Wednesday, March 28, 2018

Lake Levels Stay Near Year Lows Despite the Rains

As I look out on the lake every morning I'm still a little surprised as to how low the level remains for for this time of year.  By my record keeping, the five year moving average lake level for this date (indicated in orange in the chart), March 28th is 655.36 feet, more than a foot higher than it is today.  So what gives?

Obviously the threat of flooding is on Ameren's mind and from the chart below, which is an incomplete graph for this month, they are adjusting flow (in green) through the dam in direct response to rising lake levels. It's a clear attempt to keep lake levels where they are in what appears to be a purely reactionary response to the rains as they come. Ongoing repairs to the dam may be the prime mover here since there's really no other reason to keep levels this low now.

Thursday, March 15, 2018

Lake Draw Down 2018 - Are We There Yet? Final Update

March 15th -. I could easily be jumping the gun here, but I'm going  to go out on a limb and say we hit the draw down peak yesterday around 9am with a low of 654.30.  With discharge flow dropping below 4,000cfs it appears Ameren is content to let whatever rain occurs in the next 72 hours to accumulate and mild temperatures means there's no real demand for power generation. With all that in mind, and given we are nearly two weeks past the average peak low date, I'm pretty confident lake levels will begin the slow and steady rise toward spring numbers.

Below is the 9 year chart of lake levels for the period January-April. Yes, I know It's only March 15th and things could change, but I was kind of anxious to get this post done. No, that's no glitch in the data on the far right. The lake rose over four feet in about 36 hours last year.

Update = I've got a jump on the chart for March here

The chart, with nine years of data it's getting difficult to keep neat. Here's how to read it. The current levels for this year are in red, while the nine year average is in bold green.  The previous years are in various shades of grey starting with black for last year fading with each successive year further back in time.

March 22nd update below - yep, I called it. Lake levels are rising from the low of 654.3 on 3/14.

March 27th update below - Nope. I didn't call it.  Lake levels have dropped since the last update to it's lowest level of the year, 653.91 at 8am this morning. It's come up slightly since then but I won't venture to think we've hit the low.  I swear, sometimes I think Ameren reads this blog and adjusts levels just to prove me wrong.  ;-) As you can see, we're just about to match the latest date for reaching low level in the past 9 years which happened March 31st, 2011.

Final Update: Given the low levels late in the year for 2018 I decided just to wait until May 1st before a final update. The maximum drawdown level for 2018 came on March 27th at 653.91. A very typical peak low level.  Nine year data average for date and level is now March 11th, at an average level of 654.82.

Below is a simple graph of just 9 year hourly levels average. (= Green graph above)

Friday, March 02, 2018

February 2018 Lake Levels and Flow Rates

Ameren announced in early February that the low level draw down would probably occur on February 19th.  Looking at the chart above would seem to confirm they hit their target at just under 655', but I wouldn't count on the draw down being over  just yet. As you can see the recent rains elevated the lake by nearly a foot and half and power generation (green spikes) has already begun bringing levels back down. Typically early March (see the orange 5 year average line) is when the lowest levels are reached and the spring rains haven't begun in earnest so it is possible they will draw the lake back down toward the 655' mark.