Channel Islands Harbor Water Quality

The Channel Islands Harbor is the fifth largest harbor in the state of California and is a waterfront resort, recreation, and dining marketplace. The horse-shoe shaped harbor contains 166 acres of water surrounded by 126 acres of land and supports more than 2,500 vessels, four yacht clubs, and nine full-service marinas. The harbor waters connect to four residential communities including Seabridge, Westport, Mandalay Bay and Harbour Island.

In June of 2018, the harbor experienced a water degradation event, resulting in brown, murky water and some marine life death. The City quickly mobilized, forming a response team and setting up a hotline number for residents to report issues and concerns. City staff began performing daily water quality testing in 26 locations for dissolved oxygen, temperature, salinity and pH. Additionally, bacteria testing has been completed and all results have come back within state standards and there is no threat to public health and safety. Water quality testing has continued and those results can be found on the interactive map below.

Oxnard Harbor Water Areas & Inflow Sources

Water Sampling Data

Clean Water Team

The Channel Islands Neighborhood Council (CINC) and the City of Oxnard formed a citizen-science water quality monitoring team, the Clean Water Team. The Clean Water Team is part of the State Water Board’s SWAMP program. The Surface Water Ambient Monitoring Program has over 150 citizen monitoring groups in California.

Surface Water Ambient Monitoring Program (SWAMP) | California State Water Resources Control Board

The SWAMP procedures ensure that the data collected meets the Water Board’s scientific quality standards so the data can be used to reduce and prevent pollution of the waters in Channel Islands Harbor, Mandalay Bay and Edison Canal.

DRAFT – Quality Assurance Project Plan

The Clean Water Team is always looking for more volunteers. If you want to volunteer, click on Channel Islands Neighborhood Council – CINC (cineighbors.com) and select “Contact Us” for more information about the program.

Channel Islands Neighborhood Council – CINC (cineighbors.com)

Our goal is a thriving, swimmable and fishable CI Harbor.

Clean Water Team Sample Collection Training Video

Water Quality Reports

Channel Islands Harbor: Nutrient Sources and Sinks Study (Rev Jan 2022)

Remote Sensor Reading

Continuous water monitoring in the affected areas is of high importance to the City. To provide transparent data, the City will regularly post readings from two (2) remote sensors that are currently located throughout the Channel Islands Harbor. These data are downloaded from each sensor on a weekly basis. Each graph displayed indicates the location of the sensor, i.e. Mandalay West (station 20), and shows both the Dissolved Oxygen and Chlorophyll readings (vertical axes) for the designated time frame (bottom axis.) Dissolved Oxygen and Chlorophyll are being monitored to assist with the anticipation of any additional degradation in the water which could include a potential algal bloom. Please be assured that the data will be regularly reviewed by Aquatic Bioassay & Consulting, who will notify the City of any emerging issues indicated by the water quality monitoring. The public will be apprised on any issues discovered through the monitoring process by the City.

View all data prior to calendar year 2023 here.