Locks and Dams

It's a lot easier than portaging from my perspective!

The river drops, and that gravity would help our speed if the river was allowed to maintain its current, but each pool (between each lock) is relatively flat.

The Upper and Lower St. Anthony Falls Lock and Dams are now closed, and for some reason there's #5 and #5a, so there are 28 locks to go through. I am in Pool 15 currently, meaning I just passed through Lock 14. I'm half-way through all the locks

The Mississippi River is basically broken into 3 sections:  The Headwaters, The Upper Mississippi River, and the Lower Mississippi River.  The Headwaters are wild and go from Lake Itasca to Minneapolis.  There are a bunch of dams, but no locks, so all the dams in the Headwaters must be portaged.  The Lower Mississippi River goes from Cairo, Illinois, where the Ohio River joins the Mississippi, to the Gulf of Mexico and has no locks or dams.  The Upper Mississippi River goes from Minneapolis to Cairo, Illinois, and there are 28 dams, all with locks.  The US Army Corps of Engineers keeps the river navigable to barge traffic from Minneapolis to the Gulf by dredging a 9 foot deep channel, and maintaining the locks and dams of the Upper river.   The dams control water flow and levels of water in the pools between dams.  Locks are compartments at the edge of the dams that allow boats and barges to pass through.  You pull into the lock, a door closes behind you, the water adjusts to the level of the water  on the other side of the lock (drops in my case), and off you go. 

In this video, you can see what the process is like, and meet Don, a lockmaster.  He shares his perspective on plastics in the river.