State Water Board - Telemetry Requirements

Telemetry Requirements

Regulation and Background

By January 1, 2020, diverters who meet one of the following requirements shall provide telemetered diversion data via a public website:

  • Diverts more than 10,000 acre-feet annually; or
  • Owns or operates a reservoir or pond with a storage capacity of 10,000 acre-feet or more; or
  • Diverts during the period from June 1 through September 30, and directly diverts more than 30 cubic feet per second at any time.

These diversion thresholds apply to all rights, claimed rights, or combinations of rights and claimed rights to divert from a single or shared point of diversion if the sum of such rights or claimed rights meets the threshold criteria (23 CCR §933(b)(4)).

This class of diverters accounts for over 90 percent of the surface water diverted in California and have the potential to dramatically affect stream conditions.

In the future, this page will provide a listing and links to telemetered diversions.

Telemetry Reporting Requirements and Guidelines

The sections below describe how diverters subject to the telemetry reporting requirements should provide their data. Rather than establish complicated (and expensive) new telemetry reporting requirements, staff have developed simple tools that can retrieve data from a public website. The telemetry reporting primarily requires that each diverter publish their data to a publicly accessible website, from which the Board will gather and compile information. The website can be owned and maintained by the diverter or hosted by a third-party service. The data should be in a specified format, and the website URL included as part of the diverter’s annual reporting information.

Website Requirements

  • Data for each point of diversion/measuring device shall be posted on its own dedicated web page (one page per device).
  • The web page(s) should be accessible to the public and not require login credentials.
  • Provide the exact URL of the web page hosting the data in the appropriate box in Question M26 of the Measurement Device/Measurement Method Information section in the diverter’s annual report.

Measurement data shall be displayed in a tabular format, and shall include the following columns, in order:

  • Date (MM/DD/YYYY or YYYY-MM-DD format)
  • Time (Local time in 24-hour format, not required if reporting daily values)
  • Measured Value
  • Measured Value Units (cfs, gpd, feet, acre-feet, ft/sec, for example)
  • Amount Diverted (in acre-feet)

A measurement device web page that meets the requirements for displaying hourly data would look similar in form to the following image:

Image illustrating the structure of a telemetry data web page. The top three lines of the page should display the Owner, Water Right ID, and Measuring Device ID, respectively. Below that is a sample HTML table containing the required columns: Date, Time, Measured Value, Units, and Amount Diverted.

A table reporting data on a daily timestep would look similar, but without the Time column. Diverters may include additional data beyond what is required here, provided that the data format includes that information after the required columns.

The web page should contain the entire measurement record for the calendar year to date, but can be reset at the beginning of each calendar year.

If multiple parties share the same point of diversion/measurement device, only one instance of the measurement data needs to be posted to the web. The owner names and Water Right IDs of all rights diverting from the single POD should be listed on the page.

Data Retention and Submittal

In addition to providing the telemetry data via a public website, each diverter must submit a data file to the Board as part of their annual water diversion reporting requirements. The data file should be in one of the following formats: Microsoft Excel-compatible spreadsheet, comma-separated values (CSV file), or tab-separated values (TSV file), with the same format/structure as described above. The Board is requiring the raw data submittal in order to conduct compliance and accuracy verification.

If you are required to measure hourly, but provide telemetry data on a daily basis, you must submit the hourly data with your annual diversion and use report. Questions regarding telemetry requirements should be directed to