deep water

May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
i just read that lake michigan and lake huron will be a foot higher over datum this summer than last year.
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY

DougM

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Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
This was last summer. The deck of my boat was even with the walk on top of the seawall.
My place is 500 yards from Lake Michigan. If the lake level is that much higher now, I will be stepping up to get onto the boat. A few years ago I had to build a set of “steps” into the seawall to get down to the boat, and we were talking about having to dredge the marina. It goes in cycles.
164B20C3-26FB-4D9A-B094-A868C58FDFBF.jpeg
 

capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
Whoda thunk?
I always figured you lake sailors didn't have the same problems us lesser saltwater sailors do.
 
Apr 11, 2010
946
Hunter 38 Whitehall MI
We
Whoda thunk?
I always figured you lake sailors didn't have the same problems us lesser saltwater sailors do.
Well we don’t have tides but we have experience record low and record high water levels within a relatively short period of years. A few years ago we had record lows to point where marinas were racing to dredge. As we were planning for spring launch it was touch and go that my 5 foot draft boat was going to be bumping bottom in my slip. We had a really wet rainy April and the lake gained over a foot in depth in just one month. That’s an amazing volume of water when you factor in the size of the Lake Michigan / Lake Huron system.

And then we have had this thing called a seiche. DougM can tell you about that as Manistee where he’s located took the brunt of that a while back. Reports were that the surge of water wiped out most of the municipal marina, several private marinas, and part of the board walk on the Manistee River.
 
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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
On the ocean the tides are fairly predictable and on short cycles. On the Great Lakes there are long term variations and short term variations. As @quadrille38 noted, we get seiches. These are caused by frontal passages with the lakes acting like a bathtub. Air pressure and winds drive water to the opposite (usually East) end of the lake and then the water sloshes back and forth like in a bath tub. One day I watched the water level in Oswego, NY drop about 3 feet in a very short time as a front approached. It was pretty amazing.

Here's a link to the water level monitoring station in Oswego, NY. You can see when todays front passed as the lake level increased. https://tidesandcurrents.noaa.gov/map/index.shtml?id=9052030

The seiches are short term effects and don't cause much concern. The bigger issue for us at the low end of the chain is water level on the upper lakes. Lake Superior's level is controlled by the Sault Set Marie dam and locks. After that there is no control until the water reaches the St. Lawrence River. When the upper lakes are high that water flows unimpeded down to Lake Ontario. The St Lawrence River Dams have to control water levels to protect shore lines and to provide safe navigation for the freighters. If the dams allow too much water to flow the current in the St. Lawrence becomes too fast for safe navigation and it floods Montreal.

Because Lake Ontario is the smallest of the lakes there is a multiplier effect. I did the math awhile ago (so I may be off in remembering) but Lake Erie is about 1.5 times the size of Ontario, so 1 foot of water on Erie is about 1.5 feet on Ontario. the Michigan/Huron system is much much larger, so the effect of high waters on those lakes is considerably greater. Throw in a wet spring and it spells trouble for us. The worst was in 2017, that's when the photo I posted earlier was taken.
 
Nov 8, 2007
1,523
Hunter 27_75-84 Sandusky Harbor Marina, Ohio
Lake Erie is forecasted to be 4 1/2 feet over chart datum next month! Not worried about our marina, but expect to see shrinking beaches in the Islands this summer.
 
Jan 13, 2009
391
J Boat 92 78 Sandusky
Hey Dlochner. Lake Ontario is 30% smaller than Lake Erie in surface area but Lake Ontario has 3 times the water volume- 393 cu mi vs 116 cu mi. Your theory on the multiplier effect might be a little off.
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
The surface area is what matters in terms of adding water height. Think about a graduated cylinder - Adding 1 mL of water will raise the level by the same height whether the water is close to the bottom or the top.
 
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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Hey Dlochner. Lake Ontario is 30% smaller than Lake Erie in surface area but Lake Ontario has 3 times the water volume- 393 cu mi vs 116 cu mi. Your theory on the multiplier effect might be a little off.
It is the surface area that matters.
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Let me expand on my earlier answer a bit.

Imagine you have an area of 130 square feet covered with water 1 foot deep. That gives you 130 cubic feet of water.

If you take that 130 ft^3 of water and place it in a container that is 100 square feet the water will be 1.3 feet deep.

Same thing happens to the lake. The bottom doesn't change its position relative to sea level, the surface of the water is higher.

Some may find it interesting that the deepest point in Lake Ontario is about 550 feet below sea level. A large amount of the lake's bottom is below sea level. The average surface is about 246 feet above sea level and the average depth is 283 feet.
 
Oct 22, 2014
352
Pearson P303 #221 RockPort Maine
I would say that its "conservation of water" fault. See it all started when we disrupted the recycling process much like our new wells that have a good flow rate at the start that's calculated in seconds to assure a continued and supporting earth filtered water is met. This means all water on earth gets absorbed thus building a water table to be used by us. Now, when you disrupt the flow or the recycling efforts with dumping chemicals and water conservation it has to take a toll on water tables being abnormal and higher causing our oceans, streams, lakes, and rivers likewise to reverse its normal process. Why take a look at California dried up when it does rain, it floods not being absorbed by just rain! IF you take 2 glass that is half full and a paper filter over the opening of one glass and proceeded to dump the other glass into the filtered covered glass how much water will go through the filter and into the glass? The answer is about 5 tablespoons the rest will flow off and onto your floor. Why? That's because the filter is acting like "the earths soils" after it's saturated it always takes the lower resistance and move on. This is all a good thing. However, Now you add any oily substance to the filter and now you have only 1/4 teaspoon of the water from the glass. thus, even more, water went onto the floor. Now the water table is lower and starving for more water to feed the people water. So you say I Knew It! Fossil fuels that the issue coating our earth like the glass and filter examples. The real truth is in the cover or blanket that we have put on the earth surfaces like more roads, wider roads, bigger parking lots, bigger and more malls and let us not forget big cities. so where does the water go when it rains? Well, it doesn't go into the ground but floods to our lakes and oceans. IMO
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
There's would also be a topological consideration. If the banks are steeper on one lake than on another, the same change in volume between two equal sized lakes may not translate to an equal change in height. The Great Lakes cover a vast amount of area and differences in terrain are to be expected.

-Will (Dragonfly)
 
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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
There's would also be a topological consideration. If the banks are steeper on one lake than on another, the same change in volume between two equal sized lakes may not translate to an equal change in height. The Great Lakes cover a vast amount of area and differences in terrain are to be expected.

-Will (Dragonfly)
The effect has nothing to do with volume, it is all about surface area. You are correct however, in that shoreline contours will have an effect in that funnel shaped shorelines increase the surface area, whereas steep vertical shorelines don't. Shoreline variation has a local effect especially with erosion.

Comparing Erie and Ontario there is 30% difference in surface area. In order to accommodate that 30% difference water would flood several miles inland. If that should ever happen, I don't want to be here.
 
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