County Board of Supervisors gave the Western
Obtain the services of a professional heli-
Sarpy Drainage District permission to blast the
copter pilot and use of a helicopter.
ice jam on 16 March.
Obtain necessary permits for explosives and
Blasting began the afternoon of the 16th and
necessary quantities of explosives.
continued until the 18th. At the peak of the flood-
Advise the Federal Aviation Administration
ing, the jam extended nearly four miles, but it
so that aircraft can be kept away from the
was about 22.5 miles when blasting began. Ini-
blast area.
tial blasting efforts began at the upstream end of
Contact the U.S. Fish and Wildlife Service to
the jam in the hope of creating a channel to a
determine if any endangered species are in
small levee breach at about the midpoint of the
the blasting area.
jam, so that water levels would drop enough to
Designate an area reasonably close to the
allow repair of other breaches. On the 17th, how-
blast site as a base of operations. All opera-
ever, blasting began at the toe of the jam near
tions should be done from this site, includ-
Thomas Lakes. According to the Omaha World-
ing charge preparation and charge loading.
Herald, charges up to 25 lb were used initially.
Follow all safety precautions when handling
Charge sizes were reduced while blasting near
explosives. A good set of safety precautions
Thomas Lakes. A channel was blasted through
for ANFO has been developed by the U.S.
the jam on the 18th, and water levels began to
Bureau of Mines (1963).
decrease gradually. Overflows through the breach-
Notify those in the blasting area prior to
es, however, were not stopped until the breaches
blasting so that nobody is in the proximity
were repaired. An estimated 10,000 lb of explo-
of blasting.
sives were used during the blasting operations.
Have another helicopter or emergency res-
Some other uses of explosives about which lit-
cue vehicle available at all times in case the
tle is known include:
helicopter carrying explosives goes down.
Near Columbus on the Platte River near the
Coordinate with local law enforcement offi-
Burlington Northern Railroad bridge on or
cials to keep "sightseers" out of the area.
about 24 February 1971;
Estimating charge size, total charge quantity and
On the Platte River near Ashland on or
time of blasting operation. Research on the use of
around 20 March 1978;
explosives on ice jams in rivers such as the Platte
Near the mouth of the Elkhorn River in Feb-
is quite limited. However, the results of research
ruary 1981; and
elsewhere can be used for estimating the size of a
Near Valley on the Platte River on or around
blast crater created with a charge of a given weight.
12 March 1929.
For shallow rivers such as the Platte, complete
removal of an ice jam by using explosives is diffi-
Suggested steps to take
cult, especially if flows are bypassing the jam. It is
for blasting operations
possible to blast a "pilot" channel through the
Blasting operations are hazardous because of
length of the jam to allow more water back into
the potential for disaster if something goes wrong.
the main channel. In turn, this may help slowly
Untimely detonation of the charge could lead to
remove more ice from the jam. The selection of
serious injury or death to one or more individuals.
charge size is often best based on experience but
Blasting can also cause property damage to facili-
will vary depending on the ice thickness and the
ties in the vicinity of operations. Explosives can
proximity to dwellings or other structures. It may
also have an adverse impact on the environment.
be necessary to adjust charge sizes after a few
For these reasons, certain general steps and
drops. One guide for selecting the smallest effec-
precautions listed below (not in any particular
tive charge size can be found in theoretical re-
order) should be taken before initiating blasting
search done by Van der Kley (1965). Van der Kley
operations. Other guidelines for blasting opera-
developed a relationship for the minimum charge
tions are contained elsewhere in the report. These
of TNT placed at varying depths below the ice
guidelines should be incorporated into an emer-
surface required to break ice of a given thickness
gency response plan so that exact details of each
(Fig. 23).
step are known ahead of time so that blasting can
Usually the ice thickness will not be known
readily be accomplished.
but must be estimated by judging the amount of
Obtain the services of an explosives expert to
ice above and below the water surface. Once the
advise on use and placement of explosives.
ice thickness is estimated, then the depth below
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