I remember my first trip to Alexander City a couple of years ago. I was talking to the locals and I kept hearing about the upcoming Plug Day. Everyone seemed so excited about it. I personally had never observed this occasion before, but was intrigued to learn more. I’m not one to play it off and pretend I know what someone is talking about. I couldn’t anyway-my facial expressions usually give that away. So, as my new friends looked at my confused face, I just came on out and asked-OK, so what is Plug Day? Do I get off of work for this day? Will there be cake in honor of Plug Day? Do we exchange gifts? Is there a celebration?
It turns out that this is a really joyous occasion-and this year it happens on February 18th. There’s a fun explanation to it, and a technical explanation. I will tell you a little about each so that when someone tells you “Happy Plug Day” you will know what it means and will look a lot less confused than I did that day.
Let’s start with the fun explanation! Credit for the fun part has to be given to Lake Magazine. They created this special little holiday to celebrate the start of the rising of the lake water-as Lake Martin transitions to what is called Summer Pool. Think of when you put a plug in a bathtub, and you see the water level start to rise-that is kind of what starts happening to Lake Martin on Plug Day. I know you are thinking it-because I certainly was too-and no, there is not an actual plug that makes it happen. (More on the how in the next paragraph that talks about the technical stuff.) However, it really does work the same way, and is cool to think of the virtual plug at the bottom of the lake as you see the water continue to rise over the next several weeks. During that time, we celebrate everything about Lake Martin, and start to look forward to those Summer days out on the lake cruising around, hanging out on an island, swimming, or wakeboarding and skiing. It’s a time when we think about our memories from past Summer days on the lake, and start planning for the upcoming Summer.
Now, that I have ruined it for you and let the secret out that it’s not really a giant plug that is allowing the water to rise, let’s talk technical. This is the part you can impress your friends with. Alabama Power holds a license from the Federal Energy Regulatory Commission (FERC) to operate Martin Dam. The terms of that license are determined by an environmental impact study that is about 400 pages long. We are certainly not going to get into all of that today, but I will give you the cliffs notes version. The current license says Alabama Power has to keep Lake Martin’s water at very specific levels-491 mean sea level feet in the Summer and 484 mean sea level feet in the Winter. The Summer levels and Winter levels are commonly referred to as Summer Pool and Winter Pool. As with anything, there are some exceptions that sometimes allow for drought, flood control, scheduled drawdowns for maintenance, and emergencies. Those levels are the norm most years though. FERC even tells Alabama Power the exact dates at which they must start making the transition between water levels. This is all controlled at an Alabama Power facility in Birmingham.
February 18th is when the water level starts it’s rise to Summer Pool levels. At that time, it is 481 msl feet. One thing that is important to note is that this year the lake level was lowered an additional 3 feet in order to comply with Alabama Power’s license with FERC. The license was renewed back in 2015-and the updated license says that once every six years, Alabama Power is required to lower the winter operating water level 3 feet below the normal level of 484 feet. This extra 3 feet of drawdown allows more access to the lakebed, and gives residents a chance to complete construction projects and maintenance on shoreline structures.
They have to make sure that Lake Martin reaches Summer Pool levels-491 msl feet-by April 19th at midnight. That schedule of water level change is called the rule curve. If all things were perfect in nature, you could follow the rule curve and know exactly what the water level will be each day. If we’ve learned anything about nature though, we know that it can be unpredictable. We can get lots of rain, or no rain-you never know. Flood control is what affects the rule curve the most in the Spring. For example, Alabama Power could hold extra water in the Lake Martin reservoir to prevent downstream flooding. What we do know is that by April 19th, Lake Martin will be at full Summer Pool. You can always check the current level of the lake here. Most of us can’t contain ourselves that long though, and as the water level starts rising and weather allows, we are already enjoying the lake fully by that time.