Lake Merritt Advance Restoration Plan Project

Lake Merritt, located in Oakland, is a 150-acre tidal lagoon that is listed as impaired under Clean Water Act Section 303(d) for and organic enrichment/low dissolved oxygen (DO).

To address the DO impairment, the Water Board is developing a Total Maximum Daily Load (TMDL) Alternative, also referred to as an Advance Restoration Plan (ARP). The objective of the ARP is to identify and evaluate management actions that will improve DO conditions in Lake Merritt to support aquatic life, including benthic invertebrates and fish.

This effort became a high priority following a harmful algal bloom of Heterosigma akashiwo in 2022, which extended from San Franciso Bay into Lake Merritt and caused a large-scale fish kill. During this event, DO concentrations dropped to zero in most of the lake for several days.

The ARP will produce recommended management actions for the City of Oakland to include in a comprehensive Lake Management Plan. Implementation of these actions is intended to improve both short- and long-term DO conditions, support designated beneficial uses, and provide additional benefits for non-contact recreation such as rowing and sailing.