miles of ice behind it, and no ice had yet passed
Aroostook River
The Aroostook River breakup also began on
over it. The open river above the ice reached to 1
28 March and was also a slow and orderly pro-
mile above the Route 1 bridge in Presque Isle. At
cess that only produced minor overbank flow in
Fort Fairfield, fractured sheet ice extended from
some low flood plains. On 29 March the majority
below the bridge to 1 mile upstream. The toe of a
of the river reaches had some water flowing on
1-mile jam was located at this point and the rest
top of the ice, with occasional areas being up to
of the river to Caribou was now open.
100% flooded. More than 1 in. of rain had fallen
On 10 April the intact ice observed above Cari-
in the upper basin and the air temperatures were
bou had been reduced to 6 miles in length and
about 35 to 40F.
the open water reach extended to 2 miles above
On 30 March, we observed more flooding of
Presque Isle. The Crouseville jam had shrunk to
11/2 miles in length. We measured many ice
the ice cover and a continuing rising stage. A
small jam began to form at the GarfieldAshland
blocks on shore to obtain their thickness and
line at about 1230 hours. The ice also began to
found them to have a range of 618 in. This indi-
break up near the Caribou Water Works, located
cated that there had been considerable melting of
about 1 mile below the dam, at 1700 hours. A
the ice, at least half of the original thickness, prior
flight taken on 31 March revealed that the entire
to the ice runs. The highest elevation of ice blocks
length of the Aroostook was primed for breakup.
above the existing water surface was about 5 ft,
The ice was flooded nearly everywhere and there
with the average range being 23 ft. This corre-
were numerous small jams and open leads. On 1
sponded to the river being almost bankfull dur-
April the stage continued to slowly rise but the
ing the ice runs and jams in most locations. The
ice conditions remained relatively unchanged. By
ice was completely out from below the Masardis
2 April it was apparent that there would be no
gage to Ashland and there was a small jam at the
rapid breakup, although the ice had finally re-
confluence of the St. Croix River.
leased from shore and was floating freely.
On 13 April the Masardis village reach was
A 7 April flight, taken to continue document-
fully open, with some ice still remaining between
ing the breakup, revealed that the numerous
it and the gage. The river was then open until a
open leads and small jams were continuing to ex-
small jam near the Sheridan RR bridge. The jams
pand and the extent of open water had increased
at Wade and Crouseville appeared to be un-
changed. The Caribou Dam had about 5 miles of
significantly. A 3-mile reach was now open be-
ice behind it and Fort Fairfield had approximate-
low the confluence of Squa Pan Stream in Masar-
ly 1 mile of jammed ice above the bridge. There
dis and another 3-mile open reach existed down-
was an additional 1/2 mile of slush accumulated
stream of the dam in Caribou. A small accumula-
upstream.
tion of fragmented floes was located near the
The Gardner Brook Road jam had melted
USGS Washburn gage, where open water had
down to 1/2 mile in length and the Crouseville
been observed on 4 April.
jam was reduced to 1 mile by 17 April. On 18
There was an open reach about 600 ft long be-
April the dam in Caribou had only 2 miles of ice
low the Masardis gage on 9 April and the open
remaining behind it and still no ice had passed
reach downstream of Squa Pan was now 6 miles
over it. The Fort Fairfield area had only sheet ice
long and ended at a small jam below the Ashland
left with its upstream edge now being 1/ mile be-
bridge. Another small jam was located at Sheri-
4
low the bridge. The little remaining ice ran over
dan Village. A significant jam that had been at
Caribou's dam on the morning of 20 April.
Washburn since 8 April released at about 1430
1500 hours on 9 April and re-jammed at the Vil-
lage of Crouseville. This new jam was 2 miles
SUMMARY OF FIELD OBSERVATIONS
long and produced some flooding of a small
Freezeup
junkyard located in a low floodplain on the right
Based on our observations and field measure-
bank at 1700 hours. Open water extended up-
ments, which identified the river ice hydraulic
stream of the jam through the Washburn gage
characteristics, we feel that the freezeup process
site to Donnelly Island in Wade. Sheet ice began
that we observed throughout the St. John Basin
there and continued upstream to a 1-mile jam,
was, in general, the typical event: a rapid and
whose toe was just below the Gardner Brook
easy freezeup with no apparent problems. There
Road boat launch.
obviously are variations that could occur if the
On 9 April, the dam in Caribou still had 7
11
Previous Page
