portedly used to open a channel along the east
the Vencil's Island area. It is possible that the two
bank of the Platte and Elkhorn Rivers.
jams reported were actually the same jam.
In March 1978, ice jams formed in many places
In 1993 an ice jam formed in the vicinity of the
along the Platte River. Ice jams in the Elkhorn
Thomas Lakes development on 7 February, fol-
Platte confluence area flooded both sides of the
lowing the breakup of the ice cover on the lower
river and Vencil's Island. A crane equipped with
Elkhorn River. The ice cover on the Platte River
a wrecking ball was operated from the Highway
below the confluence with the Elkhorn River did
6 bridge to facilitate ice movement through the
not break up, and a solid ice cover extended about
bridge. Blasting was done on 19 and 20 March in
two miles downstream from the Thomas Lakes
an attempt to increase flow conveyance through
development (USAED, Omaha 1993). A jam
the area.
formed in this area when the movement of the
Nebraska Civil Defense records indicate that
broken ice was stopped by the competent ice
on 24 February 1980 an ice jam was located be-
cover. This jam did raise stages slightly, and levees
tween Memorial Hall and the north edge of Camp
along the east bank were monitored. However,
Ashland. High stages caused by the jam were en-
the water stage remained within bank and the
tering both Camp Ashland and the Thomas Lakes
jam eventually froze in place.
development. The jam broke up on its own at
This jam was still in place when the rising tem-
noon on 25 February.
peratures, precipitation and snowmelt of early
Lowland flooding was first reported on 19 Feb-
March caused both an increase in discharge and
ruary 1982, in the vicinity of Highway 6 and the
the breakup of additional ice upstream on the
Guard Camp. On 20 February it was reported
Platte and Elkhorn Rivers. The jam both length-
that an ice jam on Salt Creek was backing water
ened and thickened at this time, and by 8 March
up into the Thomas Lakes area. Ice jammed in the
the ice jam was about 2.5 miles long, causing wa-
Thomas Lakes area and near Camp Ashland on
ter to overtop a levee on the east bank (Sarpy
21 February 1982. According to Civil Defense re-
County) and a levee on the west bank (Saunders
ports, a number of homes were evacuated from
County). The Sarpy County levee failure report-
Thomas Lakes and from Vencil's Island farther
edly occurred in the same general area as a break
upstream. Blasting of the ice jam began on 23
during the 1966 and 1969 events. In addition, a
February but was cut short due to bad weather.
second levee failure occurred on the east bank
The jam failed soon after.
somewhat downstream from the first. The
On 14 February 1984, an ice jam in the vicinity
Thomas Lakes development and Camp Ashland
of the Thomas Lakes development again forced
were flooded, and the City of Lincoln's well field
water into the development, flooding some cab-
was threatened, with two pipelines washing out.
ins. There was solid ice between the jam and the
East bank flooding caused the closure of I-80 for
Highway 6 bridge downstream, with water flow-
at least a day, and two Highway 6 bridges were
ing over the ice. A minor ice jam at the mouth of
damaged. The discharge during the March 1993
the Elkhorn River was reported by the NWS on 16
event was estimated at 130,000 cfs (FEMA 1993),
February 1984. This jam was apparently affecting
but only about 55,000 cfs was measured at the
Table 9. Summary of ice-related flood events at the confluence of the Platte
and Elkhorn Rivers near Ashland.
Date
Description
February 1966
levee break on Elkhorn River; I-80 damaged; blasting done
March 1978
flooding along east and west banks of the river; blasting done;
wrecking ball used at Highway 6 bridge
24 February 1980
flooding in Camp Ashland and Thomas Lakes
21 February 1982
flooding of Camp Ashland, Thomas Lakes, east side of river,
and Vencil's Island; blasting done
14 February 1984
flooding in Thomas Lakes and Vencil's Island
FebruaryMarch 1993
Thomas Lakes flooded; levee break in same place as 1966 and
1969 and a second break downstream; Highway 6 bridges
damaged; blasting done
15
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