Abstract:
This data layer represents the inventory and fish passage evaluation of stream crossings in the Russian River watershed conducted between May, 2001 and March, 2003 under contract with CDFG, by Ross Taylor and Associates. Features from the original source data (see Originator information) were selected based on their spatial location within the Russian River watershed in Sonoma and Mendocino counties in California (the study area boundary of the Russian River Watershed Adaptive Management Plan project). This metadata file incorporates much of the information that was available in the final report titled Russian River Stream Crossing Inventory and Fish Passage Evaluation, 2003 of the original source data. This information is indicated in quotation marks.
"The inventory and fish passage evaluation of stream crossings within the Russian River
watershed was conducted between May, 2001 and March, 2003 under contract with CDFG. The
primary objective was to assess passage of juvenile and adult salmonids and develop a projectscheduling
document to prioritize corrective treatments to provide unimpeded fish passage at
road/stream intersections. The inventory was focused primarily on Sonoma County and
Mendocino County- maintained crossings within anadromous stream reaches within the Russian
River basin known to historically and/or currently support runs of coho salmon (Oncorhynchus
kisutch), chinook salmon (O. tshawytscha) and /or steelhead (O. mykiss irideus). However, a
number of crossings within city limits and on private property were included.
The inventory and assessment process included:
1. Locating stream crossings within anadromous stream reaches.
2. Visiting each crossing on an initial site visit to determine the type of crossing and assessment
of stream channel as suitable fish habitat.
3. At County- maintained sites with culverts - collecting information regarding culvert
specifications and surveying a longitudinal profile.
4. Assessing fish passage using culvert specifications and passage criteria for juvenile and adult
salmonids (from scientific literature) by employing a first-phase evaluation filter and then
using FishXing computer software on a subset of sites defined as partial/temporal barriers by
the filter.
5. Assessing quality and quantity of stream habitat above and below each culvert.
The prioritization process ranked stream crossing sites with culverts by assigning numerical
scores for the following criteria:
1. Presumed species diversity within stream reach of interest (and federal listing status).
2. Extent of barrier for each species and lifestage for range of estimated migration flows.
3. Quality and quantity of potential upstream habitat gains.
4. Sizing of current stream crossing (risk of fill failure).
5. Condition of current crossing (life expectancy).
The initial ranking was not intended to provide an exact order of priority, rather produce a firstcut
rank in which sites could be grouped as high, medium, or low priority. Professional judgment
was a vital component of the ranking process. Site-specific information that was difficult to
assign a discrete numerical value was also considered. "
Purpose:
This data layer was edited from its original source data set for inclusion in the Russian River Watershed Adaptive Management Plan (RRWAMP) and RRWAMP Baseline Watershed Assessment project. The intended use of this data layer in this project is to examine landscape or human factors to promote ecological health and sustainability within the Russian River watershed.
"Fish passage through culverts at stream crossings is an important factor in the recovery of
depleted salmonid populations throughout the Pacific Northwest. Although most fish-bearing
streams with culverts tend to be relatively small in size with only a couple of miles or less of
upstream habitat, thousands of these exist and the cumulative effect of blocked habitat is
probably quite significant. Recent research regarding watershed restoration considers the
identification, prioritization, and treatment of migration barriers to restore ecological
connectivity for salmonids a vital step towards recovering depressed populations (Roni et al.
2002). Culverts often create temporal, partial or complete barriers for anadromous salmonids on
their spawning migrations (Table 1) (adapted from Robison et al. 2000).
Typical passage problems created by culverts are:
· Excessive drop at outlet (too high of entry leap required);
· Excessive velocities within culvert;
· Lack of depth within culvert;
· Excessive velocity and/or turbulence at culvert inlet; and
· Debris accumulation at culvert inlet and/or within culvert. "