Salmon Snapshots

Big River

Stream Habitat Conditions


Characterizing and inventorying the physical conditions that define in-stream habitat for salmonids and trout is an important part of the habitat restoration process. The National Marine Fisheries Service (NMFS) compiled in-stream habitat data in support of recovery plans for coho salmon, Chinook salmon, and steelhead in the North Central California Coast Recovery (NCCC) Domain – from Redwood Creek in Humboldt County to Aptos Creek in Santa Cruz County. NMFS used the most robust dataset available – the California Department of Fish and Wildlife (CDFW) stream habitat summary data collected through habitat typing according to Flosi et al. 2010. This data informed NMFS’s assessment of watershed conditions and limiting factors in the NCCC Domain. The CCC coho salmon assessments are available on the Miradi Share website (choose "NOAA Fisheries Recovery" under "Select Program").

Here a table shows a subset of important stream habitat characteristics summarized by watershed in the NCCC Domain. Click the map buttons to view these stream conditions by reach, stream, population, diversity strata, and Evolutionarily Significant Unit or Distinct Population Segments.

Survey Details

  • Number of surveys - 97
  • Stream miles surveyed - 190.97 of 476.58
  • Date range - 1993 to 2011

Note: This data may not reflect current on-the-ground stream conditions given the survey extent and more recent restoration activities in the watershed

Download GIS Data

Stream Habitat Metrics

Big River
(Coho, Chinook, Steelhead)
Canopy 81.8%
Embeddedness 2.7
Shelter Rating 28.9
Primary Pools 40.9%
Pools 42.6%
Riffle 5.3%
Flat Water 52%
Dry 0%
Large Woody Debris per 100ft* 0.6

*based on new survey protocol starting in 2004

Habitat Metric Scale

Note: This range is based on survey observations in the NCCC Domain, not recovery criteria rankings or habitat conditions needed by fish

Big River Habitat Image

"Water driving on Big River." This photo shows a log drive in the Big River watershed circa 1924. The flood created by the log drive erodes the banks of the river. © The Robert J. Lee Photographic Collection of the Mendocino Historical Society


The California Department of Fish and Wildlife (CDFW) in-stream habitat data includes measurements of a variety of physical and aquatic stream attributes that collectively reveal a great deal about stream condition for salmonids and trout and is critical to determining restoration priorities and identifying salmonid refugia. The CDFW in-stream habitat GIS data and inventory reports are available on the CalFish website.

NMFS's recovery plans have assessed stream habitat conditions using The Nature Conservancy’s Conservation Action Planning (CAP) methodology. The CAP analyses for CCC coho salmon are available on the Miradi Share website (choose "NOAA Fisheries Recovery" under "Select Program").

The stream habitat summary data, compiled from surveys collected from 1990 through 2012, is derived from the stream summary application developed for CDFW in 2008 by the University of California - Division of Agriculture and Natural Resources - Hopland Research and Extension Center GIS Lab under the Fisheries Restoration Grant Program.


Flosi et al. 2010. California Salmonid Stream Habitat Restoration Manual (3rd edition). California Department of Fish and Wildlife: Sacramento, California.

Feirer, S. T, 2009. Stream Summary Report. Description of Attributes in Tables produced in the Stream Summary Application. University of California, Hopland Research and Extension Center: Hopland, California.