Flooding Threat To Union City From Rising Sea Levels

UNION CITY, CA — Union City might get smaller in 100 years, due to rising sea levels that threaten cities along San Francisco Bay — flooding structures, roads, and other infrastructure.

In Alameda County, sea level is predicted to rise six inches by 2030, 11 inches by 2050 and 36 inches by 2100, relative to levels in the year 2000. The predicted rise in sea level doesn’t account for storms, which temporarily raise the water level further.

At raised water levels in Union City, 1,177 acres of land below three feet and 9,177 people would be exposed to flooding, Risk Finder predicts. Floods at the raised sea levels could affect 2,533 housing units and 36 miles of road.

One report, by the California Ocean Protection Council Science Advisory Team Working Group, makes an even more dire projection, that sea level in the Bay Area could rise up to 6.9 feet by 2100, relative to levels in the year 2000.

As sea levels rise, the risk of coastal flooding and erosion increases for all Bay Area properties, and groundwater sources could be contaminated with saltwater. If combined with major storms, higher sea levels can cause flooding that damages local structures and cuts off roads and transportation options.

With even four feet of flooding over the next 40 to 100 years, the Bay Area would either lose or need to relocate nearly 104,000 existing jobs, and 85,000 new or planned jobs would not be created, or would be created outside the region, a 2020 report from Adapting to Rising Tides predicts.

The report also says nearly 13,000 existing housing units will no longer be habitable, insurable or desirable, and that 70,000 new or planned units won’t be built, or will be built outside the Bay Area.

The report also calculated the effect of flooding on the community, finding that more than 28,000 socially vulnerable residents would become more vulnerable by having to deal with daily flooding in their homes and neighborhoods.

View Risk Finder's report on Union City

View Adapting to Rising Tides Bay Shoreline Flood Explorer

Read Adapting to Rising Tides Bay Area Short Report