Water Stewardship Information Sources

Citation Perrin, CJ and Bennett, S. 2010. Quality of streams in the Upper Skagit River watershed using the reference condition approach. Prepared for Sakgit Environmental Endowment Commission.
Organization Skagit Environmental Endowment Commission
URL http://skagiteec.org/skagit-research-library/sp-files/limnotek-water-quality-final-report-feb2010
Abstract/Description or Keywords The reference condition approach (RCA) was used to describe baseline water
quality in streams of the 1,054 km2 Skagit River watershed north of the Canada/USA
border. Reference condition describes a suite of biological and habitat attributes found at
sites having little or no exposure to stressors caused by land use and other human
activities. The premise behind the RCA is to sample a large number of sites in reference
condition and use relationships between biological and environmental descriptors to
build a predictive model that allows comparison of a test site with a reference condition.
The Skagit model was called the Beast Assessment of Skagit Streams (BASS) in which
“Beast” is an acronym for “Benthic Assessment of Sediment”, a type of RCA model that
has been developed in Canada as a national bioassessment protocol. The
bioassessment procedures are explained on the website called CABIN
(Hhttp://cabin.cciw.ca/application/welcome.asp?Lang=en-caH ). The project provides the
Skagit Environmental Endowment Commission (SEEC) with an overview of present
water quality in the Canadian portion of the Skagit watershed and a framework for
monitoring potential development and natural changes to water quality in future years.
A total of 49 reference sites were sampled throughout the Skagit watershed in
late August of 2007 and 2008, resulting in a sample density of 22 km2
/sample, which is
among the most dense sample layouts in regional scale RCA programs worldwide. Ten
additional sites were sampled downstream of the Sunshine Valley Resort, the Giant
Copper mineral exploration site on Silverdaisy Mountain, near highway drainage, or near
unstable roads and range lands where cattle grazing was occurring. These “test” sites
were potentially disturbed and were excluded from reference condition modeling.
Assemblages of benthic invertebrates were sampled because they are good indicators
of water quality. Accompanying environmental data was measured in the field or derived
from GIS data layers. It included geomorphic variables, forest and riparian cover,
physical habitat attributes, land use variables, water temperature, and concentrations of
nutrients, basic chemical analytes, and metals in water. The benthic invertebrates were
sampled using kick net procedures and family level enumerations were used in the RCA
Information Type report
Regional Watershed Lower Fraser
Sub-watershed if known Skagit River
Aquifer #
Project status complete
Contact Name
Contact Email