California Harmful Algal Blooms (HABs) Portal

The CA HABs Portal is the central resource for HABs in the state of California. HABs can pose a health risk to people and animals, harm aquatic ecosystems, and limit the use of drinking and recreational waterbodies due to the toxins, odors, and scums or mats they can produce.

The Portal is an informational resource for the public and also functions as a tool to support coordination with statewide partners to address HABs. The content is developed by the California Cyanobacteria and HAB (CCHAB) Network and participating state agencies.

The content included here focuses on freshwater and estuarine HABs; similar content for marine (coastal) HABs is provided by the California Harmful Algal Bloom Monitoring and Alert Program (CalHABMAP) webpages.


Healthy Water Habits Video
Understanding the Dangers of Blue-green Algae (Cyanobacteria)
Credit: Department of Water Resources

Healthy Water Habits Video


HAB Incident Reports Map
HAB Incident Reports Map provides data on voluntarily reported blooms in California.
The data may include reports under investigation and/or confirmed incidents of HABs.

HAB Incident Report Map


HAB Data Viewer
HAB Data Viewer presents individual maps that displays data from satellite imagery
and special assessments conducted at local waterbodies.

HAB Data Viewer map