King County GIS Center
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Seattle, WA 98104

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- 122.33136 W

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- 122° 19' 52.90"


Agricultural Waterway Classification

Description | Contacts | Attribute Information | Constraints

Data layer thumbnail image


Layer name: AG_WWAYS_CLASS
Subject category: hydro
Title: Agricultural Waterway Classification
Feature Count: 1558
Feature Type: Line
Abstract: Waterway Classification within Agricultural Production Districts developed as a resource for the Agricultural Drainage Assistance Program (ADAP) .The first component of the classification is whether the waterway is a natural stream, a modified stream, or an artificial ditch. The second component describes the expected presence or level of abundance of juvenile salmonids during the standard construction window.
Purpose: A classification of waterways in order to guide decisions on allocation of best management practices for fish protection and restoration of fish habitat and water quality during agricultural waterway maintenance dredging. To rate potential level of juvenile salmon use at time of maintenance, the classification applies local, credible knowledge of salmon abundance or density, water flow and temperature, or, where such knowledge is lacking, King County Geographic Information System (GIS) data to predict the potential for high, moderate, or low levels of salmon use in a given Agricultural Production District (APD) waterway. .
Status: Complete
Updated: As needed
Time period of content: (single date,as YYYYMMDD):: 20180319
Time period of content: (date range, as YYYYMMDD):: -
Spatial reference: WA State Plane North
FGDC Documentation: Classic or FAQ
Open Data Availability: Not Available
Place Keywords: Pacific NW, King County, WA, Washington state,
Theme Keywords: hydro, salmonids, agriculture, drainage, farming, biota, environment,
Lineage: Available
Supplemental Information:


Maintained by:
King County IT, GIS Center
Primary: Todd Klinka, GIS Analyst, 206-477-4412
(How to e-mail a County contact)
Secondary: KCGIS Center; This mailbox is monitored during business hours.

Attribute Information

_WRIA_NO_Water Resource Inventory Area NumberWater Resource Inventory Area Number
_WRIA_NAME_Water Resource Inventory Area NameWater Resource Inventory Area Name
_WTRSHD_NAME_Watershed NameWatershed Name
_BASIN_NAME_Basin NameBasin Name
_Juv_fish_use_summer_Knowledge of known use by juvenile salmonidsKnowledge of known use by juvenile salmonids : Yes or Unknown
_Fish_passage_barrier_Presence of fish passage barrierPresence of fish passage barrier: total, partial, none or uknown
_Fish_passage_citation_Citation for fish passage Citation for fish passage information
_Summer_flow_local_knowledge_Knowledge of summer flow
_Upstream_catchment_Existence of upstream catchment
_Water_Source_Water source
field drainage/farm pondfield drainage/farm pond
known shallow groundwater interceptionknown shallow groundwater interception
known springknown spring
known tributaryknown tributary
known valley-wall-based seepageknown valley-wall-based seepage
suspected shallow groundwater interceptionsuspected shallow groundwater interception
suspected springsuspected spring
suspected tributarysuspected tributary
suspected valley-wall-based seepagesuspected valley-wall-based seepage
_Channel_configuration_Type of channel configuration
modifiedModified waterways are natural waterways that have been straightened, usually as a consequence of diversion, dredging or diking, and have not reestablished a natural meander pattern.
naturalNatural waterways are naturally occurring water bearing features, typically with headwaters, that have not been significantly altered from their historical meandering flow path or floodplain in any manner or, if historically altered, have reestablished a meandering course passively or through active restoration
_Extent_of_channel_modification_Extent of channel modification
low (5 - 25% affected)low (5 - 25% affected): Definition of code value [low (5 - 25% affected)] in CVD extent_of_channel_modification
majority (50 to 75% affected)majority (50 to 75% affected): Definition of code value [majority (50 to 75% affected)] in CVD extent_of_channel_modification
mostly or all (75 to 100%)mostly or all (75 to 100%): Definition of code value [mostly or all (75 to 100%)] in CVD extent_of_channel_modification
none or only trace (LT 5%)none or only trace (LT 5%): Definition of code value [none or only trace (LT 5%)] in CVD extent_of_channel_modification
_Classification_Current_Waterway classificationWaterway classification: low, moderate, or high plus natural, modified, or artificial, or else unknown
_Question_Num_classification_Decision tree question (for making classification determination)
1Is there credible knowledge of fish use (e.g.,density or population estimates, fish removal counts, or visual counts by a qualified fish biologist during mid- to late-summer low-flow period? If yes, does that knowledge/information definitively indicate either high or low/no use?
2If no credible salmonid use information is available, or if such information is ambiguous or may be unreliable, is there a total fish passage barrier identified in an existing GIS database or through other credible local information? If a total barrier is present, then the use of the waterway is classified as “low.”
3Is there known to be summer flow, a spring present, or is the channel a side channel to a mainstem river?
4If flows are unknown or uncertain, is the contributing (upstream) watershed area sufficient to generate summer flow?
5Is there a geomorphic feature present that indicates seepage, or is there a backwatering effect causing standing water and that is also connected to a perennial stream?
_APD_name_Agricultural Production District NameName of APD,


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