Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Chapter 2. Alternatives
Trail System Options
Based on the segments described above, three trail system options are being
considered as part of the Project alternative. These are described below.
Trail System Option 1
This option would include all five of the proposed trail segments (Segments 1, 2,
3, 4, and 5). This option would build out the greatest total length of trails across
the Sears Point site and trails would provide access adjacent to all habitat types
across the area.
Trail System Option 2
This option would include all five trail segments included in Option 1. Segment 1
would be seasonally closed during critical breeding seasons for the California
clapper rail and California black rail to reduce potential trail user/listed species
conflicts. However, the same level of construction activity would be required to
implement Trail System Option 2 as would Trail System Option 1.
Trail System Option 3
This option would include Segments 2 through 5 included in Option 1 but would
not include Segment 1. An at-grade or underpass crossing would connect the
eastern end of the Bay Trail from Sonoma Baylands to the origination of trail
segments 2 and 5. This option would offer relatively reduced potential trail
user/listed species conflicts. However, this option would offer fewer recreational
options and eliminate the Bay Trail’s preferred bayfront spine alignment at Sears
Point.
North of Highway37—Diked Seasonal Wetlands
As shown in Figure 2-2, the low-lying diked bayland parcel at the northeast
corner of the Highway 37/Lakeville Highway junction, which currently includes
about 40 acres of bottomland diked baylands consisting of weed-dominated
pasture with shallow pools, would be modified to become a seasonal marsh and
pond dominated by native perennial marsh vegetation. Approximately 60,000 CY
of surface soils would be removed to a depth of about two feet below current
grade to form a single, large shallow depression with low-gradient side slopes.
Excavated soil would be placed within the tidal marsh restoration area south of
the SMART rail line for use in constructing interior graded topographic features
or the flood control levee if soil quality is suitable.
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
At the north end of the enhancement area, a 1,300-foot long, 2,400 cubic yard
berm would be constructed to an elevation of +5 feet NAVD to ensure that
ponded water would not flow north onto the adjacent Silva property to the
immediate north. A subsurface cutoff wall would be constructed beneath the
berm to prevent subsurface groundwater movement onto the Silva property.
Additionally, a storm water pump and 2 culvert flap gates would be installed in
an existing drainage ditch (D-1) on the north side of the pump to maintain
stormwater drainage for the Silva property to the immediate north and to utilize
2-31
April 2012