Catalina Island News

Answers to Common Questions about Catalina's Water Supply

Catalina Island Conservancy

The ongoing drought and the start of mandatory rationing are generating a lot of discussion about how we arrived at this point (again), and what we might do next. To better inform the conversation and help us all understand the Island water issue, we should look at some basic "facts of life" about water on Catalina Island.

This column is the first in a series of columns in which we take a look at the physical and biological realities of water on Catalina Island.  As stewards of 88% of the Island’s land and Catalina residents, we too are grappling with the water shortages and are also concerned about our water future. To help us understand the situation, we wanted to provide answers to some of the most common questions about Catalina’s water supply.

Who owns the land?
Until 1975, the Santa Catalina Island Company (Company) owned nearly all of Catalina Island.  In 1975, the Company transferred 88% of the Island's 76 square miles to the Catalina Island Conservancy.

Under its Articles of Incorporation, the Conservancy is a not-for-profit corporation established to ensure the long-term protection and health of Catalina's natural ecosystems (Conservation); promote increased knowledge of how to live in a healthy balance with the Island (Education), and allow the proper use of its land for nature-based recreation (Recreation).

The Island Company retained about 11% of the Island. The rest is owned by private landowners, the City of Avalon and USC.

Who owns and delivers the water?
It may come as a surprise, but the two main Island landowners (the Company and Conservancy) do not own the water on or under their land.  In 1962, the Company transferred nearly all  its water rights to SCE.  This is common: Most utilities and water districts own groundwater sources in California. However, SCE’s rights to take water from the ground and its rights to use portions of the land for the infrastructure necessary to deliver water are subject to a detailed legal agreement entered into in 1962 (the “1962 Agreement”). This agreement applies to both the Company and the Conservancy with regard to the land each owns.

As a public utility, SCE is responsible for maintaining and operating Catalina's public water supply system.  Specifically, SCE must “properly and adequately serve with water the inhabitants of the territory for the service of which it has such franchise.” To this end, SCE is regulated by the California Public Utilities Commission (“CPUC”).  The largest part of this system is the portion that delivers drinking water to Avalon. But the 1962 Agreement provides that SCE cannot use the surface of the land for drilling wells, laying pipelines or other uses without the express written consent of the landowner.

What are the sources of Avalon’s water?
All of Avalon’s drinkable water comes from three shallow (less than 100 foot deep) wells in Middle Canyon, or the ocean via the desalination plant. These wells draw water from a thick layer of deposited soil (called alluvium) in the area of Middle Canyon around Thompson Reservoir.  This underground water source is often called the "alluvial aquifer” and the wells “alluvial ground water wells.”

The desalination plant, which was built as a requirement of the Hamilton Cove development, can provide nearly 85 acre feet of water per year, according to SCE’s filings with the CPUC. An acre-foot is a volume of water 1 foot deep spread over 1 acre, or 325,851 gallons.

Contrary to popular belief, water is not pumped from Thompson Reservoir. Instead, the reservoir is used to store surface water that then helps recharge (replace) the groundwater in the aquifer.

Who regulates the water?
More than a dozen federal, state or local agencies may have a say about a particular aspect of the Island's water system.  But three agencies always have a say in every water production project on Catalina Island: the CPUC sets rates and determines whether SCE is delivering “clean, safe and reliable water to its customers at reasonable rates;” the Los Angeles County Department of Regional Planning oversees the use of land in unincorporated areas of the county, and the California Department of Public Health regulates drinking water quality.

Five-part water series from the Catalina Island Conservancy
Part 1: Answers to Common Questions about Catalina's Water Supply
Part 2: Facts about Catalina's Water Supplies
Part 3: The Future of Water on Catalina Island
Part 4: Ways to Increase Catalina’s Water Supply
Part 5: Making a Difference in Catalina's Water Future

By John J. Mack
John J. Mack is the Catalina Island Conservancy’s chief conservation and education officer. For more information about the Conservancy, please visit  The Catalina Island Conservancy has been an active participant in the Catalina Island Consortium, a group of Island stakeholders that has sought to maintain an affordable and sustainable fresh water supply for the Catalina Island community.  The Consortium, working with SCE and CPUC, was recently successful in averting significant water rate increases on the Island.