Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.5. Biological Resources
Full-Tidal Alternative
Impacts from the loss of agricultural lands resulting from restoration under the
Full-Tidal Alternative would be the similar to that described above for the
Project. The Full-Tidal Alternative would additionally result in the loss of
agricultural lands between Highway 37 and the SmartSMART rail line,
ultimately converting approximately 1,055.6 acres of agricultural lands and 94.9
acres of farmed seasonal wetlands to tidal marsh. Because habitat functions
associated with tidal marsh are relatively more beneficial than those carried out
by farmed hay fields, impacts from the Full-Tidal Alternative are considered
beneficial. No mitigation is required.
Conclusion: Beneficial Impact.
Impact BIO-2: Loss of Seasonal Wetlands (including
Vernal Pools, Seasonally Saturated Annual Grasslands
and Farmed Seasonal Wetlands)
Proposed Project
Seasonal wetlands south of Highway 37 (between Highway 37 and the SMART
rail line) including 35.2 acres of vernal pools and 116.8 acres of seasonally
saturated annual grasslands would be managed to reduce impacts of agricultural
activities. These management measures would include changing tilling practices
and modifying grazing practices to minimize adverse effects on wetland plants,
enhancing existing ponds, creating additional shallow depressions, and
establishing patches of marsh and riparian woodland. These activities would
improve seasonal wetland and habitat functions. This would result in a beneficial
impact to seasonal wetlands.
Restoration activities south of the SMART rail line would convert approximately
94.98acres of farmed seasonal wetlands to tidal marsh. Because farmed seasonal
wetlands are substantially disturbed, their wetland functions are minimal.
Restoring the historic tidal marsh would restore the historic functions carried out
by wetland habitats in this area. Tidal marsh restoration would also provide
suitable habitat conditions for special-status species not currently known onsite,
including the federally and state-listed endangered California clapper rail and salt
marsh harvest mouse (also state fully protected), and the state-listed threatened
California black rail. Although wetland habitat type conversion would occur, the
habitat functions of the restored marsh would greatly exceed those of the current
farmed seasonal wetlands. The Project would therefore result in a beneficial
impact on farmed seasonal wetlands.
North of Highway 37, actions to enhance California red-legged frog habitat
seasonal wetlands wcould include minor excavation and regrading of the existing
wetlands, construction of a berm across the north edge of the wetlands, and
installing a pump on the north side of the berm to move water into the wetlands.
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.5-31
April 2012