Clear Lake HOS

About this Project

UC Davis is piloting a Hypolimnetic Oxygenation System (HOS) in the Oaks Arm of Clear Lake to improve water quality and address the root causes of harmful algal blooms. By delivering oxygen to deep waters, the system reduces the release of phosphorus from lakebed sediments — helping restore ecological balance and protect habitat, recreation, and water quality.

Led by UC Davis researchers, the project builds on years of interdisciplinary study identifying low-oxygen conditions as a key driver of the lake’s decline. The Oaks Arm of Clear Lake was selected for its persistent water quality challenges, making it an ideal location to test this approach.

Since 2018, UC Davis has partnered with state agencies, Tribal communities, and local stakeholders through the Blue Ribbon Committee for the Rehabilitation of Clear Lake, which oversees this work and provides actionable recommendations to the Governor and Legislature to improve the lake’s water quality and ecosystem. As a pilot, the project will generate data to guide long-term restoration strategies and support a healthier, more resilient future for Clear Lake.

Learn more about UC Davis' Clear Lake rehabilitation efforts