The Merced River, with its headwaters in Yosemite National Park, is recognized as a Wild and Scenic River. Stillwater Sciences has been involved in restoration and monitoring efforts in the Merced River since 1999. We began by establishing the Merced River Stakeholder Group and Technical Advisory Committee for the lower 52 miles. This group oversaw and provided input into developing the Merced River Corridor Restoration Plan [report, pdf, 42M], also focused on the lower watershed.

Site-specific assessments and restoration implementation
We have conducted several site-specific assessments and pilot projects along the lower Merced River corridor over the past 10 years as part of restoration planning and implementation. These include:

• Channel and floodplain design criteria, based on model reaches in the lower watershed, including sediment transport modeling and bed mobility assessments.
• Sediment supply thresholds analysis, using a combination of empirical observations and numerical modeling at 3 sites.
• Vegetation distribution and species composition maps for the entire lower corridor, including field verification of the over 3,000 polygons generated in 15 cover class types
• Pilot studies to assess vegetation response to flow regulation and the recruitment of pioneer riparian trees at 3 sites.
• Restoration of Merced River Ranch [report, pdf, 8M], an 318-acre parcel owned by CDFG, that included detailed topographic surveys, facies mapping, estimates of flood flow inundation levels, estimates of sediment transport potential, assessment of mercury content in tailings and surrounding waters, and periodic surveys to establish abundance and diversity of birds, fish, and benthic macroinvertebrates. 

Watershed-scale baseline monitoring
Stillwater just finished conducting a multi-year biological assessment of the entire watershed, compiling and synthesizing existing biological data and creating over 120 miles of GIS aquatic habitat maps. This effort also included multi-season monitoring of fish, birds, and aquatic macroinvertebrates. This is the first comprehensive assessment of species composition along both the upper and lower watersheds.
 

Overview

Location:
Merced River, Merced County, California

Clients:
California Bay-Delta Authority Ecosystem Restoration Program (CALFED)
East Merced Resource Conservation District
State Water Resources Control Board

Partners:
URS Corp., KSN Inc., River Partners, Frontier Geosciences, Slotten and Ayers [UC Davis], Point Reyes Bird Observatory, Geomatrix, Inc., and McBain & Trush   
 

Project Lead(s)

Zooey Diggory
email | profile

Work Products

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Project Abstract