Prepared by:
SR-37 Corridor Adaptation Study
Prepared for: SEGMENT A-1 ADAPTATION STRATEGIES This corridor adaptation study is funded through Senate Bill 1 (SB 1) 2018 Adaptation Planning Grant
Summary of Marin County Section of Highway 37 Corridor Adaptation Studies Table of Contents 2. Summary of Studies Glossary Acknowledgments of Terms 1.05 1.04 1.03 Segment 1.02 Basis 1.01 Study A-1 Grant of Introduction Outreach Challenges Purpose Study 2.11 2.10 Trail Baylands 2.09 NVTA TravelBay Behavior andTransit Feasibility Report 2.08 Passenger RailServiceNovatotoSuisunCityFeasibilityStudy Plan Ecosystem 2.07 District4Vulnerability AssessmentSummaryReport Trail 2.06 StudiesHabitat 2.05 TheProjectStudy Report -ProjectDevelopment SupportforSR-37 Plan 2.04 SR-37SegmentASeaLevelRiseCorridorImprovement Study H California Goals 2.03 SR-37Transportation andSeaLevel Rise CorridorPlan 2.02 TheState Route 37Transportation ConceptReportState 2.01 Highway37Stewardship Study (CaseStudy) Transportation Rail Studies Plan 1.10 1.09 Project Next Stakeholders Steps 1.08 Visions 1.07 SegmentA-1Related Studies Key Findings for 1.06 Resiliency Segment A-1 Opportunities Figure 1.NVision Figure 1.MVision4(Proposed)Section icial” Figure 1.LVision3“Multi-Bene Figure 1.KVision2“MovetheLine” Figure 1.JVision2ProposedSection Figure 1.IVision1“HoldtheLine” Figure 1.RVulnerabilityFigure Mapof Novato 1.QExistingPublicLandFigure Ownership 1.PMaximizeHabitat,Figure MinimizeRiskStrategy 1.OLongFigure Term Restoration Novato Creek Figure 1.ESR-37/US-101InterchangeFigure Considerations 1.DLowerFigure Novato Watershed Creek Flow 1.F Corridor Roadway 1.CUnderstanding Figure Elevation Requirements SeaLevel 1.BFuture Figure Rise Inundation Land Use 1.AKeyFigure IssuesAlongSR-37inMarin
4 “BuyingTime”
21 16 60 56 55 52 50 48 47 46 32 38 14 39 18 19 15 13 40 41 33 9 30 29 28 63 34 26 53 46 12 37 46 12 11 11 62 35 10 62 7 5 Summary of Marin County Section of Highway 37 Corridor Adaptation Studies References Ecosystem 2.47 GrandBayway CommonGround (2018) 2.46 LeveeOwnershipSurvey Memorandum 2.45 AddressingSocialEquity WhitePaper Additional 2.44 2.43 TheGovernanceofSeaLevelRiseintheSan FranciscoBayArea Plans 2.42 Paying ForClimateAdaptationInCalifornia:APrimerforPractitioners Living 2.41 State ofCaliforniaSea-LevelRiseGuidance and 2.40 with 2.39 MarinCountyBayWAVE: MarinShorelineVulnerability Assessment Studies 2.38 Rising a 2.37 SeaLevelRise&AdaptationWhitePaper Sea Sea Seas Rising 2.36 SimmonsSloughDrainageSystem ImprovementsProject Level Level in Bay 2.35 DeerIslandBasinTidalWetlands Restoration Project Rise Rise California 2.34 NorthDeerIslandFloodDiversionWeir andDetentionBasin Studies Policy 2.33 NovatoCreekFloodProtectionandWatershed Program(2016) 2.32 NovatoCreekEconomicAnalysis(2016) Guidance 2.31 NovatoCreekHydraulicAlternativesAnalysis(2016) 2.30 FloodControl2.0NovatoBaylandsVision 2.29 Pacheco Pond Water ManagementPlan(2014) Marin 2.28 HydraulicAssessmentofExistingConditions County 2.27 NovatoCreekEIRComments(1984) 2.26 NorthBayWater Reuse ProgramFinalEIR/EIS Flood 2.24 GreenPoint CommunityPlan(1998) 2.23 BlackPoint CommunityPlan(1998) Control 2.22 NovatoSanitaryStrategic PlanUpdate 2.21 NovatoBicycle&Pedestrian Plan(1998) 2.20 NovatoGeneralPlanUpdate(1998) Novato 2.19 SanPablo Baylands:EnsuringaResilient Shoreline 2.18 BelMarinKeys Wetland Restoration ProjectPreliminaryDesignReportArea 2.17 ComprehensiveConservationandManagementPlan 2.16 SanPablo BayNationalWildlifeRefuge ClimateAdaptationPlan Studies 2.15 TheBaylandsandClimateChange 2.14 AdaptingtoSeaLevelRiseAlongtheNorthbayShoreline 2.13 Recovery PlanforTidalMarshEcosystemsofNorthernandCentralCalifornia 2.12 SanFranciscoBayAreaWetlands Ecosystem GoalsBaylands Environmental Studies
SF BayR Novato CreekCorridorWideningR Restoration Project (Ongoing) Novato Creek Watershed Project estoration Authority(Current)&
Species
and
Community
estoration Projects
rfls 64 Profiles
DeerIslandBasinWetlands
84 76 75 75 75 74 74 72 71 70 69 69 67 66 66 94 94 94 93 92 91 90 89 87 83 82 82 80 80 91 89 94 76 76 85 89 63 94 72 96
Acknowledgments ADAPTATION STUDY SPONSORS • Golden Gate Bridge Highway and • County of Marin Transportation District • Transportation Authority of Marin • Green Point Advisory Committee • Marin County Flood Control and Water • Marin Audubon Society Conservation District • Marin BayWAVE Steering Committee • Marin Community Foundation TECHNICAL WORKING GROUP • Marin Conservation League • Dan Dawson County of Marin • Marin County Farm Bureau • Joanna Dixon Marin County Flood Control • Marin Economic Forum and Water Conservation District • Marin Open Space District • Nick Nguyen Transportation Authority of • Marin Sonoma Vector Control District Marin (MSVCD) • Chris Blunk City of Novato • Metropolitan Transportation Commission • Erik Brown Novato Sanitary District (MTC) • Kelly Hirschberg Caltrans • North Bay Leadership Council • Bill Gamlen Sonoma-Marin Area Rail Transit • North Marin Water District (NMWD) • Jessica Davenport California Coastal • NOAA - National Marine Fisheries Conservancy • North Bay Watershed Association (NBWA) • Mark VanGorder PG&E • North Bay Water Reuse Association • Noemi Camargo-Martinez Bel Marin Keys (NBWRA) Community Services District • Novato Chamber of Commerce • Novato Sanitary District COMMUNITY STAKEHOLDERS • Sonoma County Transportation Authority • Adjacent private landowners (SCTA) • ABAG (Bay Trail) • San Francisco Regional Water Quality • Bay Area Regional Collaborative (BARC) Control Board (RWQCB) • Bay Institute • SFBay Joint Venture • Bay Planning Coalition • Sierra Club, Marin Chapter • Baylands Group • State Water Resource Quality Control Board • Bay Conservation and Development • Sustainable Marin Commission (BCDC) • Sustainable Novato • Blackpoint Improvement Club • Trout Unlimited • California Department of Fish and Wildlife • US Fish and Wildlife Service (USFWS) (CDFW) • California Native Plant Society, Marin CONSULTANT TEAM Chapter • CSW/Stuber-Stroeh Engineering Group • CA Assembly Member Marc Levine • Civic Knit • CA Congressman Jared Huffman • WRA Environmental Consultants • CA State Senator Mike McGuire • Mark Thomas • Federated Indians of Graton Rancheria • Stetson Engineers, Inc. • Ducks Unlimited Summary of Marin County Section Highway 37 Corridor Adaptation Studies This page intentionally left blank Glossary of Terms
ABAG Association of Bay Area Governments NBWRP North Bay Water Reuse Program
ACOE US Army Corps of Engineers NEPA National Environmental Policy Act
BAAQMD Bay Area Air Quality Management District NMWD North Marin Water District
BARC Bay Area Regional Collaborative NOAA National Oceanic and Atmospheric Association
BATA Bay Area Transit Authority NPDES National Pollutant Discharge Elimination System
BCDC Bay Conservation and Development Commission NVTA Napa Valley Transportation Authority
BMKCSD Bel Marin Keys Community Services District NWP(RR) Northwestern Pacific Railroad (Network)
BMKV Bel Marin Keys Unit V OPC Ocean Protection Council
CCC California Coastal Commission PA/ED Project Approval and Environmental Document
CDFW California Department of Fish and Wildlife PTC Positive Train Control
CEQA California Environmental Quality Act RAMP Regional Advanced Mitigation Program
CoSMos Coastal Storm Modeling System RM-3 Funds toll revenue allocated by MTC to address Bay
DAA Design Alternative Assessment Area traffic congestion
DMU Diesel Multiple Units RWQCB Regional Water Quality Control Board
ESA Endangered Species Act SCC California State Coastal Conservancy
FHWA Federal Highway Administration SCTA Sonoma County Transportation Authority
GGBHTD Golden Gate Bridge Highway and Transportation Segment A-1 Portion of SR-37 between US Hwy 101 and District Petaluma RIver Bridge
GHG Green House Gas emissions SHOPP Project (Caltrans) State Highway Operation and Protection Program IPCC Intergovernmental Panel on Climate Change SIP (FHWA) Safety Improvement Program ITS Intelligent Transportation Solution SLR Sea Level RIse LTS Level of Traffic Stress SMART Sonoma-Marin Area Rail Transit MCF Marin Community Foundation SR-37 State Route 37 MCFCWCD Marin County Flood Control and Water Conservation District STA Solano Transportation Authority
MCY Million cubic yards (measurement) TAM Transportation Authority of Marin
MHHW Mean Higher High Water TRB Transportation Research Board of the National Academies MOU Memorandum of Understanding UPRR Union Pacific Railroad MTC Metropolitan Transportation Commission USGS United States Geological Survey NAVD88 North American Vertical Datum of 1988
NBWRA North Bay Water Reuse Assocation
JANUARY 2020 | 7 This page intentionally left blank
1/10/20
e
n
i
L
T
R
Legend A
M S public awareness and public utility operations Restoration In Progress Habitat Restored Open Space Protected Continuing Public Wastewater, Flood Continuing Public Wastewater, & Utility Operational Facilities Potential Marshland Restoration Sites Priority Levee Analysis Locations Interchange Key Adaptation Issues Multi-beneficial Levee siting, design, and flood Compatibility with wastewater, Accommodation of established and requirements re-design SR 37 interchange Long-term habitat governance and Diverse and equitable funding strategy control, marshlands planned at Atherton & US 101 Sea Level Rise planning management management • Integrated highway, transit, rail, and trail • • • • •property Impacts to private • • Expanded • SR 37-US 101 Interchange San. Pond Cheda Creek Novato Pacheco Bel Marin Keys V Wetlands Restoration Wetlands Private Private Novato Bel Marin Keys Pond USFWS State of California Managed by MCFCD Scottsdale Lynwood Basin
h Marsh Heron’s Beak Pond g MCFCD
u Scottsdale
o
l
S
s
Rowland Blvd Rowland
MCFCD n o m
Duck Bill Pond
m
i
S
Deer Island
Novato Creek Basin Restoration Sanitary District Deer Island Open Space Preserve Mulroy Preserve Stonetree Novato San. Novato
Day Island Marin USFWS
Marin Sonoma Audubon
Atherton Ave Interchange Olive Ave Olive Atherton Ave Atherton JANUARY 2020 | 9 Park & Ride Lot Figure 1.A Key Issues Along SR-37 in Marin 1.A Key Figure 1.01 Introduction The County of Marin (County), the Transportation Funding to complete this study originates from a Sen- Authority of Marin (TAM), and Marin County Flood ate Bill 1 (SB 1) Adaptation Planning Grant provided Control and Water Conservation District (MCFCWCD) by the State of California. Additionally, the County are jointly committed to helping California and our and TAM have each contributed funds to this study region respond to the challenges that climate change to maximize their understanding of the challenges poses to our transportation infrastructure. This SR-37 and choices facing not only Caltrans, but also public Corridor Adaptation Study (Study) seeks strategies infrastructure, private property, and the general public to protect California State Route 37 (SR-37) between along the SR-37 corridor. This report summarizes the US Highway 101 (US-101) and the west bank of the decades of earlier studies related to transportation Petaluma River, known as Segment A-1, from the planning, climate change, ecology, and land use com- increasing impact of sea level rise and storm surge, pleted by public agencies, environmental groups, and which will eventually inundate the roadway making private entities for the SR-37 corridor. In addition, it travel impossible. summarizes the key challenges and opportunities, as well as gaps in information that will require resolution This study does not provide alternatives to solve the in order to support the selection of a preferred alter- flooding issues that occurred along the corridor in native that reduces the impact of sea level rise to the 2017 and 2019, as the State of California Department corridor. of Transportation (Caltrans) is actively working to im- plement solutions to correct the conditions that led to This report is intended to support both Caltrans and the recent inundation events. Rather, this study seeks MTC in their current in-depth research, analysis, and to collect and distill findings from the disparate body public outreach associated with developing an ap- of existing research into visions for the aid of trans- proach to improving SR-37. Based upon the previous portation planners, policymakers, and governmental studies as well as discussions with stakeholders and leadership tasked with implementing a long term community members, the report presents several solution for the corridor’s 45,000 daily users. visions to protect SR-37 from sea level rise. The vi- sions range from a traditional levee model; a robust While the County, TAM, and MCFCWCD are the spon- causeway that restores marshlands; and a near term sors of this study, numerous other public agencies improvement to protect the corridor. Each vision provided technical support and comments during provides public agencies and the larger stakeholder a series of working group meetings held on three community an opportunity to consider trade-offs be- occasions during 2019. Special contributions were tween time of completion, cost, ecological integration, made by the Sonoma County Transportation Author- and other civic interests. Most important, the report ity (SCTA), Novato Sanitary District (NSD), Sonoma prioritizes the next steps required to build momentum Marin Area Rail Transit (SMART), North Marin Water towards developing a lasting solution. District (NMWD), and Bel Marin Keys Community Services District (BMKCSD). Additionally, the public While many variables must be weighed, the Ultimate had opportunities to review the study and comment Solution eventually pursued will need to address the ons it findings on November 21, 2019, as well as at critical importance of SR-37 to both the region and the State Route 37 Policy Committee meeting held on the North Bay’s transportation system. At the same December 5, 2019. time, the outcome should reflect the best practices available for nature-based solutions as a reflection of
10 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY the sustainable development ethos embodied by the provided direction and comment on the study’s ap- community of Marin County. proach and findings. The TAG met on April 18, June 6, and November 12, 2019 and invited the following 1.02 Grant Purpose members to participate: On April 28, 2017 the governor signed Senate Bill 1 • County of Marin; (SB 1), the Road Repair and Accountability Act of 2017 • Transportation Authority of Marin; which invests $54 billion over the next 10 years to • County of Marin Flood Control; repair roads, freeways and bridges in communities • Bel Marin Key Community Services District; across California. These funds are equally split be- tween state and local investments and administered • State of California Department of Transportation; by Caltrans. In addition to improving infrastructure, SB • California Coastal Conservancy; 1 provides planning funds of $20 million over three • City of Novato; years through Adaptation Planning Grants offered • Pacific Gas and Electric (PG&E); to local and regional agencies for climate change adaptation planning. The program specifically seeks • Sonoma County Transportation Authority; to identify solutions to climate change impacts on • Sonoma Marin Area Railway District; California’s transportation assets such as sea level • Novato Sanitary District rise (SLR), high heat and storm surge. The County of Marin applied and received a grant to develop a To supplement the outreach effort, the study team resiliency strategy for Segment A-1 on SR-37. Specific completed in-person meetings with the following requirements to comply with the grant requires this agencies and parties: study to include the following elements: • City of Novato including a field trip to the US-101/ SR-37 interchange area on August 27, 2019; • Collect previous studies and synthesize contents • Novato Sanitary District on September 10, 2019; related to SR-37 Segment A-1; • North Marin Water District (by phone and email); • Identify additional information needed to identify a preferred approach increasing resiliency to cli- • Sonoma County Transportation Authority on Sep- mate change; tember 5, 2019; • Provide guidance to Caltrans and MTC regarding • Sonoma Marin Area Rail Transportation Authority approach alternatives and priority next steps to on September 6, 2019; protect the corridor from flooding resulting from • Pacific Gas and Electric (PG&E) (by phone and high tides, sea level rise, and storm surge email); and
Marin County Department of Public Works adminis- • Representatives of private property landowners tered the grant and must complete the study by the adjacent to Segment A-1 on August 22, 2019. end of February 2020. On November 21, 2019, the County and TAM spon- sored a community presentation at the Hamilton 1.03 Study Outreach Community Center in Novato to review a draft of the study’s finding and receive public comment. On The SR-37 Corridor Adaptation Study implemented December 5, 2019, the County presented the study’s a combination of outreach techniques to support findings to the State Route 37 Policy Committee Board its preparation. A Technical Advisory Group (TAG)
JANUARY 2020 | 11 for review by the community members and the corri- This SR-37 Corridor Adaptation Study builds on dor’s stakeholders. these efforts in its analysis of alternative approaches and recommended near-term actions for Segment 1.04 Basis of Study A-1. The SR-37 Corridor Adaptation Study follows eight years of ongoing state and regional transportation 1.05 Segment A-1 agencies’ planning efforts focused on the entire 21- mile SR-37 corridor between US-101 in Marin County Challenges Segment A-1 is typically not subject to the trav- and I-80 in Solano County. Segments of SR-37 also el delays found in the eastern segments of SR-37. travel through Sonoma and Napa Counties. However, the storms of 2017 and 2019 illustrate how In February 2018 the Metropolitan Transportation flooding in Segment A-1 can disrupt the North Bay’s Commission (MTC), Solano Transportation Authority transportation network and impact SR-37’s 30,000 (STA), TAM, SCTA, Napa Valley Transportation Author- daily users. Segment A-1 is especially at risk to the ity (NVTA), and Caltrans published the SR-37 Transpor- impacts of climate change and sea level rise as it has tation and Sea Level Rise Corridor Improvement Plan the lowest elevation of the entire corridor and is gen- which expresses three broad goals: erally protected by levees originally constructed to create agricultural lands. The following summarizes • Integrate transportation, ecosystem and sea level specific challenges for the segment: rise adaptation into one design; Public Urgency • Improve mobility across all modes and maintain The public seeks a near-term solution to the SR-37 public access; and Segment A-1 flooding and is frustrated that solving • Increase corridor resiliency to storm surges and the problem may take more than 15 to 20 years. This sea level rise. sentiment was clearly made by the general public and The integration of environmental restoration into the stakeholders in focus groups held in Marin, Sonoma, planning of SR-37 follows the nearly 30 years of work Napa, and Solano Counties as part of MTC’s SR-37 that groups have invested to restore tidal marshes corridor-wide planning process. Public comment in the North Bay along the SR-37 corridor. These made during preparation of this study reinforced this restoration projects include the development of the priority. To address the potential for flooding in the San Pablo Bay National Wildlife Refuge including ex- near term along Segment A-1, Caltrans completed pansions of the Cullinan and Haire Ranch restoration emergency repairs in 2017 and 2019 which raised the projects. To advise regional transportation planners pavement, installed floodwalls, and repaired levees. on the ecologic benefits along the SR-37 corridor, a They are currently developing a long term solution coalition of environmental non-profit organizations identifying a preferred alternative by 2023 through as well as the California Coastal Conservancy formed a State Highway Operation and Protection Program the Baylands Group. In October 2017, they published (SHOPP). the San Pablo Baylands: Ensuring a Resilient Shoreline which offers, “concerns around the critical impor- Increasing Frequency of Flooding tance of protecting, enhancing, and restoring the tidal The most defining issue for SR-37 Segment A-1 is its wetlands, natural resources, ecosystem services, and vulnerability to closure because of flooding. In the habitats of the San Pablo Baylands.” past 100 years, Novato has experienced major floods
12 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY at a rate of one per decade. Levees were breached tical Datum of 1988 (NAVD88). This is the high-risk intentionally in 2006, 2008, and 2014 to protect No- aversion category and includes the current base flood, vato’s downtown and residential neighborhoods from three feet of wave action, and the estimated sea level greater flooding. SR-37 was closed for 27 days in rise by the year 2100. winter 2017 due to flooding. In 2019, flooding caused As the existing roadway within Segment A-1 is about closure of SR-37 Segment A-1 for 7 days, further in- 2 to 6 feet in elevation, the roadway would need to be creasing public and legislative focus on the problem. raised at least 21 feet to an absolute elevation of 23 Flooding impacts extend well beyond the SR-37 high- feet as shown in Figure 1.C to minimize the impact of way; US-101, Atherton Avenue, Redwood Boulevard, flooding by the end of the century. Marsh Road, Hanna Ranch Road, and Rowland Bou- levard all remain at risk, as well. The railroad lines Highly Sensitive Environmental Setting owned by SMART located parallel to SR-37 segment In the 1800’s settlers to the North Bay drained the A-1 are also vulnerable to flood impacts. marshlands and constructed levees to farm the area adjacent to the present-day SR-37. Currently, SR- Climate change resulting in higher temperatures will 37 Segment A-1 lies within an area fully involved in exacerbate flooding. The Ocean Protection Council marshland restoration to improve habitat and eco- in its 2018 report entitled Rising Seas in California logical connectivity. Examples include the Coastal note that flood water could reach an elevation of Conservancy’s 1,600-acre Bel Marin Keys Unit V Res- 23 feet at the bridge and causeway, and 21 feet on toration and Marin County’s restoration planning embankments, based upon the North American Ver-
Figure 1.B Future Sea Level Rise Inundation the above graphic shows the extent of flooding resulting in future sea level rise if improvements to levees are not made.
JANUARY 2020 | 13 for Deer Island Basin through a San Francisco Bay for integrating individual agency needs into a com- Restoration Authority Measure A-A planning grant. prehensive adaptation solution. Closer coordination among the many public agencies, stakeholder organi- 38 animal and 28 plant special status, endangered, zations, and private interests is beneficial to develop a or threatened species and habitats have been docu- holistic solution and inclusive funding plan. mented within five miles of SR-37, protected by one or more statutes and agencies. Based on comments While there is general agreement on the perceived received during MTC’s corridor-wide focus groups, risk of doing nothing to SR-37, there is less agreement Marin County stakeholders expect transportation im- provements to also protect environmental resources.
Few Mobility Options Automobile travel is the only real means of travel be- tween the US-101 and the west bank of the Petaluma river. There is currently no transit service available and the Travel Behavior and Transit Feasibility Study com- pleted by NVTA concluded that dynamic ridesharing solutions (carpooling supported by social networks) is the primary alternative. In order to implement transit service, the current bottlenecks that create congestion during peak travel hours must be eliminated.
Caltrans allows bicyclists to use SR-37 but high vehicle speeds and volume, coupled with limited shoulder width and debris, greatly discourage their use. In 2019, SMART evaluated the cost to provide passenger rail service along the corridor, but no implementation funding is currently available. Park and Ride facilities exist at the Atherton interchange, but no bus stop or organized ride-sharing programs currently operate from there.
During MTC’s Focus Groups, expansion of regional transit options was recommended. Additionally, re- gional planners seek to include a Class 1 trail along SR-37 corridor consistent with the goal of completing the San Francisco Bay Trail.
Governance During MTC’s Focus Groups, public comment identi- fied a lack of a formal process as an impediment to expeditiously advancing the improvements to SR- Figure 1.C Understanding Roadway Elevation 37. Currently, no formal governance structure exists Requirements visually demonstrates how the elevations are derived, and illustrates the relationship between the various components involved in determining the process of sea level rise 14 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY on how to define the merits of potential options and Increase Mobility Choices fund the improvements. Through MTC’s research, Improving the corridor provides the option to inte- the public has expressed an aversion to creating new grate the San Francisco Bay Trail into the preferred regional authorities or the assignment of collective alternative and make available options for bicyclists responsibility to any existing agency. and pedestrians to safely experience the area, as well. The development of electric-assist bicycles also makes Funding biking a commute option for corridor users. Based Full funding for Segment A-1 transportation modifi- on the recently completed transit feasibility study cations has not been identified. Caltrans has reported managed by Napa Valley Transportation Authority, that relying solely on existing state and local funding vanpools, improved park & ride facilities, expanded sources would require as many as 60 years. A tolling car sharing, and targeted express bus services on SR- feasibility study undertaken by MTC in 2017 estimated 37 could be included in both near-term and long-term that a $6 toll in one direction on SR-37 would gen- improvements. Finally, SMART has expressed interest erate approximately $1 billion for the entire corridor in active participation in long-term corridor planning over a 50-year period; well below the total cost. At the to provide passenger rail service. same time, MTC’s focus group research indicated that public support for new tolls cannot be relied upon. Integrate Marshland Restoration SR-37 Segment A-1 traverses the San Pablo Baylands, As project financing and tolling decisions are made, an area that has been a restoration priority of Federal the financing program should address needs of disad- Segment A-1 Related and State resource agencies, scientists, and environ- vantaged travelers. Funding strategies should reflect Studies Key Findings mental non-profits for over thirty years. It is identified Caltrans’ environmental justice goal of ensuring that as the prime candidate for demonstrating the natural when transportation decisions are made, low-income protection benefits that restored marshes can provide and minority communities have a full opportunity to within the entire San Francisco Bay region. participate in the decision-making process and receive an equitable distribution of benefits, and not a dispro- Tidal marsh habitat stores more carbon from the portionate share of burdens. atmosphere than almost any other habitat type on earth. Reengineering levees to create gently sloping The costs for permanent Segment A-1 highway im- transition zones would buffer storm-wave run-up and provements could exceed $1 billion, and additional erosion, lower flood risk, while facilitating landward ecosystem investments in the corridor will add con- migration of the marsh within an adequate transition siderably to that amount. At the same time, MTC’s zone. Focus Group analysis determined that currently public support for new tolls does not exist. Including marshland habitat restoration within an integrated transportation design solution is consistent 1.06 Segment A-1 with the approach being used by both Caltrans and Opportunities MTC across the entire SR-37 corridor. Build a Collective Partnership The extensive study along SR-37 provides a strong basis for identifying solutions to minimize the impact SR-37 is not the only public infrastructure in the study of climate change. The opportunities include the area at risk from increasing flooding and sea level following: rise. SMART infrastructure, potable water, wastewater, and electrical utilities all face increasing capital and
JANUARY 2020 | 15 operational challenges resulting from sea level rise. 1.07 Reaching consensus on the scope and structure of an Segment A-1 adaptation-based partnership could focus the effort Related Studies Key and increase delivery effectiveness. Findings Partners would be brought to the table early to help MTC, Caltrans, Federal and State resource agencies, design the relationship, increase buy-in, and maximize and numerous environmental groups have reached the likelihood that the partnership takes full advan- consensus that transportation solutions should inte- tage of the resources and capabilities of the groups. grate ecological restoration and climate adaptation A partnership could lay out clear objectives, including into planning and development. There have been six specific goals, a project delivery approach, roles, re- State, regional, and local studies published since 2013, sponsibilities, funding sources, and communication addressing SR-37 corridor transportation and climate change issues. Most of the studies included significant strategies. public outreach and stakeholder engagement. Such However, partnerships do not manage themselves an approach could be less risky and more beneficial and require commitment to maintain relationships for both environmental and transportation needs. The and momentum. There should be especially strong section “2. Summary of Studies” on page 46 is effort to collaborate with the Sonoma County Trans- comprised of a summary of all known public studies portation Agency, given the shared interest in the completed for SR-37, however, the following are key Petaluma River Bridge, the RM-3 funds, MTC’s current findings that are useful in understanding basic condi- tions along the corridors: SB 1 Adaptation Planning Grant study, and overall performance of the highway. Memorandum of Understanding (MOU) The trans- Collaborate with the Community portation agencies in Solano, Napa, Sonoma, and The closure of SR-37 Segment A-1 several times in Marin executed a SR-37 memorandum of understand- the past three years has increased public interest in ing (MOU) in 2015. The MOU commits all parties finding a solution to the flooding. In addition, the to collaborate on the entire corridor, while allowing Marin Audubon Society, Marin Conservation League, individual segments to proceed independently. There Sustainable Marin, North Bay Leadership Council, No- is a 12-person policy board comprised of three elect- vato Chamber of Commerce, adjacent private prop- ed officials from each county, an Executive Steering erty owners, nearby homeowner associations, and Committee (ESC) of transportation agency senior bicycling advocacy groups have long been involved management, and a Project Leadership Team (PLT) in matters related to or within the vicinity of the high- with technical staff from each agency. way. Developing a framework for informing and in- Low Elevation Segment A-1 has the lowest road- cluding these and other stakeholders will be especially way elevation within the entire SR-37 corridor. It useful to creating a sustained level of support over the traverses historic marshlands comprised of bay mud long time frame that will be required to complete all which is a thick deposit of soft, unconsolidated silty improvements. clay, saturated with water. From Novato Creek to Atherton Avenue, SR-37 is relatively low-lying with an elevation of approximately 4 to 6 feet NAVD88 and relies upon the Novato Creek levees, which range in elevation from approximately 10 to 13 feet NAVD88
16 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY for protection. The MCFCWCD inherited these levees widened to accommodate stormwater flows. from previous agricultural use, which were never de- Levee Ownership A significant portion of the Nova- signed to function with a level of protection suitable to Creek left bank levees are upon land owned and for flood control purposes. The placement of fill managed by the Marin County Flood Control and atop the existing bay mud to raise elevation will often Water Conservation District. Segments of the levee cause consolidation of underlying soils and differen- system south of SR-37 are owned by SMART or the tial settlement. Ronsheimer Trust. Levee ownership in other areas Vulnerability Assessment Caltrans developed a Cli- remains uncertain. mate Change Vulnerability Assessment that provides Connecting to SR-37 Interchanges at US-101 and guidance to identify segments of the State Highway Atherton Avenue will need to be reconfigured to System vulnerable to the impacts of precipitation, conform to a raised SR-37 elevation. Existing access temperature, wildfire, storm surge, and sea level rise. from SR-37 to Novato Sanitary District (NSD) lands The report anticipates an increase in the scale and also must be maintained or relocated, both north frequency of flooding on SR-37 and proposes a three- and south of the existing highway alignment. Water, step follow-up process to: wastewater, and electricity utility lines may require 1. identify specific asset exposure; relocation. 2. determine the consequence of expected impacts; State Rail Plan The Caltrans’ 2018 State Rail Plan 3. prioritize necessary actions. recommends linking SMART commuter rail with Cap- Sea Level Rise SR-37 Segment A-1’s road surface itol Corridor trains by 2040. SMART’s Passenger Rail needs to be raised approximately 20 feet to address Service Feasibility Study, published in 2019, estimated long-term impacts of sea level rise and storm surge. that limited service could begin on the 41-mile-long Previous parties have developed conceptual solutions “Brazos” line between Novato and Suisun City stations for the segment, which include a continuous raised withino 4 t 6 years after funding is identified. Costs causeway as well as a hybrid that includes raising a were estimated to be between $780 million to $1.3 portion of the roadway on embankments. The cross- billion depending on the amount of reconstruction ings of Novato Creek and Simmons Slough must be included. An operating agreement with Union Pacific
JANUARY 2020 | 17 would be required from American Canyon to Suisun impedes the opportunity to provide transit access as City. No sea level rise considerations were included, there is no potential to reduce travel time. and no SR-37 studies have integrated rail and bus Marshland Removal The majority of Novato Creek transit with highway planning to date. marshlands were leveed, drained, and reclaimed for Transit Access In 2019, the State Route 37 Policy agricultural land uses between 1850 and 1920. Dis- Committee received a report entitled the Travel Be- connecting marshlands from tidal action reduced havior and Transit Feasibility Report which evaluat- sediment deposition, causing decomposition of peat ed current demand and propensity to use transit or soils and subsidence to occur. These historic practices non-single occupant vehicle options on SR-37 to haved ha a negative impact on flood safety and the relieve congestion and address equity concerns. The ecology of the area. analysis included fixed-route transit, micro-transit, Biological Conditions The 1999 Baylands Ecosystem and improved pooling service along the corridor. The Habitat Goals report was the first comprehensive corridor serves mostly long-distance work-related assessment of historical and current biological condi- trips to and from Marin. In 2018, during the 4-hour tions of the San Francisco Baylands. It recommend- morning commute peak, there were approximately ed restoring a wide, continuous band of tidal marsh 25,000 westbound trips with 30 minutes of delay. along Marin’s bayfront with a natural transition to During the 4-hour evening commute peak, there were uplands and an upland buffer beyond. Its 2015 up- approximately 28,400 eastbound trips with 80 minutes date, The Baylands and Climate Change identified five of delay. Congestion between Vallejo and Sears Point overarching recommendations:
Figure 1.D Lower Novato Creek Watershed Flow shows the relationship between MCFCWCD infrastructure and the movement of water through the watershed (graphic: Marin County Flood Control and Water Conservation District, 2019)
18 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY Highway 37 Corridor Adaptation Study CivicKnit FigureSR-37 1.E SR-37/US-101 / US-101 Interchange Interchange Considerations Considerations
Rowland
Lynwood Basin
SMART 3
US 101 SR 37 Hanna Ranch Rd 2 1 N o v Dr a Marsh t S Novato Blvd o
C re 4 e k Key Interchange Considerations 1 - US-101 faces ooding due to sea level rise between the SR-37 interchange and the De Long exit requiring a protective levee or elevation of the highway and the interchange Bel Marin Keys Legend 2 - New on/o ramps at Hanna Ranch Road and Marsh Bel Marin Keys Blvd Lagoon SMART Path Drive necessary to connect with elevated roadway n Dr Bay Trail ot l 3 - Access to Novato Sanitary District lands impacted by i Planned Trails m Pacheco elevating SR-37 Potential Link a Pond H Potential Levee 4 - Potential exists for new road and trail connections from Bel Marin Keys Blvd. to SR-37 NSD Access • Restore estuary–watershed connections that nour- those that work with natural processes. They em- ish the baylands with sediment and freshwater. phasized the importance of marsh plain and stream • Design complexity and connectivity into baylands sediment management, reconnecting marshlands landscape at various spatial scales. to adjacent areas, building wide sloping levees, dis- persing wastewater on horizontal levees, and rerout- • Increase coordination among baylands stake- ing creeks to support seasonal wetland habitat with holder organizations to promote the successful freshwater and sediment inflow. Removing levees implementation of landscape scale restoration. on Novato Creek downstream of SMART’s mainline • Create plans that factor in ecological outcomes bridge and reestablishing tidal inundation within the after extreme events and other disasters. historic tidal marsh would increase floodwater con- • Engage the citizenry in stewardship of the bay- veyance. Where restoration of seasonal fresh wetland lands. systems is precluded by development, upper edges of transition zones could provide for limited high-marsh Endangered Species 38 animal and 28 plant species and brackish-marsh zones by discharging treated designated as protected by one or more statutes wastewater and storm water along wide, sloping en- have been identified within five miles of SR-37. The gineered terraces. 2013 USFWS Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California addressed land Elevating SR-37 and the SMART rail line either partially management for five endangered species: California or wholly onto a viaduct structure would allow tidal clapper rail, salt marsh harvest mouse, Suisun thistle, flows to approach historic extents. soft bird’s-beak, and California sea blite. Additionally, Novato Creek Widening Novato Creek’s channel at the stretch of Novato Creek within the project area the SR-37 crossing would be beneficial above and has been designated by USFWS NOAA as critical hab- below the highway crossing. The channel width in the itat for steelhead. Lower Baylands Reach (downstream of SR-37) varies Natural Flood Protection SFEI and MCFCWCD stud- from approximately 140-feet wide at the mouth to ies proposed redirecting flood protection strategies about 40-feet wide near SR-37 today. Based on his- from more traditional, hard engineering solutions to torical maps, the 1854 channel width was estimated to be 900 feet wide at the mouth and 300 feet wide at the SR-37 crossing.
Sediment Needs Tidal marsh restoration will require significant amounts of sediment to raise elevations in subsided areas. Also, while re-engineering levees to create gently sloping transition zones can buffer storm wave run-up, reduce erosion, lower the flood risk, and facilitate landward marsh migration, ecotone profiles also require significant fill.
Marshland Restoration Effort Substantial marshland Recent flooding along Segment A-1 resulted in restoration projects are well underway within the intermittent closures of the highway from Atherton Avenue to US-101 in both 2017 and 2019. SR-37 Segment A-1 Study Area. The State Coast- al Conservancy is restoring its 1600-acre Bel Marin
20 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY Keys Unit V property, plus 200 adjacent State Lands toration would disrupt the District’s operations and Commission acres to a mosaic of tidal, seasonal, and require alternative means of water treatment. transitional habitat by constructing flood control fea- Simmons Slough Simmons Slough is currently tures, placing dredged material to elevate the diked, drained by pump facilities operated by the MCFCWCD subsided baylands, and reintroducing tidal waters to and the NSD. The approximately 1,840-acre watershed bayside portions of the site. At BMK, the restoration is comprised primarily of agricultural lands bounded will include vegetated ecotone slopes, constructed by small field dikes, with residential uses in upland on top of the base protection levee to accommodate areas. Fields drain predominantly through small shal- the retreat of transitional habitat as the sea level rises. low flow channels, including Simmons Slough, to the The Marin County Flood Control and Water Conser- pumping facilities. vation District is planning for the Deer Island Wetland Pacheco Pond Pacheco Pond is an artificial lagoon restoration project which will reconnect areas within created as mitigation for construction of an adjacent Deer Island Basin to the tidally influenced section of industrial park in 1980. The entire Pacheco Pond area adjacent Novato Creek. They sit at a critical habitat is approximately 120-acres. Before the pond was con- junction, where fresh flows from Novato Creek enter structed, a slough drained Pacheco Creek and Arroyo the mixed salinity flow regime of San Pablo Bay; one den Sa Jose into Novato Creek. Outflows are limited of only a handful of locations in the entire Bay within by water levels in Novato Creek. Larger storm events this mixing zone where potential remains to restore generate reduced outflows from Pacheco Pond, which tidal marsh. The primary constraints on flood control fills and overtops to adjacent parcels during 50 year and habitat enhancement are the NSD facilities; res- and 100 year storm events.
Figure 1.F Corridor Land Use Illustrates how land use around SR-37 has changed over the last century (graphic: San Francisco Estuary Institute)
JANUARY 2020 | 21 Sea Level Rise The State of California Sea-Level Rise grated into existing and planned management activ- Guidance recommends using the upper end of SLR ities on California’s coastlines. Additionally, to ensure scenarios for critical infrastructure. For the San Fran- resilient communities, coastal and ocean planning cisco Bay Area, those numbers range from 2 to 7 feet must consider the differential impact of climate risks in 2050 and 2100 respectively under the 1-in-200 when evaluating whether disadvantaged communities chance (.5%) scenario. The report states that it is more face unequal burdens from climate risks or inadequate likely that sea level rise will not exceed one foot by resources to respond to these risks. An explicit effort mid-century and 3.5 feet by 2100. must be made to build capacity and address resource gaps for adaptation in these communities. Coordination and consistency in selecting sea-level rise projections among permitting entities was rec- Local SLR Guidance Two local SLR guidance reports ommended, as was prioritizing implementation of agree on Novato’s exposure to climate change. The consistent or complementary adaptation strategies County of Marin Bay Waterfront Adaptation and Vul- in order to achieve efficiency of scale. Insuring pro- nerability Evaluation (BayWAVE) and Novato’s Sea tection of vulnerable communities was also identified Level Rise White Paper both identified Novato trans- as a priority. Evaluation of lifetime costs of various portation facilities that are vulnerable to sea level rise: sea-level rise scenarios was encouraged. • State Route 37 between Atherton Avenue and US Climate Risk The 2018 update to the Safeguarding Highway 101 California Plan is a roadmap showing how Califor- • US Highway 101 at the US-101/SR-37 Interchange, nia’s state government is taking action to respond to Novato: This vulnerable 3,100-foot stretch is cur- climate change. It was produced with assistance from rently protected by levees and pumps operated representatives of 38 state agencies. The report states by others. that climate risks and impacts need to be fully inte-
Figure 1.G Historic and Modern Extent (SFEI, 2015)
22 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY Novato’s SLR white paper recommends updating the and to raise and maintain levees as sea level rises and City’s Multi-Hazard Mitigation Plan in order to be opportunity for gravity drainage becomes increasingly eligible for outside funding sources. limited.
Collaboration Conflict UC Davis’ The Governance of The following studies provide further ecologic Sea Level Rise in the San Francisco Bay Area identified guidance related to Segment A-1: improved collaboration between organizations to address sea level rise as a major challenge. It also Baylands Ecosystem Habitat Goals Report (1999) & Baylands and Climate Change: What We Can indicated that while stakeholders desire an appro- Do (2015) priate mix of “gray” and “green” infrastructure, there The Baylands Ecosystem Habitat Goals Report (Goals is an aversion to creating any new regional authority Report, 1999) recognizes the conservation values of or assigning responsibility to an existing agency to the San Pablo baylands for their undeveloped charac- coordinate selection. The report concluded that the ter and high restoration potential. The Goals Report risk is not exclusively from SLR, but the combination sets acreage targets in different habitat goal catego- of rising sea levels and extreme weather events. ries for protection, restoration, and enhancement, and Importance of Marshlands The San Francisco Bay identifies the following additional recommendations Estuary (SFBE) is the largest estuary system on the Pa- for the San Pablo baylands: cific coasts of North and South America and is globally • restore a broad swath of tidal marsh along the recognized for its historic and continued importance shore as soon as is feasible; to water birds, fish, marine mammals, and other wet- land-dependent species. The SFBE provides wintering • manage the marsh bordering northern San Pablo habitat for more than half of the diving duck popula- Bay to sustain high waters as sea levels rise; tion in the Pacific Flyway, is a Shorebird Reserve Site of • reconnect major tributaries (Napa River, Sonoma hemispheric importance, and a RAMSAR designated Creek, Novato Creek, Tolay Creek, and Petaluma wetland of global importance despite the devastat- River) to the bay and extend tidal wetlands into ing habitat loss that has occurred. An estimated 90 the watersheds; percent of the historic tidal marshes in SFBE have been filled or significantly altered over the past two • restore riparian corridors to connect the baylands centuries, and an estimated 82 percent in San Pablo to the lower watersheds; Bay, one of three large bays that comprise SFBE. • protect wet meadows, vernal pools, and swales Historic baylands were leveed off from the bay in in the lowlands adjacent to the baylands, and in- the late 1800’s through the early 1910’s. Devoid of crease their connectivity to the baylands; bay water to keep peat from oxidizing, and without a new sediment supply brought in on the rivers and • work with willing sellers to conserve valleys and tides, these lands are generally subsided 3 to 7 feet plains with low-intensity agriculture adjacent to below surrounding marshes, depending on when they tidal areas for future marsh and transition zone migration; and were leveed off and subsequent land use history (see Figure 1.F). These baylands will continue to subside • elevate SR-37 and modify or realign rail lines and relative to surrounding marshes and will require sub- other infrastructure to allow the unimpeded pas- stantially greater level of effort to pump water out sage of water, sediment, and wildlife.
JANUARY 2020 | 23 Specific to the Novato Creek region, The Goals Report factors led non-profit conservation organizations, (1999) recommends restoring a wide continuous band landowners, and the California State Coastal Con- of tidal marsh along the bayfront from Black Point to servancy to form a collaborative working group to Gallinas Creek, and along Gallinas and Novato Creeks, provide restoration and sea level rise adaptation rec- ensuring natural transition zones from wetlands to ommendations for the State Route 37 (SR-37) corridor uplands, and enhancing managed marshes and sea- to the Metropolitan Transportation Commission that sonal ponds in areas not restored to tidal marsh. The would integrate restoration planning with transpor- Goals Report (1999) recognizes the unique values of tation infrastructure planning to achieve both resto- this area for restoration because of the rural character, ration and transportation objectives while increasing and opportunity to restore full ecosystems, including resilience of the marshes and the infrastructure. tidal, flats tidal marshes, natural upland transition Flood Control 2.0 and Novato Creek Baylands zones, with connectivity to adjacent upland wildlife Vision corridors. The Goals Report (1999) also recognizes the San Francisco Estuary Institute, Marin County Flood opportunities for integrating wastewater discharge for Control and Water Conservation District (MCFCWCD), freshwater habitat benefits. the San Francisco Bay Joint Venture, and multiple oth- The 1999 report was updated with new recommenda- er partners collaborated to develop flood protection tions to incorporate climate change, in the Baylands strategies for the historic baylands around Novato and Climate Change: What We Can Do (2015). The Creek that focused on natural processes that aimed to 2015 Update urges swift action to restore historic both increase flood protection and restoration, while baylands to increase their likelihood of staying apace improving water quality and increasing resilience to with sea level rise, and makes the following overarch- sea level rise. An outgrowth of that effort was the ing recommendations: Novato Creek Baylands Vision: Integrating Ecological Functions and Flood Protection Within a Climate-Resil- 1. restore estuary–watershed connections that nour- ient Landscape (2015). Several management strategies ish the baylands with sediment and freshwater; were highlighted, including removing levees along 2. design complexity and connectivity into the bay- lower Novato Creek, re-establishing tidal inundation lands landscape at various spatial scales; within historic baylands, and reusing treated wastewa- ter to create brackish and freshwater plant communi- 3. increase coordination among baylands stakehold- ties and expand marsh habitat. These strategies would er organizations to promote the successful imple- reduce cost of dredging, alleviate flooding and levee mentation of the recommendations in this report; erosion, and reconnect subsided baylands.
4. create plans that factor in ecological outcomes Sea Level Rise Adaptation Framework after extreme events and other disasters; and Point Blue, SFEI, and the County of Marin co-devel- Sea Level Rise Adaptation Framework 5. engage the citizenry in stewardship of the bay- oped the (2019), lands. which includes an evaluation of restoration and ad- aptation opportunities for the Novato Creek region. Baylands Group: Ensuring a Resilient Shoreline The Maximize Habitat Minimize Risk Strategy (see The San Pablo Baylands have incredible habitat value Figure 1.P) was highlighted as the best strategy for and even greater restoration potential. Both of these reduced maintenance costs, biodiversity support, and
24 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY recreation, though upfront investment was higher.
Current Nearby Restoration Project Descriptions Novato Creek has numerous restoration opportunities as well, including the recently restored Hamilton Air Force Base, Bel Marin Keys V (in planning), Deer Island, and Simmons Slough, among others. These join a growing fringe of wetlands along the north shore of San Pablo Bay. Major large-scale restoration has been implemented along the Napa River corridor of the San Pablo Baylands, beginning with the restoration of the former salt production ponds and the salt production facility known as the Napa Plant Site, followed by the passive restoration of 1,249-acres at Cullinan West. Similar efforts are in the early planning stage along the lower Sonoma Creek corridor, and the Petalu- ma River corridor. The thousands of acres of Novato Creek baylands in public ownership provide a real and viable restoration opportunity and a chance to achieve the 1999 and 2015 Goals Report recommendations for this region.
JANUARY 2020 | 25 1.08 Visions for All of the options include the following components: • Bridging of Novato Creek with a structure de- Resiliency signed to meet the year 2100 sea level rise high- This report presents and compares four alternative Vi- risk; sions to address the challenges facing SR-37 resulting • Construction of a new Class I Bay Trail facility south from climate change. These Visions are summarized of the existing SR-37 (except in Vision 4 where it as follows: may not be possible); • Vision 1 referred to as “Hold the Line” seeks to • Allowing the continued operation of Novato San- adapt the corridor to future seal level rise by rais- itary District’s dewatering ponds; and ing and strengthening the existing levees. • Completion of the Deer Island Wetlands Resto- • Vision 2 known as “Move the Line” places SR- ration project to reduce upstream flood risk and 37 on a levee restoring the area to the south as expand marsh habitat. marshland. The following elaborates on the features and con- • Vision 3, most robust model, is referred to as siderations associated with each alternative: “Multi-Beneficial” and places the roadway on an elevated viaduct restoring hydraulic connectivity north and south of SR-37. • Vision 4 is known as “Buying Time” and places levees to elevations that will meet mid-century sea level conditions.
Figure 1.H Visions Breakdown This figure illustrates the relative merits of the various Visions with respect to their sea level resiliency, enhancement of environmental resources, time required to implement, and lifecycle and capital costs. The “Buying Time” Vision has the highest lifecycle cost of the all the Visions as the levees will require maintenance and there will need to be a future effort to modify the highway to protect it from SLR. While being the most expensive to imple- ment, Vision 3 has the overall lowest lifecycle cost as the maintenance of the causeway structure will be comparable to other concrete structures with long service lives.
26 | HIGHWAY 37 CORRIDOR ADAPTATION STUDY Vision 1 - Hold the Line • Modifications to elevate Atherton Avenue at the This vision would adapt existing highway and rail in- SR-37 off and on-ramps. frastructure, add a new segment of Bay Trail south of Key benefits of this vision would be: SR-37, and meet 2100 SLR high-risk standards by re- • Minimizes road and rail replacement; constructing and elevating the existing Novato Creek’s • Novato Sanitary District facilities unchanged; and left and right side levees (looking downstream), and adding new Novato Creek crossings and associated • Allows Deer Island Basin to be restored transitions for each mode. Key limitations of this vision would be: Key features include the following: • Limits marshland restoration; • A 300-foot-long highway causeway section over • Reduced flood protection; Novato Creek at an elevation of 26 feet NAVD88 • Substantial fill required; and with transitions of up to 600 feet in length on each • Requires ongoing levee monitoring and mainte- side; nance • A 300-foot-long rail causeway section over No- The total cost in 2019 dollars to implement this vision vato Creek at an approximate elevation of 26 feet is approximately $223 million, which includes the NAVD88 with rail transitions of up to 1000 feet in components included in the Vision 1: Hold the Line length on each side; table below: • Construction of a Bay Trail consistent with the VISION 1: HOLD THE LINE Class 1 standards south of SR-37; Tasks Cost • Reconstruction of the existing Novato Creek left Mobilize and Erosion Control $17,022,000 side (looking downriver) levee from SR-37 to the Clearing and Grubbing $1,085,000 Bay; Levee Construction $60,704,000 • Reconstruction of the existing Novato Creek right Causeway - Novato Creek $94,000,000 side levee from Lynwood Basin to the Pacheco Simmons Slough Crossing $2,000,000 Pump Stations $500,000 Pond outlet, at an approximate elevation of 19.7 Construction Cost $175,311,000 feet NAVD88; Soft Costs $47,333,818 • Within Simmons Slough located north of SR-37, Total Costs (Rounded) $223,000,000 expand the storm water retention capacity, install new pumps, place flap gates, and add approxi- mately 100 feet of 48” diameter culvert under the rail line at Simmons Slough crossing; • Completion of Deer Island Basin restoration, in- cluding increased levee height to protect Novato Sanitary District’s dewatering facilities; • Modifications to Olive and Atherton Avenues to reduce the potential of flooding; and
JANUARY 2020 | 27 CivicKnit FigureVision 1.I Vision 1 -1 “HoldHold the the Line” Line
N
o v Legend a Atherton Avenue t o Olive Avenue Existing Roadway Remains C re e New Elevated Bridge k New Highway Transition Reengineer levee Rowland Plaza Remove Existing Levee Deer Island Increased Tidal Marshland Basin S i Restoration m P m Sanitary District Operations o n P s Upgraded Flood Retention & S l Deer o Pumping Facilities u
Lynwood Island g
US 101 h Basin Flood Gate & Arched Culvert Wastewater Transmission SR 37 P Bay Trail Rail Causeway
Does not address Black Bel Marin Keys Point flood risk N
BMK Unit V Restoration Vision 2 - Move the Line • Removal of the existing Novato Creek right side This vision increases the resilience of existing highway levee south of SR-37 to Bel Marin Keys CSD prop- and rail infrastructure as well as increases flood plain erty; and restores tidal marsh to year 2100 SLR high-risk • Modifying Simmons Slough (as described in Vision standards. This would be accomplished by shifting 1); the existing levee located along Novato Creek to • Completion of Deer Island Basin (as described in just south of SR-37 allowing the restoration of tidal Vision 1); marshlands. • Restoration of flood plain and tidal marsh on Key features include the following: MCFCWCD lands south of SR-37; • Building a causeway crossing Novato Creek (as • Modifications on Olive and Atherton Avenues to described in Vision 1); reduce flooding; • Creating a rail causeway crossing Novato Creek (as • Modifications to elevate Atherton Avenue at the described in Vision 1); SR-37 off and on-ramps; and • Constructing a new Novato Creek levee along the • Relocation of approximately 7,000 feet of waste- left side (looking downriver) at a location south of water transmission line operated by NSD south and parallel to SMART’s right-of-way; of SR-37. • Construction of a new right-side levee between Key benefits of this vision would be: Lynwood Basin and Bel Marin Keys CSD property, • Provides the ability to meet 2100 SLR high-risk including a new road connecting Bel Marin Keys standards while retaining the existing highway, Boulevard to SR-37; rail, and wastewater infrastructure; • Construction of a paved Class I Bay Trail facility on • Few Novato Sanitary District facility changes re- the new levee protecting SR-37; quired; • Removal of the existing Novato Creek left side • Reduces flood risk; levee south of SR-37 to the Bay; • Improves US-101 resiliency to SLR;
Figure 1.J Vision 2 Proposed Section Illustrated the typical configuration for levee relocation south of SR-37
JANUARY 2020 | 29 CivicKnit FigureVision 1.K Vision 2 - 2Move “Move the the Line” Line
N
o v Legend a Atherton Avenue t o Olive Avenue Existing Roadway Remains C re e New Elevated Bridge k New Highway Transition Reconstructed Rail Line Rowland New Connection to SR-37 Plaza Deer Bay Trail Island S
i Basin m New Levee Restoration m o n Remove Existing Levee s
S l Deer o Increased Tidal Marshland u
Island g US 101 Lynwood h Sanitary District Operations Basin P Upgraded Flood Retention & SR 37 Pumping Facilities P Flood Gate & Arched Culvert Wastewater Transmission Line
P G& Relocate Wastewater Line E B
e Development Opportunity l M ari n K ey s C SD Bel Marin Keys Black Point