PITTSBURGH – A football coach manages players. An air traffic controller manages planes coming and going through the sky.
But who manages the nation’s waters?
Water management is, indeed, “a thing.” In fact, it is more than just a thing. Managing the flow of riverways is a core function of the U.S. Army Corps of Engineers and its Pittsburgh District.
Rivers are critical to navigation, industries, and ecosystems, but rivers can also devastate lives when a flash flooding submerges towns and rips away homes. So, how can anyone keep rivers under control?
In reality, no one can outright control a river, not any more than you can control your cat from howling in the middle of the night. All you can do is throw a balled-up sock at your cat when you do not feel like getting out of bed (not that the author is an expert in the subject).
Therefore, the Pittsburgh District does not control rivers, but they do manage them.
Water management in the district starts with a system of 16 reservoirs built over several decades, some dating back to the late 1930s. To help better understand the complexities of water management, we interviewed a few experts who could break it down “Barney Style.”
Megan Gottlieb is the Pittsburgh District Water Management Unit lead, with 15 years of experience in the field. We also interviewed biologists Carl Nim and Amy Jensen, who serve as environmental scientists for the district. Why biologists? Because water management involves science and stuff.
So, let’s get started.
PITTSBURGH DISTRICT: Let’s start by defining water management. What does it mean?
MEGAN GOTTLIEB: Water management helps ensure we use the water from the sky as best as possible.
PD: Wait, wait, wait. The sky? I thought we were talking about rivers. Do you control the clouds?
MG: No. We do not control the clouds. But water has to come from somewhere. So, it either rains down from the sky, or it melts from the snow.
PD: Rain and snow. Got it. Go ahead.
MG: If you think about it, our reservoirs are just like giant bathtubs. They hold back water from the rain and snow melts. All that water flows into our reservoirs, and their lake levels come up. Our reservoirs are just sitting there patiently, storing all this extra water. If it weren’t for those reservoirs, we would have a lot more flash floods in the region. Downstream communities and the Point of Pittsburgh would flood a lot more frequently. The parkway would get shut down regularly.
PD: Pause there. When you say “reservoirs,” do you mean “lakes”?
MG: Our reservoirs are all man-made lakes. The Army Corps built dams at strategic locations turning creeks and rivers into massive reservoirs. Without our dams, those lakes wouldn’t exist today.
PD: So, how do these reservoirs work?
MG: Each reservoir has a dam with gates that allows us to control their outflow. Our reservoirs help us referee water to reduce flood risks downstream. You can equate it to a traffic controller. Each dam is like a traffic light, and we can decide which light goes green or red depending on what rivers need.
PD: What’s it like to manage all that water?
MG: It’s a juggling act. It’s challenging. It’s very, very technical. You have to look at the current water conditions, plus forecast conditions in the future, and be able to communicate those conditions across the entire district. We work holidays and weekends. We have someone on duty every day. If we expect flooding at the Point of Pittsburgh, that’s a stressful and deliberate operation to reduce the risk of that flood. It’s challenging. You have to know the conditions of 16 reservoirs and their relationship to each other. We make decisions every single day. We need to know all the nuances about each reservoir: summer pools, winter pools, how they all function, inflows, outflows, water temperatures, stakeholders and public citizens.
PD: Why do you lower lake levels in the winter? Why can’t you keep a constant water level year-round?
MG: In the summer and fall months, water levels downstream typically start to dry up, so we need water stored in the reservoirs to help water flow year-round. That’s why the summer pool exists. It’s storage for the dry seasons. Rivers are like a checking account, while reservoirs are like a savings account. If you experience low-income months, but your bills stay the same, you tap into your savings account to pay your bills. Your bank account is going to decrease until you have more money coming in. The rivers need water, and that water has to come from somewhere – the reservoirs. The reservoirs are there to benefit the rivers.
PD: So why not let the rivers flow freely without reservoirs?
MG: Because flooding. We just talked about that.
PD: Oh. Right, right. We knew that.
MG: See what I mean? It’s a lot to manage.
PD: How do you know how much water to store and release at each reservoir?
MG: Each reservoir has its own guide curve we follow throughout the year. The guide curve at each reservoir projects where the lake should be if we had the perfect amount of water. However, sometimes we don’t have enough water, so we lower the lake levels to meet downstream flow targets. We drawdown reservoirs in the winter to allow for additional flood storage for the spring rain and snowmelt.
PD: What’s the risk if we don’t follow those guide curves?
MG: There are several risk factors to holding a lake above its guide curve, but a major one deals with hurricane season. Reservoirs cannot hold unlimited amounts of water. We begin releasing water in the summer into hurricane season. If a reservoir is full, and a hurricane brings in more water, that water has to go somewhere. The reservoir could overflow. Holding the water later and longer could mean a bigger release during a high-water event, which means more erosion and flooding in a flash. We don’t want that.
PD: Why can’t we hold water after summer to enjoy boating a little longer? The weather is so beautiful in August and September!
MG: Holding more water at the reservoirs later in the year means depriving rivers, navigation, industries, and communities from the water they need downstream. Again, reservoirs exist to benefit the rivers. If we hold water longer at our reservoirs, we’d be saying reservoirs are of greater priority than the rivers, which is the opposite reason these reservoirs were built. Our reservoirs exist to protect and enhance rivers systems downstream, not the other way around.
PD: What other benefit do reservoirs provide besides flood risk reduction and navigation?
WATER QUALITY (Carl Nim & Amy Jensen): Step aside Megan, we got this.
PD: Oh, well, hey there, Carl and Amy! So, what other benefit do our reservoirs provide?
WC: They contribute significantly to water quality.
PD: Can you define water quality for us?
WC: Water quality, by definition, is inherently interdisciplinary. It looks at how chemical, physical and biological components in the water interact with each other. Seemingly independent things have complex effects on one another.
PD: Wow. Well. That was an incredibly scientific answer …
WC: We are scientists, so …
PD. Can you break it down so non-scientists can understand?
WC: The water quality mission is based on history. Historically, industrial development has been hard on the waterways, either through pollution or by changing the river’s water temperature. Reservoirs help water quality by diluting pollution and sewage downstream as well as cooling waters, offsetting the damage caused by some industries.
PD: Why is water temperature important?
WC: Temperature has a lot to do with what can live in the water. Every critter needs a specific temperature to thrive and survive. Throughout the year, we try to meet different temperature standards in the water. Historically, some parts of the Mahoning River reached 100-105 degrees Fahrenheit, where maybe the maximum temperature aquatic life in that river can withstand is 89 degrees. Just like we don’t like 105-degree weather, aquatic animals don’t like it either in the water. We have cold water and warm water fisheries throughout the district. We discharge water at reservoirs that help level rivers at habitable temperatures.
PD: How can reservoirs change water temperatures?
WC: Colder water is denser, and therefore colder water tends to stick to the bottom of our reservoirs throughout the year. Some of our dams have gates that open up at different elevations, so we can release water at different temperatures to meet downstream targets.
PD: How do industries cause rivers to become too hot?
WC: Industries heat up water through discharge. It’s called thermal pollution. For example, coal fired-power plants on the river pull in cold water to cool down their boilers and discharge it into the water.
PD: If we were to remove our dams, would we see a definite worsening in water quality?
WC: Things were in a bad state before our dams were built. Pittsburgh had dead rivers. There was little to no aquatic life because of industry until the 1960s. The rivers were in bad shape. The Kiskiminetas was a dead river, essentially because of all the acid-mine drainage. Water quality is extremely nuanced. There are people who don’t like having controlled water flows, but overall, it has benefitted the rivers. For example, the reason life is resuming in the Allegheny River is because of the water releases from the Kinzua reservoir.
PD: What about drinking water?
WC: The Pittsburgh District doesn’t make operations or decisions based on drinking water because it’s not within our authority. The states manage and set up their own standards for drinking water. However, the water quality mission we support improves aquatic life, which also means better drinking water for the surrounding communities.
PD: So, who benefits most from our water quality mission?
WC: It’s an ecosystem driver. The releases of our dams are heavily tied to the health in our rivers and our ecosystems. Aquatic and plant life benefit, which also benefit their surrounding habitats and communities. It’s a benefit that quadruples itself.
PD: Who are your partners in improving water quality?
WC: Water quality is strong because of its partnerships. We rely heavily on our partners to evaluate and maintain water quality. Our partners include the Department of Environmental Protection and the Fish and Boating Commission, not just here in Pennsylvania, but in all five states where our reservoirs are established.
PD: Thank you for taking the time to discuss our water management and quality missions in the Pittsburgh District! Any final thoughts?
WC: Whenever we were kids, our moms would always tell us, “Don’t go swimming in the Monongahela River. You know it’s nasty!” Now people my age are bringing their kids out there swimming and fishing because it’s improved that much. It’s a testament to nature’s resiliency.
MG: I love working in water management. People don’t have a phone number for mother nature, but they call up water management to find out how the rivers might behave. Our reservoirs hold water that impact the lives of thousands downstream. It’s not a joke. It’s not a boat ride. It’s an honor to operate the reservoirs the way they were intended.