December 12, 2024
San Mateo County Flood & Sea Level Rise Resiliency District
1700 S El Camino Real, Suite 502
San Mateo, CA 94402
Attn: Makena Wong, Project Manager, <mwong@oneshoreline.org>
Summer Bunday, Dir. of Project Management, <sbundy@oneshoreline.org>
Re: Comments on the Three Fall Alternatives (2024) for the Millbrae and Burlingame Shoreline Resilience Project (MBSRP)
The Sierra Club Loma Prieta Chapter Bay Alive Campaign thanks OneShoreline for extending to us this opportunity to comment on the three “Updated Draft Alternatives” for the Millbrae-Burlingame Shoreline Resilience Project. We commented last fall on the original alternatives: the “offshore barrier” and lagoon and the “shoreline barrier with and without tide gates.” As you will recall, we had substantial concerns about the proposed offshore barrier and lagoon alternative as well as the lack of transparency and public engagement prior to issuance of the Notice of Preparation for CEQA review of the project. Subsequent to that, OneShoreline has reached out to stakeholders, including Sierra Club and other environmental groups, for input. We are pleased that the offshore barrier and lagoon alternative has been eliminated and we appreciate the openness in OneShoreline’s approach. In this spirit, we have reviewed the current Alternatives and offer our comments in the hope that they will be useful going forward.
The Millbrae-Burlingame Shoreline Resilience Project is timely in that BCDC has just released its Regional Shoreline Adaptation Plan (RSAP), which requires all Shoreline Adaptation Plans to meet BCDC’s RSAP guidelines. The RSAP’s One Bay Vision brings the whole region together to promote collaboration, protect shared assets and achieve common goals. These guidelines ensure a strategic, and forward-looking regional response to sea level rise that accommodates local variations and protects both vulnerable communities and a broad spectrum of public “assets,” including the societal and economic benefits provided by our Bay and its habitats as we plan for the realities with which sea level rise is confronting us.
The RSAP emphasises that the health of the Bay habitats is as much at risk from sea level rise as the communities and infrastructure along the shoreline. For this reason, we are extremely concerned about planning efforts that could lead to potential harms to the Bay ecosystems such as encroachment, with fill, onto habitat in the Bay and we wish to express our deep concern over the proposed alternatives.
The three alternatives that we have seen are all very conceptual. This makes it difficult to comment on them with accuracy. However, we have the following initial observations.
- All three Alternative solutions are based on encroachment into the Bay.
Alternatives A, B and C would all, to increasing extents, use fill to extend over and destroy existing tidal habitat in order to create new shoreline infrastructure and amenities. The resulting major changes to Bay ecosystems, loss of tidal wetlands and mudflats, and the corresponding loss of biodiversity across this ecologically rich shoreline is of major concern.
There are no alternatives included that explore how the cities could create flood protection without encroaching into the Bay. We expected that OneShoreline, in collaboration with the cities, would develop alternatives that explore protection solutions which stay substantially within the shoreline and that are protective of the Bay and its ecosystems to the greatest extent feasible. This was especially the case since Burlingame has a sea level rise ordinance in place.
From the SFO-Millbrae tidal marshes at the Western end of the shoreline, which are habitat for endangered species, south-eastwards, in Burlingame, along Bay mudflats that attract thousands of resident and migrant shorebirds, and ultimately along Burlingame’s easterly shoreline where waters deepen and serve an array of fish, this shoreline provides rich feeding grounds for many species. The Burlingame Shorebird Sanctuary at the mouth of Mills Creek is listed on the City website for its many bird species including endangered ones.
Every year flocks of thousands of smaller shorebirds use these mudflats for foraging and preparing for migration. As traffic at San Francisco Airport is not threatened by small migratory shorebirds as much as by the larger shorebird species, there is good reason to protect marshes and mudflats habitat and avoid disruption of sediment accretion. As sea levels rise, hopefully (and potentially with planned protection) these wetland marshes and mudflats will keep rising too.
At Millbrae’s Bayfront Park, the proposed steep riprap Bay edge (3 to 1 slope) indicates new fill over the entire park that will cover and destroy the existing productive salt marsh habitat. This habitat serves several resident and endangered species for foraging, resting and nesting. This loss of existing wetland habitat is also cause for great concern.
- Additional Nearshore Concerns:
The current hydrology of the Millbrae-Burlingame cove, partially sheltered by the Airport's runway extension, sustains one of the Bay’s few eelgrass beds as reported in the project’s preliminary biological resources report. These beds are of considerable value from an ecological benefit point of view and are not easy to replace or recreate.1 In California, an estimated 20% of the state’s eelgrass is located within San Francisco Bay. Eelgrass is a sentinel indicator of bay ecosystem health and water quality and may be impacted by a wide range of factors.
Earthen levees and installation of structures for oyster reefs: These actions are both featured in all of the Alternatives. At a location directly facing the impacts of the daily tidal cycle, it is impossible to avoid the conclusion that an earthen levee will steadily erode without immediate protective strategies. At the same time, the oyster reef structures indicated just bayward of the foot of the levee, suggest that their primary purpose is as a breakwater while some coarse beach and vegetation such as marsh or eelgrass is indicated between the breakwater and the levee. While we are very supportive of oyster reefs, beaches and marsh/eelgrass as nature-based adaptation, optimal placement is very dependent on location and a variety of factors. There is scant evidence that oyster colonies would develop on those structures. Currently no sustained oyster colonies exist in the South Bay. Further we wonder if the shallow location on mudflats and the local water quality are appropriate for oyster colonization and eelgrass establishment. The project must seek out expertise in Bay oysters and tidal vegetation for success in pursuing this route.
Bay Trail: We note that all the Alternatives propose moving the Bay Trail offshore, into the Bay, which ignores requirements of the Burlingame Sea Level Rise ordinance. In the Ordinance, the City requires shoreline developers to provide space for the Bay Trail using the BCDC Band. The proposed Peninsula Crossings project plans to follow this ordinance. We recommend that future alternatives include the Burlingame planning policy guidance.2
- Managing flow of creeks.
The Alternative proposals raise serious questions regarding significant alterations of the hydrology and ecology of the shoreline. The Alternatives appear to be as much about solving creek stormwater flooding issues as they are sea level rise flooding protection, since stormwater systems drain into the creeks that convey the stormwater to the bay. Two of the Alternatives propose reengineering creek outflows into buried tunnels or an open stormwater holding basin “waterway”, respectively, designed to reduce the number of outflow points into the Bay. These solutions appear to be done without study of the impacts of alteration of outflows into the Bay shoreline ecosystems nor possibly sufficient analysis of existing or potential creek flow information. They raise questions about volume and capacity during extreme storm events, alteration of creek water quality during containment, potential overflow flooding at containment, attracting larger species of shorebirds to the “waterway” solution, dredging issues, as well as the significant issue of alteration of baylands due to loss of flow or excessive outflow. Such options require substantial study prior to consideration.
Therefore, we are not able to comment on whether this is a suitable creek management solution. However, we are concerned about the changes to the hydrology and the ecology of the cove and shoreline as a result.
- Missing Alternatives
We are disappointed that the project did not put forward other alternatives such as:- Onshore Alternative(s): Although included in the 2023 NOP, no onshore alternative was provided for public comment and review. As noted in comments above, the alternatives provided were all predominantly offshore (nearshore) and, as a group, will substantially impact the Bay, habitats and hydrologic conditions including potential impacts to drainage from the creek watersheds.
We expected a similar set of alternatives that explored solutions that stay substantially within the shoreline. We note for example that, along the shoreline, there are significant segments of the shoreline that are less developed and underutilized at the present time, with large areas of surface parking and several small building properties. This could make easements and selective acquisitions viable considerations. In addition, Burlingame has a Sea Level Rise Ordinance that requires a setback from the shoreline and raising the ground level for new construction.
We believe an onshore alternative or alternatives needs to be included. During earlier NOP discussions, staff cited prime real estate and high implementation costs of that approach as primary hurdles. While cost is not an environmental impact, providing comparative feasibility studies of onshore vs offshore implementation, including costs, would be informative. Besides the environmental costs, it is generally understood that levees on Bay mud are much more expensive than onshore levees.
- Adaptive or Phased Alternative needed:
The three Alternatives, we understand, are designed to protect against sea level rise for 75 years, thru the end of the century. However, there is little possibility of build-out as a “one and done” project because- The impacts on the Bay over this extended period have not been considered. Long term impacts to the Bay habitats and the creek outflows cannot be assessed with accuracy over this period.
- Creek water and storm water management over such an extended period would need to be more carefully considered.
- Anticipated groundwater rise impacts over this period are difficult to predict as there is incomplete information currently on groundwater rise.
- Onshore Alternative(s): Although included in the 2023 NOP, no onshore alternative was provided for public comment and review. As noted in comments above, the alternatives provided were all predominantly offshore (nearshore) and, as a group, will substantially impact the Bay, habitats and hydrologic conditions including potential impacts to drainage from the creek watersheds.
The project could be phased by actions that need time to establish prior to the next phase and time to monitor these changes. That is what is now planned by the San Francisquito Creek JPA’s SAFER Bay project involving grey-green hybrid portions of that project.3 4
- Inadequate Information of Impacts on Bay Ecosystems: We are particularly concerned about the lack of consideration for the impacts on the Bay and its ecosystems over the 75 years. In accordance with the guidelines of the RSAP, all the conceptual alternatives need to include an understanding, even at a conceptual level, of anticipated impacts to the Bay and habitat as well as how Bay habitat and ecosystems will be supported and enhanced. This is required as a minimum standard for adaptation plans.
Similarly, without a watershed study and more information on the creeks’ flood water, Alternatives B and C seem hypothetical and could potentially be ineffective or, worse, exacerbate flooding problems at the shoreline. We note that even much simpler flood protection solutions, like the Foster City’s shoreline levees, have been adjusted 2-3 times - about every 30 years. This is also true of Redwood Shores’ levee system.
A set of 25-30 year phasing horizons, over 75 years, leaving open alternative paths ahead, seems a more reasonable approach when planning flood protection into an uncertain future. It affords the cities, businesses and landowners time to adapt with adequate reaction time and would allow the Bay and its ecosystems time for changes to be studied and adapted over this period.
- LEDPA or Least Environmentally Damaging Practicable Alternative
With other members of the public, we were asked to help select a LEDPA alternative. Given the omission of a sufficient range of Alternatives, and the concerns we have mentioned above regarding the conceptual Alternatives provided, we do not believe any of the Alternatives proposed nor combination thereof will stand up to scrutiny as the Least Environmentally Damaging Practicable Alternative.
In summary
- We do not support the three proposed Alternatives because they encroach into the Bay and destroy valuable existing habitat along the shoreline at both cities.
- We believe that the studies are incomplete without exploring alternatives for substantially land-based sea level rise flood protection.
- All the three alternatives need to include an understanding, even at a conceptual level, of anticipated impacts to the Bay and habitat as well as how Bay wetland ecosystems will be supported and enhanced.
- Looking at the implications and potential advantages of a phased solution or solutions, an Adaptation Pathways approach, would be extremely useful.
- Finally, we also assert that, unfortunately, in our opinion, none of the three Alternatives proposed would stand up to scrutiny as a LEDPA (Least Environmentally Damaging Practicable Alternative).
We regret that we cannot be more positive about the alternatives proposed. We hope, however, that our concerns provided herein are of some value as you plan the future direction for this critical shoreline. BCDC’s recently adopted RSAP includes pertinent guidance on local challenges as well as regional priorities in designing sea level rise plans and we believe that it could prove a helpful resource. The Adaptation Atlas also provides valuable insights on the unique opportunities for working with nature for sea level rise planning for each stretch of Bay shoreline. We thank you again for the opportunity to provide you with some comments and we look forward to continued involvement with the adaptation planning for this important shoreline.
Regards,
Gita Dev, Vice Chair
Sierra Club 3-Chapter Coordinated Bay Alive Campaign
Susan DesJardin, Chair, Steering Committee
Sierra Club Bay Alive Campaign
Jennifer Hetterly, Staff Coordinator
Sierra Club Bay Alive Campaign
CC Len Materman, CEO, OneShoreline, <Len@oneshoreline.org>
Dave Pine, Chair OneShoreline Board of Directors <dpine@smcgov.org>
Debbie Ruddock, Vice-Chair One Shoreline Board of Directors, <DRuddock@hmbcity.com>
Ray Mueller, San Mateo County Bd of Supervisors, Dist. 3, <SMC_SupMueller@smcgov.org
Donna Colson, Burlingame City Council, <dcolson@burlingame.org>
Adam Rak, San Carlos City Council, <arak@cityofsancarlos.org>
Lisa Gauthier, East Palo Alto City Council,<lgauthier@cityofepa.org>
Marie Chaung, Hillsborough City Council, <MChuang@hillsborough.net>
Harriet Ross, BCDC Regulatory Dir., harriet.ross@bcdc.ca.gov
Jaclyn Perrin-Martinez, BCDC, Senior Climate Adaptation Planner, <jaclyn.perrin-martinez@bcdc.ca.gov>
San Francisco Bay Regional Water Quality Control Board, Eileen.White@Waterboards.ca.gov
City of Millbrae, Sam Bautista, Dir of Public Works, PWAdmin@ci.millbrae.ca.us
Gail Raabe, Citizens Committee to Complete the Refuge, <glraabe@sbcglobal.net>
Aundi Mevoli, San Francisco BayKeeper,<aundi@baykeeper.org>
Alice Kaufmann, Green Foothills, <alice@greenfoothills.org>
Joshua Quigley, Save the Bay,<jquigley@savesfbay.org>
Chris MacIntosh, Sequoia Audubon Society, <chrismac@alumni.upenn.edu>
1 The Importance of Eelgrass November 07, 2014. “ NOAA Fisheries is providing guidelines to prevent further loss of one of nature’s most valuable and productive habitats in the marine environment—eelgrass...The new guidelines – called the California Eelgrass Mitigation Policy and Implementing Guidelines, or CEMP – provides federal agencies consulting with NOAA Fisheries with comprehensive and consistent information to ensure their actions result in “no net loss” of eelgrass habitat function. This is an important goal for one of California’s most productive and rare marine habitats.”
2 Burlingame Sea Level Rise Zoning Ordinance 2021: https://www.burlingame.org/DocumentCenter/View/2208/Section-2512050-PDF
3 San Francisquito Creek Joint Powers Authority, https://www.sfcjpa.org/safer-bay-project, Excerpt: “We are also conducting scientific evaluations to inform the SAFER Bay design, including the recently completed Draft Refugial Habitat Assessment that can serve as a model for other areas of the Bay. “
4 San Francisquito Creek Joint Powers Authority, Draft Chapter 2, Project Description, Nov. 2024: https://static1.squarespace.com/static/5f21f9097be3cf17ef8a9984/t/673cd7f3b54f5544d140ad79/1732040695766/2.0_Project+Description_Nov2024_withAppendices-compressed.pdf