HAB Incident Reports Map

SWRCB LogoThe HAB Incident Reports Map is maintained by the State Water Resources Control Board. This map and corresponding table only show locations where harmful algal blooms (HABs) have been voluntarily reported. Colored dots on the map represent reported locations with pop-up windows providing additional details for each HAB report. Dots are symbolized based on the current advisory status and the time since the report was last verified by staff (refer to map legends for details). These details are also available in the adjacent table sorted by county.

Several routine monitoring programs exist for some locations (Klamath BasinEast Bay Regional ParksSWAMP Logo Clear Lake, and reservoirs along State Water Project), which share monitoring data to present in this map. Practicing Healthy Water Habits is recommended even for waterbodies not included below. Where noted, recommended advisories and corresponding signage are based on California voluntary guidelines for recreational waters. For questions please contact the HAB Hotline by email (CyanoHAB.Reports@waterboards.ca.gov) or phone (1-800-222-1222).

To download the full data set, including reports from all years, go to the California Open Data Portal.

Disclaimer:  The exact location, extent, and toxicity of the reported bloom may not be accurate and may not be affecting the entire waterbody. Please use data presented in this map for general purposes only. The data are subject to change as new information is received. Please check back for daily updates.

Latest HAB Weekly Updates List