Locks and Dams are better for the Environment!

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Why are there locks and dams on the Mississippi River?

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Stairway of Water

   The Mississippi has long been used for transportation; however, navigation has been forced to accommodate its whims; deep-flowing but turbulent in times of flooding; placid but shallow to the point of non-navigability in times of drought. Other obstacles included swift and treacherous rapids, submerged rocks and boulders and uncharted sand bars and tree snags, which ended the life of many steamers in the nineteenth century.

   As early as the 1830’s, the Federal Government began improvements on the river in the interest of navigation. In 1930, after extensive studies by the US Army Corps of Engineers, Congress authorized the nine-foot channel navigation project on the Upper Mississippi River. This legislation provided for a navigation channel of 9-foot depth and a minimum width of 400 feet, to be achieved by construction of a system of locks and dams, supplemented by dredging. Construction of this system mainly occurred in the decade 1930-1940.

   In the 669 miles of river between the first lock at the Falls of St. Anthony area of Minneapolis-St. Paul, Minnesota and the last lock of the a project (Lock #27) at St. Louis, Missouri, the Mississippi has a fall of about 420 feet. The purpose of the locks and dams is to create a series of “steps” which river tows and other boats either “climb” or “descend” as they travel upstream or downstream. Locks and dams on the Mississippi were not built for flood control; there is very little to no compact reservoir behind each dam to hold water back.

Locking a Boat (Headed up river)

   In the picture below, the towboat is wanting to go up river. It is on a lower step wanting to move to a higher step. How can it do this? It needs an “elevator,” or lock. The lock chamber is filled or emptied with gravity. There are four valves: Two upper and two lower, with a connecting 12’ x 12’ tunnel – one set in each wall. By closing the lower valves and opening the upper valves, the water flows into the tunnels and out of the 4’ x 4’ port holes that lead off of the tunnels and into the chamber, thus filling the chamber. The reverse of this process is done to empty the chamber.

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   Before the boats enters the lock, the lock chamber is filled with water by opening the filling valves. The water flows through big tunnels and then into the lock.

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   As the water drains out, the lower gates are opened, and the towboat leaves the lock. For a towboat heading down river, the procedure is reversed.

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Commonly Asked Questions
On the Mississippi Locks and Dams:

Q: What cargo is carried in the barges?
A: Generally grain travels down the river. Coal and fertilizer travel upward. In 1996, 80,372,000 tons of cargo were shipped by barges on the upper Mississippi

Q: How long does it take to get through all the locks and dams on the Mississippi (St Paul, MN to St. Louis, MO)?
A: By towboat, it takes approximately 7-9 days to cover the 669 miles.

Q: How many people work on a tow?
A: About nine people work on each tow: One captain, one pilot, two mates, two deckhands, one call watch person, one cook and one engineer. There people keep the tow running around the clock. They work six hours on duty and six hours off for about 30-45 days at a time.

Q: Who pays for this lockage? How much do the towboats pay? How much does it cost for pleasure boats that use the river?
A: The expense of lock and dams is covered by the US Government, under control of the US Army Corps of Engineers; however, it is subsidized by the towing industry, which pays a substantial fuel tax to cover the upkeep of the lock and dams. Pleasure boats lock through with no direct charge.

Q: How do you get the first half of the tow out of the lock chamber?
A: The first half or “first cut” of a tow is pulled out by a “tow haulage,” or winching device. After a short pull, the weight of the barges act as momentum to carry the first cut clear of the gates.

Q: Who locks first: Pleasure or commercial vessels?
A: Lock personnel have a priority list of which boats lock first: Government vessels first, passenger craft for hire lock second, commercial craft lock third and pleasure craft lock fourth. Lock staff do take consideration for pleasure craft and lock then between commercial craft. Outside of this order, boats are locked on a first-come, first-serve basis, thus keeping waiting at a minimum.

Q: What are the poles in front of the barges at the head of the tow used for?
A: The poles are transducers, which inform the towboat’s pilot of the depth of the river under the front of the tow.

The US Army Corps of Engineers

   The Corps of Engineers is a world wide organization that provides engineering services, environmental restoration and construction support for a wide variety of civil and military projects. Additional missions of the Corps include: Managing federal real estate, assisting communities with emergency operations and recovery and providing recreation opportunities. The Corps also manages major construction projects undertaken by other federal agencies to include the cleanup of Superfund sites for the Environmental Protection Agency.

Welcome to Rock Island District

   Greetings from the US Army Corps of Engineers, Rock Island District. We are one of the six districts that make up more than 78,000 square miles and includes Missouri, 268 miles of the Illinois La Grange Lock and Dam, southwest of Beardstown, Illinois. We have a diverse staff that includes both advisory and administrative personnel who manage district operations, and a technical staff comprised of specialists and technicians representing a variety of scientific and professional fields. About half of our staff work at construction field offices, lock and dam sites and flood control reservoirs.

At the Rock Island District, We pledge to:

• Provide our services to the nation in times of emergencies
• Plan, design and construct water resources and infrastructure projects
• Manage and conserve natural resources consistent with ecosystem management principles while providing quality outdoor experiences
• Operate and maintain lands and facilities under our jurisdiction
• Implement regulatory authorities that protect our nation’s resources.

For more information, contact:

District Engineer
Rock Island District
US Army Corps of Engineers
Clock Tower Building
Rock Island, Illinois 61204

Http://www.mvr.usace.army.mil