Thursday, May 25, 2017

Memorial Weekend 2017 Finds the Lake Still in Cleanup Mode

Since the Summer of 2017 begins in earnest this weekend, I thought we might take a look at lake conditions beforehand and get a little early jump on this month's chart.

Believe it or not, lake level and flow rates are still under the influence of the torrential rains at the end of April.  Let's take a look at Truman Lake first to see why we are still where we are with flow rates.

Ten Year Graph of Truman Lake Levels

Truman Lake is controlled by the Corps of Engineers while Lake of the Ozarks is not, but there is a Memorandum of Agreement which says Ameren must coordinate operations with the CoE, especially during flood events.  As we can see above Truman Lake reached its highest level in the last 10 years at the end of April, while Lake of the Ozarks barely exceeded 661ft, and only briefly at that. Between the two lakes, Truman did its job protecting the Lake of the Ozarks from a *major* flood event that would have surpassed 2015s (both of them). But with the rains subsiding this month, Ameren has kept flow rates through Bagnell Dam well above average in an attempt to lower Truman Lake.  It's a very slow process and will likely continue through the first holiday weekend.  With that in mind, let's take a look at May's levels and flow rates.

May of course started with the lake at it highest levels for the year, and likely the highest for the entire year.  Discharge from Bagnell Dam remains above full turbine flow which means flood gates are still partially open sustaining nearly 50,000cfs.  For Memorial weekend, lake levels are just slightly below the 5 year average, but doable for those of us in shallow waters. As for all that water that's passed through Bagnell Dam? We'll examine just how much water in the regular end of the month report when the final data comes in.

For now just be advised that the lake is (relatively) murky and full of debris coming down from Truman.  Running your boat will be a little more risky this weekend as debris is everywhere.  As for night running, I will definitely be adopting a cocktail cruise speed.  On plane even at legal speed will be very risky to your outdrives.

Be safe. Have fun.

Monday, May 01, 2017

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