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Showing Water Rights in California

A water right is a granted permission to withdraw water from a river, stream, or ground water source for a "reasonable" and "beneficial" use.

Water rights vary from very small domestic use water rights to very large state and federal projects to provide water for irrigation districts, hydropower, and cities.

Select a water right to learn more about it.

water right 0-10,000 acre-feet per year (AFY) Diverted
water right 10,000-500,000 AFY Diverted
water right 500,000+ AFY Diverted
water right Irrigation
water right Stockwatering
water right Power
water right Municipal
water right Fire Protection
water right Fish and Wildlife Protection and/or Enhancement
water right Domestic
water right Recreational
water right Industrial
water right Dust Control
water right Frost Protection
water right Fish Culture
water right Mining
water right Other
  • Colors are based on use codes, such as Irrigation, Stockwatering, Power, Municipal and more. Hover over a marker to see what it is used for.
  • Diverted means that water is moved from the stream into the environment. Usually this means that the landscape was altered to dam up or redirect water. Often to a field, to recharge groundwater, to create power and many other uses.
  • We have included the year of first use for records where available.
  • Amounts are measured in acre-feet per year. An acre-foot is roughly equivalent to 1 football field filled with water 1 foot high.
  • The face amounts are calculated by the State Water Resource Control Board. Face amounts are the total amount of water a water right holder is permitted to use.
  • Some face value amounts may be very large because a large water project is allowed to grow into more water usage in the future. Estimates of uses represent a conservative estimate of the maximum possible usage, and actual amounts used may be significantly less.
  • 0 value amounts may represent incomplete data, water rights left for the ecosystem, or water rights that are inactive for some reason.
  • Please also see our FAQ section for answers to more complicated questions.

These are Stream Gauge Sensors.

Showing Stream Gauge sensors from USGS data.

Select a sensor to see if the water is flowing normally.

  • Search by County: 'county:napa'
  • Search by Watershed: 'watershed:yuba'
  • Search by Water Body: 'waterbody:Russian River'
  • Search by Name (slower): 'name:PACIFIC GAS AND ELECTRIC COMPANY'
  • Search by Use (slower): 'use:stockwatering' or 'use:irrigation'
  • Search by Status (slower): 'status:licensed' or 'status:adjudicated'
  • Search by Year of first use (exact matches only): 'year:2000'
  • Keyword search (slower): crops or grapes

California Water Rights

Providing citizens with better tools for understanding how water is used in our state.

The Right To Bear Knowledge

“If you can't measure it, you can't manage it.”

Peter Drucker

The primary challenge with water in California is not its scarcity, but rather how we manage it. Many experts have mutually concluded, that a major first step to improving our management of water is by reforming how we account for it. Whether a lack of adequate statements of diversion for surface and subsurface waters, or the existence of a fine grained environmental monitoring network, it is clear that we could do a better job of recording and measuring. New instruments and institutions are necessary to accomplish this. It is not a question of technology, but one of techniques. The technology is available and affordable, but the institutions and practices of how we measure and document our water resources are not fully mature. We must get control of our understanding of what is in the system at any given point. We owe it to ourselves, our economy, and our ecosystem. This effort benefits all stakeholders.

Using This Site


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Citizens of California

This map is for citizens, journalists, legal professionals, policy analysts, institutional ratepayers, farmers, and water professionals who seek a comprehensive comparison of water usage in our state. By providing an intuitive and searchable interface, we hope to advance the understanding of the geographic distribution of water resources for all stakeholders.

Data Visualized

The above interactive map overlays points of diversion (water rights) from data collected by the State Water Resources Control Board, and daily stream gauge values maintained by the U.S. Geographical Survey. It includes a search feature, multiple map layers, and a basic API for retrieving machine-readable data. We are currently optimizing the interface for mobile devices

Information Age Tools

Data on water rights in California is difficult to navigate, impossible to query, and is not provided in a machine-readable format. This modest prototype demonstrates that we can do better. This is a first in a series of interactive maps that will consolidate data from disparate agencies, and bring clarity to how water is managed, governed, and distributed in the state.

Data & API

We want to encourage other developers to build interfaces and visualizations with the water rights data. JSON formatted water rights data is available through a simple RESTful interface for the following datasets.

The entire current dataset can be found as a mongo database on Github.



Holder Name