Harmful Algal Bloom (HABs)

Freshwater and Estuarine Harmful Algal Bloom Program

Harmful algal blooms (HABs) are a progressing and critical issue because their presence in surface waters may threaten many of the beneficial uses that the public enjoys. Over the past decade, severe blooms have impacted drinking water systems across the state including the State Water Project. They have been identified in lakes, rivers, and streams in all parts of the state, and have caused suspected illness in humans, pets, livestock, and wildlife. Since the Water Boards began tracking HABs in 2016, the number of HAB incident reports submitted by the public, Water Board staff, and local agencies annually has sextupled. The negative effects of HABs are wide-reaching and can degrade nearly all beneficial uses that the Water Board aims to protect for the people of California.

With the Freshwater and Estuarine Harmful Algal Bloom Program Bill (Assembly Bill 834) being approved by the governor in 2019, an official program was established. The Program aims to protect water quality and public health from harmful algal blooms. The bill also requires the coordination of immediate and long-term algal bloom event incident response, as provided, and conduct and support algal bloom field assessment and ambient monitoring at the state, regional, watershed, and site-specific waterbody scales.

  For more information about HABs please visit the State HAB Portal.

Lahontan Regional Efforts

Within the Lahontan Region we have a dedicated HAB coordinator and support staff working to implement mandates outlined in Assembly Bill 834. Over the next few years Region 6 aims to focus on collaboration with partner entities to build an efficient region wide HAB response and monitoring program, pre-holiday assessments of popular waterbodies in order to inform the public of areas HABs are occurring during high-use holiday periods, and continuing special studies that help further our understanding of HABs.