Lake levels

[bgallinger]

The US Army Corps of Engineers has published recent findings on lake levels. Right now lakes Erie, Ontario and St.Clair are down 20 inches+ from a year ago. Forcasts are showing lake levels to rise just inches above datum. My guess is we will be dealing with thin water levels in the Great Lakes this year.
Any thoughts?

[Teknav]

When fresh water levels go down, ocean water will move in and replace it. Look at Egypt's Nile delta; the sea has converted a portion of the Nile into a waste land salty marsh. Look at the mouth of the Mississippi river, the Gulf has seeped in, as not enough river water is keeping "the ocean at bay". That is what is going to happen to the Great Lakes; it is just a matter of time. Mauritz

[tropicalescape]

Originally Posted by bgallinger

The US Army Corps of Engineers has published recent findings on lake levels. Right now lakes Erie, Ontario and St.Clair are down 20 inches+ from a year ago. Forcasts are showing lake levels to rise just inches above datum. My guess is we will be dealing with thin water levels in the Great Lakes this year.
Any thoughts?

I read somewhere that there were places in the southern Great Lakes area that were no longer considered "water front"..cant get to the water from some piers that were accessable just a few yrs. ago...

[roverhi]

Unless water has begun flowing up hill, the Great Lakes aren't going to see salt water anytime soon. The Great Lakes are hundreds of feet higher than sea level.

The Great Lakes go up, the Great Lakes go down. They are dependent on rain fall over a fairly large area of the mid west for their water. We had drought last year so the lake levels dropped. In the early '70s, lake levels were too high. If there is a normal winter snow fall and rains this year, lake levels will be back to normal.

Originally Posted by Teknav

When fresh water levels go down, ocean water will move in and replace it. Look at Egypt's Nile delta; the sea has converted a portion of the Nile into a waste land salty marsh. Look at the mouth of the Mississippi river, the Gulf has seeped in, as not enough river water is keeping "the ocean at bay". That is what is going to happen to the Great Lakes; it is just a matter of time. Mauritz

[Nicholson58]

Originally Posted by Teknav

When fresh water levels go down, ocean water will move in and replace it. Look at Egypt's Nile delta; the sea has converted a portion of the Nile into a waste land salty marsh. Look at the mouth of the Mississippi river, the Gulf has seeped in, as not enough river water is keeping "the ocean at bay". That is what is going to happen to the Great Lakes; it is just a matter of time. Mauritz

The Great Lakes are generally about 500 feet above sea level. Not only would water totally have to leave the lakes but Niagara Falls would have to flow backwards. You probably also think we fight off wolves and wild indians every winter.

The Lakes were way low once in my lifetime when I was about 8 and according to the old timer we rented from, also about 50 years prior to that. It may be really inconvenient, but this happens on a regular basis. The major difference since then is that the Corps of Engineers dredged the river at St Claire Lake. The inrush scowered out the new channel significantly deeper than planned and now L Michigan and L Huron are painfully lower than any of the other lakes. (go figure) This might have been tollerable in times of surpluss waterfall but presently, it represents a significant percentage of the available water. Evaporative losses added to that have forced levels too low for many of us to get to our slips next season. We will easily get into Lake Muskegon as the channel is deep for ocean going ships but the private basins are a wreck. In many, it is not a matter of additional dredging because that would undermine sea walls and pilings. We draw 6'-8" and I can almost walk to our slip from the nearby trailer launch. We pulled out a month early for lack of water.

[silversailor]

In November Lake Michigan hit record recorded lows. Since evaporation takes about 30" off the Lake each winter we need significant precipitation to replace it and cold and ice formation to protect against additional evaporation. That's not happening so expect the Lake to be lower in 2013 than last yr and the loss of depth will continue until we retn to above average rain/snow. In the South Haven harbor, one municipal marina has already been dredged and the other two, along with the channel, will be dredged, hopefully by May. It will be one of the non-commercial harbors that will be able to accommodate deep draft vessels.

[SURV69]

"Right now lakes Erie, Ontario and St.Clair are down 20 inches+ from a year ago."

Is that 20" down from this date 365 days ago?

I suffer a chronic case of wanting to remember facts as I read(past tense), them, even if I don't remember them.

But, if I remember right Lake Erie is expected to again be something like 30 or so inches above datum in 2013, although I think Lake Huron was supposed to be quite a bit less over datum.

In any case, I was at the lake yesterday and it looks to be about 1/2' above datum right now, which means it's about 2' under the high, spring & early summer level..

[Finistere]

Originally Posted by Teknav

When fresh water levels go down, ocean water will move in and replace it. Look at Egypt's Nile delta; the sea has converted a portion of the Nile into a waste land salty marsh. Look at the mouth of the Mississippi river, the Gulf has seeped in, as not enough river water is keeping "the ocean at bay". That is what is going to happen to the Great Lakes; it is just a matter of time. Mauritz

The Great Lakes are a few hundred feet above sea level, and then there is Niagara Falls, better bone up on your geography a bit. Maybe not impossible but highly improbable.

[Blue Stocking]

I can recall that in 1971 the Georgian Bay level at Midland was high enough to cover the 50ft of beach in front of a friends house. Blamed it on the C of Eng. Pissed him
right off.

Question about an earlier comment re: dredging the river > lower levels. I am familiar with volume/cross sectional/ water flow physics, but would think that there would have to be huge inconsistencies in the excavation calcs (by nature or C of E) to be responsible.
Surely, increased speed of current flow with a smaller cross sectional area would balance slower flow with larger cross sectional area.
Same amount of water controlled by head pressure. Big hose, small hose characteristics.

[Teknav]

The rise of sea levels due to iceberg melt is a well known fact. The Maldives islands, in the Indian Ocean, are expected to vanish in about 20 years or less; they already are making preparations as they will be flooded to extinction. Much of the US eastern seaboard is prone to permanent flooding within a decade or so. Where do you think, the rise in sea levels is going to move to? Granted that the Great Lakes are 500-600 ft above sea level, but they are not being replenished as they once were. In the meantime, sea levels are increasing an "inch at a time". It doesn't take a genius to figure out what is going to happen next. Mauritz

[Kenomac]

Climate has been changing since time began billions of years ago. The lake levels go up, then they go down, then the cycle repeats. The other day, I was reading a book written in 1992 on weather and disasters. At that time scientists were worried about the global cooling being caused by multiple volcanos. The world's climate is in constant change, so are lake and ocean levels.

[bgallinger]

Here is the link to the US Army Corps report. There is a forcast on the same site which is informative and shows lake levels returning to just inches above Datum in June. No mention at all about the Maldives vanishing or folks on the eastern seaboard building arks.

USACE - Detroit District - Weekly Great Lakes Water Levels

[SURV69]

Howstuffworks, has some simple calculations regarding all the ice on earth melting and indicate about 220' total rise.

Lake Erie's datum is set at 569.2', which is about 300'+ above mean sea level datum. Presently(and supposedly in 2013), Lake Erie will remain about 30" or so above datum.

Now, Lake Ontario's datum is about 243', so it could be within the realm of that lake nearing the elevation if all the ice on earth melted.

[Mike OReilly]

There is an excellent resource at the Great Lakes Environmental Research Laboratory where you look at actual data over time. A cursory examination of the trends suggests (to me) that the upper lakes (Superior, Huron & Michigan) are into a significant declining period which may be unprecedented. Since the late 1990s these lakes have been well below the long-term average. There was a similar low-level period in the late 1950s to early 1960s, but the current levels appear more stable at their low level rates.

For Erie and Ontario, what strikes me is how stable the depths have been since the late 1990s. There's more variability with Erie vs Ontario, but both appear to be hovering right around the long-term average depth. Makes me wonder if the lower lakes' water levels are being more actively managed.

So the reality indicates that the lower lakes are pretty stable around the long-term average depths, while the upper lakes are into a decline which may become unprecedented. As someone has already said, the major reasons for the lower water levels in the upper lakes appears to be decreased inflow from rain and snow, but more importantly, the increased evaporation rates due to decreased ice coverage.

According to a recent NOAA paper, "Total annual average ice cover on the Great Lakes has shown an overall decline of 71%, while the annual maximum ice cover shows an overall decline of 52% over the period 1973-2010 (38 years)." According to another recent paper published in the Journal of Great Lakes Research looking at Lake Superior's ice rates, "Analysis of the data indicates that the duration of ice cover on Lake Superior at Bayfield, Wisconsin has decreased over the past 150 years at the rate of approximately 3 days/decade or 45 days over the course of the study."

With regard to the St. Claire River dredging, the research I've read suggests that while there is some contribution to lowering Huron, Michigan and Superior, it remains a small effect compared to evaporation and diminished water inputs (rain and snow).

[Kenomac]

No matter what happens regarding the climate, water levels up, water levels down.... We always live at sea level with a beautiful water front view from our aft deck.