GIS Data Catalog

Erosion Hazard Areas

Learn how to use GIS Open Data 🗺

Use this Data

Links How to use in ArcGIS Pro
Sharing Status	Public

Summary

Defines erosion hazard areas for unincorporated areas of King County first mapped for the King County Sensitive Areas Ordinance and published in the 1990 Sensitive Area Ordinance Folio.

Description

The 1990 King County Sensitive Ares Ordinance (SAO) defines significant erosion hazard areas as those soils in King County that may experience severe to very severe erosion hazard.

The 1990 KC SAO adopted the soils definition in the US Department of Agriculture Soil conservation Service (SCS) 1973 King County Soil Survey and the then current draft of the Snoqualmie Pass Area Soil Survey (No Date).

The full text included in the 1990 Sensitive Areas Ordinance Folio is included below.

I: Erosion Hazard Areas.

Erosion is a natural process of wearing away of land surfaces by falling and running water, wind, and glacial scour.

Of these geologic forces, erosion by running water is by far the most important within the Puget Sound Basin.

The susceptibility of any soil type to erosion depends upon the physical and chemical characteristics of the soil, in addition to its protective vegetative cover, topographic position (slope length and gradient), the intensity of rainfall, and the velocity of runoff water.

Whereas erosion is the wearing away of material, sedimentation or deposition is the accumulation of eroded matter where water carrying sediment is slowed.

The effects of sedimentation are most pronounced where streams enter Puget Sound and in lowland lakes, ponds, wetlands, and stream channels.

The natural geologic processes of erosion and sedimentation are frequently accelerated by land use modifications and urban development.

The erosion hazard maps show areas of King County where-soils are particularly susceptible to increased erosion as a result of development.

II: Definition.

The Sensitive Areas Ordinance (SAO) defines erosion hazard areas as those soils in King County that may experience severe to very severe erosion hazard.

The SAO adopts the soils definitions in the US Department of Agriculture Soil Conservation Service (SCS) 1973 King County Soil Survey and the current dra

Layer information

Layer Name	erode_area
Subject Category	Environment
Title	Erosion Hazard Areas
Feature Count	481
Feature Type	Polygon
Next Update	None planned
Spatial reference	EPSG:2926
Control ID	295
Place Keywords	Washington State, King County, WA, Pacific NW
Theme Keywords	Natural Resources, Environmental, Enviro, Erosion, Hazard, Environment
Supplemental Information	None

Table Preview

Attribute information

Shape From ESRI	Description Feature Geometry Domain Coordinates defining the features
HAZARD From DDES	Description hazard type Domain ERS - erosion
EDIT_DATE From DDES	Description editi date Domain Not Found
OBJECTID From ESRI	Description Internal feature number. Domain Sequential unique whole numbers that are automatically generated.
Shape.STArea() From SQL Server	Description Returns the area of a geometry instance in square units, based on the spatial reference identifier (SRID) of the geometry. Domain Double
Shape.STLength() From SQL Server	Description Returns the total length of the elements in a geometry instance. Domain Double

Contact information

Maintained by	DLS - Permitting
Primary	Paul McCombs paul.mccombs@kingcounty.gov

Terms of Use

License	Terms of use and copyright