Canals in Missouri?

On our flight from Memphis, TN to Iowa City, IA, today, we were
diverted around the Lindbergh MOA. This took us over the small town of
Kennett, MO, which brought us over a pretty amazing sight.

Just east of the Kennett Airport (KTKX) there is (what looks for all
the world like) a "freeway canal" -- with multiple lanes! It stretches
from horizon to horizon, with four "lanes" of canals, each with
elevated solid ground between them.

Here is a Google Map satellite image of the canals. (It's that
impossibly straight, multi-lane line on the right side of the
picture.)

http://tinyurl.com/yryfxc

From our lofty perch at 7500 feet, we couldn't tell if the land
between "lanes" contained roads (for tractors to pull barges?) -- but
there was NO visible boat traffic. It appeared that only two of the
"lanes" were still dredged and navigable, but no one was using them
when we flew over.

I've done some searching around the internet, and can find nothing
about this remarkable engineering feat. This thing must've taken years
to build -- yet I've never heard anything about it. Was it really a
"two-way" highway for boats? Why would they go to all the work of
making multiple lane canals, rather than just one wide one?

Can any pilots from the Show-Me State shed any light on this?

Thanks!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"