June 25, 2014
Province Announces Lake St. Martin Emergency Outlet Channel will Reopen
– – –Over 200 Per Cent of Average Rainfall Swells Lakes, Rivers: Minister Ashton
Work will begin as early as July 2 to reopen the Lake St. Martin Emergency Outlet Channel following record rainfall over the last few months, Infrastructure and Transportation Minister Steve Ashton announced today.
“Many areas of Manitoba, Saskatchewan and northwest Ontario have experienced record rainfall in the last while which has resulted in abnormally high levels on lakes and flows on rivers here,” said Minister Ashton. “The emergency channel operation has received necessary approvals and consultations have been initiated. Opening the channel will drop the level of Lake St. Martin and in turn, through the Fairford River, allow a drop in the level of Lake Manitoba.”
Minister Ashton noted the federal government has approved the operation of the Lake St Martin Emergency Channel if lake levels reach 803 or more feet above sea level (fasl). Those levels are expected to be reached as early as July 2. The process will take approximately five days to reopen the channel. He added activities to this point include:
- receiving approval from federal agencies to reopen the channel;
- ongoing consultation with First Nations;
- positioning equipment for a quick start of the reopening process;
- removing debris from Buffalo Creek downstream of the channel; and
- setting up a channel flow monitoring system.
Lake St. Martin Emergency Outlet Channel
The initial discharge will be approximately 5,600 cubic feet per second (cfs) and this operation will likely be in place until spring 2015. With forecast normal weather on Lake St. Martin, elevations with the outlet channel operating will be 801 fasl to Oct. 31, maintaining near 801 fasl around March 31, 2015.
The maximum benefit of the channel operation for Lake St. Martin under a normal weather scenario is approximately a 1.2-foot reduction, and with a wet weather scenario, 1.5 ft. The maximum benefit of the channel winter operation for Lake Manitoba, with normal weather would be about half a foot and with wet weather, six-tenths of a foot. Future forecast normal weather Lake Manitoba elevations with the outlet channel operating will be 812.70 fasl by Oct. 31 and by March 31, 2015, 812.10 fasl.
“The province may also operate the Portage Diversion and the Red River Floodway if the combination of more rain and increasing river flows occurs,” added Minister Ashton. “The heavy rain in northwest Ontario has dramatically increased water levels on Rainy Lake, which drains into Lake of the Woods which in turn drains into the Winnipeg River and into Lake Winnipeg.”
Whiteshell
Areas of the Whiteshell have experienced heavy rain. The Winnipeg River system is experiencing very high flows due to significantly higher than normal precipitation in eastern Manitoba and northern Ontario. The Lake of the Woods Control Board has been directing a series of outflow increases from the dams at the outlets of Lake of the Woods and Lac Seul in response to these conditions, with a goal of balancing the high inflow conditions being experienced throughout the region.
Nutimik Lake, which is part of the Winnipeg River system, is at 907.9 ft., a record high level on the lake. The water level at Nutimik Lake is expected to rise by four to six inches over the next week but this increase may be higher if heavy local rainfall occurs.
Manitoba Conservation and Water Stewardship will be contacting campers, cottagers and property owners regarding water levels.
Portage Diversion
The operation of the Portage Diversion will depend on wet weather and increases in outflows from Shellmouth Diversion. Readings near Brandon are slowly increasing. However, the Souris River and Assiniboine River tributaries between Brandon and Holland are on the decline. The diversion would be operated to maintain 10,500 cfs along the lower Assiniboine from Portage downstream. If the diversion is operated, about 1,000 cfs would be sent along the channel, which would increase Lake Manitoba levels one-sixteenth of an inch after a month. The lake is currently 1.8 ft. below natural levels as a result of Fairford Channel draw down.
Red River Floodway
The Red River at James Avenue is forecast to go up to 16.7 ft. and will stay above 14 ft. until mid-July. Further heavy rain could require an operation of the floodway to help reduce basement flooding in Winnipeg.
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