You’ve heard the stories about cracks and leaks and man-eating fish, but are they really true? There are many stories about Bagnell Dam that have been told and retold and in some cases, embellished in the Lake area for decades. Let’s dive in and set the record straight!
They can’t get divers to inspect the Bagnell Dam because there are huge catfish at the bottom of the lake large enough to eat a man.
NO. 1 – Actually, the dam gets a full underwater inspection every two years, and spot inspections more frequently. Local diver Terry Hart tells us that although he sees lots of fish when he dives at the dam, there are certainly no fish large enough or aggressive enough to eat a diver! “After you get down 40 feet or so, visibility is gone and you need a light just to see a couple of feet in front of you. Besides, I wouldn’t be crazy enough to dive the dam if there were man-eating fish down there,” Terry explained.
Greg Stoner of the Missouri Department of Conservation tells us that the largest fish in the Lake are actually spoonbill. Spoonbill don’t eat meat, and they certainly don’t eat people. They are called “filter feeders” and feed on microscopic organisms called “plankton.” The current Lake of the Ozarks record spoonbill (and former state record) is mounted and displayed at Willmore Lodge in Lake Ozark. It was caught in 1998 on the Niangua Arm of the Lake, weighing in at almost 135 pounds and measuring six feet, four inches long. Stoner also told us that the biggest catfish he has seen on this Lake was a blue cat caught in 1990 that weighed 92 pounds. So there you have it — no divers have been lost at the dam. This story, although great fodder at the barber- shop, is a myth.
There is a window in the dam where you can look out and see the fish.
NO. 2 – There are several inspection tunnels that run through the dam, partly to give the operators access to equipment, and partly to give the engineers an opportunity to inspect the quality of the interior concrete. But sorry, folks, there are no windows looking out into the Lake. Remember, even if there were windows, there’s no visibility that deep anyway. We hate to disappoint, but although there are lots of windows in the dam, and some of them are great for eagle watching, none of them is underwater. So, this one’s a myth as well.
When they were pouring concrete while building the dam, a man fell in. It was cheaper to pay off his wife than to sop pouring concrete, so there is a man buried in the dam.
NO. 3 – Now, we have heard this one flying around for years. It was one of the favorites in the author’s hometown of Tuscumbia just downstream from the dam. Although the story will never be proven, I have spent more than 30 years looking at records and reports dating back to the construction days, and have never found any documentation of such an event. Also, through the years, many drilling cores have been taken from the dam, and guess what? No bones have ever been found. But since there are more than 500,000 yards of concrete in the dam, and we haven’t drilled holes in all of them, we’ll just call this one a mystery. If we ever find a bone, we’ll be sure to let you know.
There is a crack in the dam leaking water
NO. 4 – Call out the little Dutch boys! Okay, don’t be alarmed about this, but there are lots of cracks in the dam. Any pour of concrete is going to crack, and Bagnell Dam is no exception. And, yes, it is true, some of the cracks leak water, and they have leaked water for years. As the engineers perform quarterly inspections, leaks are noted and measured to see if there are changes. It may be of interest to our readers to know that the leaks are heavier in the winter than they are in the summer. Actually, there is a good reason for that phenomenon. In the summer, the concrete in the dam is warm and expands with increasing temperature. As the concrete swells, the cracks tighten up, and virtually close off any leakage. During winter, the concrete cools and contracts. The cracks open slightly and leakage is again present. This goes on year after year and does not pose any safety problem to the dam.
But you might ask: “What about the drilling we saw from the road? Wasn’t that done to stop leaks?” The answer to that question is “yes.” The dam was actually designed to leak, and there is an elaborate system of vertical and horizontal drains throughout the structure to handle that leakage. In recent years, some of the vertical joints were increasing in leakage rate. To remedy this, Ameren installed water-filled tubes called “water stops” in a few of the joints by drilling down the joint from the top of the dam. This was first done in the 1980s and was repeated again in 2008. The water stops have worked very well. For the story about leaking cracks in the dam — we’ll call this one a fact. But as far as the little Dutch boys, we don’t need‘em!
They’re going to lower the dam 30 feet this winter to work on the dam.
NO. 5 – It seems we hear this one every winter about this time. There are no current plans, nor have there ever been, to drastically drop the Lake for work on the dam or on any bridge. In the new operating license for Bagnell Dam issued in 2007 by the Federal Energy Regulatory Commission (FERC), there is a guide curve that gives both guidance for seasonal variation of Lake levels and an absolute minimum Lake level. The Lake is typically lowered each winter about six feet to make room for anticipated spring rains.
You may be interested to know that the dam was originally built and designed for a 30-foot Lake level fluctuation. To support this, as land for the new reservoir was cleared in 1929 and 1930, all the trees with tops extending above elevation 630 were cut down. That was to be the minimum Lake level — 30 feet below the full Lake level of 660. So how low does it actually go? Since the filling of the Lake, the lowest Lake level was in 1948 at 639.95. In more recent years, the Lake was lowered to 646.25 in 1977. In this decade, the lowest Lake level occurred in 2002 at 653.87, barely more than six feet below full.