The California Coastal Mapping Program

The California Coastal Mapping Program is a comprehensive effort to combine seafloor mapping data with shoreline data to create seamless onshore-offshore maps of California’s coastline.

The coastal area of California is diverse, ranging from towering coastal bluffs to dense urban development and rolling pastoral lands. Immediately offshore, the underwater topography is equally varied with deep canyons, seamounts, and small shelves extending from the shoreline.

Accurate maps and recorded data on  are essential to ensuring the California’s marine and coastal areas are understood and effectively managed.  California’s coastal region is home to numerous existing and proposed activities and sea level rise and climate change impacts will change the coast as we know it. With such a myriad of interests, uses, and potential impacts, the OPC is taking a leading role to record the coastal area and ensure important geospatial data are available to resource agencies.

The California Coastal Mapping Program has three major initiatives under way to achieve this objective:

• The California Seafloor Mapping Project
• The California Shoreline Mapping Project
• The Collaborative Geospatial Data Management Project:

The CGDME was started in 2009 to identify and promote sharing of datasets needed by the numerous state agencies with coastal and ocean interests, such as the Department of Fish and Game, the California Coastal Commission, the Bay Conservation and Development Commission, the State Lands Commission, and California State Parks. Datasets from federal agencies may also be incorporated into an interactive and accessible tool or framework designed to provide relevant data to resource managers, scientists, and the public for improved decision-making.

Integrating these three initiatives is a long-term goal. The topographic mapping data can be merged with the seafloor mapping data to produce a seamless onshore-offshore map that would greatly enhance the understanding and management of the coastal area. This modern high-resolution map can form the baseline map of any coastal geospatial decision-support tool. Following this integration, the OPC and California will be better prepared to:

• Better understand and mitigate the impacts from sea level rise
• Evaluate sites for renewable ocean energy and aquaculture projects
• Better understand sediment transport and sand delivery
• Ensure vessel safety
• Help identify tectonic faults and fault dynamics
• Forecast storm inundation and coastal erosion
• Better understand coastal earthquakes and tsunami potential
• More effectively regulate offshore coastal development
• Contribute to the federal process of Marine Spatial Planning
• Quantify cumulative impacts for different activities in the same location
• Identify key habitats that should be prioritize for protection

For example, the OPC funded a study to project inundation and erosion impacts from future sea level rise; however, the mapping data available for this project was less than optimal. In the future, such data will be readily available to anyone and will set the stage for a better understanding of our coastal and marine environment and how humans interact with this landscape.