Amid dramatic ocean swells and drenching atmospheric rivers, a new report lays bare a hidden aspect of sea level rise that has been exacerbating flooding in the Bay Area.

The report, which was released Tuesday, maps areas that could flood from groundwater hovering just a few feet, or even inches below ground. This layer of water gets pushed upward as denser water from the ocean moves inland from rising tides. On its way up, even before the water breaks the surface, it can seep into the cracks of basements, infiltrate plumbing, or, even more insidiously, re-mobilize toxic chemicals buried underground. Continue reading New Bay Area maps show hidden flood risk from sea level rise and groundwater