Monday, February 03, 2020

January 2020 Lake Levels and Flow Rates

I haven't even posted some of the summary data and graphs for the last decade and here it is February already and time for the first month of 2020 information! The annual draw down has started in earnest as we can easily see from the hourly detail graph below

Or I suppose more easily seen in the candlestick summary.

New background color for 2020!

I think what is more striking is the volume of water passing through Bagnell Dam for January. While certainly nothing extraordinary, daily discharge was at a brisk pace and steady for the entire month. Something that is a bit unusual for January.


Tuesday, January 28, 2020

The Decade That Was (2010-2019) - Enter Climate Change

A new decade is upon us so it's time to take a look a the decade that was in terms of data. Getting right to it, below is the candlestick summary chart for lake levels and flow for the period of 2010-2019. If you're not familiar with this style of chart you can click here for a full explanation.

Lake Levels and Flow Rates for 2010-2019
The graph (click to enlarge) is a construct of 10 years of hourly data consisting of 87,600 data points. While I wouldn't dignify that much data as Big Data, it is a significant enough number that certain trends might be statistically significant.

So what can 87,600 data points tell us about the Lake of the Ozarks? Obviously it can show what has happened over the past ten years, but more interesting is that it may also indicate what will happen in the future. I'm not talking about predicting daily lake levels, or flow rates, but rather trends. One trend that stands out, almost visually, is the gradual increase in total flow over the years. If you compare the actual data for total yearly flow from 2010-2014 to the period of 2015-2019, you'll see that 10.652 trillion gallons passed through Bagnell Dam in the first half of the decade and 16.107 trillion gallons in the second half. That's an increase of 66% which is rather significant. You can easily see this trend by the graph alone comparing the left half orange bar heights to the right half. The latter half of the decade also contains the highest monthly flow rates and two record flooding events in July and December of 2015.

If that's not obvious from the first graph, let's look at a comparison of the first five years of the decade and the last from an average daily flow point of view. Below is a two-line graph, the green representing 2010-14, and the red 2015-19. From this graph it's even easier to see the difference in the latter half of the decade. With the exception of early spring, which in of itself may be statistically relevant, the period from 2015-2019 consistently shows a higher average flow rate. Even more interesting is that flow rates remain high throughout the summer months, rather than tapering off after spring. This means, more water, flowing all the time.

Climate change is not just about a hotter earth but the impact it has on the water cycle which has far reaching effects. The Lake of the Ozarks is very much a part of that water cycle and Bagnell Dam's ability to manage the changes in the water cycle is critical to the future of the Lake of the Ozarks. We'll be exploring this subject in greater detail in coming posts.

Friday, January 03, 2020

2019 Full Year Lake Level and Flow Rates Review

The amount of water that has flowed through Bagnell Dam this year is truly astonishing. Here's the big picture.

Nearly 3 times the "normal" flow for one year due to flooding. While the Lake of the Ozarks suffered no direct effects of the surrounding waters, over 37% of operational time was spent in maximum turbine flow conditions. How much of that interpolated into power generation, only Ameren knows, but it was there for the taking.

Here's how December itself looked on the daily candlestick graph.

And the hourly detail.

And finally we can now see the daily candlestick graph for the entire year. (click any image to enlarge)

And the monthly summary version

Tuesday, December 03, 2019

November 2019 Lake Levels and Flow Rates

November is usually a very quiet month for the lake, and this year is no real exception. Some rains reached "toad strangling" intensity, but nothing of any real duration to affect levels or flow. It's taken most of the year, but Ameren has finally dropped flow rates down to minimum (about 1000cfs), with no power generation in the last half of the month.

Here's the daily candlestick chart for the month.

And for those detail oriented, the hourly.

Tuesday, November 05, 2019

October 2019 Lake Levels and Flow Rates

A little late this month, but I've been under the weather.

October lake levels were well above average and and total discharge added nearly another 3 Trillion gallons to the year's tally. If not another drop flowed through Bagnell Dam through the end of the year, it would still end up being one for the record books.  Here's the monthly summary:

And for those who like too see levels charted by the hour:

And finally, monthly summaries for the year so far:

Tuesday, October 01, 2019

September 2019 Lake Levels and Flow Rates

Ah, the end of Summer, how bittersweet. While on the one hand Fall brings thoughts of winterizing boats, kids back in school, and piles of leaves, this time of year also brings some of the best boating on the Lake of the Ozarks, especially for those of us fortunate enough to live here year round. The main channel is calm and the sunsets are gorgeous.

It's been a remarkable year for the Lake as the effects of Spring rains are still being measured. Take a look at Septembers candlestick chart.

See those blue bars along the bottom? That is a steady flow rate more than twice the average for this time of year and with little rain, with the exception at the end of the month (causing the largest change in lake level in a single day for the month). Bagnell Dam continues to release vast quantities of water. The low flow of September 28th is the rare exception, and didn't last long.

Here's the detailed chart: 

It's clear from the annual summary below that while flow remains heavy, things are slowly returning to normal.

Tuesday, September 03, 2019

August 2019 Lake Levels and Flow Rates

A very high quantity of water continued flowing through Bagnell Dam in August, but flow rates seem to be dropping into a more normal range albeit on the high side. Lake levels themselves are well within norm and we should see things dropping slowly to about 658 by September's end.

Looking at the dam itself we can still see 3 of the "rake gates" open partially, indicating some flow over the spillways, but overall flow seems point too reduced power generation. It's an odd configuration with flood gates partially open, and power generation low, but I suspect the goal is to get surface currents moving to get some of debris out of the water. The lake has had a lot of organic debris in it all summer.  Here's the candlestick graph.

And the hourly detail graph for those interested...

and the monthly summary candlestick.  So much water!