It is July, the Mississippi River is at a low level and we now have our minds directed toward the barbecue grill, swimming, etc. When next spring comes we will go back into our panic mode in fear of floods. Instead of looking forward to spring we dread this time of year along the Mississippi River Valley.
Every year we are threatened with severe flooding in the heartland from the Mississippi River. Many factors come into play with the cause of flooding which seems to be more often in recent years. Climate warming, amount of snow melt off in the northern portions of the upper Mississippi River Valley with a combination of heavy spring rains and rock dikes causing displacement, are a few of the main causes.
Let it be clear that my intentions are not to downgrade the U.S. Army Corps of Engineers, whom I have high respect for. As a river pilot I have seen great performances by them. They have accomplished much toward flood control and river navigation making it more navigable. But I do not agree with their theory that rock dikes doesn’t cause any displacement of water in the river.
Common sense must dictate that putting millions of tons of rock in the river with the building of rock dikes has caused a narrowing of the river with an appreciable amount of water displacement. Some might think that a few rocks in the river would not cause displacement and they would be correct, but we are talking about millions of tons of rock that push the water level up at normal times.
Rock dikes have served a purpose directing current into a channel which in turn cuts out sand and silt maintaining a deeper channel. This method was used in earlier times with wood piling dikes which allowed much of the water to run through them. Rock dikes replaced the wooden piling and diverted much more of the water into the channel.
Just think of years dumping rock in the river how it must have had an effect on displacement. All one has to do is drop a quarter-pound rock in a nearly full gallon of water and displacement will run it over. While this may not be too scientific, I think it will prove my point.
Common sense is a sound and prudent judgement man makes without formal training. It is a judgement based on vision and what the eyes tell us. Surely one can see that millions of tons of rock dumped into the water will make in time, a lesser space for water at its normal level. I am talking of an operation that is practiced by the U.S. Army Corps of Engineers on a yearly basis.
As stated before, rock dikes have done a great job in deepening the channel of the river, but the contribution it has on flooding which is a negative effect, far outweighs the positive of good done in deepening the channel.
I have no schooling in the field of instruments, formulas, elevations, volumes, displacements etc., but I do have some common sense. Technology is a great thing. Common sense tells me if technology and common sense were both applied, our accomplishments would be much greater.