Flood Risk & Demographics
UPDATE: Additional customizable maps and downloadable data are now available in English and Spanish via Climate Central (Click on "Choose Map" and select "Toxic Tides Facilities" or "Toxic Tides Regions"). This work has also now been published.
This map series shows the risk of flood exposure at hazardous facilities under a high greenhouse gas emission scenario (RCP8.5) in California in the years 2050 and 2100. Facilities included in these maps are those located in counties with low-lying land. A facility is considered at risk of flooding if a quarter of its elevation (25th percentile) falls below the water level. Flood risk estimates are averages of multiple simulations of future sea levels, corresponding to about 3 feet of SLR by 2100. Given the uncertainty involved, we additionally consider more extreme levels of sea level rise.
Facility boundaries are approximated using tax parcels when available. When not available, facility boundaries are estimated using circular buffers around facility addressees. Buffers vary based on the typical size of facilities within each category.
Facilities with less than a 1% chance of being flooded (more rare than a 100-year flood) are considered to be of indeterminate risk since our analysis does not account for all sources of flooding and flooding scenarios.
The categories and number of facilities included in the analysis are listed in the table below. For mapping purposes, we made these categories mutually exclusive, but some facilities may belong to more than one category.
NOTE: Facility flood risk projections are based on sea level rise, tides, and storm surge and do not include groundwater contamination due to SLR. Lack of groundwater data coupled with imprecise estimates of facility boundaries may lead to potential underestimates of the number of at-risk facilities. The facilities considered in this analysis also do not represent an exhaustive list of all potentially hazardous sites. For more details, please see a description of our methods.
For additional information about other sites at risk of SLR flooding in the San Francisco Bay Area that are not included in our maps, such as underground storage tanks, additional clean up sites, and brownfields, visit the Bay Shoreline Flood Explorer and BayKeeper SLR & Pollution Risk to the Bay websites.
Expected annual flood-risk events at individual facilities
Instructions: Marker size represents the expected number of times a facility will experience a flood event in the given year, and marker color represents facility categories. Use the left box to choose between target years of 2050 and 2100. Use the right box to present certain facility categories. The right box also shows the number of facilities by category within the current map extent. Click on the three dots next to the title in the right box to show the options for a target year. Use category names in the spreadsheet above or in the left box (e.g. power plant). Do not use specific facility names when searching.
Clicking on a facility provides more detailed information, including the number of people living within a 1 km buffer of the facility and a link to more details about the facility, when available.
To open the map in a new tab, click here.
Census block groups with at-risk facilities within 1 km buffer
Instructions: For each census block group, the map displays the number of facilities, all categories combined that have at least a 1% chance of flooding (100-year flood) in the given year, within a 1 km buffer from residential parcels in the block group. The impacted population is the sum of the population of impacted residential parcels in the given year. Population estimates are based on the 2017 American Community Survey (ACS) 5-year estimates.
To open the map in a new tab, click here.
Demographics of census block groups with at least one at-risk facility within 1 km by the year 2100
Instructions: For each census block group, the map displays demographic information based on 2017 American Community Survey (ACS) 5-year estimates and the Statewide Database. Impacted population is the sum of the population of impacted parcels assuming no change in population growth by 2100. Average in the legend is the mean for demographic indicators for those block groups with at least one facility at risk in 2100.
Note that only one demographic variable can be displayed on the map at a time.
To open the map in a new tab, click here.