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Layer: Wetlands_TRPC (ID:0)

View In:   Map Viewer

Name: Wetlands_TRPC

Display Field: NWI_CODE

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: The "Wetland Indicator" maps for the Thurston Region were prepared from 1992 to 2002. All of Thurston County has been mapped except, lands zoned Long-Term Forestry and Military Reservation. The coverage includes portions of 615 sections (square miles) with the last maps completed in June 2002. Phase one of the mapping effort included all of northern Thurston County, including the cities of Olympia, Lacey and Tumwater; and then the remaining portion of the Deschutes River watershed (WRIA 13). That coverage included approximately 340 sections, and the mapping occurred in 1993 and 1996, respectively. The initial phases were mapped using the following protocol. Wetland consultant prepared wetland delineations based upon unrectified color infrared aerial photographs at a scale of 1:12,000 and taken in March 1992. The aerial photos within the urban growth area boundary were twice that size or 1:6,000. The consultants had available to them the National Wetland Inventory (NWI) and Soil Conservation Service (now NRCS) at the scale of 1:24,000. Wetlands were delineated into various categories using the Cowardin methodology used for the NWI mapping. Thurston Regional Planning Council (TRPC) digitized these wetland boundaries and rubber sheeted the wetland coverage to the Thurston County tax parcel maps. In 1997 TRPC undertook an independent evaluation of the relative accuracy of this mapping layer. It was found that there were a high number of false positives were associated with particular soil types and others on wetland types. Based upon these findings the entire coverage was scrubbed to eliminate these problems. A second recommendation to use the newly available 2 foot contour maps was implemented in the subsequent phases. In 1999 TRPC began wetland mapping for the remaining portions of rural Thurston County which were not zoned Long-Term Forestry and Military Reservation. TRPC staff prepared wetland delineations on work maps at the scale of 1:6,000 which contained a black and white orthohoto, the Thurson County 2 foot contour, NWI, and SCS soils layers. The color infrared aerial photos were consulted as needed, and the boundary lines were digital mapped. The staff generated wetland delineations used the same the QA/QC protocol established by the wetland consultants. In 1999, a local wetland consultant was hired to ground truth a sample of the new wetland delineation maps, and found that the new protocol was equal to if not superior to earlier 1993 mapping, with fewer false positives. In 2001 & 2002 the black and white orthophotos were replaced with color aerials taken during the summer of 2000. This greatly improved the ease of mapping relatively flat topography.

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Min. Scale: 0

Max. Scale: 0

Default Visibility: true

Max Record Count: 1000

Supported query Formats: JSON, geoJSON, PBF

Use Standardized Queries: True

Extent:

Drawing Info:

HasZ: false

HasM: false

Has Attachments: false

Has Geometry Properties: true

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Object ID Field: OBJECTID

Unique ID Field:

Global ID Field:

Type ID Field: COWARDIAN_CLASS

Fields:
Types:

Is Data Versioned: false

Has Contingent Values: false

Supports Rollback On Failure Parameter: true

Last Edit Date: 3/3/2022 10:51:35 PM

Schema Last Edit Date: 3/3/2022 10:51:35 PM

Data Last Edit Date: 3/3/2022 10:51:35 PM

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