Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Chapter 2. Alternatives
The ridges would follow the contours of major outside bends of the pilot
channels, and would support well-drained high marsh vegetation such as
gumplant and pickleweed that trap tidal debris. The intertidal slopes of the ridges
would be stabilized by wave-damping tidal marsh vegetation that would in turn
provide important high tide flood refuges within the marsh. At maturity, these
marsh patches would provide potential dispersal habitat for the clapper rail.
Counter LeveeSidecast Mounds
As discussed above, excavated materials from the pilot channels would likely be
used to construct approximately 250 counter-leveesidecast mounds (counterlevee
referring towhich would be placed on the opposite bank of levees or from
sidecast ridges). These mounds would consist of small (less than 5 feet across)
irregular, un-engineered piles of spoil with crest elevations reaching or exceeding
approximate MTL. These mounds would be located at intervals along banks of
constructed trunk channels, and would serve to hasten the onset of marsh
vegetation establishment and stabilization along the banks of channels.
Habitat Levee Edges
Gently sloping habitat levee edges with gentle, wide, planted slopes ranging
between 10:1 to 20:1 would be constructed along the marsh side of the new flood
control levee to dissipate wave energy and minimize erosion potential while
maximizing the width of high marsh transition zones. Incorporation of this
feature into levee design would ensure rapidly forming fringing high marsh
zones, which would serve as critical habitat for small mammals inhabiting the
tidal marsh.
Specifics regarding construction of the erosion/habitat levees are discussed in the
“Geotechnical Stability Toe Berms and Erosion/Habitat Levees” section above.
Building and Infrastructure Demolition
Building demolition in the south of the railroad tidal wetland area would include
removing all buildings and appurtenances associated with the Dickson Ranch and
the Black Point Sports Club. In addition, approximately 12,000 CY of
contaminated surface soils from the vicinity of the club’s skeet shooting range
would be placed within the used for constructing the core leveegeotechnical
stability berms and/or erosion protection/habitat slopes, as described above (see
Figure 2-9).
The Dickson Ranch structures include 3 large barns, 2 houses, an airplane
hangar, and numerous shops, sheds, pumps, and related agricultural debris. The
largest barn is a metal structure that is relatively new and in good condition. This
structure has a high potential for disassembly and off-site reuse. All other
buildings are older wooden and wooden-framed sheet metal-clad structures in
various conditions that would likely be demolished. SLT will make every effort
to sort and recycle demolition debris; debris that cannot be recycled will be
placed in local landfills. Several pumps and wells are also located on the property
and would require abandonment; the pumps would be removed from the wells as
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
2-16
April 2012