Lake Drawdown Watch 2024

 

With my newly updated 14 year average (in orange), we can now track the current year's drawdown.

The precipitous drop in mid-January was due to the extreme cold nationally, and Bagnell Dam was producing power (based on flow rates).

As you can see by the multi-year average, we're not at the bottom yet, but things seems to be progressing along as expected. With today's level at 656.3 we have at least another foot to go.

On my Bingo card, I have March 10th, at 10:00am, with a level of 654.57 as the time and level for the lowest point of the year. A point in time I like to think of now as the "Unofficial End of Winter at the Lake"

What 14 Years of Lake Level Data Says About the Annual Drawdown

 I'm finally caught up on adding the last few years of data to my long running tally of lake levels and analysis. The data set now includes hourly levels and flows from 2010-2023. Below is the detailed graph of hourly lake levels averages for that time period throughout the year.

Not much has changed from my last big average chart for 2010-2019, the additional four years of data only smoothed out the graph a bit. Of note though, is the little bump at the end of the year caused by the intense flooding in December 2015, which is still impacting the averages for that time of year.

As far as the annual drawdown is concerned, 14 years of data shows the longest, lowest stretch is from March 6th-13th with lake levels averaging just under 655ft, with a peak low of average of 654.57 on March 9th.

The End of Tunnel Dam

I've been a fan of the Tunnel Dam ever since I discovered it while looking for places to kayak in the lake area many years ago. My "discovery" was a bit embarrassing actually. I spent a lot of time at Ha Ha Tonka even before it was a state park and I had never heard of Tunnel Dam until the early 2000s.

The big news is that Show Me Electric Power Cooperative has elected to not renew the license to operate the hydro-electric facility, and it appears power generation will cease this year. Lake Expo has a very good article on the situation and I recommend reading it for more information on the local impact, including this nice history link from the Show Me Electric Power Cooperative. 

Best described by Show-Me Electric, "Attention was especially attracted to one potential site where a natural cave or tunnel pierced the base of a narrow ridge, bypassing a meander of the river, thus affording the opportunity of obtaining an artificial fall of water and creating a forty-foot head for a hydraulic turbine." In the case of Tunnel Dam, this 300 ft. wide ridge cuts through six miles of "meandering" river.

Satellite view of Tunnel Dam next to its Generator House

By creating Tunnel Dam, Lake Niangua was also created, which is fed by the Niangua River, a river as beautiful as any in Missouri, only less protected, and surrounded mostly by private farm land. Lake Niangua is very tranquil and beautiful as well, but is too small to be anything more than a nice place to fish.

Tunnel Dam is five miles southwest of Ha Ha Tonka (as the crow flies). The image below tries to show location and scale of everything.

The Niangua River is a major source of water for the Lake of the Ozarks, and with the fate of the dam structure itself, and the lake it forms, in question we need to examine the potential impact to the Lake of the Ozarks.

If the dam is removed in a controlled manner, the impact on the Lake of the Ozarks would be negligible, but if the dam remains, but not properly maintained, it could ultimately fail. A catastrophic failure, a total and rapid collapse, would cause a great deal of damage downstream, all the way into the Lake of the Ozarks.

But lets assume the dam is decommissioned in a controlled manner, whereby it is removed and any sudden deluge of water avoided. What this means for the Niangua River is an uninterrupted flow of water from Hwy 44, past Bennett Springs, all the way into Lake of the Ozarks. We already have a sanctioned 12 mile float below Tunnel Dam, called the Big Niangua River Trail that ends at the Lake of the Ozarks, but with the Tunnel Dam removed, this could turn into many dozens of miles. The potential for floats and water traffic goes beyond just kayaks and canoes. I have paddled up river from Lake Niangua and can say it is a very serviceable river for small power boats. My jet boat runs the Current River all the time in water barely knee deep, even less. Who knows how far up the Niangua River one could reach from the Lake of the Ozarks without the Tunnel Dam structure in the way. 

NOTE: Full disclosure, Whistler Bridge, just below Tunnel Dam is an impassable low water concrete bridge so any boat traffic would have to remain above or below it, but that barrier too could be removed. While I am a bit sad Tunnel Dam's life is ending, I think the idea of the Niangua River being a serviceable recreational artery all the way into the Lake of the Ozarks intriguing.