Lake Manitoba update: April 30, 2017

Lake Manitoba continues to rise, though the rate of rise is slowing. Strong and shifting winds this week have made tracking lake level difficult. The current estimate of the level of the lake is 813.59 feet. Natural inflows from the Waterhen (11,513 cfs) and Whitemud Rivers (978 cfs) are roughly in balance with outflow at Fairford (12,148 cfs). The continued rise of the lake stems from the operation of the Portage Diversion that the province has announced is scheduled to remain open until the end of May. The good news is that flows on the Diversion are falling steadily, currently 8,476 cfs, as flows on the Assiniboine (17,658 cfs at Holland) decline. Water is still being stored in the Shellmouth Reservoir (1399.61 feet), reducing downstream flows on the Assiniboine.

With the high inflow from Fairford, Lake St. Martin has risen and is now just under its flood level of 803.0 feet, sitting at 802.93 feet this morning.

High inflow from the Waterhen River is being maintained by the high level of Lake Winnipegosis that itself continues to rise, now sitting at 834.15 ft. Lake Winnipegosis remains well above its average level and as long as it does, Lake Manitoba will remain high.

River update
Time: 8:00 AM April 30, 2017
Portage Diversion: 8,476 cfs
Assiniboine at Holland: 17,658 cfs
Assiniboine at Headingly: 10,842 cfs
Waterhen: 11,513 cfs
Whitemud: 978 cfs
Fairford: 12,148 cfs
 
Lake update
Time: 8:00 AM April 30, 2017
Steep Rock: 813.48 ft
Westbourne: 813.70 ft
Mean level Lake Manitoba: 813.59 ft
Lake Manitoba desired operating range: 810.5 to 812.5 ft
Lake St. Martin: 802.93 ft
Lake St. Martin desired operating range: 797.0 to 800.0 ft
Lake Winnipegosis: 834.15 ft
Shellmouth Reservoir: 1399.61 ft

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Update on ALMS Activities

The ALMS executive continues to work on behalf of members. Going into the current high water season, we met with the Minister of Infrastructure reviewing existing means of managing Lake Manitoba water levels, proactive means of mitigating against wind and water events and support for municipal emergency planning.

Proactively, the Government kept the Fairford water control system running over the winter months which reduced natural inflow into Lake Manitoba. They also created water storage capacity at the Shellmouth Reservoir in anticipation of higher than average flows on the Assiniboine from Saskatchewan. They also did not use the Portage Diversion until flows on the Assiniboine warranted its use. They balanced its use with high flows on the river from Portage to Headingly. The result of these efforts is that the Lake is in better shape than if these measure weren’t taken. Since 2011, ALMS has pressured Government to follow these measures each winter, and we were very pleased to see them followed this year. We are now entering the “wet season” and Lake Manitoba is lower than it would have been without action. If we have good weather(ie. Relatively dry), the Lake is projected to peak just below flood stage.

It was clear that no new initiatives were being planned to mitigate against high water, wind and wave set up. The Government is committed to a new outlet. Your executive will be watching with interest for access roads to be constructed this year. The completion date for the outlet remains 2021.

While the Province acknowledged that ownership for GeoTubes and Super Sandbags rested with municipalities, they did encourage the municipalities last year to keep this protection in place given expected high water. ALMS met with a consultant from the Province to discuss flood preparedness as part of the municipal mandate for emergency planning. Local community councils and emergency coordinators have action plans at the ready should flooding occur.

Though flood risk at this time, is lower than originally anticipated, the risk remains high and vigilance is still needed. We understand all too well the factors that put us at risk – the Portage Diversion, natural sources and weather. Those of us who live along the lake know all too well the effect of wind and precipitation especially given that lake levels exceed the operating range. Historically high lake levels of Lake Winnipegosis result in maximum flows from the Waterhen River – a situation that will continue in the foreseeable future.

ALMS will continue to work with government on your behalf. We encourage you to work with your local municipalities/government to assist with their emergency planning. ALMS will continue to provide up to date information and data pertaining to Lake Manitoba on our website, often reposted by member Associations. The website provides important information and analysis. It also gives others and opportunity to share perspectives.

As a reminder, the government listens to ALMS and follows our website.
As is the case in all good planning – hope for the best but prepare for the worst.

ALMS Executive

Lake Manitoba update: April 23, 2017

Lake Manitoba continues to rise and has reached 813.41 feet this morning. The levels have been bouncing up and down due to shifting winds the last couple of days. The lake is currently rising about 0.04-0.05 feet per day but that will slow as flows on the Portage Diversion decline. And flows down the Portage Diversion are now falling steadily (currently 13,137 cfs) as flows on the Assiniboine (23,873 cfs at Holland) decline.

The best-case scenario is for a stretch of dry weather and the closure of the Diversion in the next 10 days. In that case, Lake Manitoba will peak at a level around 813.7 feet. With adverse weather (a storm system carrying heavy rain), the lake will quickly exceed its flood level of 814.0 feet. As a rough guide, an inch (25 mm) of rain causes the lake to rise one-tenth of a foot in a day. April is the end of the dry season in southern Manitoba and average precipitation rises quickly in May and peaks in June.

At the moment, the equilibrium level of the lake is 813.7 feet. That is the level where the current natural inflow (about 12,500 cfs) from the Waterhen (11,407 cfs) and Whitemud (1,141 cfs) Rivers, and other minor tributaries is balanced by outflow at Fairford. While flows on the Whitemud River have been falling, flows on the Waterhen River continue to rise as the level of Lake Winnipegosis rises (834.07 ft).

While the Diversion has been the proximate cause of the rapid rise in lake level in April, the stage was set by the high level of Lake Winnipegosis. Even after the Diversion closes, Lake Manitoba will remain high as long as Lake Winnipegosis remains high. Lake Winnipegosis is currently extraordinarily high, more than 3 feet above its average level. It has remained above its long-term average level continuously since January 2005. That is the primary reason Lake Manitoba remains vulnerable to flooding every time the Portage Diversion is opened for any length of time.

High inflows to Lake Manitoba causing the lake rise result in higher outflows at Fairford, currently (11,689 cfs). This in turn causes the level of Lake St. Martin to rise. It is now closing in on its flood level of 803.0 feet. The current level is 802.86 feet.

River update
Time: 8:00 AM April 23, 2017
Portage Diversion: 13,137 cfs
Assiniboine at Holland: 23,873 cfs
Assiniboine at Headingly: 12,855 cfs
Waterhen: 11,407 cfs
Whitemud: 1,141 cfs
Fairford: 11,689 cfs
 
Lake update
Time: 8:00 AM April 23, 2017
Steep Rock: 813.30 ft
Westbourne: 813.52 ft
Mean level Lake Manitoba: 813.41 ft
Lake Manitoba desired operating range: 810.5 to 812.5 ft
Lake St. Martin: 802.86 ft
Lake St. Martin desired operating range: 797.0 to 800.0 ft
Lake Winnipegosis: 834.07 ft
Shellmouth Reservoir: 1397.47 ft

Lake Manitoba update: April 16, 2017

The week has seen rising lakes and high river flows, but the end of the week brings a brightening outlook. Peaks flows on the Assiniboine reached only 39,000 cfs midweek, well below forecasts of 46,000 cfs, and have now begun to subside markedly. Flow at Holland is currently 31,000 cfs and dropping. Flows in the Diversion were also less than forecast, remaining at or below 24,000 cfs except for one brief period last Wednesday. Flow in the Diversion is now dropping currently sitting at 19,175 cfs.

Lake Manitoba is currently at 813.16 feet and rising about 0.05 feet per day with the current level of inflow from the Diversion. That rise will slow as Diversion flows fall. A gauge recalibration at Westbourne early in the week also resulted in a lower estimate of the level of Lake Manitoba.

The combined natural inflow to the lake from the Whitemud (1,342 cfs) and Waterhen Rivers (11,124 cfs) is about 12,500 cfs. When the Diversion flows end, that level of natural inflow would take the lake level to about 813.6 feet (outflow at Fairford is 12,500 cfs at a lake level of 813.6 feet). How high the lake will now reach will now depend upon the duration of the opening of the Diversion and how much rain we get.

High outflow at Fairford (10,736 cfs) continues to drive the level of Lake St. Martin higher. It currently sits at 802.67 feet.

Conditions upstream on Lake Winnipegosis remain the long-term concern. The lake currently sits at 834.07 feet, more than 3.5 feet above its long-term average level. Lake Winnipegosis is larger than Lake Manitoba and its level changes slowly. This will keep flows on the Waterhen River high for the foreseeable future. That in turn will keep Lake Manitoba high into the fall.

The Ministry of Infrastructure has continued to take every reasonable step we could have asked for to reduce the risk of flooding on the lake. Fairford was left wide open over winter, and remains wide open now. Flows on the Assiniboine have been reduced by holding water back in the Shellmouth Reservoir (currently 1395.93 feet). And MI is doing a difficult balancing act between sending water down the lower Assiniboine (which remain high) and sending it down the Diversion that increase the level of the lake. Local flooding on the lower Assiniboine starts when flows exceed 8,000 cfs and grows more significant at higher flows, as is the case right now at St. Francis Xavier, which is under a state of emergency. No matter where the water goes, it creates problems for someone.

River update
Time: 9:00 AM April 16, 2017
Portage Diversion: 19,176 cfs
Assiniboine at Holland: 31,077 cfs
Assiniboine at Headingly: 15,256 cfs
Waterhen: 11,124 cfs
Whitemud: 1,342 cfs
Fairford: 10,736 cfs
 
Lake update
Time: 9:00 AM April 16, 2017
Steep Rock: 813.06 ft
Westbourne: 813.25 ft
Mean level Lake Manitoba: 813.16 ft
Lake Manitoba desired operating range: 810.5 to 812.5 ft
Lake St. Martin: 802.67 ft
Lake St. Martin desired operating range: 797.0 to 800.0 ft
Lake Winnipegosis: 834.07 ft
Shellmouth Reservoir: 1395.93 ft

Minister Pedersen Reaches Out

Fellow members, Minister Pederson reached out personally on Thursday and spoke with ALMS Chief Scientist, Dr Scott Forbes, indicating they are doing everything they can to try and mitigate the flood waters using the controls at their disposal. 

It’s important for our members to recall that Minister Pedersen met with the ALMS executive in the fall and has continued to provide open dialogue. This winter he took actions to make sure the Fairford was left running at maximum capacity as well as empty the Shellmouth reservoir – actions which have helped reduce the severity of the current situation.  Members will recall in the fall of 2010 the opposite occurred  – the Fairford was closed and the Lake was left dangerously full and calls to counter this were ignored. 

While we at ALMS would like there to be no flood water, or diversion for that matter, and a channel built six years ago, we do appreciate openness and the efforts of the Minister. 

We will continue to press all levels of  Government to take any and all action possible to protect the people whose lives are impacted by Lake Manitoba flooding. 

ALMS Issues Flood Warning for Lake Manitoba

FLOODWARNING

The Association of Lake Manitoba Stakeholders(ALMS) as of 7am today, April 10th, is issuing a Flood Warning for Lake Manitoba to all members.

The current forecast of rain as well as current forecasts from the Hydrologic Forecast Centre of the Province of Manitoba indicate a high probability that Lake Manitoba will reach flood Levels within the next 9 days.

The strength and power of massive waves and wind tide on Lake Manitoba, which is similar to oceans, can produce waves and wind tide in excess of 5 feet.  As demonstrated by the horrific events of  May 31st 2011, flood levels combined with sustained wind and wind tide easily destroys homes, roads, and causes overland flooding.

Unlike River Floods, once Lake Manitoba reaches Flood Stage, it will take 12 to 18 months for the Flood to subside.

ALMS recommends that members take immediate action to secure and protect property as soon as possible. ALMS further recommends that members consider relocating movable property(RVs, vehicles, Trailers, mowers, etc)  sitting at an elevation below 818 feet should be moved to higher elevation.

Members are reminded that powerful waves combined with debris quickly destroy sandbag protection and should consider Super Sand bags, Heavy Rock, Geo Tubes, or other protection which is designed to protect against strong wave activity.