ASTM D5674-95(2014)
(Guide)Standard Guide for Operation of a Gaging Station
Standard Guide for Operation of a Gaging Station
SIGNIFICANCE AND USE
5.1 This guide is useful when a systematic record of water surface elevation or discharge is required at a specific location. Some gaging stations may be operated for only a few months; however, many have been operated for a century.
5.2 Gaging station records are used for many purposes:
5.2.1 Resource appraisal of long-term records to determine the maximum, minimum, and variability of flows of a particular stream. These data can be used for the planning and design of a variety of surface water-related projects such as water supply, flood control, hydroelectric developments, irrigation, recreation, and waste assimilation.
5.2.2 Management, where flow data are required for the operation of a surface-water structure or other management decision.
SCOPE
1.1 The guide covers procedures used commonly for the systematic collection of streamflow information. Continuous streamflow information is necessary for understanding the amount and variability of water for many uses, including water supply, waste dilution, irrigation, hydropower, and reservoir design.
1.2 The procedures described in this guide are used widely by those responsible for the collection of streamflow data, for example, the U.S. Geological Survey, Bureau of Reclamation, U.S. Army Corps of Engineers, U.S. Department of Agriculture, Water Survey Canada, and many state and provincial agencies. The procedures are generally from internal documents of the preceding agencies, which have become the defacto standards used in North America.
1.3 It is the responsibility of the user of the guide to determine the acceptability of a specific device or procedure to meet operational requirements. Compatibility between sensors, recorders, retrieval equipment, and operational systems is necessary, and data requirements and environmental operating conditions must be considered in equipment selection.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D5674 − 95 (Reapproved 2014)
Standard Guide for
Operation of a Gaging Station
This standard is issued under the fixed designation D5674; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1941 Test Method for Open Channel Flow Measurement
of Water with the Parshall Flume
1.1 The guide covers procedures used commonly for the
D3858 Test Method for Open-Channel Flow Measurement
systematic collection of streamflow information. Continuous
of Water by Velocity-Area Method
streamflow information is necessary for understanding the
D5129 Test Method for Open Channel Flow Measurement
amount and variability of water for many uses, including water
of Water Indirectly by Using Width Contractions
supply, waste dilution, irrigation, hydropower, and reservoir
D5130 Test Method for Open-Channel Flow Measurement
design.
of Water Indirectly by Slope-Area Method
1.2 The procedures described in this guide are used widely
D5242 Test Method for Open-Channel Flow Measurement
by those responsible for the collection of streamflow data, for
of Water with Thin-Plate Weirs
example, the U.S. Geological Survey, Bureau of Reclamation,
D5243 Test Method for Open-Channel Flow Measurement
U.S. Army Corps of Engineers, U.S. Department of
of Water Indirectly at Culverts
Agriculture, Water Survey Canada, and many state and pro-
D5388 Test Method for Indirect Measurements of Discharge
vincial agencies. The procedures are generally from internal
by Step-Backwater Method
documents of the preceding agencies, which have become the
D5389 Test Method for Open-Channel Flow Measurement
defacto standards used in North America.
by Acoustic Velocity Meter Systems
1.3 It is the responsibility of the user of the guide to
D5390 Test Method for Open-Channel Flow Measurement
determine the acceptability of a specific device or procedure to
of Water with Palmer-Bowlus Flumes
meet operational requirements. Compatibility between sensors,
D5413 Test Methods for Measurement of Water Levels in
recorders, retrieval equipment, and operational systems is
Open-Water Bodies
necessary, and data requirements and environmental operating
D5541 Practice for Developing a Stage-Discharge Relation
conditions must be considered in equipment selection.
for Open Channel Flow
1.4 The values stated in inch-pound units are to be regarded
2.2 ISO Standards:
as standard. The values given in parentheses are mathematical ISO 1100 Liquid Flow Measurement in Open Channels—
conversions to SI units that are provided for information only
Part I: Establishment and Operation of a Gauging Station
and are not considered standard. ISO 6416 Measurement of Discharge by Ultrasonic (Acous-
tic) Method
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3.1 Definitions—For definitions of terms used in this guide,
bility of regulatory limitations prior to use.
refer to Terminology D1129.
2. Referenced Documents 3.2 Definitions of Terms Specific to This Standard:
2 3.2.1 control—the physical properties of a channel, which
2.1 ASTM Standards:
determine the relationship between the stage and discharge of
D1129 Terminology Relating to Water
a location in the channel.
This guide is under the jurisdiction ofASTM Committee D19 on Water and is 3.2.2 datum—a level plane that represents zero elevation.
the direct responsibility of Subcommittee D19.07 on Sediments, Geomorphology,
3.2.3 discharge—the volume of water flowing through a
and Open-Channel Flow.
cross-section in a unit of time, including sediment or other
Current edition approved Jan. 1, 2014. Published March 2014. Originally
approved in 1995. Last previous edition approved in 2008 as D5674 – 95 (2008).
DOI: 10.1520/D5674-95R14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Measurement of Liquid Flow in Open Channels, ISO Standards Handbook 16,
Standards volume information, refer to the standard’s Document Summary page on 1983.AvailablefromAmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,
the ASTM website. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5674 − 95 (2014)
solidsthatmaybedissolvedinormixedwiththewater;usually broad, for example, between major tributaries. Constraints for
cubic feet per second (f /s) or metres per second (m/s). a management-type station may require a location just below a
dam, contaminant discharge point, or other point at which
3.2.4 elevation—the vertical distance from a datum to a
discharge information is required specifically.
point; also termed stage or gage height.
3.2.5 gage—a generic term that includes water level mea- 6.2 Site Requirements—Certain hydraulic characteristics of
suring devices. the stream channel are desirable for collecting high-accuracy
data of minimal cost. Hydraulically difficult sites can still be
3.2.6 gage datum—a datum whose surface is at the zero
gaged; however, accuracy and cost are affected adversely.
elevation of all of the gages at a gaging station. This datum is
Desirable conditions include the following:
often at a known elevation referenced to the national geodetic
6.2.1 The general course of the river should be straight for
vertical datum (NGVD) of 1929.
approximately 300 ft (100 m) above and below the gage.
3.2.7 gage height—the height of a water surface above an
6.2.2 The flow is confined to one channel at all stages.
established or arbitrary datum at a particular gaging station;
also termed stage. 6.2.3 The stream bed is stable, not subject to frequent scour
and fill, and is free of aquatic growth.
3.2.8 gaging station—a particular site on a stream, canal,
6.2.4 The banks are sufficiently high to contain flow at all
lake, or reservoir at which systematic observations of hydro-
stages.
logic data are obtained.
6.2.5 A natural feature such as ledge rock outcrop or stable
3.2.9 national geodetic vertical datum (NGVD) of 1929—
gravel riffle, known as a “control,” is present in the stream. It
prior to 1973 known as mean sea level datum, a spheroidal
is necessary and practical in some cases to install a low-head
datum in the conterminous United States and Canada that
dam or artificial control to provide this feature. Additional
approximates mean sea level but does not necessarily agree
information on man-made structures is given in Test Methods
with sea level at a specific location.
D1941, D5242, and D5390.
3.2.10 stilling well—a well connected to the stream with
6.2.6 Apool is present behind the control where water-level
intake pipes in such a manner that it permits the measurement
instrumentsorstillingwellintakescanbeinstalledatalocation
of stage in relatively still water.
below the lowest stream stage. The velocity of water passing
sensorsinadeeppoolalsoeliminatesorminimizesdraw-down
4. Summary of Guide
effects on stage sensors during high flow conditions.
4.1 Agaging station is usually installed where a continuous
6.2.7 The site is not affected by the hydraulic effects of a
record of stage or discharge is required. A unique relationship
bridge, tributary stream entering the gaged channel, down-
exists between water surface elevation and discharge (flow
stream impoundment, or tidal conditions.
rate) in most freely flowing streams. Water-level recording
6.2.8 A suitable site for making discharge measurements at
instruments continuously record the water surface elevation,
all stages is available near the gage site.
usually termed stage or gage height. Discharge measurements
6.2.9 Thereisaccessibilityforconstructionandoperationof
are taken of the stream discharge to develop a stage-discharge
curve. The discharge data are computed from recorded stage the gage.
data by a stage-discharge rating curve.
6.3 Site Selection—An ideal site is rarely available, and
judgement must be exercised when choosing between possible
5. Significance and Use
sites to determine that meeting the best combination of
5.1 This guide is useful when a systematic record of water
features.
surface elevation or discharge is required at a specific location.
6.3.1 Offıce Reconnaissance—The search for a gaging sta-
Some gaging stations may be operated for only a few months;
tion begins with defining the limits along the stream at which
however, many have been operated for a century.
the gage must be located on topographic maps of the area. The
5.2 Gaging station records are used for many purposes: topographic information will indicate approximate bank
5.2.1 Resource appraisal of long-term records to determine
heights or overflow areas, general channel width, constrictions,
the maximum, minimum, and variability of flows of a particu- slope, roads, land use, locations of buildings, and other useful
lar stream. These data can be used for the planning and design
information so that promising locations can be checked out in
of a variety of surface water-related projects such as water the field.
supply, flood control, hydroelectric developments, irrigation,
6.3.2 Field Reconnaissance—If the range of possible gage
recreation, and waste assimilation.
locations is large, flying over the stream at a low altitude in a
5.2.2 Management, where flow data are required for the
small aircraft is an efficient way of checking for promising
operation of a surface-water structure or other management
sites.Theviewfromtheaironacleardayismuchmorehelpful
decision.
than peering off of a few highway bridges. Traversing the
channel in a canoe or small boat is an alternative method. Field
6. Site Location
reconnaissance is best performed during low flow conditions;
6.1 The general location of the station will be dependent on however,additionalreconnaissanceathighflowconditionsand
the purpose for which the station is established. Location under ice-covered conditions for northern streams adds data
constraints for a resource appraisal-type station may be quite that result in improved site selection.
D5674 − 95 (2014)
6.3.3 Logistical Reconnaissance—Once a site has been readandrecordedmanuallyinanappropriatenotebookonceor
selected that meets hydraulic considerations, and before design more each day. For details on non-recording gages, see Test
or construction begins, the following should occur: Methods D5413, ISO 1100, and Refs (1-4).
6.3.3.1 Property ownership must be ascertained and legal
7.2 Recording gages are usually nonattended installations
permission secured to install and maintain the gage. This may
that require a sensor in direct contact with the water that is
include multiple landowners, especially if a cableway is
connected mechanically or electrically to a recording device.
required from which to make discharge measurements.
7.2.1 Stilling well-type gages use a vertical well installed in
6.3.3.2 Necessary permits must be obtained from applicable
the stream bank with small-diameter intake pipes connecting
governing agencies for, but not limited to, building and
the river to the well. In this type of installation, a float on the
excavation, stream bank permits, and FAA notification for
water surface in the well drives a recorder housed in a shelter
cableways or other local requirements.
over the well by mechanical means (Fig. 1). Stilling well gages
6.3.3.3 Where electrical or phone service is required for
tend to provide more reliable data because water-level sensing
operation, the availability of this service should be verified.
as well as recording components of the system are protected
6.3.3.4 Most gaging stations are intended to record over the
from direct installation in the stream. Disadvantages are
range of stream stages. It is therefore important to obtain any
locations with unstable stream channels that may move away
local information available on historical flood levels and to
from the intakes and higher initial cost. For details on stilling
makeestimatesofstagefora100-yeareventusinglocallyused
well gages, seeTest Methods D5413, ISO 1100, and Refs (1-3,
flood-frequency equations.Across-section survey of the chan-
5).
nel should be obtained during field reconnaissance to aid in
7.2.2 Bubbler-type gages consist of a gas supply, usually
estimating high flow stage.
nitrogen, which is fed through a controller and tube to an
6.4 More detailed information is available in Refs (1-3)
orifice attached near the bed of a stream. The gas pressure is
and ISO-1100.
equal to the liquid head in the stream. A pressure transducer,
mercury, or balance-beam manometer senses this pressure and
7. Types of Gaging Stations
passes this information either mechanically or electronically to
7.1 Non-recording stations can be as simple as a permanent
a compatible recorder (Fig. 2). The advantage to this system is
staff gage attached to a bridge, pier, or other structure, which is
less expensive construction costs, which is especially desirable
for short-term gages or in locations in which stilling well
installations are difficult. Disadvantages are maintaining the
The boldface numbers in parentheses refer to the list of references at the end of
orifice in a stable mounting on the river bed. Keeping the
this standard.
FIG. 1 Stilling Well Gage
D5674 − 95 (2014)
FIG. 2 Bubble Gage
orifice from being buried in silty streams is also a problem. For 8.1.3 Stillingwellsmaybefabricatedfrompouredconcrete,
details on bubble-gages, see Test Methods D5413, ISO 1100, concrete blocks, galvanized steel, concrete culvert pipe, or
and Refs (1-3, 5, 6). other suitable material. The well must have a sealed bottom to
7.2.3 AcousticVelocityMeter(AVM)stationsdirectlysense preclude the interchange of water from the stream and ground
and record the velocity observed between two transducers at
water.
fixed elevations in the channel cross section. The AVM gages
8.1.4 Stilling wells are usually installed in a stream bank for
are used in locations in which stage-discharge relations are
protection and to minimize freezing in northern climates. They
unreliable, usually in deep, slow-moving channels or where
may be attached to bridge piers or wing walls in some
tidal or bidirectional flow occurs. Additional information is
applications but must be protected from damage by floating
given in Test Method D5389.
debris and
...
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