Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Chapter 2. Alternatives
Full-Tidal Restoration Alternative
This alternative is based on the Full-Tidal Alternative presented in the Sears
Point Wetlands and Watershed Restoration Project Final Preliminary Plan
(February WWR 2007).
This alternative would:
• restore approximately 1,335352 acres of tidal marsh;
• improve tidal exchange in Tolay Creek along the eastern edge of the project
boundary;
• provide public recreation access south and possibly north of Highway 37;
• enhance40 acres of non-tidal seasonal wetland north of Highway 37; and
• create15.5 acres of additional breeding habitat, including 0.5 acres of
excavation in the floodplain , for the California red-legged frog near the
northern project boundary.
Figure 2-11 shows an overview of the Full-Tidal Alternative and the following
sections summarize the major restoration components. For convenience, these are
separated by geographic segment (i.e., south of Highway 37, north of Highway
37).
South of Highway 37—Tidal Marsh
New Levees
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
Under this alternative, full tidal influence is maximized across the site, bringing
the full range of the tides north of the SMART rail line and up to Highway 37
and the natural upland edges south of Highway 37. Implementation of this
alternative would require construction of three flood control levees, with a total
combined length of approximately 19,000 feet, to protect the rail line, Highway
37, and Reclamation Road. Each levee would consist of two components: a
“core” levee and habitat geotechnical stability berm with erosion
protection/habitat slopes. These structures are described below and shown in
(Figures 2-12 and 2-13).. It is anticipated that these project-related actions would
be coordinated around an active rail line, which would require the construction
and use of a temporary bypass line to ensure no disruption to rail service during
the project’s construction.
Core Levees
Core levees would be similar in design to those described for the Project, and
include a cut-off-trench where needed. The construction of the core levees for
this alternative would require placing a total of 520,000 CY of approved alluvial
fill (see Figure 2-12). This fill would primarily be provided for from the upper
level excavation of on-site pilot tidal channels. In addition, the eastern 6,000 feet
of the SMART railroad levee would contain approximately 12,000 CY of
2-34
April 2012