Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.5. Biological Resources
• Restored habitats and supporting hydrology are expected to stabilize under
each of the restoration alternatives within 50 years of implementation of the
proposed restoration. This assumption is based on the design criteria
anticipating future conditions including sediment input levels and potential
sea level rise scenarios.
• All potential sources of surface and subsurface hazardous materials on the
Project site will be removed or isolated before the selected restoration
alternative is implemented.
• All dredged material and other fill material used for construction will meet
the criteria and standards established by the DMMO and other regulatory
agencies with jurisdiction over the site.
Impact Mechanisms
The following types of activities associated with implementation of the
restoration alternatives could result in loss of or disturbance to aquatic, wetland,
and grassland habitats and associated species.
• Creating a staging areas to provide temporary storage of topsoil, heavy
equipment, fuel and supplies, and building demolition debris;
• Excavating topsoil and removing it to a staging area;
• Operating equipment and other construction activity, including constructing
internal and perimeter levees and, trails, and roads; levee lowering;
constructing internal and topographic features; grading,; and excavating
channels and levee breaches;
• Dredging Tolay Creek;
• Placing dredged material for restoration of wetland habitat areas;
• Reintroducing tidal flow to currently nontidal lands;
• Installing drainage and other water-control infrastructure;
• Performing management and maintenance activities necessary to maintain
target habitats (e.g., activities associated with control of noxious weeds),
maintain operation and integrity of infrastructure (e.g., water drainage and
control structures), and control mosquito populations;
• Colonization of invasive non-native vegetation species that displace or
prevent establishment of native vegetation potentially lowering the habitat
value of restored wetlands; and
• Constructing, accessing, and using the Bay Trail and other trail segments.
It should be noted that potential impacts related to methyl mercury are not
discussed in this section, but are discussed in Section 3.3, Water Quality.
Changes in methyl mercury availability could affect special-status wildlife
species, such as California Clapper Rails; however the mechanism of impacts is
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.5-27
April 2012