I sent a request for clarification on the water level issue to some folks I know at NOAA in Ann Arbor. If the Coast Guard is tasked to prevent flooding, and they are doing their homework, we should expect to see them in the main river up above St. Clair......
Begin forwarded message:
From: David Schwab
Date: February 17, 2010 8:56:51 AM EST
To: Charles Miller
Cc: Jennifer Read
Subject: Re: Rapid decline in water level
Dear Mr. Miller,
After looking at records from the NOAA water level gages at St. Clair State Police (9014080), Algonac (9014070), and St. Clair Shores (9034052) here is my guess at what happened:
1) The St. Clair River was flowing freely until 2/6. The water level drops between gages look normal.
2) On 2/6 it appears an ice jam formed between St. Clair State Police and Algonac gages, severely restricting the flow in the river.
3) The water level at the St. Clair State Police gage rose 0.5 m in 24 hours on 2/6.
4) The water level at the Algonac gage dropped 0.5 m 0n 2/6.
5) The ice jam appears to have moved further upstream past the St. Clair State Police gage since then as there is now about a 1m drop between the Dunn Paper gage and the St. Clair State Police gage.
You can monitor the condition of water levels in the river using the graphs on our 'Huron to Erie Connecting Waterways Forecasting System (HECWFS)' web page at:
http://www.glerl.noaa.gov/res/hecwfs/
Note that the computer model that is used to simulate and predict water levels profiles does NOT include the effect of ice, so when there is a large discrepancy between the observed levels and the predicted levels, it generally indicates that ice is having an effect on the river flow.
I hope this information is useful to you.
Sincerely,
Dr. David J. Schwab
Charles Miller wrote:
Jen/David:
Please help a confused citizen. I've been looking at water levels in the St. Clair River. Specifically, I was looking for how (or if) the NOAA/USACE stations picked up the changes due to ice dams, etc. Something really crazy happened on the 6th of February in the lower river. We had a drop of three feet within 24 hours.
I initially attributed it to an ice dam break (Coast Guard?) but the more I look at longer term plots and year over year plots for stations up and down the river, the less convinced I become.
The effect of the 3 foot drop is not seen above the St. Clair Sate police gauge.
The effect manifests itself to varying degrees all the way to the Gibralter gauge (same time frame).
The year over year comparison for the same time period suggests to me that the normal water level just went through the floor and it has nothing to do with an ice jam.
ME BAD CONFUSED.
See attached. NOAA ODIN data and Corps.
Charles Miller
President
Harsens Island St. Clair Flats Association
cmiller79@comcast.net
Dr. David J. Schwab
NOAA Great Lakes Environmental Research Laboratory
4840 South State Road
Ann Arbor, MI 48108
734-741-2120
734-741-2055 (FAX)
Charles Miller
President
Harsens Island St. Clair Flats Association
cmiller79@comcast.net
Tags: Harsens Island, Harsen's Island Michigan,
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