Water Measurement

Definitions of Key Water Measurement Terms

  • American Water Works Association (AWWA)
    An international nonprofit scientific and educational society dedicated to the improvement of water quality and supply.  The AWWA conducts research and provides publications, information, certified water supply training, and technical assistance to water supply systems. www.awwa.org.
  • Amount Diverted
    The amount diverted is total amount taken from a water source over a period of time. This would be analogous to the odometer on your car. Examples of units for the amount diverted are gallons, cubic feet, or acre-feet over a specific period of time.
  • Beneficially Use
    Beneficial use of water is defined as one of the following uses in Sections 659 through 672, title 23 of the California Code of Regulations (CCR) and includes water for Domestic Use, Irrigation, Power Use, Frost Protection Use, Heat Protection Use, Municipal Use, Mining Use, Industrial Use, Fish and Wildlife Protection and Enhancement, Aquaculture Use, Recreational Use, Water Quality Use, and Stockwatering Use. Definitions of each of the beneficial uses listed above can be found in Section B1 of the Division booklet: How to File an Application. Beneficial use does not include waste or unreasonable use, unreasonable method of use or unreasonable method of diversion of water.
  • Best Available Technologies
    ‘Best available technologies’ means technologies at the highest technically practical level, using flow totaling devices and, if necessary, data loggers and telemetry (Water Code Section 5100).
  • Best Professional Practices
    ‘Best professional practices’ means practices attaining and maintaining the accuracy of measurement and reporting devices and methods (Water Code Section 5100).
  • Calibrated/Calibration
    Calibration is the setting or correcting of a measuring device or base level, usually by adjusting it to match or conform to a dependably known and unvarying measure.
  • Consumptively Used
    The amount of water which has been consumed through use by evapotranspiration, percolated underground, or been otherwise removed from use in the downstream water supply as a result of direct diversion or diversion to storage.
  • Data Telemetry
    Data Telemetry refers to the method and action of transferring measured data to the home office. In some cases, the “home office” could be the world wide web. Data Telemetry is often done with some variation of radio signal, which may include cell phone signal, satellite signal relay, microwave signal, or wi-fi. Data can also be transmitted using land lines such as coax cable, fiber optic, or telephone wires through the use of modems.
  • Directly Diverted
    Water taken from a water source, such as a surface stream or subterranean stream. and used without being placed into storage.
  • Diversion
    ‘Diversion’ means taking water by gravity or pumping from a surface stream or subterranean stream flowing through a known and definite channel, or other body of surface water, into a canal, pipeline, or other conduit, and includes impoundment of water in a reservoir (Water Code Section 5100).
  • Hydrographer
    A hydrographer is a person qualified to use high-tech equipment to measure, describe and map the surface waters, including oceans, seas, rivers, lakes, estuaries and the water in channels and pipes, and groundwaters. The hydrographer may be certified by the American Congress on Surveying and Mapping (www.acsm.net).
  • Licensed Civil or Agricultural Engineer
    A Licensed Civil Engineer is a professional engineer holding a license in good standing with the California Department of Consumer Affairs - Board for Professional Engineers, Land Surveyors, and Geologists. The status of a Civil Engineer’s or Agricultural Engineer’s license can be reviewed on the Board’s Website: www.pels.ca.gov.
  • Locally Cost Effective
    Water Code Section 5100 does not include a definition of “locally cost effective.” However, Water Code section 10608.12(k), which addresses agricultural water conservation, defines "locally cost effective" as “…the present value of the local benefits of implementing an agricultural efficiency water management practice is greater than or equal to the present value of the local cost of implementing that measure." Factors that might contribute to a conclusion that use of best available technologies and best professional practices to measure water diversions is “not locally cost effective” include the geography, topography, weather, accessibility, size of the diversion, frequency of diversion, availability of power sources, and whether the cost of the device is high in relation to the economic value of the diversion.
  • Manufacturer’s Recommendations
    The manufacturer’s recommendations are literature provided with the equipment or made available by the manufacturer on how to properly install, maintain and/or operate devices and materials including meters, pipes, and linings.  Manufacturer’s recommendations can include tool requirements, environmental limitations, media specifications, operating parameters, power requirements, calibration requirements, and troubleshooting recommendations.  Manufacturer’s recommendations should be followed to ensure accurate readings and longevity of devices and materials.
  • No Power at Diversion Point
    Means that electrical power is not readily or reliably available to operate a water meter, data storage device, or modem at the point of diversion.
  • Person
    ‘Person’ means all persons whether natural or artificial, including the United States of America, State of California, and all political subdivisions, districts, municipalities, and public agencies (Water Code Section 5100).
  • Rate of Diversion
    The rate of diversion is a water flow measurement that is analogous the velocity recorded on your car’s speedometer. Examples of rate of diversion units are: gallons per minute, gallons per day, cubic feet per second, and acre-feet per day.
  • Storage
    Storage is defined as water diverted to storage and not bypassed to the stream downstream. Water diverted into a tank for domestic water supply is usually considered to be direct diversion.
  • Water Measurement Data Logger
    A data logger is an electronic device used to automatically record data, typically water elevation or stage, at set time intervals. Data storage can be analog or digital. Depending on the system, digital data can be transmitted wirelessly using cellphone-like signal relay, satellite relay, signal repeaters or wi-fi.
  • United States Geological Survey (USGS)
    The USGS (www.usgs.gov) is a bureau of the United States Department of the Interior and has four major science disciplines: biology, geography, geology, and hydrology. The USGS provides scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect the quality of life. Two of the USGS’s primary water roles are (1) development of topographic maps and (2) installation and maintenance of surface water gaging stations for California’s rivers and streams. USGS’s streamflow data are available at water.usgs.gov/nwis.