All watersheds are Hydrologic Units.


Classic Watershed. A land and water area that has all the surface drainage within its boundary converging to a single point.


Catchment. A classic watershed representing the smallest delineated portion of a watershed unit necessary to characterize a watershed of interest.


Contributing Area. The total area flowing to an outlet

- produces contributing volume

- catchment


Watershed Unit. A discrete area of the landscape surface that reflects hydrologic properties that have been delineated for management purposes.


Hydrologic Unit (HU). A hydrologic unit is a drainage area delineated to nest in a multi-level, hierarchical drainage system. Its boundaries are defined by hydrographic and topographic criteria that delineate an area of land upstream from a specific point on a river, stream or similar surface waters. A hydrologic unit can accept surface water directly from upstream drainage areas, and indirectly from associated surface areas such as remnant, non-contributing, and diversions to form a drainage area with single or multiple outlet points. Hydrologic units are only synonymous with classic watersheds when their boundaries include all the source area contributing surface water to a single defined outlet point.


Hydrologic Unit Code (HUC). The numerical identifier of a specific hydrologic unit consisting of a 2-digit sequence for each specific level within the delineation hierarchy.


Headwaters Watershed. A catchment that has no upstream contributing area(s).


Major Watershed Unit. An administrative watershed unit delineation that exists at the highest formally defined level in the Minnesota watershed unit hierarchy.

- always composed of Minor and 11-Digit Watershed Units

- are made of catchments.


USGS 11-digit Watershed Unit. An administrative watershed unit delineation that exists between the formally defined Minnesota DNR Major and Minor watershed hierarchal levels.

- always composed of minor and 11-digit watershed units

- are made of catchments.


Minor Watershed Unit. - an administrative watershed unit delineation that exists at the lowest formally defined level in the Minnesota watershed unit hierarchy.

- are made of lake watershed catchments.


Basin Watershed Unit. - An administrative watershed delineation that exists at the lowest formally defined level in the Minnesota watershed unit hierarchy.

- entire contributing area


Lake Watershed. - An area of land that drains water to a lake outlet.

- Collection of all catchments up-stream from a lakes outlet.

- Includes both contributing watershed volume plus landlocked lake watershed contributing volume.

- Lake Watersheds are Hydrologic Units.

- Lake Watersheds contain or include DCA's.


Direct Contributing Area (DCA). An area bounded by a height of land delineation that contains the land, noncontributing areas, adjacent wetlands, channel flow, and other hydrologic features that route overland flow directly into the watercourse, watercourse segment, lake or wetland basin of interest.

- DCAs are Hydrologic Units.

- DCAs can also be called Local Area Watershed or Local Area Catchment.

- DCAs can be defined volumetrically as the contributing area’s volume flowing through a pour point minus any delineated upstream contributing catchment’s volume.

- DCAs do not include concentrated flow from upstream-delineated watersheds.

> DCAs that have upstream contributing areas are not true catchment or classic watershed delineations. Therefore, DCAs with upstream contributing areas used alone are not suitable for hydrologic analysis.

- If the DCA has no upstream contributing areas the delineation defines a Headwaters Watershed.

- DCAs are not Lake/Wetland Watersheds unless they are a Headwaters Watershed.

- DCA delineations are often used because available time and lake or wetland project-based funding ties the scope of projects to the direct contributing area.

- DCAs include concentrated flow sources that would result in a Remnant Watershed if the conveyance feature were delineated separately.


Watershed Area to Lake/Wetland Surface Area Ratio. A measurement (ratio) relating how much lake/wetland area there is relative to the contributing watershed area.

Typically, water quality decreases as the ratio of watershed area to lake/wetland area increases. This results in general, because as the watershed to lake/wetland area increases there are additional sources (and volumes) of runoff to the lake/wetland.


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Created by sevaughn, Created on 05/12/2006 23:51:00

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DEVELOPMENT OF A SYSTEMSBASED APPROACH TO INTEGRATED WATERSHED MONITORING
DRAFT FOR REVIEW BY THE WRIA 9 WATERSHED ECOSYSTEM
EAST BRANCH FISHING CREEK WATERSHED ATMOSPHERIC DEPOSITION TMDL SULLIVAN


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