Watershed Maps and GIS Data

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Disclaimer

The State of California and the Department of Conservation make no representations or warrantees regarding the accuracy of the data from which these maps were derived. Neither the State nor the Department shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of these maps.

The identification and location of landslide hazard areas are based on review of limited aerial photographs that are listed on each specific map. In most cases, only two sets of aerial photographs were used to construct the landslide and geomorphic features maps. Due to time constraints all available data were not necessarily reviewed and used in construction of these maps. The quality of data used is varied. The information depicted on the maps has been drawn as accurately as possible at 1:24,000 scale. The maps and reports provided on this web site are subject to change without notice, and the latest available versions will be posted on this web site.

Information on the maps are not sufficient to serve as a substitute for site specific geologic and geotechnical site investigations as required under the Chapters 7.5 and 7.8 of Division 2 of the Public Resources Code.

Special Report 217: Revised Geologic Compilation of Quaternary Surficial Deposits in Southern California

Cover image from Special Report 217

North Coast Watersheds Mapping Project

North Coast Watershed Mapping CD cover
  • Subtitle: Geology and Geomorphic Features Related to Landsliding
  • Sixty 7.5 minute quadrangles for parts of Mendocino, Humboldt, and Del Norte counties
  • Released as Open File Reports from 1982 to 1985
  • Digitized and re-released in 1999 on compact disc (CD 99-002)
  • Scale 1:24,000
  • Explore North Coast Watersheds Mapping Project

Watershed Mapping Series

  • Covers nine watersheds in Humboldt, Mendocino, and Sonoma counties
  • Maps depict geologic and geomorphic features related to landsliding, and landslide potential
  • Released on compact discs from 2001 to 2005
  • Scale 1:24,000
  • The WMS is a product of the North Coast Watersheds Assessment Project
  • Related: OFR 95-06 (Mokelumne River watershed).
Thumbnail image: map of East Noyo River watershed Thumbnail image: map of West Noyo River watershed

Noyo River Watershed

  • Watershed Mapping Series, Map Set 1, CD 2001-03
  • Map of Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Noyo River Watershed, Mendocino County, California
  • Landslide Potential Map with Geologic and Geomorphic Features, Noyo River Watershed, Mendocino County, California
  • Scale 1:24,000
  • Explore WMS Map Set 1, Noyo River Watershed
Thumbnail image: map of Jackson Demonstration State Forest

Jackson Demonstration State Forest

  • Watershed Mapping Series, Map Set 2, CD 2002-05: Jackson Demonstration State Forest
  • Preliminary Map of Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Jackson Demonstration State Forest, Mendocino County, California
  • Preliminary Landslide Potential Map with Geologic and Geomorphic Features, Jackson Demonstration State Forest, Mendocino County, California
  • Scale 1:24,000
  • Explore WMS Map Set 2, Jackson Demonstration State Forest
  • Related: OFR 95-08.
Thumbnail image: map of Freshwater Creek watershed

Freshwater Creek Watershed

  • Watershed Mapping Series, Map Set 3, CD 2002-06
  • Digital Representation of OFR 99-10 and OFR 99-10a, Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Freshwater Creek, Humboldt County, California
  • Digital Representation of OFR 99-10 and OFR 99-10a, Relative Landslide Potential with Geologic and Geomorphic Features, Freshwater Creek, Humboldt County, California
  • Scale 1:24,000
  • Explore WMS Map Set 3, Freshwater Creek Watershed
Thumbnail image: map of Elk River watershed

Elk River Watershed

  • Watershed Mapping Series, Map Set 4, CD 2005-01
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Elk River Watershed, Humboldt County, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Elk River Watershed, Humboldt County, California
  • Scale 1:24,000
  • Explore WMS Map Set 4, Elk River Watershed
Thumbnail image: map of north Gualala River watershed Thumbnail image: map of central Gualala River watershed Thumbnail image: map of south Gualala River watershed

Gualala River Watershed

  • Watershed Mapping Series, Map Set 5, CD 2002-08
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Gualala River Watershed, Sonoma and Mendocino Counties, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Gualala River Watershed, Sonoma and Mendocino Counties, California
  • Potential Restoration Sites and Habitat Limiting Factors for the Gualala River Watershed, Sonoma and Mendocino Counties, California
  • Scale 1:24,000
  • Explore WMS Map Set 5, Gualala River Watershed
  • Related: OFR 95-05.
Thumbnail image: map of Redwood River watershed

Redwood Creek Watershed

  • Watershed Mapping Series, Map Set 6, CD 2002-10
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Redwood Creek Watershed, Humboldt County, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Redwood Creek Watershed, Humboldt County, California
  • Scale 1:24,000
  • Explore WMS Map Set 6, Redwood Creek Watershed
Thumbnail image: map of north Mattole River watershed Thumbnail image: map of central Mattole River watershed Thumbnail image: map of south Mattole River watershed

Mattole River Watershed

  • Watershed Mapping Series, Map Set 7, CD 2002-09
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Mattole River Watershed, Humboldt and Mendocino Counties, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Mattole River Watershed, Humboldt and Mendocino Counties, California
  • Scale 1:24,000
  • Explore WMS Map Set 7, Mattole River Watershed
Thumbnail image: map of Albion River watershed

Albion River Watershed

  • Watershed Mapping Series, Map Set 8, CD 2004-03
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Albion River Watershed, Mendocino County, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Albion River Watershed, Mendocino County, California
  • Scale 1:24,000
  • Explore WMS Map Set 8, Albion River Watershed
Thumbnail image: map of west Big River watershed Thumbnail image: map of east Big River watershed

Big River Watershed

  • Watershed Mapping Series, Map Set 9, CD 2005-02
  • Geologic and Geomorphic Features Related to Landsliding (color and black-and-white), Big River Watershed, Mendocino County, California
  • Relative Landslide Potential with Geologic and Geomorphic Features, Big River Watershed, Mendocino County, California
  • Scale 1:24,000
  • Explore WMS Map Set 9, Big River Watershed

Title II Geologic Data Compilation Project

  • Subtitle: Geology and Landslides in Selected North Coast Quadrangles of Northern California
  • The project encompassed more than 70 quadrangles from Del Norte County south to Santa Cruz County
  • Geologic and landslide data were compiled at a scale of either 1:62,500 (north of San Francisco) or 1:24,000 (south of San Francisco)
  • Released in 1979
  • Title II project maps and supplemental material are available only by request, due to the maps being outdated and other limitations of the data.
  • Please refer to the more recent and more detailed north coast mapping products listed elsewhere on this web page.

More information about the Title II Project

‭(Hidden)‬ CSS
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