Flood Adaptation Strategy for State Route 4 through the San Joaquin Delta River

The San Joaquin Council of Governments (SJCOG), in partnership with Caltrans District 10, proposes a study to develop a Flood Adaptation Strategy (FAS) for State Route 4 (SR-4) through the San Joaquin Delta River. SR-4 is at high flood risk as it (1) runs through FEMA’s 100-year floodplain (2) serves as a goods movement connector and commuter route (3) and acts as an evacuation route for San Joaquin River Delta residents. The proposed FAS will assess flood impact, including the impact a flood event on the San Joaquin River Delta will have on evacuation routing, and generate a list of priority flood-resilient capital improvement projects that SJCOG, in partnership with Caltrans District 10, could program on SR-4.

The FAS was identified as a Priority Adaptation Strategy in the agency’s 2022 Regional Resiliency Implementation Plan and Adaptation Guidance and aligns with state and federal climate and transportation priorities. The purpose of the proposed FAS, therefore, is to build on the 2022 Regional Resiliency Implementation Plan and Adaptation Guidance and develop a data-driven investment strategy for SR-4 as it experiences increasing flood risk. The proposed strategy will improve and enhance the resiliency of our regional transportation network to a flood event by ensuring the network can more easily absorb, recover from, and adapt to a flooding event. In addition to promoting climate and infrastructure resilience, the proposed strategy will also address public safety, economic resilience, and cost-savings, in the region with a focus that will provide public benefits by (1) minimizing injuries and fatalities as the SR-4 will be able to better support evacuation and emergency response (2) ensuring the continuous flow of people, goods, and services on the regional transportation network during a flood event (3) and reducing maintenance and repair costs on this transportation asset.

Proposals should include information demonstrating the consultant’s understanding of the project, expertise and past performance conducting similar projects and project team as outlined in this solicitation. The top-ranking consulting firm, after evaluations are conducted by the evaluation panel, will enter contract negotiations with SJCOG.

The Project cost estimate to complete the work as outlined in the RFP is $325,000. SJCOG anticipates the Project work will be completed within 12 months of receiving a notice to proceed.

The proposed Flood Adaptation Strategy (FAS) is a result of on-going collaboration and partnership between SJCOG and Caltrans. As a metropolitan planning organization and regional transportation planning agency, SJCOG collaborates with Caltrans to develop goals, objectives, plans, and policies to create a reliable and sustainable regional transportation network. This FAS will be a joint effort to protect SR-4 against current and future flood risks and ensure the continued safety and reliability of the regional transportation network.

In 2020, SJCOG conducted a Climate Adaptation and Resiliency Study to identify current risks and vulnerabilities in the San Joaquin County’s regional transportation network. The study used the best available greenhouse gas emissions projections and climate stressor data to examine the projected impacts each climate stressor, including flooding, would have on the region and its critical transportation assets. This assessment revealed the Project Area, SR-4 between eastern Contra Costa County and western San Joaquin County, is the region’s most critical and vulnerable transportation asset to sea level rise and riverine flooding. The Project Area currently runs through FEMA’s 100-year floodplain. As climate change intensifies, the risk of a flood is likely to increase due to rising sea levels and extreme precipitation.

The Project Area is a two-lane rural road in California’s Central Valley surrounded by the rivers of the San Joaquin Delta and farmlands and intersects an SB535 Disadvantaged Community, or a community that is highly burdened by pollution and poverty. The community ranks in the 93rd percentile of California census tracts with high pollution, poor health outcomes, and poverty. This community also ranks at the 76th percentile for linguistic isolation, or the percentage of limited speaking households.

The primary objective of the FAS is to build climate and infrastructure resilience in the region by protecting the Project Area against current and future flood risks and ensuring the continued safety and reliability of the regional transportation network. The FAS will meet this objective by including flood-resilient implementation strategies that will improve and/or promote:

• Air Quality by allowing drivers to continue to use the SR-4 during a flood event. Closure of SR-4 would force drivers to add more VMTs to get to their destinations, which adds to the production of harmful air pollutants.
• Economic Resiliency by ensuring the continuous flow of people, goods, and services on SR-4 during a flood event.
• Environmental Sustainability by ensuring that the Delta’s ecosystem is protected.
• Public Health and Safety by minimizing injuries and fatalities during a flood event.
• Workforce Development by creating jobs in construction and road maintenance.

To accomplish this, SJCOG and Caltrans will engage with a diverse set of external stakeholders and the public to obtain input on flood-resilient implementation strategies.