Martis Valley Groundwater Management Plan - Placer County Water ...

Groundwater subbasin – A subdivision of a groundwater basin created by dividing the
basin using geologic and hydrologic conditions or institutional boundaries.
Hysteresis – The maximum difference in output, at any measured value within the
specified range, when the value is approached first with an increasing and then a
decreasing measured property. Hysteresis is expressed in percent of the full-scale
output.
Instrument Drift – A change in instrument output over a period of time that is not a
function of the measured property. Drift is normally specified as a change in zero (zero
drift) over time and a change in sensitivity (sensitivity drift) over time.
Irrigation well – A well used to irrigate farmland. The water from the well is not
intended for domestic purposes.
Metadata – “data about data”; it is the data describing context, content and structure of
records and their management through time.
NFM – This stands for National Field Manual. This is a living, online, document of the
USGS. It is the protocol document for USGS methods of surface water, groundwater,
and water quality field activities. The portion of the NFM that related to the field methods
of collecting groundwater levels is in the following reference: U.S. Geological Survey,
2006, Collection of water samples (ver. 2.0): U.S. Geological Survey Techniques of
Water-Resources Investigations, book 9, chap. A4, September, accessed 12/30/09
at: http://pubs.water.usgs.gov/twri9A4/
Nonflowing well – A well in which the water level is below the land surface.
Pressure head – The height of a column of groundwater above a point that is
supported by pressure at that point.
Pressure transducer – A type of measurement device that converts pressure-induced
mechanical changes into an electrical signal.
Production well – A well with a pump installed that is used to bring groundwater to the
land surface. This is a general term that can be applied to a domestic well, irrigation
well, or public-supply well.
DWR Groundwater Elevation Monitoring Guidelines 31