HISTORICAL NEWS SEARCH - Government of British Columbia

Early June 1993
Event type: Spring runoff flooding.
Precipitation: Smithers (126.8 mm/30 days), June 1993.
Source: Terrace Review, June 6, 1993; The Interior News, July 7, 1993.
Early June some flooding occurred in the Terrace area. According to Mike Zylicz, North Coast Road Maintenance
manager, flooding was a real concern in some areas. Part of Usk flooded but the situation was not nearly as serious as that in
Prince George and the Fraser Valley. There was 1 ft. (30 cm) of water on the road near Old Remo. The Greenville Road was
flooded but this was considered more an annual than an emergency event. Flooding at the Esker overpass construction site on
Highway 16 west of Terrace was only prevented when workers used fill from the overpass approach to raise the level of the
detour there.
Smithers recorded the wettest June on record. A total of 126.8 mm of rain fell, breaking the previous record of
113.5 mm set in 1946. *1) During the wet periods, just after June 1 and around June 22, logging operations and road
building in the Kispiox Forest District were shut down.
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*1) The average rainfall for Smithers for June is 42 mm (The Interior News).
September 6-7, 1993
Event type: Glacial outburst flood.
Precipitation: Not applicable.
Source: Eero Karanka, pers. comm. Dept. of Fisheries and Oceans, Prince Rupert, B.C.; D. Diana, pers. comm. Skeena
Sawmills, Terrace, B.C.
During the late afternoon or early evening of September 6, in the Kitimat Range an ice dam break and subsequent
rapid draining of a lake from beneath the glacial ice occurred. Close to the source, sediment was deposited over banks and in
backchannels.
On the morning of September 7, a sediment slug or a wall of mud was observed moving down the Kitimat River.
The event was apparently first noticed around 10 a.m. by a field crew at km 17 of the Kitimat Main (River km 53). Around 2
p.m., the discharge reached the 8 km bridge at MacKay Creek (River km 43.3) and the Highway 37 bridge (River km 38.3
km) around 3 p.m. Dino Diana, Skeena Sawmills field operations supervisor, also estimated the plume covered a distance of
15 km. At its junction with the Kitimat River he reported seeing muddy backwaters, and signs of flooding in the trees,
including a “blackish ooze.”
When first noticed the sediment slug had traveled some 25 km. The rate of movement of the front of the plume
down the Kitimat River between the time it was first spotted and the time it arrived at the mouth was estimated at 2.5 km/h. If
the plume was 15 km long and moved at the same speed since its arrival in the Kitimat River, it took six hours to form,
beginning in the late afternoon or early evening on September 6. (Karanka, pers. comm.).
The source was determined from a glacier within the Kitimat Range. According to Dr. J.J. Clague, since small
glaciers tend to be more fractured from their surface to their base, they may be more susceptible to in-glacier ponding. If the
drainage channels become temporarily plugged water can build up in the fractures and then release when sufficient hydraulic
pressure builds up.
On September 8 at 11 a.m. a large sediment plume was evident at the mouth of the Kitimat River (E. Karanka,
pers. comm.). The Fish Hatchery at Kitimat reported that the water was dirty, but diluted by the time the plume reached
Kitimat.
November 1-2, 1993
Event type: Landslides and flooding.
Precipitation: Prince Rupert A (115.4 mm/2 days), November 1-2, 1993; Prince Rupert M. Circ. (126.1 mm/2 days),
October 31-November 2, 1993; Terrace A (93.2 mm/2 days), November 1-2, 1993; Kildala (58.1 mm/1 day), November 2,
1993.
Source: Prince Rupert This Week, November 7, 1993; The Daily News, January 19, 1994.
Two days of torrential rains accompanied by strong winds caused two slides near Prince Rupert. The largest one
came down at 12:30 p.m. on November 1, on Wantage Road ca. 100 m past the Mount Hays gondola chalet. An empty
World War II vintage concrete building helped channel the flow of mud and trees into a ravine behind the old city dumpsite.
The slide, which funneled down near the disused BC Tel dynamite shack, caused the closure of Wantage Road past the city
yards. It narrowly missed the BC Hydro powerlines along the road. A smaller slide came down on November 2, from the
middle of the cut on the gondola path and into the trees, causing no damage to the road.
A geotechnical report released on January 17, 1994, recommended to reduce risk to the public, the Mount Hays
access road remained closed till the site could be further studied. The report from the geotechnical engineering firm Golder
and Associates of Vancouver advised there was risk of further slides in the area. The engineer conducting the survey had
been prevented from fully assessing the slopes because of high water levels shortly after the slide occurred.
November 2, flooding occurred in the Terrace area.
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