HAMILTON ARMY AIRFIELD WETLAND RESTORATION
CONSTRUCTION

PROJECT LOCATION AND DESCRIPTION

The Hamilton Wetland Restoration Project (HWRP), is composed of two separate elements, the Hamilton Army Airfield (HAAF) element and the Bel Marin Keys Unit V (BMKV) element.  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 of the former military airfield (HAAF), adjacent California State Lands Commission (SLC) areas, and the 1,612-acre Bel Marin Key Unit V (BMKV) parcel. The levee-protected site had subsided below the elevation of the surrounding properties, including the tidal wetlands immediately adjacent to San Pablo Bay.

The HWRP completed the first phase of restoration at the Hamilton Army Airfield (HAAF) when the airfield’s bayside levee was breached in April of 2014. Addionally, in June of 2014, 2.7 miles of a new public trail at the edge of the wetlands was completed at HAAF.  The HAAF levee breach in 2014 opened the site to bay for the first time in over in over 100 years and resulted in 648 acres of restored wetland habitat, with the use of LTMS in the San Francisco Bay and the site is continually evolving.  The HAAF element is currently following the monitoring and adaptive management requirements.  Monitoring of HAAF is required for 13-years after breach, until 2027.

With the restoration of the HAAF element in 2014, a total of 5.8 million cubic yards of dredged material was placed at site, which included 3.5 million cubic yards from the Port of Oakland 50' Deepening Project.  The HWRP could allow for the total beneficial use of up to 24.4 million cubic yards of dredged material total.  There remains the opportunity the place up to 13.8 million cubic yards of dredged material at the BMKV element and the possibility of up to 3 million cubic yards at the SLC site.  This HWRP restoration project can continue advance the beneficial use of dredge material from San Francisco Bay as part of the Long Term Management Strategy (LTMS).

FY22 ACCOMPLISHMENTS

• Continuation of the 13-year HAAF monitoring and adaptive management plan.
• Completed year 6 of the monitoring and adaptive management of the HAAF element.
• Held annual Technical Advisory Committee (TAC) meeting as required by HAAF project permits.

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 completed design and construction of the BMK V Project Levee in 2022, with a Section 221 Memorandum of Understanding (MOU), dated 8 Mar 2017, for work provided or performed prior to execution of a Project Partnership Agreement in place. 
• 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 differently than that in the plan recommended in the General Reevaluation Report (GRR) authorized by Congress in WRDA 2007, the Corps must undertake an integral determination analysis to determine whether the completed 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

• 2^nd District, Rep. Jared Huffman

POINT OF CONTACT

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

Updated on 14 February 2023

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