Helping transportation planners adapt to sea level rise

Roadside flooding in Marin County
Client:   Marin County Public Works

San Francisco Bay Area roads are at risk from sea level rise. In Marin County, major highways often run on low-lying lands that were once marshes. Marin County’s Public Works Department wanted to provide data about sea level rise to planners and engineers who work on road projects. GreenInfo Network and Tom Robinson Consulting built Marin County’s Resilient Roads application for that purpose.


Areas around Novato, San Rafael, and Corte Madera are examples of locations that might get flooded with future sea level rise. And yet the engineers who work on road maintenance and capital projects rarely have access to data about sea level rise, and the impacts of sea level rise are rarely considered as they plan and build new roads and bridges.

In 2022, Marin County’s Public Works Department began an innovative project to create the data engineers would need if they were to include sea level rise in their project planning. The county engaged Tom Robinson Consulting to develop a range of new datasets to combine regional sea level rise projections with Marin’s excellent baseline open data about roads, stormwater infrastructure, and other aspects of the transportation network. In late 2022, GreenInfo joined the team to design and build a web application for the county and its partners to use in future planning.

The Work

Design Research

We began the project by engaging directly with potential users. User research is always important, but it was especially so in this case since, as far as the project team knew, no one had attempted to build a tool quite like this one for traffic planners and engineers. We used a survey followed by one-on-one interviews to understand how traffic planners and engineers might use the tool.

At the highest level, our user research suggests that users of the application will want help making the case for action in specific locations more often than they will want help deciding where to act.

We then created a list of data and feature requests that together formed an outline of how the application should take shape.

Visual Design

Working from that outline, we developed visual designs in Figma that showed how users would move through the application, from signing up for an account to browsing the map to creating and saving specific project locations.

During the design process, we also developed a content-rich home page for the application. This helps provide context for users who might not be familiar with sea level rise. Though this application is accessible only to specific users approved by the county, we still needed to allow for a wide range of knowledge about sea level rise, since the topic was new to many in our target audience.


We built the application using the open source Django application framework, backed by an open source spatial database called PostGIS. We were able to quickly ingest data from Tom Robinson Consulting and build out the full application, including user account requests and approvals, user login and profile management, project creation and editing, and data downloads.

Results: The final application allows traffic planners and engineers in Marin County to consider the impacts of sea level rise when they are planning road improvements such as repaving. The tool also provides unprecedented visibility for county staff into previously obscure datasets about stormwater infrastructure.

Project Years: 2023

GreenInfo Network creates, analyzes, visualizes and communicates information in the public interest. We specialize in mapping and related technology for nonprofits and public agencies, focusing on using it for conservation, social equity, public health, environment and foundation grant making.
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