Government of New Brunswick
Nashwaak Bridge
Saint-Léonard
Indian Island
Rivière-Verte
Bloomfield, Kings County
Grand Falls
Woodstock
Hartland
Florenceville
Upper Kent
Morrell Siding
Beechwood
Fredericton
Durham Bridge
Norton
Stanley
Hampton
Taymouth
Nashwaak Village
Mactaquac
Plumweseep
Penobsquis
Simonds
Perth-Andover
Bathurst
Ice jam
Mild Weather
Snowmelt
Heavy rain
$30,000,000.00

Affected Areas


General: During the winter of 1986-87, the total snowfall was significantly below normal in the north, and near normal in the south. However, early-March snowfalls and the absence of any mid-winter thaws contributed to an above normal snowpack in the southern parts of the basin by mid-March. High soil moisture and below normal temperatures in the late fall of 1986 limited infiltration of meltwater into the frozen soil, and no significant thaws occurred prior to March 17. Warm temperatures preceded the flood, with light to moderate rain falling on a heavy snowpack. The resulting floods peaked early in April. Though the rainfall and snowmelt were the primary causes of the high flows, much of the flooding and damages were caused by ice. Snowmelt was the major source of runoff for this event as compared to the 1979 flood, in which rainfall and snowmelt were almost equal contributors. The Saint John River Basin sustained the majority of the damage and in particular the Perth-Andover area was hard hit. Serious structural damage also occurred in the Woodstock area. Above the Mactaquac Dam most damage was ice related whereas below Mactaquac it was essentially an open water event, except in the Stanley area where ice jams resulted in flooding. Upstream of Grand Falls, the flooding was modest and the reported damage insignificant. However, at some locations on the river from Grand Falls to Beechwood, and Beechwood to Mactaquac, the Saint John River attained water levels that were the highest, or among the highest, on record. Saint John River, upstream of Grand Falls: Upstream of Grand Falls there were no significant floods. The only observed ice jam in this reach was at Rivière Verte early on March 31, and this rejam gradually moved downstream to Sainte-Anne-de-Madawaska, with ice accumulating over a 19 kilometre stretch. At 10:00 hours on April 1, the head of the jam was observed at St. Leonard, and by 18:30 hours of that day, it had dislodged. The high water levels were reported to have inundated the parking lot at the U.S. Customs office, opposite St. Leonard. Saint John River, Grand Falls to Beechwood: Between Grand Falls and Beechwood a series of ice jams and breakups occurred that caused high water levels at numerous locations between March 31 and April 2. On March 31, an ice jam on the Saint John River near Morrell, approximately five kilometres upstream of the confluence of the Aroostook River, was observed. At midnight on the same day, the jam released and moved pass Perth-Andover to stop about six kilometres downstream of the community. This resulted in a three metre rise in the water level at Perth-Andover between midnight and 05:00 hours on April 1. At noon on April 1, the jam moved through Upper Kent, resulting in a rapid drop in the water level at Perth-Andover. At about 13:00 hours, the jam was observed at the mouth of the Upper Guisiguit Brook. At 18:00 hours, ice started to pass through the spillway of the Tinker Dam on the Aroostook River. This ice passed through Perth-Andover at 19:00 hours, resulting in increasing water levels at Lower Perth. At 20:00 hours, ice started to pass through the Grand Falls Dam, arriving at Upper Guisiguit by 02:00 hours on April 2. The ice piled up and resulted in further increases in the upstream water levels. Water levels at Perth-Andover continued to increase until it reached the bottom chord of the railroad bridge between 05:00 and 06:00 hours on April 2. Ice began to lodge against the bridge, causing some sideways movement of the bridge. Ice from upstream continued to arrive at Perth-Andover and accumulated upstream of the railroad bridge, forming a secondary jam. At approximately 09:00 hours, the railroad bridge collapsed, releasing the secondary jam, causing water levels to surge. A maximum water level of 79.3 metres was reached in Perth-Andover, which is the highest on record. At about 09:30 hours, April 2, the ice jam at Upper Guisiguit released causing the water level at Beechwood Dam to increase by over three metres in less than 20 minutes. The dam began to spill ice at 09:45 hours, and by 14:00 hours all the headpond ice had passed through the Beechwood Dam. This was the first time that ice had passed Beechwood Dam since the plant began operation in 1957. The surge at Beechwood created by the dislodgement of the Upper Guisiguit jam resulted in discharges from the dam of about 5 300 cubic metres per second to 8 800 cubic metres per second between 09:00 hours and 10:30 hours; a 65% increase in discharge in 90 minutes. Over the next few days, water levels at Perth-Andover and the Beechwood Dam outflow gradually decreased. Saint John River, Beechwood to Mactaquac: Ice runs between Beechwood and Mactaquac began on March 30 with the formation of small ice jams at the TransCanada Highway bridge in Florenceville, and then later at Buckwheat Bridge. On March 31, the Beechwood Dam outflow increased, resulting in the dislodgement of the Buckwheat Bridge jam during the afternoon of March 31. At 15:45 hours, ice moved through Simonds and lodged at a location upstream of the Town of Hartland, causing the water level to gradually increase at Simonds. At 16:40 hours, the ice at Hartland started to move and stopped at Lower Becaguimec Island. By 17:00 hours, the water level at Hartland was reported to have risen 1.5 metres in 20 minutes. At 18:40 hours, the head of the Lower Becaguimec Island jam was observed at Simonds. Water levels continued to increase at Simonds, resulting in the flooding of Route #103 by 19:20 hours. A maximum water level at Simonds of 49.2 metres was reached at 21:00 hours, where it stabilized for several hours. (The abrupt rises and falls in water level at station 01AJ009, Saint John River at Simonds are clearly shown on Figure 4.6). Following the earlier movement of the Hartland jam, which stopped at Lower Becaguimec Island, the water level at Hartland continued to increase until 21:35 hours on March 31. Then the ice at Lower Becaguimec Island moved again, and the water level dropped. As the Hartland water level dropped, the water level at Simonds did not change, suggesting the existence of a secondary jam above Hartland, but below the Simonds gauge. Local consolidation of the jam at Lower Becaguimec Island then took place and the Hartland water level showed no significant change until 23:00 hours, when the water level started rising again, reaching a peak of 47.7 metres at 01:00 hours, April 1. At 01:20 hours, April 1, the water level at Simonds started to subside when the jams below Simonds and at Lower Becaguimec Island released. The water level at Simonds fluctuated between 46.6 and 47.3 metres for the rest of the day. The water level at Woodstock rose rapidly while the level at Hartland dropped as the Lower Becaguimec Island jam moved. The jam stopped in the west (main) channel at the Sharps Island railroad bridge. By 11:00 hours, the water level at Hartland was rising again because of that jam. The jam in the west channel at Indian Island diverted a large amount of the river flow to the east (secondary) channel causing the undermining of one pier and the west abutment, and as a consequence, the collapse of two bridge spans occurred at about 11:15 hours. After the bridge failure, banks in the east channel eroded, and some ice from the jam in the west channel moved to the east channel. By 14:45 hours the ice was clear from the east channel, but it was still lodged against the bridge piers in the west channel. At noon on April 1, ice was lodged at the Woodstock pumping station and the water level behind the jam was rising. At 13:00 hours, the jam moved to lower Woodstock and then to the Bulls Creek area. On April 2, shortly after the dislodgement of the Upper Guisiguit Brook jam, the Beechwood outflow peaked at 8 800 cubic metres per second at 10:30 hours. The inflow to the Mactaquac headpond peaked at 16:00 hours later the same day at about 9 700 cubic metres per second. As the ice released from the Beechwood headpond reached Simonds and Hartland, the water level in these areas increased to reach secondary peaks, at approximately 13:00 hours. When that ice arrived at the Bulls Creek jam, the Trans Canada Highway near Bulls Creek was innundated. At 13:45 hours, the jam at Bulls Creek released. At 16:35 hours, the ice was observed moving near Temple before it stopped at its final lodgement point at Sullivan Creek. When the Bulls Creek jam released, the water level at Woodstock dropped. At 22:00 hours, the Woodstock water level rose again because of the Sullivan Brook jam. On April 3, the water level continued to increase at Woodstock, forcing the closure of the Trans Canada Highway at Bulls Creek at 02:00 hours. Because of the Sullivan Brook jam, water levels rose once again until 11:00 hours. At 19:00 hours, the rising water level at Woodstock reached its maximum level of 43.9 metres, which was the highest on record. After 21:00 hours, it started to drop gradually. During April 4 and April 5, the Sullivan Creek jam gradually eroded, resulting in lower water levels everywhere upstream. Saint John River, below Mactaquac: Even though water levels below Mactaquac were relatively high, it was evident that the flooding below Mactaquac was not caused by ice jams but was an open water event. In terms of frequency, the maximum water level at Fredericton (7.817 metres) was the third highest open water flood on record, ranking only behind 1979 and 1973 when water levels were 8.062 and 8.608 metres respectively. Nashwaak River: During the last week of March, the ice cover between Stanley and Nashwaak Bridge began to deteriorate quickly due to the mild temperatures and rain. On March 28, the ice cover began breaking up and moving downstream, creating an ice jam situation in the Stanley area. By March 31, water began flooding in and around several houses on the west bank of the Nashwaak River at Stanley, forcing some residents to evacuate. The ice then moved out of the McLaggan Bridge area, to stop about 1.6 kilometres north of Nashwaak Bridge. The ice cover at Nashwaak Bridge had moved slightly, but was still unbroken. On April 2, the ice jam at Stanley had released by 15:00 hours and moved downstream approximately 10 km through the McLaggan Bridge area and jammed again on the north tip of an island about 0.5 km upstream of Nashwaak Bridge. This forced water and sheets of ice over the west bank of the Nashwaak River onto Route 107, blocking the highway overnight. The jam moved out of the Stanley area at 15:00 hours, April 3, and the floodwaters receded very quickly in the Stanley area. The downstream movement of the ice jam caused significant flooding of the west bank of the Nashwaak River onto Bubar Flats and points further south. By April 4, there was an open water situation in the Stanley and Nashwaak Bridge areas. On April 1, increased flows raised the ice cover and caused flooding in the areas between Nashwaak Bridge and Taymouth. No houses were endangered except for one cottage on the northwest bank at Taymouth. By April 5, the ice had moved through the Taymouth reach of the river, leaving open water and lower water levels. Nashwaak River, Taymouth to mouth: By April 4 the ice jam previously located at Nashwaak Bridge had moved downstream to the McBean Brook area where it jammed, forcing flood waters over the west bank of the Nashwaak River, flooding the Edney Flats, and encircling four houses and a barn. By April 1, the ice moved downstream of the Durham Bridge area and stopped just south of Roberts Restaurant, causing another ice jam, which diverted water over the east bank of the river flooding the lowlands. On April 2, this ice jam diverted water over the west bank into Nashwaak Village. The resultant floodwater over Route 8 was not deep enough to close the highway. On April 4, at about 20:00 hours, the ice jam situated near McBean Brook let go, and the ice went through the Durham Bridge/ Nashwaak Village area, moving the ice jam situated south of Roberts Restaurant, and creating an open water situation from Stanley to the Marysville Dam by April 5. Accumulated ice between the Marysville Bridge and the Barkers Point bridge caused flooding in the Marysville and Barkers Point area of Fredericton. This situation remained for several days, and by April 9, the ice had moved out of the Nashwaak River into the Saint John River, creating an open water condition in the Nashwaak River from the Union Street bridge to Stanley and points further north.The Union Street underpass was also inundated. Kennebecasis River Basin: During the mid-morning of April 1, an ice jam formed at Norton. Water levels rose rapidly, nearing some houses, but none were flooded as the jam broke by mid-afternoon. The ice moved downstream to Bloomfield where it jammed again. The water level was very high, coming within 0.3 metres of the Bloomfield covered bridge and very close to covering the section of road between the two bridges, before receding on April 2 when the jam broke. The valley flooded from McCully Station to Roachville, and in the Fox Hill-Apohaqui area. The road near the covered bridge at Plumweseep was flooded to a depth of 0.2 m to 0.3 m. High flows caused Smiths Creek to overflow its banks at the covered bridge near its mouth, but only hay fields were affected. Water levels on Trout Creek at the Maple Avenue bridge in Sussex rose two metres above normal, due mostly to the inflow from Parsons Brook and Wards Creek. The Kennebecasis River at Penobsquis began overflowing its banks on April 3. This was attributed to high flows on the South Branch of the Kennebecasis River. By April 5, much of the snowcover in the area was gone, and water levels in all areas except Hampton decreased slowly. The levels at Hampton increased, slowly creeping into the back yards of homes near the river banks. Although levels began to drop on April 13, they remained higher than normal, and this was attributed the effects of downstream ice conditions. Northeastern New Brunswick: On April 2, an ice jam resulted in the flooding of three homes and four camps along Middle River. The flooding occurred near Bathurst, about six miles [about 13 km] from the St. Anne Street and Middle River Road intersection. Three families were evacuated for six days. The jam was described as being about 1 000 feet [about 300 m] long, and occurred near an island and an "S" turn in the river. The floodwaters were over two feet 0.6 m] in depth.
General: The effect of high spring flows was greatly magnified in many locations by the large backwaters created by the ice jams. Since much of the flooding was caused by ice jams, it is difficult to relate the magnitude of the flooding to river discharge and their return periods. Subsequent failure of the ice jams occassionally created very high instantaneous flows. Saint John River Basin: In Perth-Andover, water levels peaked at 79.3 metres on April 2, the highest on record. On April 2, following release of the ice jam at Upper Guisiguit Brook, the water level at Beechwood Dam increased by over three metres in less than 20 minutes, causing the dam to spill ice for the first time since the plant began operation in 1957. This surge at Beechwood resulted in discharges from the dam of approximately 5 300 cubic metres per second to 8 800 cubic metres per second between 09:00 hours and 10:30 hours. This represented a 65% increase in discharge in 90 minutes. The water level at Woodstock peaked at 43.9 metres on April 3, the highest on record. The water level in Fredericton exceeded six metres from April 1 to April 10, and peaked at 7.817 metres on April 2. Kennebecasis River Basin: At Rockville, the highest water level observed was 0.15 m below the staff gauge at the Bell bridge. The road near the covered bridge at Plumweseep was flooded to a depth of 0.2 m to 0.3 m.
Approximately $30 million in direct and indirect damages has been conservatively estimated for the Saint John River Basin. Some 483 claims for disaster assistance were processed for payments totaling $8 650 936 of which the Federal Government contributed some 65.4%.