Despite its biases and uncertainties (e.g., mea-
the potential depth and extent of flooding might
surement errors, source reliability), the CRREL Ice
have prevented some of the damage. At the time
Jam Database can be a useful source of ice event
of the 1992 ice jam, the database was in its nascent
information. Presented in the following sections
stages, and there were few entries for Montpelier.
are several potential applications of the database:
However, current entries show that the area
flooded and the stage reached in the 1992 event
Using ice event information in ice jam emer-
virtually duplicated the ice jam flood of 13 Feb-
gency response efforts.
ruary 1900. The flood of 9 January 1978 was also
Preparing a thumbnail sketch of ice jams in
similar, although less damaging. Past ice jam miti-
a particular state.
gation measures are also described; as recently as
Characterizing ice jams on a regional basis.
1973, blasting was used successfully to clear ice
Characterizing ice jams by year.
jams at Montpelier. If an ice event occurs at this
location in the future, the database can provide
rapid access to information needed by emergency
USING THE ICE JAM DATABASE
response agencies, including the ice jam removal
TO IMPROVE EMERGENCY
methods used in the 1992 event.
RESPONSE TO ICE JAMS
Emergency response
Using database information to
Emergency response to ice jams is often less
guide search for additional information
effective than it could be because of a lack of
The database is useful for an emergency
information on past ice jam locations, stages, and
response to an ice jam in other ways. For example,
mitigation measures. If ice jamming is infrequent
knowing the dates when large numbers of ice
in a river, contemporary emergency response
events occurred allows an efficient search of his-
agencies or coordinators may have no useful
torical records for ice events not already in the
knowledge about previous ice events. CRREL
database. This method proved useful in Connecti-
personnel are often asked to provide technical
cut, where ice cover breakup is generally unevent-
information in ice jam emergencies. In the past,
ful. In 1994, unusually cold weather resulted in
this effort involved scouring IERD files for infor-
thicker than normal ice and local officials were
mation on past jams at a site or locating a person
concerned that the unusual conditions might
who had responded to past events there, all
cause jams and flooding at breakup. They were
within a very short time. In some cases, more
aware of a few previous ice events but suspected
complete, site-specific technical advice could
that there were several unreported ice events at
have been provided if the information had been
other times and locations. The officials were con-
readily accessible.
cerned that emergency response would be hin-
Since the advent of the database, information
dered with no knowledge about where and when
on past ice events at the site can be rapidly located
ice events had occurred in the past, what damage
and passed on. This is particularly important
resulted, and what, if any, mitigation measures
when information on the success or failure of past
had been used. A search of the database produced
mitigation measures is available. In addition, the
entries for Connecticut and a list of ice event dates
sources used in developing database entries, such
in the upper Connecticut River basin back to 1900.
as relevant publications and newspaper articles,
The latter was provided with the expectation that
are now available in the IERD Ice Jam Archive
lower Connecticut River basin events might have
(Herrin and Balch 1995).
happened at about the same time. Knowing these
dates allowed a rapid search of historical records
for useful ice event information.
Using information about historical
The database can also be searched for particu-
ice data and mitigation at a site
The database contains information that is im-
lar words or phrases such as "blasting," "dust-
mediately useful in emergency response, such as
ing," or "ice jam removal, "to obtain information
for the Winooski River in Montpelier, Vermont,
regarding the success or failure of applying dif-
where ice covers form and break up annually.
ferent techniques (Fig. 4) and points of contact
Although Montpelier has suffered several dam-
knowledgeable about carrying out such mitiga-
aging ice jams in the past, the jam of 11 March
tion measures. For example, the entry for Saranac
1992, which caused about million in damage,
River, Morrisonville, New York, in 1996 includes
came as a shock to many residents. Knowledge of
the following: "two bulldozers and a backhoe
6
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