August 1993
the monthly newsletter for people who live, work or play on the Upper Mississippi River
Bluegills, Silver Maples and Civil Engineers Cope with a Bigger River By ReggiÂŁ McLeod
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The banks of the Middle Mississippi are still a battleground, but on the upper river folks are tallying up the damage and looking to the future.
- ¡oams and Levees The flood waters will probably rewrite civil engineering manuals. Engineers design dams, culverts, levees and other structures based on estimates of the heaviest rainfall or flood likely in a 100-year or 500-year period. Because weather records cover less than 200 years in most of the Midwest, these numbers might be low and many structures under-built. Big engineering projects have become harder to fund. It's often cheaper to move a neighborhood or town than to build a dike system to protect it. Many of the dikes and levees that were weakened or destroyed, especially in the middle section of the river, probably won't be replaced or repaired.
Shipping The barge industry is having a tough season. A few months ago it was arguing to get more water released from low reservoirs into the dwindling Missouri. It was fighting the Clinton Administration over a dollar-a-gallon tax on fuel. The Army Corps of Engineers faced criticism of a long-range planning study that seemed to be a justification for expanding the system to support more river shipping. Locks 16, 17, 18, 20, 21and22 were shut down in midApril, blocking shipping from Muscatine, Iowa, to Hannibal, Mo., and separating the upper river from the lower river. That setback looked temporary, but wasn't. We may end the season with almost no shipping season at all.
(Flood, continued on page 8)
Vol. 1. No. 8
$2
Half-Buried Treasure What Will Become of the Higgin's Eye and Fat Pocketbook? By Pamela Eyden
If you see mussels stranded in two or three inches of water, or in places that will dry up when flood waters go down, do them a favor - toss them back into deeper water. Mussels can sense when conditions are changing, but they cannot move fast. They also have an unfortunate tendency to go the wrong way. ''The flood will have brought a lot of mussels inland, and they won't survive when water levels go down," said Marian Havlik, freshwater mussel expert and owner of Malacological Consultants, Inc., of La Crosse. "It's better to move them this way than to do nothing." Freshwater mussels are having enough trouble these days, without being penalized for lacking a sense of direction. Mussels spend most of their lives half-buried in the river bottom, with just the tips of their shells emerging to suck in water, food and oxygen. They are vulnerable to whatever comes downriver - pesticides, herbicides, heavy metals, silt - and to careless construction projects, dredging and improper barge tie-ups that can tear up whole colonies at once. The newest and biggest threat to native mussels may be zebra mussels. The zebra mussel is a small, exotic species with no natural predators in North American waters. They What's inside. . . reproduce in great number and cluster densely on every MNRRA 2 available surface, including Current Events 6 othermussels, smothering River Calendar 8 them and preventing them (Mussels, continued on page 4)