by Jerry Hay
 |
The June flooding on the Wabash has created a new channel
and a new island on the lower Wabash River. The force of the high water against
a bend at Mackey Island broke through the bank and cut a shortcut toward the
Ohio River. Mackey Bend is a huge bend in the river located only a few miles
from the mouth of the Wabash at the Ohio River. This is a very important event.
Besides the fact that the property owners have lost access to their
farmland, there are other notable affects. 1.) If
the new channel stays (and probably will) this new island will be the largest
on the Wabash River. The island is about 1,700 acres of land. 2.) The
new channel will likely continue to be scoured in subsequent high water since
the river will follow the flow of least resistance. If this happens, the old
channel will be captured by the new channel and the old channel will begin to
silt up from the downriver side to the upriver side of the island. This process
could take a several years but eventually the old channel may close up completely
and the Wabash River will be 6 miles shorter (see diagram below). The new
island will no longer be an island once the old channel is partially filled
with silt (forming an oxbow lake. 3.) Boaters
traveling this section of the river should be aware that the old channel may
become shallower immediately as a great deal of the water may be diverted to
the new channel. Also be aware that the current in the new channel will likely
run swifter. There are very few things that can prevent this natural
cut-off from eventually becoming the main trunk of the Wabash River. Since the
cut-off began on an outside bend, the blunt of the river current will continue
to bombard the same area and Mackey Island will also continue to divert water
in the direction of the new channel. The U.S. Army Corp of Engineers could
possibly fill in the new channel during low water, then shore up the bank with
revetment (rocks), but they have already stated that this will not be done
because they had no levee there to begin with and that the cut-off is a natural
event. As much as I feel for the farmers who cannot access thier property, I agree
that nothing should be done. This is something that rivers do and always have
done. When looking at satellite views of the river it is easy to see the many
oxbows that were once river channels. Old bends disappear and new bends form.
Building levees in this area would be a mistake. This is a natural flood plain
area and more levees will cause the river to rise even higher upstream, causing
even more flooding in areas that now do not flood. I will be traveling to this area by boat soon and have a
better assessment of what could and has occurred. I will report my findings on
this page. Below are aerial photos kindly provided by Holly Wildt of Evansville,
Indiana and an illustration taken from the Wabash River Guidebook that shows the new cut-off. More photos will be added when I
return. Please check back as I update this historical event. Jerry Hay July 15, 2008. Having just returned from a boat trip to the
new Wabash River channel, I have filed the following report and The new channel is less than a mile long and becomes wider
as it flows back into the neck of the old river bend. At first is appeared that
there was a tree still in place in the center of the lower end of the cut-off
but then I could see that is had actually been dislodged from where is had been
before the cut-off and was grounded at this location (for the time being). The lower end of the cut-off is less than a mile from the
Ohio River. While heading down to the Ohio River from that point I discovered a
new sandbar right in the middle of the Wabash River. I found this, as I have
often done, by running aground on it. After breaking loose, I discovered that
the deepest water is Is the Wabash River six miles shorter yet? No. Could it be
someday? Yes. Keep in mind that all of the measurements of current speed and
channel depth will vary as the river rises and falls. The nearest river stage
station is at New Harmony, IN. On the day that I was at this location the river
stage at New Harmony was 10.2 feet. Given this depth as a measuring standard,
one can predict with some accuracy what the river depth will be in this section,
using the depths that I indicated. What makes this area tricky to predict is
the influence of the Ohio River. For the time being, if the Wabash River is
very low, a swift current may not be Anyone with additional information or questions may feel free
to contact me. Also any agencies who would like to get hi-res downloads of the
photos may have them for no charge by contacting me. JULY 25th UPDATE Click here to open a pdf file of the updated section 35 page Click here to see videos of the new cut-off BACK TO INDIANA WATERWAYS PAGE |
photographs:
pump that was once located on land. It
was fascinating to know that I was drifting through this large, swift body of
water that was farmland only a few weeks ago.
along the left bank. An interesting new feature on the
Ohio River is the new man-made beach, just above the mouth of the Wabash River.
This was formed by the U.S. Army Corp of Engineers dredging. Since the new
cut-off carried so much sand into the Ohio River, the navigational channel on
the Ohio became to shallow for commercial traffic and was closed for a time
while they pumped the sand through a pipeline and near the Indiana shore. The "dredge spoils" as it is called, became a new beach.
about 1/3 of the speed of the new channel.
Why are these factors important? Knowing this will help to determine how
permanent this new island may be:
happens the river could eventually close up from the island to the Illinois shore and in the island chute, leaving the new channel as the only means to pass through the section of river by boat. This is a "could be" and if so, would take several years.
flowing through the new channel, but it
will continue to scour and become deeper with each high water.
©2006 Indiana Waterways