PURPOSE OF MASTER PLAN
The Hayward Regional Shoreline Adaptation Master Plan was commissioned in 2019 by the Hayward Area Shoreline Planning Agency (HASPA) a joint powers agency consisting of representatives from the City of Hayward, East Bay Regional Park District (EBRPD), and Hayward Area Recreation and Park District (HARD).
The Master Plan will develop various multi-benefit strategies for the shoreline, its existing infrastructure, and the surrounding natural habitat in order to adapt to Sea Level Rise. Ultimately, it will act as a road map and help guide the development of future projects in a coordinated effort between state and local agencies, landowners, and the public. The Plan will be a forward looking tool for preparation, mitigation, and adaptation to climate change.
GOAL #1: Create a Resilient Shoreline Environment for People and Ecology
- Enhance the shoreline’s ecological value and adapt to sea level rise
- Enhance recreational opportunities and adapt to climate change
- Create a management framework for adapting to sea level rise over time
- Provide refuge to help endangered shoreline species to adapt climate change
GOAL #2: Enhance the Shoreline Environment to Reduce Risk to Critical Infrastructure and Built Assets
- Align with and enhance existing management and capital improvement plans
- Reduce risk to regional critical utilities from sea level rise, groundwater intrusion, and flood events
- Reduce risk to transportation infrastructure from sea level rise, groundwater intrusion, and flood events
- Reduce risk to agency assets such as the San Francisco Bay Trail and marsh restoration project(s)
GOAL #3: Build Social Resilience in the Community
- Promote social equity, environmental justice, and public health
- Preserve the local economy and increase resilience to climate change
- Prevent the disruption of key community services
GOAL #4: Build Capacity for Future Generations to Adapt to Climate Change
- Build organizational and community capacity
- Provide a place for education, interpretation and understanding of the shoreline and climate change
- Foster stewardship of the shoreline’s cultural and ecological resources
MASTER PLAN PROCESS
The Shoreline Adaptation Master Plan began in 2019 with Project Initiation, where an analysis of existing conditions and stakeholder engagement were used to understand the constraints and opportunities for the project area. The Design Team then examined future risk across multiple scenarios with Sea Level Rise Modeling and Mapping across various time scales. Subsequently, the Team identified potential Adaptation Strategies to help the shoreline adapt to climate change. These Adaptation Strategies were then consolidated and combined to generate three Design Alternatives. Now the Design Team needs input to inform the selection of the Preferred Master Plan Alternative.
EXISTING CONDITIONS
The Hayward Shoreline is a mosaic of Bayland environments that support diverse ecological resources, including mudflats, salt ponds, and tidal marshes. It is an important recreational and educational asset for the community, containing parks, recreational trails like the San Francisco Bay Trail, and educational programming, including the Hayward Shoreline interpretive Center that serves local residents and the region. The Shoreline also contains and buffers critical urban infrastructure, including wastewater treatment plants, the San Mateo-Hayward Bridge (State Route 92) approach, and landfills.
Large restored tidal marsh in the north transitions to diked Baylands and landfills at the Bay’s edge. More large tidal marsh continues further south, bordered by diked storage ponds and flood control channels. Inactive industrial salt ponds and diked wetlands abut SR-92 in the southern boundary of the study area. This expansive shoreline is bordered by an industrial business neighborhood to the east and critical infrastructure, including a rail corridor and utility lines that traverse north-south.
For more information about the existing conditions, download the Background Report:
SEA LEVEL RISE MAPS
For the purposes of this Master Plan, a thorough analysis of three future sea level rise (SLR) scenarios was conducted, based on sea level rise projections for the state of California, which defined the SLR scenarios to evaluate. Sea level rise increments of 2’, 4’, and 7’ were used to prepare the updated inundation maps. As the best available science progresses, the time horizons to which the sea level increments are provided may change.
The Project Team generated digital versions of the inundation maps for the Hayward Shoreline project area. Resulting GIS data is available for display on the City of Hayward’s web platform:
These maps produced are representative of both permanent and temporary flood conditions:
- Permanent Inundation is produced by rising sea levels. Sea level rise inundates coastal areas and exacerbates inland flooding as groundwater levels increase by the same amount as sea levels along the coastline.
- Temporary Inundation is the additional inundation that is produced by storm rainfall runoff and storm surge. This is represented by the 100-year storm and groundwater maps for each SLR scenario.
2′ SEA LEVEL RISE + GROUNDWATER EMERGENCE
This map shows permanent inundation in blue, due to 2’ of sea level rise, on top of mean higher high water (MHHW). These areas would be flooded by daily tidal action.
Groundwater is represented in teal, which indicates areas that would be flooded by groundwater on a regular basis with 2’ of sea level rise.
- Northern industrial neighborhoods are impacted by groundwater before SLR inundation.
- SLR impacts tidally influenced natural features and the Oliver Salt Ponds.
- SLR impacts to recreational resources include Bay Trail, Interpretive Center, and access points.
- Areas of groundwater emergence are roughly correlated with areas of 100-year flood risk.
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2′ SEA LEVEL RISE + STORM SURGE
This map represents the inundation extent due to storm conditions for a 100-year storm with 2’ of sea level rise, which equates to an average 1% annual chance.
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4′ SEA LEVEL RISE + GROUNDWATER EMERGENCE + 100 YEAR STORM SURGE
This map shows permanent inundation in blue, due to 4’ of sea level rise, on top of mean higher high water (MHHW). These areas would be flooded by daily tidal action.
Groundwater is represented in teal, which indicates areas that would be flooded by groundwater on a regular basis with 4’ of sea level rise.
- Many areas impacted by groundwater with 2’ of SLR are now impacted by SLR.
- SLR directly impacts critical infrastructure (San Mateo, Oro Loma, railroad).
- Major SLR impacts to recreational resources include Bay Trail, Interpretive Center, and access points.
- Most natural features are impacted by SLR.
- Areas of groundwater emergence are roughly correlated with areas of 100-year flood risk.
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4′ SEA LEVEL RISE + STORM SURGE
This map represents the inundation extent due to storm conditions for a 100-year storm with 4’ of sea level rise, which equates to an average 1% annual chance.
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7′ SEA LEVEL RISE + GROUNDWATER EMERGENCE
This map shows permanent inundation in blue, due to 7’ of sea level rise, on top of mean higher high water (MHHW). These areas would be flooded by daily tidal action.
Groundwater is represented in teal, which indicates areas that would be flooded by groundwater on a regular basis with 7’ of sea level rise.
- Almost all critical infrastructure is impacted by SLR
- Major SLR and groundwater impacts to all industrial neighborhoods.
- All stormwater and flood control channels experience significant backups.
- All natural and recreational features experience severe SLR inundation.
- Areas of groundwater emergence are roughly correlated with areas of 100-year flood risk.
For more information about the sea level rise scenarios and the methodology, please download the SLR Report:
Expand Map
7′ SEA LEVEL RISE + STORM SURGE
This map represents the inundation extent due to storm conditions for a 100-year storm with 7’ of sea level rise, which equates to an average 1% annual chance.
Expand Map
ADAPTATION STRATEGIES
Based upon insight collected through public workshops and engagement, and as well as the analysis of Sea Level Rise and related risks, the Project Team compiled a catalog of potential design strategies to help the shoreline adapt to climate change. The feasibility and applicability of these strategies were evaluated across the project area, in consideration with the Project Goals and Policy Considerations. The inventory of adaptation strategies and pros/cons of each are summarized in the Adaptation Report.
NATURE-BASED STRATEGIES
Fine and Coarse Grain Beaches
Tidal Marsh Restoration
Diked Pond Management
Fine Sediment Augmentation
Tributary Connection to Baylands
Reefs and Living Breakwaters
Eelgrass Restoration
ENGINEERED STRATEGIES
Ecotone Levee
Levee Improvements
Revetments
Tide Gates & Water Control Structures
Wastewater Treatment Adaptation
Land Elevation
San Mateo Bridge Landing
Subsurface Drainage
NON-STRUCTURAL STRATEGIES
Public Access & The Bay Trail
Marsh and Mudflat Migration Planning
Managed Retreat
Hayward Shoreline Interpretive Center Relocation
Building Scale Strategies
MASTER PLAN ASSUMPTIONS
The Master Plan Assumptions help inform the planning process moving forward and summarize client and stakeholder feedback to set a framework to generate and compare Design Alternatives.
- The plan aims to preserve and enhance the ecological features of the Hayward Shoreline over time. Many Bayland ecosystems, like tidal marshes and mudflats, require connectivity to the Bay for survival, but are also vulnerable to sea level rise.
- The plan aims to reduce risk to the urban fabric (streets, buildings), economy, land use, and critical built infrastructure in and adjacent to the study area. These assets are assumed to remain in place for the planning horizon.
- The plan is considering a perimeter protection approach to critical assets and an adaptation approach to shoreline ecosystems. This approach has been developed in conversation with many stakeholders and landowners in the project area.
- Non-structural strategies, such as retreat and land elevation, will be articulated in the final plan, and would likely be required to adapt to a higher SLR scenario long-term.
- The intent is to reduce risk to critical assets from daily tidal inundation and future 100-year storm surge from 2’- 4’ of SLR on top of the current mean higher high tide.
DESIGN ALTERNATIVES
Based on stakeholder and client feedback, the Project Team has identified three Design Alternatives that represent a balanced approach to mitigate the effects of Sea Level Rise to the Hayward Shoreline. Although considered, a full perimeter protection at the Bay’s edge or a full retreat scenario were discarded because of cost implications, permitting and feasibility challenges, and lack of overall support.
The Project Team does not assume that one of the alternatives will be selected for further analysis in the final Master Plan but rather anticipates that discrete elements and projects from each alternative will be combined into a hybrid preferred alternative.
This web page provides you with the opportunity to compare the design alternatives to one another in order to inform the preferred alternative selection process.
WATCH THE HAYWARD CITY COUNCIL WORK SESSION PRESENTATION DOWNLOAD THE CITY COUNCIL MEETING PRESENTATION HERE
DESIGN ALTERNATIVE #1: CLOSER TO THE BAY
Alternative 1 shows at an alignment for the line of protection that reduces risk for a larger portion of the shoreline and urban assets with a more conservative line of protection aligned closer to the Bay.
In the north end of the project area, the line of protection ties back along the San Lorenzo Creek channel and wraps in front of Oro Loma WWTP to protect it in place. It then cuts through the middle of Oro Loma Marsh and ties back to high ground at the two existing landfills. In the south, the alignment then follows the western edge of the oxidation ponds and cuts immediately south through Hayward and HARD Marsh. A raised access road along SR-92 ties back to high ground at the intersection of Clawiter Road.
The line of protection places a larger extent of marsh inland of the line of protection where marsh tidal water levels can be more carefully managed over time. However, this strategy will most likely negatively impact the existing marsh habitat by transforming part of the tidal marsh into muted tidal habitat. A zone of tidal habitats exists outboard of the line of protection, where it may accrete any available sediment faster than the muted marsh system. This option presents permitting and regulatory challenges from impacts to existing tidal marsh habitat. It also requires more active management of the muted marsh inland of the line of protection, which will become increasingly difficult with rising sea levels and subsiding land.
DESIGN ALTERNATIVE #2: DOWN THE MIDDLE
This alternative looks at an alignment that balances risk reduction and ecological enhancement with a line of protection that runs through the middle of the shoreline area.
The line of protection is pulled back in the north along the Union Pacific Rail Corridor and ties back to high ground at the San Lorenzo Creek channel. It then ties back to high ground at the two existing landfills and follows the western extent of the oxidation ponds to the south. The alignment pulls back in the southern portion of the site and cuts through the middle of the Salt Marsh Harvest Mouse Preserve, then ties back along a new levee along the access road for SR-92.
A larger extent of tidal habitat is enhanced outboard of the line of protection. Tidal marshes, existing and restored, would be monitored over time with an adaptive management plan that could use sediment augmentation to sustain healthy mudflat elevations in strategic areas. New tidal marsh is restored at Frank’s West and Hayward Marsh. Vulnerable ecosystems, like the Oliver Salt Ponds, would also be restored to tidal marshes as sea levels rise and make perimeter levee maintenance less feasible.
DESIGN ALTERNATIVE #3: FURTHER INLAND
This alternative explores an alignment that is pulled the furthest inland to maximize ecological restoration along the shoreline and layer risk reduction infrastructure.
In the north, the line of protection is pulled back along the Union Pacific Rail Corridor and ties back to high ground at the San Lorenzo Creek channel. It then aligns to the eastern edge of Frank’s East and ties back to high ground at the two existing landfills. It is pulled to the east of the oxidation ponds and follows the eastern extent of the diked Baylands to the south before tying back to high ground with a levee parallel to SR-92 along Clawiter Road.
This alternative prioritizes a larger extent of connected tidal habitat that is Bayward of the line of protection and incorporates ecological and risk reduction infrastructure along a wider extent of Baylands. Although this alternative provides a more connected tidal habitat configuration, it also reduces the diversity of habitats and ecosystems in the study area and these ecosystems may transition to deeper water ecosystems over time with sea level rise. Tidal marshes, existing and restored, would be monitored over time with an adaptive management plan that could use sediment augmentation to sustain healthy mudflat elevations in strategic areas. New tidal marsh is restored at Frank’s West and East, Hayward Marsh, inland diked ponds, and at vulnerable locations along the Bay’s edge, such as Oliver Salt Ponds.
COMMENT FORM
The Design Team is now looking to collect feedback on the three Design Alternatives in order to inform the selection of the Preferred Alternative. As a reminder, the Preferred Alternative is not necessarily one of the three – it will likely be a hybrid that combines bits and pieces of the three Design Alternatives. Once a Preferred Alternative is selected during the month of June, the team will begin to look at phasing, funding, permitting, and we will go through a sequence of Draft iterations for the Final Master Plan.