GIS Data Catalog

TITLE: Schema change Items WTR_CRS_ID and FEATURE_ID dropped.

WTRCRS_ID is an attribute from the original early 1990s development of the layer and is no longer maintained.

FEATURE_ID was added at the beginning of PHASE 1 development as a way to related external data to features.

However it was difficult to maintain and saw limited, if any use.

After Phase II development of a measure-based route system is completed, each stream or river will have a unique feature identifier expressed as a route identifier.

TITLE: Extent of WTRCRS reduced The extent of WTRCRS is reduced to features which are encompassed by basins defined by the Phase II project plan.

The Phase II project plan includes only those basins that are wholly or part within King County.

These are basins that have both defined business requirements and for which generally adequate control is available.

The areas outside of this revised extent generally do not.

Areas outside of the newly defined bounds are covered by data provided by adjacent counties.

Users can use the new layer, WTRCRS_3CO to view a layer that composites the core King County data and adjacent county data.

TITLE: DATA DEVELOPMENT PREP This step compiled the .aml generated datasets as well as the auxillary data into one dataset.

.aml primarily used were, accumulation, slope, DEM and STRM40k.

The reference datasets primarily used were the following:idxptrmbr.shp  Provides an index in order to locate other datasetsdgm_contour  Provides information on elevationortho_2002kc_nat  Provides visual informationortho_2002usgs_nat  Provides visual informationculverts.shp  Provides information of where culverts are in King Countyrniscul.shp  Provides information of where the rniscul are in King Countyseattle_drainage.lyr  Provides drainage information for the City of Seattle In addition, a shapefile named DEMFIX was created in order for the watercourse to cross manmade barriers, such as bridges and overpasses.

This was a polygon, short integer.

The dataset is primarily for the watershed delineation process but was created in the watercourse data development prep process.

TITLE: EDITING PROCESS Heads-up digitizing was the method of updating the exisitng geometry of the streams.

In order to correct the geometry of the exisitng watercourse various datasets were used.

The heirarchy of their use is as 1.

King County 2002 Ortho Imagery 2.

USGS Ortho Imagery 3.

DEM with 50% Transparency Slope derived from 2002 LiDAR 4.

Contours derived from 2002 LiDAR 5.

Accumulation dervied from 2002 LiDAR 6.

Drainage datasets when available for certain areas The Protocol for determining confidence rating scheme: 1 = stream path is clear and evident, path can be 100% determined through the use of imagery or LiDAR Datasets 2 = stream path is obsured and path cannot be 100% determine (road, urban area).

3 = stream path is not possible due to data provided These arcs are primarily mistakes in the data set There is no possible way that the stream flows in this manner These arcs will be eliminated 4=added arcs (these arcs were added either for proper watershed delineation or from current agricultural datsets provided by WRLD).

Updates done as better information becomes available.

Acquisition of higher resolution LiDAR has been a valuable source for updates.

Field observations from King County personnel is also used.

A unique hierarchical identifier was added to each stream, RTE_ID.

All streams were routed using RTE_ID as the route id.

TITLE: LEGACY DATA HISTORY WTRCRS was created in a 1997 joint project between WA Dept of Ecology and King County Water and Land Division from an initial source coverage of the standard WA Dept.

of Natural Resources hydrography layer.

This data set is integrated from numerous sources, primarily at 1:24,000 scale.

More information about this initial version, some of which still applies to the current version, can be found in this supplemental document.

Beginning in 2001, WLRD started updating this coverage with additional information from other jurisdictions and field data.

Although this has obviously resulted in improved data accuracy, the current version also differs from the original in not having a route system.

The old routed version can be obtained from the contacts below if desired.

Spatial accuracy was improved using 2002 digital orthophotography and LiDAR data.

Limited updates were done from 2007 digital orthophotography.

Routes added in 2008/2009.

Additional updates were done 2009 to 2016.

TITLE: QUALITY CONTROL After the watercourse was edited, it was visually inspected for major errors.