COASTAL CONSERVANCY PROMOTES SEA LEVEL DEFENSE THROUGH WETLANDS EXPANSION FROM DREDGING 

By Stas Margaronis

Amy Hutzel, is the Deputy Executive Officer at the California State Coastal Conservancy, which works to protect open space, increase public access and recreation, and restore wildlife habitats along the California Coast and in the Bay Area. 

She says “climate adaptation policies have to be put into place now because the threat of sea level rise is now urgent and we may only have 10 more years before we are facing a serious crisis.”

Hutzel says wetlands expansion is a key element in guarding against higher sea levels and there is an “urgent” need for action. 

The expediting of sediment management plans is a vital part of combating higher sea levels in the San Francisco Bay Area. It requires “collaboration and cooperation from 1) local, state and federal agencies and funding sources 2) environmental organizations 3) the wetlands restoration community and 4) the U.S. Army Corps of Engineers (USACE). “

The U.S. Army Corps of Engineers maintains federal navigation channels in the Bay for shipping, which require periodic dredging of accumulated sediment.  Typically, this sediment is disposed of at In-Bay disposal sites or miles offshore at Deep Ocean Disposal Sites.  In early 2019, the Corps and the Coastal Conservancy signed a Memorandum of Agreement (MOA) allowing a small portion of the sediment from Redwood City Harbor to be placed at beneficial use sites around the Bay. 

Sediment is a valuable resource to wetlands.  Historically, sediment would have been washed down watersheds to the Bay, accreting at wetlands and replenishing sediment lost to tidal action.  After centuries of development, however, the Bay’s wetlands have largely lost their connection to sediment sources, leaving them increasingly vulnerable to inundation as sea levels rise.

“Sediment supply is one of the biggest hurdles for wetland restoration work.  Several restoration sites around the Bay are ready to receive sediment, and are in desperate need of it.” Amy Hutzel says. “The Corps is a great partner on many restoration projects, and has access to millions of cubic yards of dredged sediment every year so this was a natural fit.  We knew that if we could overcome the logistical challenges, we could use Bay sediment for Bay restoration.”

Currently, there are two restoration sites in San Francisco Bay accepting dredged sediment for beneficial use: Cullinan Ranch and Montezuma, both in Solano County. In addition, Bel Marin Keys in Marin County has gone through environmental review and permitting and is in the site preparation phase; Bel Marin Keys will be available to accept dredged sediment starting in 2-3 years. Eden Landing in Alameda County is currently in the environmental review stage and may be available to receive dredged sediment starting in 2-3 years. These four sites have the capacity to receive over 20 million cubic yards of dredged sediment.  The Corps dredges approximately 1.5 million to 2 million cubic yards of sediment each year as part of its Operations and Management dredge program in San Francisco Bay, maintaining federal navigation channels for shipping.

In May 2019, under the terms of the MOA, the Conservancy disbursed funding to USACE San Francisco District to pay for the incremental cost of placing the sediment at restoration sites.  Sediment dredged by the Corps must be placed at permitted placement sites, such as the Deep Ocean Disposal Site, or In-Bay disposal sites, or at beneficial use sites. The Corps, when implementing its navigation mission is required to place the sediment at the most cost- effective, environmentally sound site, consistent with best engineering practices, and that meets federal environmental requirements. In general, beneficial placement is usually not the most cost-effective option.  The Corps can use a beneficial placement site if the cost is paid by a non-federal sponsor.  In this case, the Conservancy acted as non-federal partner to make the beneficial placement possible.

“Initially USACE San Francisco District was only able to deliver the dredged material for in-bay disposal.  It became a win-win situation when the Coastal Conservancy joined forces with the Corps as a non-federal partner in contributing funds to the project for beneficial use upland.” said Jay Kinberger, Chief of the Navigation Program at the Corps San Francisco District.  “We are looking forward to a successful contract this year and hope to continue the partnership for future projects.”

Approximately 486,000 cubic yards of sediment was dredged from Redwood City Harbor this summer. Of that, 70,000 cubic yards will be placed at beneficial use sites helping the upland sites create thriving wetlands that are resilient to sea level rise.

On June 18th, 2019, the staff of the San Francisco Bay Restoration Authority (the Authority) announced that it recommends allocating $67.5 million of Measure AA funding to five projects to improve the health and ecological functions of the Bay.  Two of the projects were awarded funding at a June 18th Governing Board meeting; the remaining three will be presented for funding later in 2019.

 The projects in this year’s funding round include an $8 million wetland restoration project in Contra Costa County, $1 million for the restoration of a parcel of scarce San Francisco waterfront park land, and a $57 million five-year commitment, of which $11 million will be funded this year, for the design and construction of a 4-mile ecotone levee in the South Bay as the first phase of restoring 2,900 acres of managed open water ponds to tidal marsh.

 “Habitat protection, flood protection and shoreline public access are all tangible dividends of Measure AA investments, “said Dave Pine, Chair of the Authority Governing Board and a member of the San Mateo County Board of Supervisors. “The five projects proposed for Measure AA funding in this grant round advance the goal of restoring the Bay for the benefit of both people and wildlife.”

 Measure AA, the Clean and Healthy Bay Parcel Tax of 2016, was the first nine-county funding measure in the Bay Area and is generating $25 million per year for Bay restoration through a $12 annual parcel tax for the next 18 years.  The San Francisco Bay Restoration Authority is a regional agency responsible for distributing that funding to projects that restore, enhance and protect wetlands and wildlife habitat in San Francisco Bay: http://sfbayrestore.org/announcement/san-francisco-bay-restoration-authority-recommend-675-million-measure-aa-funding-5

Hutzel said that restoration work is not limited to dredging but also includes levee repairs and replacements, breaching of levees, clean-up of contaminated sites.

The process of accelerated wetlands augmentation is complicated by the fact that USACE funding is limited and that only after funding is guaranteed can one off projects be authorized thanks to contributions from State and Measure AA funding.

Historically, the bulk of dredge materials were dumped into the Pacific Ocean as part of Deep Ocean disposals and were costing about $10 above the average cost of per cubic yard dredging. 

A second classification of dredging was classified as In-Bay deposits and this material was deposited at sites such as near Alcatraz where it had flushed out under the Golden Gate and into the Pacific Ocean. The cost of In Bay dredging deposits was $20 per cubic yard above the average cost. Twenty years ago environmental organizations began to protest that these deposits were accumulating as mudflats near Alcatraz and polluting the Bay. This led to public pressure on USACE to create a third category of beneficial use dredging in which clean deposits were deposited at four sites. The cost of this classification is about $40 above the average cost of dredging. Today Deep Ocean accounts for about 40% of annual dredge deposits; beneficial accounts for another 40% and In Bay accounts for about 20% of all dredged material. On an annual basis, about 2 million cubic yards of material is dredged from the San Francisco Bay. If all this material was deposited in beneficial cites, the cost would be about $80 million above the average dredge cost, Hutzel said. 

The $57 million five-year commitment and $11 million for 2019 is allocated for the design and construction of a 4-mile ecotone levee in the South Bay as the first phase of restoring 2,900 acres of managed open water ponds to tidal marsh. This is controversial with some organizations because it reclaims open water. However, the need for natural barriers as a defense against sea level rise and flooding is also recognized, she said

Hutzel has worked in the San Francisco Bay Area Program of the Coastal Conservancy for 15 years, on wetland restoration, public access, and land acquisition projects. She has served on the boards or advisory committees of the San Francisco Bay Joint Venture, the Bay Area Open Space Council, the San Francisco Estuary Partnership, and Resilient by Design. She has a bachelor degree in urban and environmental planning from the University of Virginia. She worked as an educator at the San Francisco Bay National Wildlife Refuge, Kilauea Point National Wildlife Refuge, and Save The Bay prior to joining the Coastal Conservancy.