Tuesday, May 16, 2006
Q? Water levels of Georgian Bay in the 1600s
I was reading a newspaper article recently about local water levels and was wondering about the cycle of water level during the Ste. Marie period. Can someone point me to the commentary on the height of the Wye River at the Ste. Marie site. Someone in conversation suggested that it was 10-12 feet higher than today. This might have implications regarding the location of some villages. It might also affect line of sight between Ste. Marie and the burning village as decribed regarding the death of Brebeuf and Lalemant. Thanks...Bill
Subscribe to:
Post Comments (Atom)
10 comments:
I believe the Wye River was four feet higher than it is now (or as in 1950). I believe I read somewhere in Fr. Hegarty's notes at the Shrine archives that the posts lining the "waterway system" had a watermark four feet higher than it was when it was discovered in 1950. I do not know if or by how much modern damming systems north of Huronia effect the water levels presently.
Sorry- I forgot to mention that Fr. Hegarty's excavations related to Ste. Marie among the Hurons and the waterway system discovered there.
Kenneth KIdd says on pg 85-86 in his book on the excavation of Ste. Marie 1 "In 1941 the water level of the Wye stood at 578 ft. or 5 ft.lower than the lowest point in the moat. Measurements indicate that if there were to be any water at all in the moat system, the river level would have to be at least 6ft higher than in 1941. One ft of water in the middle basin would float a canoe; and for this to come about, the river level would have to rise 7ft. A rise of 10ft would flood the moat to a depth of 3ft near the eastern terminus and bring the water table to within 1ft of the surface."
A F Hunter speculates in his notes on village sites in Tay (1901)that the water level must have been 12ft higher for the canal to have functioned durring the time of Ste. Marie's occupation.
Bruce Trigger in his book Children of Aataentsic indicates that there was a foot of water in this channel at the time it burnt based on the burnt off states that were used to retain the walls of this moat. His observations were made in 1979 and he indicated that the water level at that time was within a foot of the base of the moat. 1979 was a moderatly high level year.
This year is at an extreme low and the trend would appear to be lower over time with a lot of up and down cycles to confuse the issue.
Some say that if the water level was up by 12ft over today that Ste Marie would have been totally flooded. There is no doubt that it was wet, hense the drainage ditches running threw the site, but these opinions do not take into account the absoption value of the wetland that currently backs onto the site. This wetland was described as a lake by the Jesuits. Even today the Wye Marsh is held back be small weir.
If one does accept the higher water levels of 10-12ft then there is no doubt that this would result in a dramatic to the current shoreline and adjust where we might search for some of the ancient landing places, fishing camps and related villages.
Good question Bill, this subject needs more attention.
We are assuming that the waterway system was part of the Ste. Marie complex. I think that the Wye Marsh interpretive centre might have a definitive answer to this important question. I do not know if recent building developments in the region have affected drastically the flow of water, run offs etc.
Regarding the water system at Ste. Marie- it was fed by a fresh water spring which was directed from the source by an aqueduct. The source of the spring is from the hill across the highway where Martyrs' Shrine stands now. The Shrine grounds still uses the spring as its water source.
Presently at Ste. Marie, the water is being pumped from the Wye R.. The Wye Marsh interpretive Centre may have the answer to water levels in the 17th Century.
More on water levels;
Large Permanent Drop Discovered In Huron and Michigan Lake Levels
Press release - January 24th 2005
“A Bigger Drain Hole in the Great Lakes Threatens Region’s Environment, Economy”
TORONTO, ONTARIO (January 24)— Shoreline alteration, historical aggregate riverbed mining and navigation dredging are resulting in ongoing erosion at the bottom of the St. Clair River and have resulted in the permanent and continuing lowering of water levels on Lakes Michigan and Huron, according to a new report issued today.
“In 1962, a shipping channel was dredged out of the St. Clair River that effectively opened a bigger drain hole in the Great Lakes,” said John Pepperell, president of Georgian Bay Association, a Canadian non-profit organization which coordinated the six-month study by W.F. Baird & Associates Coastal Engineers for GBA Foundation, a registered Canadian research charity. “Everyone knew about the one-time loss of water that was caused when that channel was first opened. However, we have now discovered that ongoing erosion is making the outlet from Lake Huron larger, allowing water to leave faster than had been recognized.”
According to the report, the channel is eroding and is now over 60 feet deep at critical sections near the outflow. It only needs to be 30 feet deep for shipping. Pepperell said that “without implementation of corrective measures, this drop represents an irreversible and ongoing decline in the long-term average levels of Lakes Michigan and Huron.”
W.F. Baird & Associates found that declines in actual water level since the mid 1800s in Lakes Michigan and Huron are double the latest International Joint Commission (IJC) estimates. According to Baird, the amount of water permanently withdrawn from the entire surface of Lakes Michigan/Huron is close to 80cm or 32 in. That is the equivalent of 28 times the volume of water in Lake St. Clair or ¼ the volume of water in Lake Erie.
“The recent riverbed erosion is unprecedented, even on a geologic time scale,” said Rob Nairn, author of the report. “It has led to a significant lowering of Lakes Michigan and Huron with corresponding implications for the economy and environment.”
Lower lake levels impact the amount of cargo that ships can transport through the lakes, the access and value of property along the shores, and the quantity and quality of habitat for wildlife. The report’s findings also have legal implications under the 1909 Boundary Waters Treaty.
“This report is a wake-up call,” said Georgian Baykeeper Mary Muter. “In recent years we have had a significant number of wetlands dry up on Georgian Bay, and the aquatic life forced out onto steep granite shorelines among the 30,000 islands cannot survive. Continued low water levels will threaten an already declining fishery. We need to protect the ecology and economy of this region, and we’re asking the Canadian and U.S. governments to take appropriate action and stop the water loss from our lakes.”
For two generations the continuing decline resulting in permanent withdrawals has gone undetected by the U.S. and Canadian governments and the agencies charged with monitoring Great Lakes water levels (the IJC, U.S. Army Corps of Engineers and Environment Canada).
In part, the problem was masked by the cyclical high water levels that dominated from the mid 1970s, through the 1980s and into the 1990s and may be related to government cutbacks in funding for the important monitoring of the finite resource we have in Lakes Michigan/Huron.
The report comes at a time when the IJC is undertaking a study of the Lower Great Lakes and the U.S. Army Corps of Engineers and Transport Canada are studying the future prospects for Great Lakes commercial navigation. The government agencies will now have to re-calculate the math for outflows and net basin supply numbers (precipitation, runoff minus evaporation, diversions and outflow).
“This report serves as a cautionary tale to those who want to tinker with our Great Lakes,” said Tim Eder, the National Wildlife Federation’s director of Water Resources. “You can’t fool Mother Nature. We can’t keep dredging deeper channels for navigation without serious repercussions for the people and wildlife who depend on Great Lakes waters.”
“The Great Lakes are more than simply a navigation corridor, and the time has come for the management of the lakes to reflect that,” said Jennifer Nalbone, habitat and biodiversity coordinator for Great Lakes United, a bi-national environmental organization. “We have to stop treating the Great Lakes as though they can be literally molded to fit our short-term economic desires. We need a transportation system that fits within the physical confines of the Great Lakes ecosystem, not vice versa.”
The study takes into account other factors which influence lake levels, including fluctuations in precipitation and the effects of glacial rebound—the rise of large masses of land that were depressed by the huge weight of ice sheets during the last ice age. The study shows that levels in Lakes Michigan and Huron have declined more than can be attributed to any factor other than erosion of the St. Clair riverbed.
Lakes Superior and Ontario have control structures to manage lake levels under a variety of climate conditions. There are no such control structures for Lakes Michigan and Huron. Once the water is gone, it is gone.
“Today, we have sophisticated methods of monitoring available but this study clearly shows the need and importance of using and making those tools available,” said Cheryl Mendoza, from Lake Michigan Federation. “At a time when Canada and the United States are negotiating how to monitor and regulate Great Lakes water usage, we are witnessing a constant and large-scale permanent loss of water under the noses of both governments.”
GBA Foundation, a Canadian research and education charity, commissioned the report in response to concerns expressed by Georgian Bay Association’s over 4,000 member families. W.F. Baird & Associates Coastal Engineers Ltd. is an internationally respected coastal-engineering consulting firm.
“Regime Change (Man-Made Intervention) and Ongoing Erosion in the St. Clair River and Impacts on Lake Michigan-Huron Lake Levels” Technical and Non Technical Summaries are available in PDF format : ---->
For Immediate Release: January 24, 2005
Contacts:
Mary Muter, Georgian Baykeeper for GBA Foundation, 416-489-8101
John Pepperell, Georgian Bay Association 416-983-3721
Jennifer Nalbone, Great Lakes United, 716-213-0408
Cheryl Mendoza, Lake Michigan Federation, 616-850-0745
Tim Eder, National Wildlife Federation, 734-769-3351, ext. 25
Jordan Lubetkin, National Wildlife Federation, 734-769-3351, ext. 49
Gregor Beck, Ontario Nature, 415-444-8419 ext. 237
Rob Nairn, W.F. Baird & Associates Coastal Engineers, 905-845-5385
Wendy Douglas, World Wildlife Fund Canada 416-484-7726
--------------------------------------------------------------------------------
©Georgian Bay Association - 2005
Re: water levels
As I have commented before there are a significant number of archaeological sites that date to 1800-2000 BC that are fairly close to modern beach lines. Furthermore if John or anyone else thinks Georgian Bay water levels were 10-12 ft. higher in 1600-1700 they must be smoking something very good indeed. Ste . Marie is completely submerged in water if those water levels are considered as accurate. Georgian Bay water levels are determined by water input from Lake Superior and rain/snow fall and evaporation rates. And while the US Army Core of Engineers have impacted the Chicago River and the St. Clair River Georgian Bay water levels remain largely the same as they have been for the last two thousand years. Yes there are seasonal and periodic flucuations but they are within historic highs and lows. Neither isostatic rebound or canal construction have affected water levels on Georgian Bay/Lake Huron. So at the time the Lakes were surveyed by Bayfield or"discovered" by Brule or Champlain you have to go back in time before the levels have appreciably changed.
Ste Maries' water system was not a Welland Canal but rather a way to remove surface water from an existing wetland. I may have played some additional defensive role related to the organization of the interior structures the well and the palisades . But to handle 25 ft. canoes for the 50 ft from the waters edge to the interior of the site, I don't think so and I didn't suddenly envision this concept either,no disrespect to Wilfrid, Kenneth or Denis.
It could be that the water levels of the 1800s and 2000 BC were similar and not too far off current levels but what I am suggesting is that the 1600 was preceded by a mini ice age and these levels may well have been higher.
Basic physics would say that if you put a larger hole in the bucket and do not increase the inflow, the levels must drop. This however didn’t happen until the mid 1960’s and can not account for the level differences noted by Kidd in the 1940’s or Hunter around 1900.
If the water levels were not up substantially, why were drainage ditches even required? Does the site get wet now? Are the ditches in use now? If not then the levels must be substantially lower now. I think that the site did flood, that the drainage ditches were required and that hence the water levels were up and the canal was a viable way of docking the canoes inside the fortification and off the open river for security and channelling the water from the drainage ditches into the river..
Did the Jesuits use the 25ft canoes? Ste. Marie was not to my knowledge a trading post. Trading canoes were not the only size of vessel used for personal travel.
Was the canal only 50ft. long? I thought that I had read that the fortification was some 44 yds. from the edge of the river. I guess I’ll have to go back and check my measurements and water levels.
Yes- some of the ditches were for drainage as I understand from Hegarty's work, but those troughs found in the east west ditch are so huge- they must have been used for something.
FYI - Wye Marsh study says level was up 3 meters.
http://www.citizenscientist.ca/ClimateChangeCD/sec4/422c.htm
Post a Comment