US Army Corps of Engineers
San Francisco District

Hamilton Airfield Wetland Restoration

 

HAMILTON ARMY AIRFIELD WETLAND RESTORATION
CONSTRUCTION


PROJECT LOCATION AND DESCRIPTION

Currently, the project is in the 13 year monitoring and adaptive management phase of wetland restoration. Known as the Hamilton Wetland Restoration Project (HWRP), the project completed the first phase of restoration when the airfield’s bayside levee was breached in April of 2014.  Opening the site to bay for the first time in over in over 100 years and resulting in 648 acres of restored wetland habitat, with the use of LTMS in the San Francisco Bay, the site is continually evolving.  In June of 2014, 2.7 miles of a new public trail at the edge of the wetlands was completed.  

The project site is located on San Pablo Bay, four miles east of the city of Novato, Marin County, California. The project includes a 988-acre parcel with a former military airfield, adjacent California State Lands Commission areas, and the 1,612-acre Bel Marin Key Unit V (BMKV) parcel. The levee-protected site has subsided below the elevation of the surrounding properties, including the tidal wetlands immediately adjacent to San Pablo Bay. This project allowed for the beneficial use of 24.4 million cubic yards of dredged material, including 3.5 million cubic yards from the Port of Oakland 50' Deepening Project. This wetlands-restoration project can continue advance the beneficial use of dredge material from San Francisco Bay as part of the Long Term Management Strategy (LTMS) with the BMKV portion.

 

TOTAL FUNDING

 

TOTAL COST

$ 286,219,000

FEDERAL COST

$ 214,182,000

NON-FEDERAL COST

$   70,037,000

 

 

TOTAL FEDERAL COST THROUGH FY 2019

$   80,885,000

FY 2020 BUDGET

$                   0

FED COST TO COMPLETE

$ 125,918,000

 

FY19 ACCOMPLISHMENTS (BASED ON AVAILABILITY OF FUNDS)

  • Continued monitoring and adaptive management of the site to ensure project performance criteria is met, as required in the project permits and the Monitoring and Adaptive Management Plan (MAMP).
  • In FY19, Year 4 of the 13 year monitoring and adaptive management phase, four years after breach, project performance, in general, is progressing well and on track to meet the project performance criteria set in the MAMP, with a few exceptions as described below.  In summary:
    • Delay in receipt of FY18 Workplan funds at the end of FY18 had various impacts to the site, including schedule, budget and on-site management.  There was a 3 month lag in awarding the monitoring and nursery contract, which most notably impacted invasive vegetation control, water management of the north seasonal wetland and planting and caring for native seedlings, resulting in deterioration of  native vegetation populations. 
    • The North Seasonal Wetland (NSW) is not performing as a seasonal wetland, due to a combination of factors including, over settlement of the berm after construction and excessive rainfall/king tides in 2017.  This caused erosion of the berm, impacting performance of 20% of the site. The NSW is not on track to meet project performance set in the MAMP or site objectives.
    • Native vegetation populations declined slightly and are still at risk from invasive species.  Revegetation is critical to the success of the site and most vulnerable in the NSW due to poor project performance of the NSW berm.
    • The tidal marsh shows nearly full tidal range, as sediment elevation rise, channels are beginning to form and is on track to meet project performance criteria set in the MAMP.
    • Results of the bird and fish use at the site continues to be encouraging, with native populations dominating the landscape. 
    • Continued monitoring of the TAC’s Action List for adaptive management and other remedial actions which include, monitoring of the South Seasonal Wetland pond berm erosion, water management in the NSW and revegetation/invasive control. 
    • Public support and volunteers at the Hamilton Wetlands is a huge factor in meeting project performance criteria.  Working to increase volunteer base to assist in recovery of lost native vegetation and increased invasive species control.  
  • Award Year 4 Monitoring Contract.
  • Complete Year 3 – 2017 Monitoring Report.
  • Hold Year 3 Technical Advisory Committee (TAC) meeting.
  • Develop North Seasonal Wetland Berm repair plans and specs.

FY20 ACCOMPLISHMENTS (BASED ON AVAILABILITY OF FUNDS)

  • Begin Year 5 of the 13 year monitoring and adaptive management phase of the site to ensure project performance criteria is met, as required in the project permits and the Monitoring and Adaptive Management Plan (MAMP).
  • Award Year 5 Monitoring Contract.
  • Complete Year 4 – 2018 Monitoring Report.
  • Hold Year 4 Technical Advisory Committee (TAC) meeting.
  • Award North Seasonal Wetland Berm construction contract.
  • Complete construction of the North Seasonal Wetland Berm.
  • Continued development to increase the number of volunteers through public outreach.

 

ISSUES AND OTHER INFORMATION

  • The California State Coastal Conservancy (SCC) is the non-Federal sponsor.
  • A General Re-evaluation Report (GRR) was completed in 2003 and a Chief's Report was signed in July 2004, recommending the adjacent 1612-acre BMKV property be added to the Hamilton Construction Authorization.
  • The BMKV parcel was authorized as part of the Hamilton project in the Water Resources Development Act (WRDA) of 2007, and an Aquatic Transfer Facility (ATF) was pursued as a more cost effective mode of transporting dredge material to the site.
  • A draft Supplemental Environmental Impact Statement/Environmental Impact Report (EIS/EIR) for the ATF was released to the public on 17 October 2008.
  • Because of environmental issues and the State budget, the Corps and State annotated technical comments and shelved the ATF Supplemental EIS/EIR draft document until further notice.
  • The San Francisco District (SPN) and NFS coordinated a PCA amendment to include BMKV per Water Resources Development Act WRDA 2007 authorization.  The approval of the PCA amendment will allow Land, Easements, Rights-Of-Way, Relocation, and Disposal Areas (LERRDS) crediting of the BMKV parcel, which was purchased by the NFS in 2001, and the use of federal matching funds for the project. However, at issue was the 65/35 project cost share for the Hamilton-BMKV project. The NFS asked for a review of the cost share ratio with the stipulation that the PCA amendment would be signed only if the original authorization’s 75/25 cost share continues. The Assistant Secretary of the Army, Civil Works (ASACW) determined that legislative action was required to maintain a 75/25 cost-share.
  • WRRDA 2014 Section 1030(d) returned the cost share percentage back to 75/25.
  • Regarding BMKV, the NFS is proceeding with design and build of the BMK V Project Levee under a Section 221 Memorandum of Understanding (MOU), dated 8 Mar 2017, for work provided or performed prior to execution of a Project Partnership Agreement. 
  • For BMKV Conservancy’s design plans will align part of the BMKV project levee differently than the description in the approved 2010 Integral Determination Report (IDR).  Because the design is configured substantially differently than that in the plan recommended in the General Reevaluation Report (GRR) authorized by Congress in WRDA 2007, the Corps must undertake an analysis to determine whether the proposed

    changes are within the existing Congressional authorization. 

  • The NFS is looking for ways to reduce the cost of BMKV, which primarily means reducing the placement of dredge material.  This would impact the region’s LTMS goals, as well as delay the restoration of BMKV to wetlands.
  • An amendment to the PCA to cost share the Bay Trail 50/50 as authorized in WRDA 2007 was executed on 20 June 2013.  Construction of the Bay Trail was completed prior to opening the site to tidal action as per environmental permit requirements.

CONGRESSIONAL INTEREST

  • 2nd District, Rep. Jared Huffman
  • Senator Kamala Harris
  • Senator Diane Feinstein

POINT OF CONTACT

  • Deputy for Project Management, Edwin S. Townsley, (415) 503-6593.

Updated on 31 January 2019

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Contact

General Questions
415-503-6708
450 Golden Gate
San Francisco, CA 94102