Understanding California Water Rights: A Guide for Rural Landowners

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Water is life in California — for our farms, families, and ecosystems. But knowing whether you have the right to use water on your land can feel complicated. California’s water law has deep roots, and there are different rules depending on where your water comes from and how you use it.

At the Rural Resilience Project, we want to make this topic easier for our community. Here are the basics every small water user should know.

Groundwater vs. Surface Water

• Groundwater: Most wells pump “percolating groundwater,” which landowners can usually use without a state permit. But if a well is closely connected to a stream (a “subterranean stream”), it may be regulated like surface water.

• Surface Water: Rivers, streams, and springs that flow off your property require a water right to divert or use.

  
  

When You Don’t Need a Permit

Some water sources don’t require approval from the State Water Resources Control Board (Water Board):

• Rainwater collected from rooftops.

• Sheetflow (rain runoff not part of a stream).

• Fully contained springs that never flow off your property.

  
  

Common Types of Water Rights

1. Riparian Rights – Belong to properties that touch a stream or river. Landowners can use water directly, but not store it for later.

2. Pre-1914 Appropriative Rights – For water uses that began before 1914 and continued over time. These are rare but powerful.

3. Post-1914 Appropriative Rights – Most new uses must be permitted through the Water Board. These include:

   • Small Domestic Use (up to 4,500 gallons/day).

   • Livestock Stockponds (up to 10 acre-feet/year).

   • Small Irrigation Use (up to 20 acre-feet/year in certain counties).

   • Cannabis Small Irrigation Use (up to 6.6 acre-feet/year, with strict seasonal limits).

     
     

The Rules Everyone Must Follow

Regardless of the type of right:

• Water must be used for a beneficial purpose (like irrigation, domestic use, or livestock).

• Use must be reasonable — not more than crops, people, or animals actually need.

• Water rights are subject to the public trust — meaning enough water must remain in streams to protect fish, wildlife, and recreation.

  
  

Reporting Requirements

Most water rights holders must file an annual report with the Water Board. Missing these reports can lead to fines, and reporting helps protect your rights in the long run.

• Riparian and Pre-1914 Rights: File a Statement of Diversion and Use by July 1.

• Post-1914 Rights: File annual reports (due April 1).

  
  

Cannabis and Water Rights

For cannabis cultivators, special rules apply:

• No diversions from April 1 – October 31.

• Winter diversions only allowed during high-flow conditions. This makes water storage a necessity for compliance.

  
  

Why It Matters

Understanding and following California’s water rights system helps protect your ability to use water, supports your neighbors, and ensures enough water stays in streams for fish and wildlife.

If you’re unsure about your situation, you can contact the State Water Board’s Division of Water Rights or consult with a qualified attorney or consultant.

Helpful links:

• California Water Board – Water Rights

• California Water Board - Statement of Diversion and Use

• Lake/Streambed Alteration Agreements (CDFW)

• Trout Unlimited: Guide to Water Rights

  
  

Takeaway: California water rights can be confusing, but with the right information, small landowners can stay compliant and contribute to a more resilient watershed.