Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Chapter 2. Alternatives
establishment. This may be done by volunteer crews, using abundant local
vegetative sources dredged from agricultural ditches on site. As salinities
increase in summer, alkali-bulrushAdditional mosquito control measures would
enter enforced dormancy, and water levels may be raised to favor growth of
pickleweed at design elevations above MSL, and minimize emergent saturated
soils that may breed mosquitoes.developed in coordination with MSMVCD, if
needed. Wigeongrass would likely become established during summer in open
shallow water conditions. The site may be adaptively managed in late
summer/fall: either maintainedwith a submerged bed, or drained.
During the second growing season, water levels may be managed similarly:
shallow low-salinity water to favor alkali-bulrush and wigeongrass growth in
spring-early summer, with flood depths 1 to 2 feet deep above the bed, and
potentially higher water levels and salinities in summer to favor pickleweed at
higher elevations, after alkali-bulrush enters induced salt stress dormancy. If bay
waters do not reach critical salinities for initiation of alkali-bulrush shoot dieback
and dormancy, the site manager may fluctuate water levels in summer between
elevations favorable to higher pickleweed and lower alkali-bulrush.
Mosquito Abatement Adaptive Management
Tidal marshes are not generally a large source for mosquito production.
However, several species of mosquitoes could potentially breed in the restored
tidal habitat. MSMVCD has indicated that excavation of ditches may be required
in the restored tidal marsh habitat in the future (once sediments have accreted to
marsh plain elevation) to improve water circulation. MSMVCD would perform
monitoring of mosquito populations, and, if trigger levels are reached, would
determine whether enhanced water circulation may reduce mosquito breeding.
Should enhanced water circulation be desirable, MSMVCD would obtain review
and approval from USFWS and CDFG and other appropriate agencies to
excavate small ditches to improve water circulation.
Railroad to Highway 37—Diked Seasonal Wetlands and
Ongoing Wetland-Compatible Agriculture
Agricultural Modifications
On the diked baylands portion of the site that extends from the SMART rail line
to Highway 37, the project proposes to retain agriculture and pasture while at the
same time enhancing seasonal wetland functions. A portion of these areas
totaling 106 acres would be managed as a “wetland priority area”, with timing of
some agricultural activities optimized for seasonal wetland and wildlife values.
Specifically, the project would enhance 40 acres of seasonal wetlands in the oathay
area andThe wetland priority area has the highest concentration and best
quality of wetlands within the site. Less than half of the wetland priority area
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
2-21
April 2012