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Wetlands Restoration Case Studies
Petaluma River Marsh
Project Goal:.............................................................................Tidal
Wetlands
Former Land Use:................................................................Hayfields
Restored Acreage:.....................................................................................................46
Tasks: Two levee breaches and improvements to a substandard interior levee
Mitigation:.........................................................................................Self
Total Cost:.................................................................................................$213,000
Land:.................................................................NA
(nonprofit/public ownership) Construction:.....................................................................................$160,000
Project Management & Permitting:.......................................................$25,000*
Engineering & Surveys:........................................................................$10,000
Ongoing Monitoring:............................................................................$20,000
* Does not include Cal Fish & Game staff time
Napa River Unit of Napa/Sonoma Marshes Wild Life Area
Project Goal:................................................................Tidal
Wetlands Former
Land Use:.....................................................................................Salt
Ponds
Restored Acreage:..........................................................................560
acres Tasks:...................................................................Blowing
a hole in the levee
Total Cost:................................................................$400
(for the explosives)
San Leandro Shoreline
Project Goal:........................................................Tidal
Wetlands Former Land Use:........................................................................Degraded
Marsh Restored Acreage:.................................................................................................172
Tasks: Excavating channels and building habitat islands (using dredged
material); dredging and debris and rubble removal; breaching, sheetpiling,
culverting, installing tide gates (four) and armoring the Bayfront levee
(and raising an interior levee); improving trails and roads
Mitigation: The restoration is mitigation for ongoing dredged material
disposal from the San Leandro marina and entrance channel on an adjacent
site.
Special Considerations: Public access & existing salt marsh harvest
mouse habitat
Total Cost:.......................................................................................$993,000
Land:................................................................NA
(local and state ownership)
Planning, Design & Engineering:........................................................$400,000*
Mobilization & Security:.......................................................................$79,500
Installation of Culverts, Tide Gates & Control Structures:.......................$357,000
Road & Trail Improvement:..................................................................$108.600
Levee Repair & Improvement:...............................................................$36,250
Rubble & Debris Removal:...................................................................$29,960
Channel Excavation & Habitat Island Creation:.....................................$380,000
* Does not include staff management time by city engineers.
Sonoma Baylands
Project Goal:..........................................................................Tidal
Wetlands
Former Land Use:.................................................................Diked
Hayfields
Restored Acreage:...................................................................................320
Tasks: Grading and construction of a new levee; building a dozen branching
peninsulas; raising the land level by pumping in slurried dredged material;
installing and removing three temporary outlet culverts and weirs; adding
concrete jackets to several power line towers; seeding levees with grasses;
decanting return water; restoring tidal action; and short- and long-term
monitoring
Special Considerations: Dredged material from Port of Oakland deepening
project and Petaluma River channel used to accelerate marsh development
Total Cost:.................................................................................$7.1
million* Land:...................................................................................about
$500,000
Preliminary Planning, Design & Engineering:....................................$290,000**
Army Corps Planning, Design & Engineering:................................$1.2
million
Excavation & Construction:..........................................................$1.3
million
Jacketing of Power Line Towers:.....................................................$170,000
Dredging & Transport of Port of Oakland Material:..........................$3.6
million*
Seeding & Mulching Levees:.............................................................$38,000
Maintenance & Monitoring:.................................................To
be determined
* Because the Sonoma Baylands project is still underway, some numbers had to be based on construction contract bids and some on actual costs. While the actual dredging cost is not necessarily directly associated with the wetland restoration cost, it is included here for background.
** Includes $40,000 in initial studies on options for larger 830 site, of which Baylands is a part. Does not include extensive project management contributed by the California Coastal Conservancy.
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