Soil Data

Soil data for the Lake Tahoe area are now available online! The Natural Resource Conservation Service (NRCS) soil maps are available from the SSURGO database.

The following info files regarding soil data are from the NRCS website ( http://www.ftw.nrcs.usda.gov):

• Readme
• SSURGO users guide (pdf file)

Data Download

Soil data are in UTM NAD27 zone 10 projection. Raw (original) data are in the following projections: data east of 120 degrees longitude are in UTM zone 11 and data west of 120 degrees longitude are in UTM zone 10. It is not possible to combine different projections in Geographic Information System (GIS), therefore, all data have been reprojected into one standard projection, UTM NAD27 zone 10 projection, for the Lake Tahoe Basin.

The following soil data have been mosaicked together from the18 7.5-minute quadrangles that cover the Lake Tahoe Basin. The mosaicked files are more convenient for looking at areas throughout the basin or areas on the edge of two quadrangles.

The following SSURGO data are stored in three different file formats, each contain the same information: soils_sdts.zip (SDTS format, 2 MB compressed) soils_e00.zip (ARC/INFO export format, 3 MB compressed) soils_shp.zip (Shapefile format, 4 MB compressed) Metadata Also important to the digital soil survey is a set of tables. These tables are included in the ARC/INFO file but are also available seperately in the soil feature tables (a comma delimited text file). The NRCS digital soil survey covers only the area within the Lake Tahoe Basin as shown in the image on the left.