Lake Superior's Water Level
Each year, Lake Superior goes through a normal fluctuation where the water level gets higher and lower. Lake levels follow a seasonal pattern, normally rising in the spring, peaking in the summer, and declining in the fall to a low during the winter. The lake level is only one factor that determines the severity of erosion. Erosion occurs regardless of how high or low the water level happens to be. However, many people feel that higher water levels make the erosion worse than if the levels were normal or below normal. It is interesting to note that when the lighthouse lost its entrance building to erosion in 1996, the lake level was higher than normal.
Factors Controlling Lake Superior's Water Level
Outflow from Lake Superior through the St. Marys River is regulated by the International Lake Superior Board of Control, which was established in 1914 by the International Joint Commission (http://www.ijc.org). (The International Joint Commission was established in 1909 by the Boundary Waters Treaty between the U.S. and Canada.) They are currently using Regulation Plan 1977-A to regulate the outflow of water from Lake Superior. In determining the appropriate outflow levels, the Board not only has to consider the level of Lake Superior, but must also consider the level of Lakes Michigan and Huron. In other words, determining the outflow is not something that can be easily done by just looking at the current level of Lake Superior.
Other factors that affect Lake Superior's water level are the amount of precipitation the Lake Superior Basin receives and the rate of evaporation (this depends on ice cover in the winter, temperatures, cloud cover, etc.).
Current Lake Level
For the past several years, the level of Lake Superior has not been a big problem for the lighthouse because it has been below normal. When the level is above normal, it seems to increase the erosion damage caused by storms. In November 2012, Lake Superior's mean water level was 600.75 feet. The long term average water level for Lake Superior in November is 601.9 feet (average was obtained from data from 1918-2011.) This means that in November 2012, Lake Superior was 1.15 feet below normal. According to the Army Corps of Engineer's Forecast, it looks as if the water level will stay below normal through May 2013. This data was obtained from the U.S. Army Corps of Engineers' web site.
Ground Cover
We need ground cover to help prevent erosion and to help trap windblown sand-- indigenous (native) beach grasses, wild roses, lilacs, cottonwood, willows, white birch, maple, and pines. It is more likely that native plants will be able to survive the harsh conditions at Crisp Point. We always need volunteers to help water the plants. If you would like to help in this way, just take a bucket or some type of container down to the lake, fill it up, and take it around to the plants. This is one easy way to help the lighthouse.
ORV Damage
Off Road Vehicles (ORVs) can also contribute to environmental damage surrounding the lighthouse. For example, vegetation that is vital to keeping and trapping sand around the lighthouse tower can be killed by ORVs. Due to the harsh conditions at the site, it may take many years for the damage to be reversed. In Michigan, some of the places where it is illegal to operate ORVs are on beaches, sand dunes, wetlands, and shorelines. For more information on ORV issues in Luce County, please visit http://www.LuceCountyORVdamage.com.
ORV / ATV Riders
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Coastal Straightening and Erosion
The process of coastal straightening is always occurring, especially during storms. Usually the worst storms that Crisp Point has to face occur in November. With coastal straightening, wave energy is concentrated on land masses that protrude into the lake, causing them to erode away and the coast to become straight. If one looks at old pictures of Crisp Point, it is easy to see that this process is definitely occurring at Crisp Point. We must keep erosion control on our minds at all times, even if things seem good now, because as we learned in November of 1996, it just takes a few major storms to take back everything we've gained.
Crisp Point Light Historical Society Webmaster: Cameron Lovett
Email me with comments about the website at cameron@crisppointlighthouse.org
Copyright © 2012 Crisp Point Light Historical Society
Last Modified December 9, 2012