Saturday, February 18, 2017

Mackinaw River Meanders and other rivers

While looking for the old Chicago & Alton bridge over the Mackinaw River, I noticed that some of the "Mackinaw River" labels were not on the river. So I looked some more along the river and found this extreme of two cut-throughs since someone at Google created the road map from a satellite image.

Satellite

Road Map
That river does some serious movement considering how small it is.

Satellite
Update:
I decided I'm not going to do a separate posting for each river that meanders. Rather I'll collect this evidence of the power of flowing water in this posting.

See Wabash River Meanderings for several examples of the river changing its banks including a rather recent cut-through at Grayville, IL.

An article about two tracks being washed out that includes a video. I love the quote: “You got a lot of people working on this.” The article explained that you may have a lot of people talking about this, but the Department of Transportation is not allowed to work on saving Highway 7 because the land is privately owned. The caption for the video indicates the railway is unused. I've seen a lot of single track routes that are unused, but this is the first time I have seen a 3-track route being idle. The price of steel scrap must be real low.

White River


While looking for the abandoned Big Four Bridge across the White River, I noted a rather fresh sandbar. As I looked upstream, I found more including this set of sandbars.
Satellite
First of all, note that the river has moved a lot since some one at Google labeled the river. Secondly, you can start a office pool as to when the base of that bend is going to cut through leaving a rather complicated (curvy) oxbow lake. I think of Southern Indiana as being rather hilly. But obviously this part is rather flat to have such pronounced and dynamic meanders. Then when I was studying the new power plant at Edwarsport, IN, I noticed a long stretch of  oxbow lakes.

Satellite
Noticing the freshness of the sandbars in the first image above, I checked the next downstream water gauge station, which is in Newberry, IN, for flood activity. The recent crest information does show there has been significant flood activity during the last couple of years. A Major Flood Stage was missed by just 3/4 of a foot.

Recent Crests
(1) 18.47 ft on 07/16/2017 (P)
(2) 11.68 ft on 06/28/2017 (P)
(3) 23.25 ft on 05/08/2017 (P)
(4) 17.20 ft on 01/22/2017 (P)
(5) 13.64 ft on 08/17/2016 (P)
(6) 15.91 ft on 04/14/2016 (P)
(7) 13.69 ft on 02/26/2016 (P)
(8) 20.20 ft on 01/01/2016 (P)
(9) 19.46 ft on 07/18/2015
(10) 17.10 ft on 07/03/2015

Flood Categories (in feet)
Major Flood Stage:24
Moderate Flood Stage:19
Flood Stage:13
Action Stage:8
Low Flow (in KCFS):0.372

Edwardsport also has a water gauge, and it also shows 10 crests above flood stage happened during 2016 and 2017.

No comments:

Post a Comment