Great Lakes HIGH water levels

[Dave Lochner]

Originally Posted by ArmyDaveNY

It will be interesting to see if the higher water increases erosion at Niagara Falls. For those not familiar with the falls, during the winter and at night during the summer, the two power authorities (Canadian and US, one on each side of the falls) drain off substantial amounts of water. During the winter and at night, fifty percent is drained for power generation and during the day in the summer "just" twenty five percent is siphoned off. This diversion has slowed the erosion of the falls. The historical rate of erosion is roughly three feet per year but currently it is only one foot per year due primarily to this diversion.

As odd as it sounds, this statement is accurate. The water flow is diverted at night because fewer people view the falls at night and it does not affect tourism. Of course all of the water still ends up in Lake Ontario which receives about ~85% of its water from the Niagara River.

https://www.niagarafallstourism.com/...ver-the-falls/

[Mike OReilly]

Originally Posted by ArmyDaveNY

There has been some grumbling along Lakes Michigan and Huron about the water being released from Superior. I suspect that the will continue to release water and those down stream will have to make adjustments. The relative lack of winter will indeed help since snowfall is in essence an above ground reservoir. I am sure the shipping lines will be happy but as has been said, things go in cycles and at some point again we will complain about low water.

I wonder how much of the lower lakes' volume is due to the downstream flow and how much is just directly fed from their own respective drainage basins. Superior is the largestby far, but the single outflow is the St. Mary's River, which really ain't that big. I believe it takes hundreds of years to cycle through it's entire volume, so I bet the vast majority of Huron/Michigan's volume is due to their own drainage basins.

[GordMay]

Outflows from Lake Superior are regulated by three hydropower plants, and a 16-gate control structure called the Compensating Works, near the twin cities of Sault Ste. Marie, Michigan and Ontario. The outflow is established on a monthly basis by the International Lake Superior Board of Control (ILSBC). The outflow is set in accordance with the current regulation plan, Plan 2012. This flow can vary from 55,000 to 134,000 cfs. The plan requires that Lake Superior not be allowed to rise above 602 feet above sea level, under normal conditions.

Lake Superior declined 7 cm overall last month and Lake Michigan-Huron declined 2 cm, which are both average declines for January. At the beginning of February, Lake Superior is 29 cm above average (1918 – 2017) and 4 cm below the level at this time last year.

In consideration of the continuing high water levels in the upper Great Lakes and to accommodate expected maintenance at the hydropower plants, the International Lake Superior Board of Control (Board) requested and received approval from the International Joint Commission (IJC) to temporarily deviate from Regulation Plan 2012 this winter.

All three hydropower plants will continue to be directed to flow at their maximum available capacity, but the total combined capacity was less than normal due to required maintenance activities in December and January.

To offset the effects of these activities, over the winter months the Board will release more water through the control structure at the head of the St. Marys Rapids by maintaining a gate setting equivalent to two gates fully open instead of the typical winter setting equivalent to one-half gate open.

As a result, total flows were less than Plan 2012 in December and January, while flows greater than Plan 2012 are expected beginning this month as hydropower capacity returns to normal. The total amount of water released through the St. Marys River this winter will be approximately equal to releases called for by Plan 2012, and the net effects on the water levels of Lake Superior and Lake Michigan-Huron are expected to be minimal by spring.

The Board stresses that hydrologic conditions are the primary driver of water level fluctuations. Water levels of the Great Lakes cannot be fully controlled through regulation of outflows, nor can regulation completely eliminate the risk of extreme water levels from occurring during periods of severe weather and water supply conditions.

Plan 2012 ➥ https://www.ijc.org/en/lsbc/who/plan-2012

[ArmyDaveNY]

Gord May and Mike O'Reilly have correctly put my comments into perspective and I apologize for my poorly worded comments. You are both correct that the primary cause is the natural drainage. I absolutely agree that nature is the primary driver of the lake levels. I was wondering however how much of an effect the ILSBC has on the lake levels. I am sure that there has to be some effect but just how much.

I did a little searching and what I found basically supports the great post by Gord May. The first link listed below was published in the Lansing State Journal and is composed of information from several sources. It essentially reaffirms what Gord and Mike said about nature being the primary controlling factor, but does present other perspectives. One engineering firms suggests that dredging has allowed more outflow from the St. Lawrence due to the hard top layer being removed. The remaining sediments are more easily washed away now.

To me this supports the idea of nature as the primary factor though since the report was published in 2005, so even with any increase in outflow, the levels are higher. The US Army Corps of Engineers in a 2000 paper (linked below) says that it would take a few months to raise or lower the levels in Lake Huron/Michigan by an inch or so. The third link talks about a possible effect of shipping causing sand build up in the Sts Clair and Detroit Rivers which MAY reduce outflows.

Great Lakes water levels

https://www.nrc.gov/docs/ML0419/ML041970128.pdf

https://www.manitoulin.ca/ijc-takes-...-lakes-levels/

[Lake-Effect]

Our club has floating docks, so we get a full season regardless... but I know that more than a few Toronto-area clubs and marinas had problems with the higher levels.

Last May I was crewing with some friends around eastern L Ontario, and we visited Cape Vincent and Henderson Harbor (both in NY) and the water level had overtopped some piers and infrastructure. and flooded a few properties.

If high is the new normal, some infrastructure bucks will have to be spent.

[ArmyDaveNY]

Originally Posted by Lake-Effect

If high is the new normal, some infrastructure bucks will have to be spent.

High is the new normal. Until it isn't. From what I have seen and read, the highs and lows are somewhat cyclical and I am willing to guess that in a few years low will be the new normal, until they are not.

I remember a decade or two ago that many were concerned about the effects of the low levels on shipping and how the low levels might lead to the end of commercial shipping on the Great Lakes.

[GordMay]

Originally Posted by ArmyDaveNY

High is the new normal. Until it isn't...

While shoreline communities now (2020) gird themselves for flooding, lake levels were at historic lows as recently as 2013.
More rapid transitions, between extreme high and low water levels, in the Great Lakes, may represent the “new normal.”

“Great Lakes Levels Are Rising—a Sign of Things to Come?”
➥ https://www.nrdc.org/stories/great-l...gn-things-come

“An Assessment of the Impacts of Climate Change on the Great Lakes”
➥ http://elpc.org/wp-content/uploads/2...nge-Report.pdf

[Dave Lochner]

Originally Posted by Lake-Effect

Our club has floating docks, so we get a full season regardless... but I know that more than a few Toronto-area clubs and marinas had problems with the higher levels.

Last May I was crewing with some friends around eastern L Ontario, and we visited Cape Vincent and Henderson Harbor (both in NY) and the water level had overtopped some piers and infrastructure. and flooded a few properties.

If high is the new normal, some infrastructure bucks will have to be spent.

My marina on the S shore of Lake Ontario on June 15.

[Mike OReilly]

Originally Posted by GordMay

While shoreline communities now (2020) gird themselves for flooding, lake levels were at historic lows as recently as 2013.
More rapid transitions, between extreme high and low water levels, in the Great Lakes, may represent the “new normal.”

“Great Lakes Levels Are Rising—a Sign of Things to Come?”
➥ https://www.nrdc.org/stories/great-l...gn-things-come

“An Assessment of the Impacts of Climate Change on the Great Lakes”
➥ https://elpc.org/wp-content/uploads/...nge-Report.pdf

This is certainly consistent with the predictions of rapid climate change.

[Durangutan]

Coincidentally, I just stumbled onto a YouTube channel called “Great Lakes Now” ( https://www.youtube.com/channel/UCNm...VqLRL4ixUH3PJg ) yesterday afternoon. Among other things, they discuss the high water levels, it’s cause and effect, etc.

[SVWalker]

I'm glad where my marina put my boat last fall was the most dry area of their outdoor storage. even when it would rain and the highway, parking lot and part of their yard was flooded the spot mine is in was dry it's the highest point on their property I think.

[Mike OReilly]

Originally Posted by Durangutan

Coincidentally, I just stumbled onto a YouTube channel called “Great Lakes Now” ( https://www.youtube.com/channel/UCNm...VqLRL4ixUH3PJg ) yesterday afternoon. Among other things, they discuss the high water levels, it’s cause and effect, etc.

Thanks for this. Good series. The final chapter of the water levels vids are very informative. The IJC guy goes into detail about how much water they can let out of the Cornwall dam. He says that they've hit their record outflows in both 2017 and 2019.

He further says the absolute maximum outflow is a small portion higher, but at that level they risk catastrophic erosion of ecosystems and infrastructure (meaning the dam). So by that I interpret that that they can't really increase the outflow much more to lower Lake Ontario.

The problem, according to the IJC folks, is that there's just too much precipitation coming into the basin. The one prof makes a clear connection to climate change.

It's gonna be another not-so-fun season for a lot of Great Lakes folks.

[thruska]

Well now may be the correct time to sell some supertanker loads of water , off Ontario , to China and Europe . Win - win.

[GordMay]

Greetings and welcome aboard the CF, SVWalker.

[capt jgw]

Originally Posted by roverhi

My parents had a cottage on a bluff on the East Shore of Lake Michigan. It had been built in the '20s and was a hundred feet or so from the edge but nearly fell into the Lake during a period of High water in the '70s. They eventually had to move the cottage as far back on the lot as they could as the bank eroded nearly to their front porch. Wonder if that cottage is still there???

Maybe not. Several have fallen off the edge or been torn down.