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Bel Marin Keys Phase of the Hamilton Wetlands Restoration

Project URL link
Sponsoring Agency Coastal Conservancy
Subregions ('North Bay',)
Counties Marin
Watershed Tributary Novato Creek
Public or private land? ('Public',)
Location (lat/lon) 38.07025760046315, -122.5198745727539
Start Date 06/01/2013
End Date 01/01/2018
Location Description Marin County. East of the City of Novato, betwixt the former Hamilton Airfield and Novato Creek.
Bel Marin Keys Phase of the Hamilton Wetlands Restoration

Restore tidal marsh and seasonal wetlands, provide flood protection and reuse treated wastewater.

The project will restore tidal marsh and seasonal wetlands on 1,785 acres of land owned by the Coastal Conservancy; as well as, provide flood protection to the local community. The project will also incorporate treated waste-water from the Novato Sanitary District to restore fresh and brackish marsh on the site.

2015
Drinking Water Supply
Water Quality Improvement
Water Reuse/Recycling
Stormwater Improvements
Groundwater Benefits
Infiltration
Habitat Protection and Restoration
Flood Protection
The ecosystem of San Pablo Bay would benefit from a major increase in new tidal marsh, mudflats and shallow sub-tidal habitat totaling over 1,500 acres. The project will improve water quality in San Pablo Bay by removing a source of waste-water that is discharged offshore during the wet season. The project will also provide new marsh habitat that will be home to a variety of bird and fish species, thereby improving several Beneficial Uses of San Pablo Bay. The treated waste-water would be used beneficially to restore fresh and brackish marsh habitat along the newly constructed shoreline. During the dry season, this waste-water is currently applied to spray-fields located between Highway 37 and Novato Creek. The project would change the management of the waste-water to a year-round diversion from bay discharge. This change will have the added benefit of making the spray fields available for other public uses (they are owned by Marin County). The Bel Marin Keys community, a 700-home residential development, will benefit from a new flood protection levee that would be integrated into the wetland design.
N/A
The project would result in a long-term change in how Novato Sanitary District manages its waste-water. The waste-water would be used to restore fresh and brackish marsh resulting in ecological benefits. Another result is that the spray-fields that currently receive summer flows could be rendered obsolete. The fields are hundreds of acres in size, are owned by the County, and are adjacent to Novato Creek. As waste-water is diverted to the Project, the spray fields can be put to other uses, for example to store flood waters or they could also be restored to wetland habitat.
The project will partner with the Novato Sanitary District related to treated waste-water reuse and pipeline engineering. The project will also work closely with the Marin County Flood Control District to address flood zoning issues and with the Army Corps of Engineers related to dredged sediment fill options.
Yes.
No. The project does not include hardscape or buildings.

Part 2 - Detail

The project will improve water quality in San Pablo Bay by removing a source of waste-water that is discharged offshore during the wet season. Instead, the waste-water would be used beneficially for marsh habitat along the newly constructed shoreline. The waste-water is currently applied to spray-fields located between Highway 37 and Novato Creek in the dry season. The project would change to a year-round diversion of which would have the added benefit of freeing the spray fields for other public uses (they are owned by Marin County). The ecosystem of San Pablo Bay would benefit from a major increase in the increase of new tidal marsh,  mudflats and shallow [sub] tidal habitat - which would total over 1,400 acres. The Bel Marin Keys community, a 700- home residential development will benefit from a new flood protection levee that would be integrated into the wetland design.  

Description of Qualitative Benefits :      For water quality, it is assumed that a sizable increase in tidal marsh will lead to improved water quality and enhance the beneficial uses of San Pablo Bay, for example recreational fishing.   The restored site would have full tidal action over 1500 acres of marsh which would have benefits for the aquatic ecosystem. In terms of restoration, the project will directly benefit dozens of fish and bird species, including several that are threatened and endangered.  Though the site is open to the public, it is not managed as a park or open space and is a partially active hay farm.  The restoration project would enhance recreation and public access by providing a higher quality environment (seasonal and tidal marsh) and will result in 0.7 miles of public trail along the margin of the site.  Types of recreation anticipated include hiking and bird watching, non-motorized boating, fishing, waterfowl hunting. The project will include a new flood management levee which will separate tidal and non-tidal areas.   The new levee would be built to a higher elevation than the existing perimeter levee and so is expected to provide a higher level of flood protection to the neighboring residential community.  

The project will be constructed in phases.  Each phase will comprise some 500 to 600 acres of tidal marsh. Some volume of dredged material will be placed in the [future] tidal portion of each phase and when the phase is complete, the outboard levee will be breached, thereby providing immediate benefits to that phase.  Dredged material will be placed against the new flood management levee to create a low gradient fill or 'bench' which will lead to immediate growth of marsh vegetation. 

 

True
Hamilton Wetland Restoration Projecct

General Information:  www.hamiltonwetlands.scc.ca.gov

Project Documents can be found at: http://hamiltonwetlands.scc.ca.gov/issues/

San Pablo Bay

Novato Creek

Pacheco Pond

San Pablo Bay and the greater San Francisco Bay has lost about 90 percent of its historic tidal marsh habitat due to farming and development.  This project would  restore over 1,500 acres of tidal wetland and mudflat habitat which will benefit a wide array of bird and fish species, including several that are threatened and endangered.  The project would also restore up to 400 acres of seasonal wetlands and provide flood protection for 700 homes.     The project will beneficially reuse waste-water.  The Novato Sanitary District (NSD) discharges an average of 10.3 million gallons per day of treated effluent into San Pablo Bay. The discharge only occurs in the wet season due to concerns over a lack of dilution at the outfall; in the dry season the effluent is discharged on to fields leased to the District by the County of Marin.  This project would use the effluent to restore fresh and brackish water habitat within the newly constructed marsh complex.  One outcome of this project is that the spray fields (currently used to dispose of summer flows) could be rendered obsolete thereby freeing up the fields for other uses.  NSD is currently working on recycling of waste-water, including a regional system (North Bay Water Reuse Authority); however, it is unlikely that in the short and medium term there will be a substantial reuse of wet weather flows due to infrastructure and storage constraints.  Reuse of waste-water at the subject restoration project provides a reuse option that is immediate and which does not preclude regional recycling in the future.  The project will restore tidal wetlands by recycling dredged sediment that would otherwise be disposed of in the bay and ocean.  The project uses the dredged sediment as fill.  The BMK property, like the adjacent Hamilton Airfield, is a subsided former baylands and across the site the current ground elevations range from five to six feet below mean sea level.  In order to accelerate marsh development, the site will be filled with dredged sediment using a suction dredge and hydraulic slurry.   Sediment is delivered by barge from dredging projects throughout the Bay Area.  Only sediment that has been tested and approved for restoration purposes will be placed onsite. The material is transferred from barges to the site as a slurry (hydraulic placement) which is far more efficient than mechanical placement and also recreates the gradual gradients found in nature. The project benefits the ecosystems of San Francisco Bay and the deep ocean because  it makes use of dredged sediment to re-construct wetlands which would otherwise be disposed of into the water column with numerous impacts (at designated dump sites). The project will protect a residential development from flooding in that the wetland design incorporates a new flood management levee.  The levee takes the place of the existing 3.3- mile long levee that runs along the perimeter of the site.  The existing levee was constructed by farming interests in the 1880s and is protected from erosion by a mixture of rip-rap and fringing salt marsh.  The existing levee has had minor failures in the last decade necessitating spot repairs totaling a half of a linear mile.  The new 1.7-mile long levee will be constructed to a higher elevation than the existing levee, will be engineered and protected from wave erosion by the newly constructed salt marsh.

The State of California (Coastal Conservancy)  will continue to incur expenses of levee upkeep and property management in order to protect the Bel Marin Keys community from flooding.  The effluent from the Novato Sanitary District will continue to be discharged into San Pablo Bay with no added benefit to the environment.  The State's investment  in the Bel Marin Keys property (over $16 million)  for fish and wildlife habitat enhancement and protection will not be realized.

Endangered and other listed bird and fish species in San Pablo Bay will continue to struggle to recover a viable population due to a lack of suitable habitat.  

Novato's waste-water, which is treated to a high standard, will continue to be discharged into the Bay in the wet season with no added benefit to the environment.

 

 

 

i. Water Supply (conservation, recycled water, groundwater recharge, surface storage, etc.)


ii. Water Quality: 

 Project will restore over 1,500 acres of tidal wetlands which will improve the water quality of San Pablo Bay (Beneficial Uses).  Also see Section iv below.   The project would also beneficially use treated waste-water from the Novato Sanitary District, changing discharge from a wet-season bay discharge to a year-around recycling to restore fresh / brackish marsh on site.  

 

iii. Flood and Stormwater Management

The project purpose is not flood and stormwater management however the wetland design incorporates a new flood management levee that will help protect the Bel Marin Keys residential community from flooding.  The existing perimeter levee that runs some 3 linear miles along Novato Creek and San Pablo Bay will be replaced by a 1.7 mile long engineered levee that will bisect the site, dividing it between tidal and seasonal wetlands.  Currently the 700-home Bel Marin Community is protected from San Pablo Bay tides by the existing perimeter levee and storage on the site. The new levee will be built to a higher elevation and will be better protected from erosion than the existing levee system.
 

...

iv. Resource Stewardship (watershed management, habitat protection and restoration, recreation, open space, etc.)

...

 Restoring the BMKV Expansion site would result in approximately 1,785 acres of tidal wetlands, seasonal, and upland habitat for fish and wildlife. Special status species that may benefit from the restoration of BMK include salmonids, salt marsh harvest mouse, California clapper rail, double-crested cormorant, California brown pelican, white-tailed kite, northern harrier, golden eagle, Cooper’s hawk, sharp-shined shooter, peregrine falcon, California black rail, short-eared owl, burrowing owl, salt marsh common yellow throat, and San Pablo song sparrow. Juvenile green sturgeon, and longfin smelt, now listed as an endangered species in the San Francisco Bay Estuary, may also benefit from the restoration project.


Special status species that may benefit from the restoration of BMK include salmonids, salt marsh harvest mouse, California clapper rail, double-crested cormorant, California brown pelican, white-tailed kite, northern harrier, golden eagle, Cooper’s hawk, sharp-shined shooter, peregrine falcon, California black rail, short-eared owl, burrowing owl, salt marsh common yellow throat, and San Pablo song sparrow. Juvenile green sturgeon, and longfin smelt, now listed as an endangered species in the San Francisco Bay Estuary, may also benefit from the restoration project.
 
Tidal marshes are among the most productive ecosystems in the world. They flourish when the rate of sediment accumulation is equal to or greater than the rate of land subsidence and where there is adequate protection from large waves and storms. Wetlands are areas of high nutrient and biological productivity that provide the detrital products that constitute the base of the food chain. Sediment and epiphytic algae are often important components of the autotrophic  community. Heterotrophic communities are often dominated by the detrital food chain of tidal wetlands, providing foraging habitat for several threatened and endangered species. In addition, tidal marshes are out-welling systems that export organic matter to adjacent estuaries.
 
Tidal marshes provide direct prey resources to several aquatic and terrestrial organisms, including listed juvenile salmonids. Because they are generally rich in invertebrate organisms, tidal wetlands and mudflats that would be created as part of the BMKV restoration project could provide high-value foraging habitat for juvenile salmonids,  Shallow tidal wetlands and salt-tolerant vegetation (grasses and rushes) can provide refugia from predators.

Some studies suggest that juvenile salmonids that rear in wetland areas grow
larger and, therefore, may be less prone to predation when they enter the marine
environment. Restored tidal wetlands may also directly benefit other species including starry flounder and English sole, which are known to use tidal wetlands for rearing, and Sacramento splittail, which may use wetland habitat for spawning and rearing.
 
Tidal wetlands may also indirectly benefit several protected species that do not directly use tidal wetland habitat (e.g., EFH-managed species that inhabit San Pablo Bay). Export of organic detritus from tidal wetlands can increase primary productivity in adjacent estuaries. Detritus that flows to the estuarine waters can sustain prey species for several aquatic organisms and help support secondary production, especially in estuaries where plankton primary production is depressed. Studies suggest that organic detritus, either filtered from the water or ingested from the sediment, is an important alternate source of energy for aquatic organisms, especially when plankton concentrations are low.
 
Tidal wetlands can act as a buffer against the effects of sea level rise by stabilizing shorelines and creating a buffer against erosion. Tidal wetlands can also sequester carbon and thereby help offset the emission of green house gases.  Creation of wetland habitat through implementation of the project would have direct benefits to fisheries and the ecological health of through implementation of the project would have direct benefits to fisheries and the ecological health of SF Bay and adjoining ocean by significantly reducing, if not completely eliminating, dredged material placement in the ocean and bay while BMK is being filled. There will also be benefits to benthic communities located at and near Alcatraz, the other two in-bay sites, and the deep-ocean water column that result from the diversion of dredged material to the ATF and, hence, to the BMK. Once the BMK is returned to tidal action, bay fishes will benefit from the newly-restored wetland habitats by reducing, if not completely eliminating, dredged material placement in the ocean and bay while BMK is being filled. There will also be benefits to benthic communities located at and near Alcatraz, the other two in-bay sites, and the deep-ocean water column that result from the diversion of dredged material to the ATF and, hence, to the BMK. Once the BMK is returned to tidal action, bay fish will benefit from the newly-restored wetland habitats.
 

 

False
False
False
About 3000 of 260,000 total, disbursed throughout county. Greatest concentration of disadvantaged persons is reported to be in the "Canal Area" of San Rafael, which is about 7 miles due south of the site.
Increases Water Supply Reliability
Advances/ Expands Conjunctive Management of Multiple Water Supply Sources
Increases Water Use and/or Reuse Efficiency
Provides Additional Water Supply
Promotes Water Quality Protection
Reduces Water Demand
Advances/Expands Water Recycling
Promotes Urban Runoff Reuse
Addresses Sea Level Rise
Addresses other Anticipated Climate Change Impact (e.g. through water management system modifications)
Improves Flood Control (e.g. through wetlands restoration, management, protection)
Promotes Habitat Protection
Establishes Migration Corridors
Re-establishes River-Floodplain Hydrologic Continuity
Re-introduces Anadromous Fish Populations to Upper Watersheds
Enhances and Protects Upper Watershed Forests and Meadow Systems
Other (Please Describe)
Increases Water Use Efficiency or Promotes Energy-Efficient Water Demand Reduction
Improves Water System Energy Efficiency
Advances/Expands Water Recycling
Promotes Urban Runoff Reuse
Promotes Use of Renewable Energy Sources
Contributes to Carbon Sequestration (e.g. through vegetation growth)
Other (Please Describe)
200 million (low) - 280 million(high)
Federal match is 75%
Land purchased by Coastal Conservancy in 2001. @ $16 million
$30,000
Conservancy WCF or other non-bond funds
once constructed project life is indefinte
Drought Preparedness
Use and Reuse Water More Efficiently
Climate Change Response Actions (Adaptation to Climate Change, Reduction of Greenhouse Gas Emissions, Reduce Energy Consumption)
Expand Environmental Stewardship
Practice Integrated Flood Management
Protect Surface and Groundwater Quality
Improve Tribal Water and Natural Resources
Ensure Equitable Distribution of Benefits
Reduce Reliance on the Bay-Delta
Reduce Water Demand
Improved Operational Efficiency and Transfers
Increase Water Supply
Improve Water Quality
Improve Flood Management
Practice Resources Stewardship
Other Strategies (Please Describe)
Groundwater Management Plan
Urban Water Management Plan
Water Meter Requirements
Groundwater Monitoring Requirements
AB 1420 Compliance
BMP Compliance
CEQA Compliance
Water supply reliability, water conservation and water use efficiency
Stormwater capture, storage, clean-up, treatment, and management
Removal of invasive non-native species, the creation and enhancement of wetlands, and the acquisition, protection, and restoration of open space and watershed lands
Non-point source pollution reduction, management and monitoring
Groundwater recharge and management projects
Contaminant and salt removal through reclamation, desalting, and other treatment technologies and conveyance of reclaimed water for distribution to users
Water banking, exchange, reclamation and improvement of water quality
Planning and implementation of multipurpose flood management programs
Watershed protection and management
Drinking water treatment and distribution
Ecosystem and fisheries restoration and protection
Reduced Reliance on the Bay-Delta
Projects that directly address a critical water quality or supply issue in a DAC
Urban water suppliers implementing certain BMPs as on page 17 of Guidelines
Be designed to manage stormwater runoff to reduce flood damage (PRC §5096.827)
Be consistent with the applicable Regional Water Quality Control Plans (Basin Plans) (PRC §5096.827)
Not be a part of the State Plan of Flood Control (SPFC) (PRC §5096.827)

Promotion of economic, social, and environmental sustainability

 

 Avoiding, minimizing, and mitigating net impacts to environment: The project will recycle dredged sediment which will otherwise be disposed of into the aquatic environment, either at a Bay disposal site or at the deep ocean disposal site.  Disposal of dredged material has negative impacts to the aquatic environment.  Transportation of dredged sediment to the ocean disposal site (which is located 50 miles west of the Golden Gate, also results in significant negative impacts to air quality in terms of emitting both diesel exhaust and Carbon Dioxide.  Because tidal marshes sequester carbon, the project not only reduces water and air impacts as compared to bay and ocean disposal) but it can partially mitigate for carbon impacts from the dredging and transport of the sediment.    

 

Maintaining and promoting economic and environmental sustainability through sound water resources management practices: The project will result in a long-term solution to dredged sediment disposal which will have a positive impact on the Bay Area maritime economy.  Uncertainties related to dredging have hampered ports and marinas for decades.  The project will provide a multi-year solution to dredge material disposal. And once filling of the site is complete (5-10 years) the same model can be applied to other sites in the Bay Area and Delta.  Restoration of tidal marsh is sustainable because there are tens of thousands of acres available for restoration, because the benefits outweigh the negative impacts and the approach has been proven to be feasible and successful.   Reuse of treated waste-water from the Novato Sanitary District will assist the District in managing its operations by providing an essentially indefinite end-use for its waste-water, which in turn helps the District plan for future work.

 

  
Maximizing economies of scale and governmental efficiencies: The project will be the largest scale project of its kind in the country.  Though there are other tidal wetland restoration projects that have higher acreages, none use dredged material to restore grades to subsided land at the scale of this project.  The filling of the site will be done in phases, with each phase being about the size of a natural tidal marsh drainge basin (500-600 acres).  The project will bring together the resources of the State of California, the Army Corps of Engineers Civil Works Program and the local sanitary district  in a unique partnership.   

 

 Providing trails and recreation opportunities:  The project will construct an extension to the 2.67-mile Hamilton Bay Trail an approximate length of 0.7 miles. The trail will meet ADA guidelines and will provide a connection between two communities that otherwise are not directly linked. 

 
Securing funds to implement solutions:  The Conservancy is the non-federal sponsor of the Hamilton Wetland Restoration Project resulting in a federal: non-federal match of 75% or 65%, depending upon the phase of project.  To date, the Corps has expended or encumbered about $85 million toward the project.


Creation, protection, enhancement, and maintenance of environmental resources and habitat:

 The project will construct a new flood management levee which will help protect the Bel Marin Keys community from flooding and will provide a flood storage volume within the newly established seasonal wetland portion of the project which could improve localized flood risk. 

 

 

Creation, protection, enhancement, and maintenance of environmental resources and habitats.  Providing net benefits to environment:  The project will restore wetlands using

sediment that would otherwise be disposed of in the aquatic environment. In essence,
dredged sediment will be recycled to be used as fill in order to restore grade
to subsided land.  With this project, the
disposal of dredged sediment in San Francisco Bay and the ocean could be
brought down from an annual volume of about 2 million cubic yards to nearly
less than fifty thousand for a decade or more. 
This will in turn have a benefit for benthic environment at or near the
designated disposal sites (primarily Alcatraz Island and the Deep Ocean
Disposal Site).  Concomitant with a
reduction in ocean disposal, there will be a reduction in air pollution and C02
emissions (from tug traffic), as the ocean disposal site is located some 50 miles
offshore of the Golden Gate and the subject restoration site is less than 10
miles from dredging sites. 
 

 

Conserving and restoring habitat for species protection; acquiring, protecting and/or restoring wetlands, streams, and riparian areas; Enhancing wildlife populations and biodiversity (species richness) Providing lifecycle support (shelter, reproduction, feeding); protecting and recovering fisheries (natural habitat and harvesting); Protecting wildlife movement/wildlife corridors; Recovering at-risk native and special status species; Securing funds to implement solutions: 

 

 The project will convert 1,785 acres of baylands that has been farmed since the late 1800s back into marsh and seasonal wetlands.  The end result will be newly created habitat that will benefit migratory waterfowl and resident shore birds. The site is expected to support the endangered California Clapper Rail and state-listed Black Rail, as well as the endangered the salt marsh harvest mouse. The channels and shallow subtidal areas will support numerous bay fish species including the endangered green sturgeon and juvenile salmon. The seasonal wetland and perimeter levees and transition zones will continue to support resident deer, coyote and small mammal populations.  The tidal wetland will feature fill placed at varying elevations in order to create “micro- topography” which will, when vegetated, provide high-tide refugia for the SMH mouse and other species. A significant (but yet to be determined) portion of the site will allow fishing and the eastern most portions of the site may allow duck hunting, as regulated by the State Department of Fish and Game.  The seasonal wetlands and western extent of the site will provide a wildlife corridor that will allow north-south transit of wildlife between the newly restored Hamilton Airfield and the marshes and diked baylands north of Novato Creek.  

  

The Conservancy purchased the subject property in 2001 for $16,000,000 with a mixture of general fund challenge grant, non-profit contributions, SWRCB Revolving Loan and state bond funding. In addition, at the adjacent Hamilton Airfield, the Conservancy has expended over $20 million to implement the restoration of that property.

  

 

 

  

 






Project team

Part 3 - Benefits