on 17 February and reported to be 0.5 mile long.
Site 5. Platte River: 1.5 miles north
The exact locations of the upstream and down-
of the Highway 64 bridge
stream ends of the jam were not identified. The
Details of this ice jam are sketchy. It is possible
ice jam went out on 18 February 1984.
that this ice jam is the one commonly described as
Nebraska Civil Defense records report evac-
being located at the Ford Farm about 2.5 miles
uations in Big Island due to ice-related flooding
upstream from the Highway 64 bridge, since the
on 7 January 1985. NWS records indicate that
upstream end of a jam is usually of more concern
the ice jam was located between the Burlington
to local observers than the downstream end.
Northern Railroad bridge and the Highway 77
The ice jam near the Ford Farm was associated
bridge. There was also minor ice-related flood-
with the Union Dike breach, which resulted in
ing in Big Island at the end of February and into
extensive flooding in the Valley area during the
early March 1985.
March 1978. The jam was blasted in an effort to
release the jam and decrease flooding. A similar
event occurred in March 1929:* "...Valley, Nebras-
Site 4. Platte River:
West Channel at Leshara
ka, residents were prepared early today for the
Leshara has been plagued by open-water flood-
second time within 24 hours to abandon their
ing as well as ice-related flooding. Because there
homes as a huge ice gorge was forming six miles
is no gage or large settlement near the jam area,
above the town. A gorge that caused water to
little has been reported about ice jams in the vi-
break through a dike near the village Tuesday
cinity. However, it is thought that the jams which
night and threatened the city was blasted away
adversely affect Leshara occur within the west
yesterday."
channel of the river. The jam that occurs north of
On 1 March 1979, the ice in the vicinity of the
the Highway 64 bridge (see below) may also af-
Ford Farm was dusted with fly ash in hopes of
fect stages and ice conditions at Leshara. For ex-
increasing the rate of deterioration of the ice and
ample, a large ice jam that formed in the west
preventing the occurrence of an ice jam similar to
channel upstream from the Highway 64 bridge
the 1978 jam (USAED, Omaha 1979). Although
on 16 March 1979 resulted in a dike breach and
ice jammed intermittently near the Ford Farm be-
flooding at Leshara the next day. This dike breach
tween 11 and 18 March 1979, no flooding occurred.
may have been located in the same place as the
Nebraska Civil Defense records reveal that an
ice jam formed between Highway 64 and the Ford
one that occurred in March 1978. The 1978 breach
Farm on 22 February 1982. The jam was reported
was not specifically identified as being due to ice
to be in the same place as the 1978 jam, which
action, but the presence of ice jams at the High-
caused so much flooding in Valley. The jam even-
way 64 bridge that year and subsequent jamming
tually failed naturally on 24 February before flood-
and flooding of the east channel of the river make
ing occurred.
it highly likely that the 1978 event was, in fact, ice
A minor jam was noted by Nebraska Civil De-
related.
fense spotters upstream from the Highway 64
An ice jam in the Woodcliff area resulted in
bridge on 12 February 1984. The NWS indicated
lowland flooding and eventually in the failure of
that the jam had caused overflows onto bottom-
a dike at Leshara on 27 February 1980. According
lands and had flooded several cabins near Lesha-
to Nebraska Civil Defense records, more exten-
ra on 16 and 17 February 1984. A minor jam up-
sive flooding occurred after the dike breached,
stream from the Highway 64 bridge was again
and some evacuations were necessary. The west
reported by the Nebraska Civil Defense on 26
channel was plugged by a mile-long jam in Feb-
February 1985.
ruary 1982, which caused lowland flooding
The Omaha World-Herald reported that water
through the breach, which had not yet been fully
levels had come within 3 ft of overtopping the
repaired.
Union Dike in the Ford Farm area on 27 February
A 28 February 1986 Omaha World-Herald news
1986, as a result of an ice jam. The location and
article reported that residences in the Woodcliff
extent of the jam were not described, but it appar-
area were flooded during an ice event when the
dike failed at Leshara. According to the article,
the dike was originally breached during the 1978
ice jam event and had not been completely re-
* Montpelier (Vermont) Evening Argus, Thursday, 14
paired by 1986.
March 1929.
13
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