ASTM D5413-93(1997)

Designation: D 5413 – 93 (Reapproved 1997)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Methods for
Measurement of Water Levels in Open-Water Bodies
This standard is issued under the fixed designation D 5413; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 5242 Test Method for Open Channel Flow Measurement
of Water with Thin-Plate Weirs
1.1 These test methods cover equipment and procedures
2.2 ISO Standard:
used in obtaining water levels of rivers, lakes, and reservoirs or
ISO 4373 Measurement of Liquid Flow in Open
other water bodies. Three types of equipment are available as
Channels—Water Level Measuring Devices
follows:
Test Method A—Nonrecording water-level measurement devices
3. Terminology
Test Method B—Recording water-level measurement devices
Test Method C—Remote-interrogation water-level measurement devices
3.1 Definitions—For definitions of terms used in this test
method, refer to Terminology D 1129.
1.2 The procedures detailed in these test methods are widely
3.2 Definitions of Terms Specific to This Standard:
used by those responsible for investigations of streams, lakes,
3.2.1 elevation—the vertical distance from a datum to a
reservoirs, and estuaries, for example, the U.S. Agricultural
point.
Research Service, the U.S. Army Corp of Engineers, and the
2 3.2.2 datum—a level plane that represents a zero or some
U.S. Geological Survey. The referenced ISO standard also
defined elevation.
furnishes useful information.
3.2.3 gage—a generic term that includes water level mea-
1.3 It is the responsibility of the user of these test methods
suring devices.
to determine the acceptability of a specific device or procedure
3.2.4 gage datum—a datum whose surface is at the zero
to meet operational requirements. Compatibility between sen-
elevation of all the gages at a gaging station; this datum is often
sors, recorders, retrieval equipment, and operational systems is
at a known elevation referenced to National Geodetic Vertical
necessary, and data requirements and environmental operating
Datum of 1929 (NGVD).
conditions must be considered in equipment selection.
3.2.5 gage height—the height of a water surface above an
1.4 The values stated in inch-pound units are to be regarded
established or arbitrary datum at a particular gaging station;
as the standard. The values given in parentheses are for
also termed stage.
information only.
3.2.6 gaging station—a particular site on a stream, canal,
1.5 This standard does not purport to address all of the
lake, or reservoir where systematic observations of hydrologic
safety concerns, if any, associated with its use. It is the
data are obtained.
responsibility of the user of this standard to establish appro-
3.2.7 National Geodetic Vertical Datum of 1929 (NGVD)
priate safety and health practices and determine the applica-
—prior to 1973 known as mean sea level datum; a spheroidal
bility of regulatory limitations prior to use.
datum in the conterminous United States and Canada that
2. Referenced Documents approximates mean sea level but does not necessarily agree
with sea level at a specific location.
2.1 ASTM Standards:
D 1129 Terminology Relating to Water
4. Significance and Use
D 1941 Test Method for Open Channel Flow Measurement
4.1 These test methods are used to determine the gage
of Water with the Parshall Flume
height or elevation of a river or other body of water above a
D 2777 Practice for Determination of Precision and Bias of
given datum.
Applicable Methods of Committee D-19 on Water
4.2 Water level data can serve as an easily recorded param-
eter, and through use of a stage-discharge relation provide an
indirect value of stream discharge, often at a gaging station.
These test methods are under the jurisdiction of ASTM Committee D-19 on
Water and is the direct responsibility of Subcommittee D19.07 on Sediments,
4.3 These test methods can be used in conjunction with
Geomorphology, and Open-Channel Flow.
Current edition approved May 15, 1993. Published November 1993.
Buchanan, T. J., and Somers, W. P., “Stage Measurement at Gaging Stations,”
Techniques of Water Resources Investigations, Book 3, Chapter A-7, U.S. Geologi-
cal Survey, 1968. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 11.01. Floor, New York, NY, 10036.
D 5413
other determinations of biological, physical, or chemical prop-
erties of waters.
TEST METHOD A—NONRECORDING WATER-
LEVEL MEASUREMENT DEVICES
5. Summary of Test Method
5.1 This test method is usually applicable to conditions
where continuous records of water level or discharge are not
required. However, in some situations, daily or twice daily
observations from a nonrecording water-level device can
provide a satisfactory record of daily water levels or discharge.
Water levels obtained by the nonrecording devices described in
this test method can be used to calibrate recording water-level
devices described in Test Methods B and C.
5.2 Devices included in this test method are of two general
types: those that are read directly, such as a staff gage; and
those that are read by measurement to the water surface from
a fixed point, such as wire-weight, float-tape, electric-tape,
point and hook gages.
5.2.1 Staff, wire-weight, and chain gages are commonly
used as both outside auxiliary and reference gages. Vertical-
and inclined-staff, float-tape, electric-tape, hook and point
gages are commonly used as inside auxiliary and reference
gages.
5.3 Documentation of observations must be manually re-
corded.
6. Apparatus
FIG. 1 Staff Gages
6.1 Staff Gages:
6.1.1 Vertical Staff Gages—Staff gages are usually gradu-
ated porcelain-enameled plates attached to wooden piers or
pilings, bridge piers, or other hydraulic structures. They may
also be installed on the inside of gaging station stilling wells as
inside reference gages. They are precisely graduated, usually to
0.02 ft or 2 mm, although other markings may be used for
specific applications (see Fig. 1).
6.1.2 Inclined Staff Gages—Inclined staff gages usually
consist of markings on heavy timbers, steel beams, or occa-
sionally concrete beams built partially embedded into the
natural streambed slope. Since they are essentially flush with
the adjoining streambed, floating debris and ice are less likely
to cause damage than for a vertical staff gage. Individual
graduation and marking of the installed gages by engineering
levels are required due to the variability of bank slope.
6.2 Wire-Weight Gage—An instrument that is mounted on a
FIG. 2 Type A Wire-Weight Gage
bridge or other structure above a water body. Water levels are
obtained by direct measurement of the distances between the
device and the water surface. A wire-weight gage consists of a the check bar, readings of the counter are compared to its
drum wound with a single layer of cable, a bronze weight known elevation as a calibration procedure. The gage is set so
attached to the end of the cable, a graduated disk, a counter, that when the bottom of the weight is at the water surface, the
and a check bar, all contained within a protective housing (see gage height is indicated by the combined readings of the
Fig. 2). The disk is graduated and is permanently connected to counter and the graduated disk.
the counter and the shaft of the drum. The cable is guided to its 6.3 Needle Gages—Frequently referred to as point or hook
position on the drum by a threading sheave. The reel is gages. A needle gage consists of a vertically-mounted pointed
equipped with a pawl and ratchet for holding the weight at any metallic, small-diameter rod, which can be lowered until an
desired elevation. A horizontally mounted check bar is exact contact is made with the water surface. A vernier or
mounted at the lower edge of the instrument. Differential levels graduated scale is read to indicate a gage height. A needle-type
are run to the check bar. When the weight is lowered to touch gage offers high measurement accuracy, but requires some skill
D 5413
and good visibility (light conditions) in lowering and raising
the device to a position where the point just pierces the water
surface. These gages are most commonly used in applications
where the water surface is calm.
6.3.1 Point Gage—A form of needle gage where the tip or
point approaches the water surface from above.
6.3.2 Hook Gage—A form of needle gage made in the shape
of a hook, where the tip or point approaches the water surface
from below (see Fig. 3). The hook gage is easier to use in a
stilling well application. As the point contacts the water
surface, overhead light will reflect from a dimple on the water
surface.
6.4 Float-Tape Gage—Consists of a float attached to a
stainless steel graduated tape that passes over a suitable pulley
with a counterweight to maintain tension. A pointer or other
index is frequently fabricated as an integral part of the pulley
assembly (see Fig. 4). Float-tape gages frequently are com-
bined with water-level recorders in a manner whereby the
pulley is the stage drive wheel for the recorder.
6.5 Electric-Tape Gage—Consists of a graduated steel tape
and weight attached to a combined tape reel, voltmeter, datum
index and electrical circuit, powered by a 4 ⁄2 to 6 volt battery
(see Fig. 5). The gage frame is mounted on a shelf or bracket
over the water surface, usually in a stilling well. The weight is
lowered until the weight touches the water surface closing the
electrical circuit that is indicated by the voltmeter. The gage
FIG. 4 Float-Type Gage
height is read on the tape at the index.
6.6 A reference point is frequently selected on a stable
member of a bridge, stilling well, or other structure from which
distance vertical measurements to the water surface are made
FIG. 5 Electric-Type Gage
by steel tape and weight. The reference point is a clearly
defined location, frequently a file mark or paint mark to ensure
FIG. 3 Hook Gage that all readings are from the same location.
D 5413
7. Calibration 9.4 Recorders may retain data in graphical, analog, digital,
or other format.
7.1 Establish a datum. The datum may be a recognized
9.5 Recorders are available that can remain unattended for
datum such as National Geodetic Vertical Datum of 1929
periods from one week to longer than six months.
(NGVD), a datum referenced to a recognized datum such as
580.00 ft NGVD 1929, a local datum, or an arbitrary datum. A
10. Apparatus
datum is usually selected that will give readings of small
10.1 Types of Sensing Systems:
positive numbers.
10.1.1 Direct Reading Systems:
7.2 Establish at least three reference marks (RMs). Refer-
10.1.1.1 Crest Stage Gage—A crest stage gage is a simple
ence marks must be located on independent permanent struc-
sensing-recording device that is installed near a water body to
tures that have a good probability of surviving a major flood or
record the highest water level that occurs between visits of field
other event that may destroy the gage. Reference marks should
personnel. A wooden rod is encased in a steel or plastic pipe
be close enough to the water-level measuring device that the
with holes for water to enter and rise to the outside water level.
leveling circuit not require more than two or three instrument
A recoverable high-water mark is left on the device by particles
setups to complete elevation verification. If the NGVD datum
of ground cork that float to the highest water level (Fig. 6).
is used, determine the elevation of the reference marks by
10.1.1.2 Tape Gage Maximum-Minimum Indicators—These
differential leveling from the nearest NGVD benchmark.
indicators include magnetic or mechanical accessories that
7.3 Set the gages to correct datum by differential leveling
record maximum or minimum travel of float-drive tape gages
from the reference marks. Use leveling procedures described in
or recorder-drive tapes.
a surveying text or “Levels at Streamflow Gaging Stations.”
10.1.2 Mechanical Sensing Systems:
7.4 Run levels to gages from RMs annually for the first 3 to
10.1.2.1 Float Tape—Consists of a float that floats on the
5 years, then if stability is evident, a level frequency of 3 to 5
water surface, usually in a stilling well, and a steel tape or cable
years is acceptable. Rerun levels at any time that a gage has
which passes over a recorder drive pulley. A weight on the
been disturbed or has unresolved gage reading inconsistencies.
opposite end of the tape maintains tension in the tape or cable.
Run levels to all RMs, reference points, index points, and to
The rise and fall of the water surface is thus directly transmit-
each staff gage, and to the water surface. Read the water
ted to the recorder.
surface at each gage at the time levels are run. Document
10.1.2.2 Shaft Encoders—These devices consist of a float-
differences found and changes made in a permanent record.
tape driven shaft and pulley assembly that converts the angular
8. Procedure
shaft position to an electronic signal compatible with electronic
recorders. Analog output potentiometers and several digital
8.1 Read direct reading gages by observing the water
format output encoding systems are available.
surface on the gage scale. Manually record this value on an
10.1.3 Gas-Purge System—This system is commonly
appropriate form.
known as a bubble gage. A gas, usually nitrogen, is fed from a
8.2 Gages that require measurement from a fixed point to
supply tank and pressure regulator through a tube and bubbled
the water surface must follow procedures provided by manu-
freely into the water body through an orifice at a fixed location
facturers of the specific instrument.
on or near the bottom of the water body. The gas pressure in the
8.3 Make a visual inspection of gages at each reading to
tube is equal to the piezometric head on the bubble orifice
detect apparent damage, which could affect accuracy.
corresponding to the water level over the orifice. Several
TEST METHOD B—RECORDING WATER-LEVEL
methods of sensing this line pressure and converting it to a
MEASUREMENT DEVICES recordable format are used (Fig. 7).
10.1.3.1 Mercury Manometer—The manometer assembly
9. Summary of Test Method
converts the gas purge line pressure to a shaft rotation for
9.1 This test method is applicable where continuous unat- driving a recorder. Mercury is used because its specific gravity
tended records of water level or discharge are required. is 13.6 times that of water, and thus shortens the length of the
Procedures de
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