2019 Flooding

I'll be posting my monthly graph of lake levels and flow rates for the Lake of the Ozarks tomorrow, or Monday, but as you will see despite the high water levels in other lakes and rivers, the Lake of the Ozarks is operating at normal levels. How can this be you may ask?

What's so special about the Lake that it is spared the ravages of flooding while the Osage and Missouri Rivers flood and Truman Lake is busting at the seams?

With the 30 day outlook calling for a wetter than normal June, things may not improve much.

The answer as to why the Lake of the Ozarks seems out of step with other bodies of water in the area is not a simple one, but it is important. It has everything to do with the very different purposes for which the two dams, Truman and Bagnell were built, who controls them, and the river basins they serve. I've spent a little time explaining it here if you're interested.

April 2017 Lake Levels and Flow Rates - over 4ft in 24 hours!

I try not to be critical of Ameren when it comes to their stewardship of the lake or how they treat lake home owners, after all they are an energy company whose only real interest in the Lake of the Ozarks is how much power they can generate and sell while fulfilling their regulatory compliance requirement for having a percentage of that energy produced by "renewable" energy sources.

But when Ameren manages the lake without any apparent consideration for ecology or property? It pisses me off.

Is that a harsh criticism? Does a lake level one foot above full pool really cause issues?  In a word, no. A lake level of 661 is not a "flooding" event at the Lake.  What is an event is rapid change. Take a look at the level and flow chart for April.  See anything striking? It's not the 661 lake level itself, but how fast it got there that is the problem.

The forecast for potential flooding rains was anticipated early in the last week of April and Ameren, as to be expected, began ramping up turbine flow on Wednesday April 26th, with full flow by Friday the 28th. But as the rains fell Ameren surely watched as lake levels began to rise at an alarming rate. This rate of change continued for nearly a day with full turbine flow (35Kcfs) having little impact on lake levels. At it's most dramatic, the lake rose one foot in just four hours on Saturday.

Ameren saw this rapid rise but did nothing until Sunday, April 30th at 6:00am. With the lake at 660.51 the flood gates were finally opened. Let's be clear here. It wasn't until the lake's level punched through 660ft (full pool) that flood gates were opened Sunday morning. This means that in just under 24 hours the Lake of the Ozarks was allowed to rise over 4 feet!

Note: My statement above, that flood gates were not opened until the lake reached 660.51 feet, is (indirectly) disputed by Warren Witt, the Director of Hydro Operations at Bagnell Dam who was quoted as saying they were opened when the lake reached 659.5 feet in a later interview with  Lake Expo. But I'm going off Ameren's own data so you be the judge (zoom in on the above chart). From the above chart the flow rate was still about 35,000cfs when the lake was at 659.5. But Witt should know of course when the gates were opened, and it is certainly reasonable that there is a delay from the time flood gates open until the change in flow rates registers with Ameren's own sensors. Flow rates measured independently by USGS seem to back up his statement that the gates were opened at 6am, so I'll have to give the benefit of the doubt here.

I'd have to check my own records, but I'm pretty sure the floods of 2015, both of them, didn't rise so quickly.  This rate of change is highly disruptive to the ecosystem and damaging to the very shoreline that Ameren makes us lake home owners all bend over backwards to protect.

I would not argue that there was anything that could have been done to prevent reaching the 661ft level given the pressures from Truman Lake and the Osage River, but I believe an earlier opening of the flood gates would have made the rate of change a little more bearable.  Management Grade? D

2015 Annual Lake Levels and Discharge Chart

It was a historic year for Lake of the Ozarks when it comes to lake levels and flow.  Two flooding events, one in July, the other in December, pushed the lake to levels not seen in decades.  The difference between the lowest level of the year and the highest was over 10ft!

Even from just the thumbnail image below, we can see the standout times when levels and flow were at their extremes.

Click here for the original drawing to see details.

Here are some highlights of the numbers.

Highest lake level:  663.83 on December 28th, at 6pm
Lowest lake level: 653.74 on March 5th.
Average lake level for the year: 658.38
Average Summer level: 659.35

Maximum Discharge: 104,617.10 cubic feet per second(cfs) on December 28th at 6pm, representing half of the dams flood control capacity.  This is nearly 3 times the maximum flow of 2014.

Total outflow from the Lake in 2015: approximately 462 billion cubic feet, or three and a half TRILLION gallons, flowing from the lake into the Osage River over the course of 365 days.

Dec 29th Flood Update - Slowly Dropping

It appears lake levels crested last night around 10pm and the lake is now dropping as Ameren continues to operate the flood gates around 40% open. The flow rate is also decreasing in tandem. This is a likely attempt to reduce the amount of current this much water is creating.  Keeping the water moving, only not too fast, helps prevent excess debris from moving downstream all at once. At this rate however, it will be several days before we see normal lake levels.  It is likely this event will delay the start of the normal winter lake drawdown.

At the current rate of decline, the lake will reach normal full pool level of  660' close to the stroke of midnight on New Year's Eve.

By contrast, the winter drawdown will lower the lake level 10 feet from where it is now.

Dec 28th Flood Upate - 4PM CST

As of 4pm the lake level continues to rise, now at 663.79.  Discharge has increased to over 103,000 cfs.  Subtracting 35,000 cfs for flow available through the turbines, means 68,000 cfs is passing through the flood gates.  The 12 flood gates are each capable of releasing 13,503 cfs for a total of 162,036 cfs.

By these numbers we can estimate that all 12 flood gates are open approximately 42%.

Docks Breaking Free

This is the Hwy 54 bridge over the Niangua Arm near Camdenton.

This was posted at LakeExpo.com

Picture by Terry Summers

December Flooding Surpasses July's

December 28th.  As of the 2pm CST reading, discharge is being held at about 102,500 cubic feet per second but lake levels are still rising, although slowing down.  Currently the lake is at 663.73.  If discharge remains above 100,000 it is possible the lake will not reach 664.

The maximum flow discharge during the summer flooding peaked at just over 85,000 cubic feet per second with a lake level high of 662.55.

Here's what's happening on the Osage River, below the dam.  Up nearly 16 feet in 48 hours.

July 2015 Lake Level Summary - The Flood

Here it is, a summary of lake level and discharge for the month of July that made history.  As we can clearly see, the surge in level over 660' on the 4th of July weekend was quickly brought back down to normal, remained stable, and very close to the 5 year average.  Discharge remained high well after the flooding to pass water from Truman lake.  The last week of July shows a fairly normal pattern of discharge flow and lake levels.  I'd like to see the lake up above 659' this time of year as rain becomes a little scarcer and Labor Day approaches.

2019 Update: Thought I'd add some of my new graph kung-fu to this old post. It was an extraordinary month after all.  Here's the daily candlestick graph for that same month.

Flood Watch 2015 - The End

8am, July 4th.  Update- The no-wake restriction has been lifted.

Lake levels are now at 660.30', effectively on the high side of "normal". Discharge remains over 40,000cfs so the floodgates are still open.  Truman Dam has been holding water since this event started and with river levels dropping it's likely they will allow some badly needed release for Truman Lake.

My guess would be continued discharge above 40Kcfs to handle Truman's water but Lake levels should continue down very slowly for the rest of the day.  I'm also betting the governor will release the no-wake restriction by this afternoon.

The flood event is pretty much over as far as the Lake is concerned, but it's effects will likely linger the rest of the summer for some folks.  This is the last update I'll do on lake levels until the normal end of month review.

Everybody get ready to get back in the pool.

Flood Watch 2015 - HD Drone Video

This video has been making the rounds, a gut-wrenching bird's eye view. My guess is that this is from the Camdenton area where "gentle slope" property is more common.

The next video is from the suspension bridge that crosses the Grand Auglaize Creek southwest of Brumley. The bridge is near where the creek flows into the Lake of the Ozarks at the State Park.

Governor Nixon Declares the Entire Lake a No-Wake Zone

The entire Lake of the Ozarks is currently under a no-wake restriction. Not since 1993 (yeah, *that* year) has such an order been given.  With the lake cresting at nearly 663', the second highest ever, damage to surrounding property and shoreline would be incalculable if normal boat traffic was allowed while the lake remains high.

It appears that if Ameren can get the lake back around 661', which could be by Saturday at the rate it's going, the ban will be lifted.

2:30pm, July 3, 2015

Flood Watch 2015 - 8pm Update

8pm - Delayed from assessing my own damage.  Jeez what a mess.  Lake levels continue slowly down but the forecast looks decent enough, with some rain in the forecast but no downpours.  If discharge continues, we'll get below 662 by morning.

No, the Lake Will Not Be Closed Due to Flooding This 4th of July

Update: Governor declares the entire lake a "no-wake" zone.

While flooding presents major problems for property owners on the lake, Ameren and the Missouri Water Patrol have both confirmed that they will not be forcing a lake-wide ban on boating this weekend, as they did in 1986. However, there may be expanded no-wake zones and all boaters are generally asked to idle until the lake reaches normal levels again.

Besides, there's going to be a lot of debris in the water this weekend and speeding along is a surprisingly effective way of finding it with an outdrive.

Flood Watch - Osage River Historical Data Reference

This is from the USGS website and shows today's and yesterdays river height in comparison to the top four historical levels.  The 1943 data point is probably the worst incident, when Bagnell Dam was almost topped and was at maximum flow, over 200,000cfs.

Flood Watch 2015 - River Gauge at St.Thomas

Here is the graph from the USGS Hydrologic unit at the Hwy B bridge near St.Thomas Missouri. This is the last measuring unit before the Osage River meets the Missouri River, about 15 miles from the confluence.  Flood level is the 23' red horizontal line, and likely to be reached within a few hours.

The Flood of 2015

Update:  Things are back to normal.  Here's my final post.

July 1, 08:00: Floodgates are open, but not all the way.  Why?  Lake levels are as high as they've been in recent memory, now at 662.34ft and still rising.  Damage around the lake is already well underway and when the boats start moving in earnest during the holiday weekend things will get very bad indeed. Unless Ameren cranks open the floodgates much more, it is unlikely we will be back at normal levels within the next 24 hours, but the Osage can only take so much more.  Flooding in the Jefferson City area downstream is already pronounced.

All 12 Floodgates are open

Here's a chart of the last four days.  I left in the last two days of June as reference.  I'll be updating this throughout the day.

Notice that at 8am, things begin deviating from the average. The rain was coming down pretty hard and by 10am Ameren opened the floodgates 10% of capacity.  Judging by the current discharge of nearly 80,000 cubic feet per second, they've opened them to about 30% capacity since. At fully open, the Bagnell Dam is capable of releasing over 200,000cfs, but that hasn't happened since the 1940's and the effect was disastrous downriver.  The current flow rate is predictably devastating to the Osage River, rising nearly 12 feet in the past 24 hours.