GIS Layer Descriptions

Parcels

  • Steward: Assessor's Office, (209) 754-6356
  • Accuracy Statement: Parcel boundary lines are accurate to a 1:250,000 scale.
  • Description: The County parcel layer was derived in 1999 from the parcel data of the Assessor's office and various utility companies in the county. The complete and contiguous parcel fabric was then registered and rectified to the best available Public Land Survey (PLS) available. This PLS layer has many inherent inaccuracies related to the original surveys completed in the late 19th and early 20th centuries. As more accurate ground controls become available, the parcel layer will be adjusted. The parcel layer is currently updated on a roughly quarterly basis.

 

Roads

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: Road centerlines are accurate to a 1:12,000 scale.
  • Description: The county roads layer consists of centerlines. The original layer was GPSed in 2000 by a contractor to an National Map Standard of +/- 10 feet or better. Additional road centerlines have been added via GPS or digitizing from the 1998 USGS DOQQs. There are still many outstanding road naming issues that are yet to be resolved. Addressing ranges will be added over time.

 

1998 USGS Digital OrthoQuads

  • Steward: USGS, http://edcwww.cr.usgs.gov/
  • Accuracy Statement: Refer to the USGS Documentation for accuracy, http://edcwww.cr.usgs.gov/
  • Description: The USGS Digital Orthographic Quarter Quadrangles (DOQQ) is a 1 meter resolution, black and white, orthorectified aerial photograph.

 

2002 Color Digital Ortho Images

  • Steward: Calaveras County GIS Office, (209) 754-6366
  • Accuracy Statement: The images were orthorectified to meet an accuracy of +/- 3 feet rms.
  • Description: The Digital Ortho Images (DOI) are a 2 foot resolution, color, orthorectified aerial photograph data set. This data set was purchased through a cooperative buying pool comprised of Calaveras County, City of Angels Camp, Calaveras Council of Governments, Calaveras County Water District, California Department of Forestry, CalTrans, and BLM.

 

USGS Topo Maps

 

Supervisorial Districts

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: Supervisorial District areas are accurate at a 1:250,000 scale.
  • Description: The Supervisorial District layer was generated from the county parcel layer to indicate the boundaries of the 5 supervisorial districts in the county.

 

Census Tracts 2000

 

Census Blocks 2000

  • Steward: US Census Bureau, http://www.censuswatch.com/http://www.censuswatch.com/
  • Accuracy Statement: Refer to the Census 2000 documentation for accuracy statements, http://www.censuswatch.com/
  • Description: The census blocks for the county with some demographic attributes attached.

 

Fire Districts

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: Fire District areas are accurate at a 1:250,000 scale.
  • Description: The Fire District layer was generated from the county parcel layer.

 

Cal Fire - Fire Response Areas

  • Steward: California Department of Forestry and Fire Prevention (Cal Fire), http://www.fire.ca.gov/
  • Accuracy Statement: Refer to Cal Fire for accuracy statement.
  • Description: This layer represents the Cal Fire fire response areas. It is a subset of the Tuolumne/Calaveras Cal Fire Fire Response Layer.

 

Township Range

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: The Township Range layer is accurate to a 1:250,000 scale.
  • Description: The Township Range layer was developed by a consultant from the best Public Land Survey (PLS) data available. The available data consisted of the BLM and USGS PLS layers.

 

County Boundary

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: The county boundary layer is from a National Data Set and is accurate to a 1:24,000 scale.
  • Description: The county boundary layer is one single polygon indicating the extent of the county.

 

Community Areas

  • Steward: GIS Office, (209) 754-660
  • Accuracy Statement: Community Areas are accurate at a 1:250,000 scale.
  • Description: The Community Area layer was generated from the county parcel layer. It represents the Addressing community boundaries.

 

Voter Precincts

  • Steward: Elections Office, (209) 754-6376, with GIS Office support, (209) 754-6608
  • Accuracy Statement: Voter Precincts are accurate at a 1:250,000 scale.
  • Description: The Voter Precincts layer was generated from the county parcel layer using the Tax Rate Area codes.

 

Zip Codes

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: Unknown
  • Description: The Zip Codes layer was copied from the ESRI Data CD.

 

TRA

  • Steward: Assessor’s Office, (209) 754-6356
  • Accuracy Statement: The TRA lines are accurate to a 1:250,000 scale.
  • Description: The TRA layer was generated from the county parcel.

 

Assessor Books

  • Steward: Assessor’s Office, (209) 754-6356
  • Accuracy Statement: The Assessor Books lines are accurate to a 1:250,000 scale.
  • Description: The Assessor Books layer was generated from the county parcel layer.

 

Main Rivers

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: The Main Rivers centerlines are accurate to a 1:100,000 scale.
  • Description: The Rivers layer was downloaded from the National Hydrography Dataset at http://nhd.usgs.gov/ . Corrections and improvements by the Calaveras County GIS Office are on-going.

 

Main Towns

  • Steward: GIS Office, (209) 754-6608
  • Accuracy Statement: The Main Towns layer is from a national data set and is accurate to a 1:24,000 scale.
  • Description: The Main Towns layer represents the most populated towns in Calaveras County as point features.