Summary of our findings after 4-years of Monitoring:

Volunteers with the Chehalis River Council have been monitoring streams in the upper Chehalis Basin since 2002.  Our objectives are to increase understanding of water quality and ecological conditions in rural streams in the Chehalis Basin, and to provide educational opportunities for volunteers and the general public.  The program is closely tied to monitoring by schools in the Chehalis Basin Educational Consortium, and was partially funded by a grant from the Washington State Department of Ecology.  

We monitor Elk Creek near Doty, the South Fork Chehalis River near Boistfort, the South Fork Newaukum River upstream of Onalaska, and the Middle Fork Newaukum River.  These sites represent a range of rural land uses and riparian condition.  Each year we sample once during a winter storm, once between storms, and once in the late summer/early fall.  We use professional methods to measure water temperature, dissolved oxygen, conductivity, pH, fecal coliform, streamflow, benthic macroinvertebrates, sediment characteristics, and riparian tree canopy. 

We maintain data quality through volunteer training, standardized methods, regular equipment calibration, replicate sampling, reference samples, and proper study design.  The vast majority of our replicate and reference sample comparisons met quality assurance targets for precision, bias, and accuracy.  We completed 11 of the 12 planned sampling events during the four-year monitoring, but missed one winter storm event in 2004 because of difficulties in matching rain events to volunteer and laboratory schedules.

The following are our most important findings about water quality in the upper Chehalis:

• Streams that have forested watersheds and strong connections to groundwater have the best water quality and biologic integrity (Elk Creek, South Fork Newaukum).  High summer baseflows in these streams help maintain high dissolved oxygen levels and low water temperatures.
• Water quality and biologic integrity were poorer in sites positioned in lower stream valleys, where land use is more intense and summer groundwater levels tend to be below the streambed (Middle Fork Newaukum, South Fork Chehalis).
• A healthy riparian tree canopy can help maintain good biologic integrity at sites that suffer from low baseflows and high water temperatures (Middle Fork Newaukum).
• The South Fork Chehalis River had the poorest combination of water quality and biologic integrity, due to poor riparian conditions and high fine sediment loading.

Based on these lessons, we will focus future efforts on promoting stewardship and monitoring within the South Fork Chehalis watershed.  This river suffers from water quality problems, but still has a rural watershed with good restoration potential.  The stewardship project will begin with environmental education, water quality monitoring, and riparian planting at Boistfort School, a K-8 school that serves the entire valley.  By involving parents and other community members, we hope this will lead to a sustainable program built on partnerships with the school, local landowners, service organizations, and resource agencies.

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