Between the Lines: Alabama Power’s Hydro team manages the complicated process of raising, lowering lake levels

When I worked in newspapers, I learned that there were a few things that we’d better NOT leave out of the paper.

Obituaries. Comics. Lottery numbers. And, of all things … lake levels.

If we left the lake levels out of the paper, or if we received them later than customers expected, we would get dozens of emails and phone calls from boaters, anglers and people who lived on the lake.

In the spring, they wanted to know when Alabama Power was going to raise the lake levels and by how much. In the fall, they wanted to know when Alabama Power was going to lower the lake levels and by how much.

As someone who doesn’t fish often, doesn’t own a boat and doesn’t live on the lake, I never quite understood what the big deal was. So, to find out, I recently sat down for a conversation with Alabama Power’s expert on lake levels.

My overall takeaway: It’s complicated. There are a LOT of factors that go into determining when to raise and lower lake levels … and by how much.

Each Alabama Power hydro plant operates under a license issued by the Federal Energy Regulatory Commission (FERC). These licenses consider the environment and aquatic life on the water, in the water and along the shorelines, in addition to taking into consideration residential access.

Never mind that all of that depends on the time of year and the amount of rainfall we receive across the state.

At the heart of Alabama Power’s work is its 14 hydroelectric generating plants that use the water to provide a portion of the electricity it takes to power two-thirds of the state’s residents, businesses and industry. Some of those lakes are “pass-through” lakes where the water that comes in goes out, and some are storage lakes where dams strategically pool the water to manage its use. (More on that later.)

Like I said, it’s complicated. But, thankfully, we have departments – Licensing and Compliance, Dam Safety, Reservoir Management and all the generating plant staff – consisting of professionals who stay on top of it all. And in one of the key roles is Lisa Martindale, the manager of Reservoir Management. Her team is responsible for moving the water in a way that’s most valuable to the system and planning for generation, which includes the required flows around license compliance, environmental factors, lake levels, rainfall, flood, drought and navigation.

“So, we make the plan for how we need to operate the Alabama Power hydro fleet based on system conditions and the requirements,” she said. “Every day.”

Hydro is one of the lowest-cost and cleanest sources of power generation that Alabama Power has, and it’s responsible for 6% to 8% of the company’s generation, depending on wet and dry conditions. This video, created for the relicensing of R.L. Harris Dam, explains how the company controls the flow of the river to generate electricity.

This week, Alabama Power recognizes Generation Appreciation Day on Aug. 21 and National Hydropower Day on Saturday, Aug. 24. Martindale, an Auburn University chemical engineering graduate, has been with Alabama Power for 22 years and has worked in Hydro since 2011.

Ask her about anything related to hydroelectricity, and a dam of details breaks open, pouring out a wave of information about what it takes to manage Alabama’s lake levels and keep the power and the good times flowing.

What is Alabama Power’s role when it comes to lake levels?

Martindale: We are responsible for managing the water within compliance of our licenses. There are two ways we manage lakes. One is, whatever is coming in at the dam is going out, which is called run of river. For example, Lay Lake is run of the river. Then we have storage reservoirs, which act as a battery for the system, and we can hold more water and use it as needed within a range. We have a summer pool and a winter pool for those storage reservoirs that is determined by our FERC license and the U.S. Army Corps of Engineers.

A primary objective for us is managing flood water. We use those storage lakes as buffers to move the water down the system. The Army Corps of Engineers sets the rules, and then Alabama Power hydro is responsible for execution.

Which lakes would be an example of storage lakes?

Martindale: Weiss, Neely Henry and Logan Martin on the Coosa River. On the Tallapoosa River, there are Harris and Martin, and then on the Black Warrior River, Smith. These are our storage reservoirs, and they all have a summer pool and a winter pool.

The winter pool is part of the water management plan to make room for the water during a large rain event when almost all the water from the watershed is coming into the reservoir.

How many lakes do we (Alabama Power) manage overall?

Martindale: We have 14 hydroelectric generating plants with 12 of these on Alabama Power lakes and dams and then two are located on U.S. Army Corps of Engineers dams, Bankhead and Holt.

How do you determine the timing for the winter and summer adjustments?

Martindale: That is based on the rule curves in our FERC license and the U.S. Army Corps of Engineers water control manuals. Information about the winter and summer adjustments can be found on the Alabama Power Shorelines app and website. This is designed to be a personal lake guide providing lake level information, generation schedule and the latest news.

So, is this one of the advantages of our generation mix of having hydro in addition to natural gas, coal, nuclear, solar, etc.?

Martindale: That’s right. We schedule the (hydro) generation that is available to be used when it’s most valuable to our customers.

Why are people so passionate about the lake levels?

Martindale: Higher levels may provide better recreational access. Also, residents say the lakes look better when they are full.

What are some advantages to lowering the lake in the winter?

Martindale: The primary need for lower lake levels in the winter is to provide storage for flood waters. If there was no storage available, then the heavy rains could result in uncontrolled flooding. For the homeowner, the lower levels provide opportunities for maintenance on their seawall or dock.

What do you wish the average person understood about lake levels that maybe they don’t, or you get questions about repeatedly?

Martindale: I think education is so important. Particularly in how weather affects our hydro generation schedule and lake levels. Weather and rainfall do not always correlate to adjustments to our generation and lake levels. From my perspective, it seems like a lot of times there is a perception that rain would drive a need for hydro generation and that is not always the case.

What about the impact on aquatic life? What is the level of concern? How is that regulated?

Martindale: The licensing process contains an extensive environmental review and has requirements on our operations to mitigate for potential environmental issues. There are minimum flow requirements below some of our dams that we must meet.

(Like I said, again, it’s complicated.)

If people want to know about lake levels or pretty much anything about the shorelines we manage, there’s an app (and a website) for that. What’s available?

Martindale: They can get the generating schedule. If we spill water, we publish the amount of spill coming out of the dam. They can see the current lake level, and they have added some enhancements (to the app). I think you can get some points of interest, alerts on changing conditions, and personalize and set up the lake you’re interested in. You can get alerts for when a generator comes on, generator goes off, when the lake level moves … We’re wanting to make it as helpful as possible for the people that live on the lakes to get that information as timely as they can. Our system, Reservoir Management, provides the data, so the customer has the same information that we are using to operate.

And if you also need to get a permit to do shoreline work, the application for those is now available through the app.

Is there anything you’d like to add?

Martindale: I want to make sure to give a shout out to the hydro team at each of the plants that make sure our hydroelectric generators are ready to run. We also work closely with Alabama Control Center hydro desk, as they operate the hydroelectric generating units at our hydro plants.

The interview with Martindale lasted more than an hour, and I have no doubt she only scratched the surface of her knowledge about lake levels.

As we recognize National Hydropower Day on Aug. 24, I do find it poetic that, if there were ever a reason to restart the grid, most of Alabama Power’s ways of generating power would rely on the one source that got everything started more than a century ago – hydro.

You can keep track of Alabama Power lake activity – including raising and lowering levels – by downloading our Alabama Power Shorelines app for Apple and Android devices.

Between the Lines is a monthly column by Alabama Power’s Anthony Cook, sharing energy education that powers our daily lives.