Hydropower: Harnessing the Power of Water for a Sustainable Future

Fort Worth District, USACE
Published Oct. 24, 2023
Person in front of a dam

Michael Rogers, the senior mechanic at the Sam Rayburn Hydroelectric Power Plant, stands outside the entrance to the dam structure. The Sam Rayburn Hydroelectric Power Plant was commissioned in September 1965. Even after a period of 58 years of operations, it still meets the electrical demands of Southeast Texas communities and regional area daily.

Generators inside a hydropower dam

The topside of the two Westinghouse generators inside of the Sam Rayburn Hydroelectric Power Plant, capable of generating up to 50 combined megawatts of electricity to the power grid. The plant was commissioned in September 1965. Even after a period of 58 years of operations, it still meets the electrical demands of Southeast Texas communities and regional area daily.

Angelina River below Sam Rayburn Dam

The Angelina River below the Sam Rayburn Hydroelectric Power Plant and dam before and after the turbines are engaged for production of electricity. The Sam Rayburn Hydroelectric Power Plant was commissioned in September 1965. Even after a period of 58 years of operations, it still meets the electrical demands of Southeast Texas communities and regional area daily.

As the gates leading from Sam Rayburn Lake open, the water rushes towards the Kaplan turbines some 100’ below. The river begins to rise and swell below the dam as the ground below your feet vibrates with the power of the water’s flow. Fifty megawatts of electricity enter the grid to power homes near and far.

“Hydroelectric generators are unique in the expedient way they can start and be producing power to the grid,” said Thomas Webb, Piney Woods regional hydropower manager for the U.S. Army Corps of Engineers, Fort Worth District. “A hydroelectric generator can start and be producing electric power in a matter of 5-10 minutes, unlike fossil fuel or nuclear power plants.”

According to the Corps of Engineers Hydropower Center of Excellence, hydropower is the largest single renewable source of electricity, generating more than all other renewable technologies combined: 27% of all renewable electricity; 6% of all electricity and 1% of all primary energy.

Hydropower is the process of converting the energy of flowing or falling water into electricity. It is a versatile and flexible energy source that can be harnessed in various ways, including dams, run-of-river systems, and tidal power. The most common method involves building dams across rivers, creating reservoirs that store water. When the water is released, it flows through turbines, which spin generators to produce electricity.

The Corps of Engineers, Fort Worth District manages three hydroelectric power plants that can provide up to 90 megawatts of power per hour to support the Texas power grid. This is enough electricity to power more than 100,000 homes.

The amount of electricity the Fort Worth District produces is based on an agreement with the Southwestern Power Administration and the amount of water in each reservoir.

While the dams were built and are maintained by the Corps of Engineers, only the flood pool behind the dam is controlled by the Corps. Everything below that level is controlled by organizations like the Brazos River Authority who develop and distribute water supplies, provide water and wastewater treatment, monitor water quality, and pursue water conservation though public education programs.

“While in flood pool we tell them to generate full time,” said Timothy Helms, a hydraulic engineer in training for the district. “There are different zones that define how much we can release from each. So, in zone one they can generate a good amount and as you move lower into the pool, we start to limit how much they can generate for water supply purposes and concerns of droughts.”

One of the key advantages of hydropower is its flexibility. Many hydropower dams, including those in the Texas region, do not have consistent water flows, and are not utilized for baseload power. These plants are oriented towards load following or peak operations. Additionally, hydropower plants can be quickly adjusted to meet fluctuations in demand, making it a flexible energy source that can adapt to changing needs.

“Hydroelectric generators can also provide condensing services, a means in which the generator acts as a motor, not producing electric power, but rather utilizing electric power from the grid, to help stabilize voltages or system frequencies on a power grid,” continued Webb. “During emergency and unscheduled power grid blackouts, certain hydroelectric generators are generally the ones who perform system “black starts” as part of a power grid system restoration plan. This means that a hydroelectric generator would start and provide electric power to the grid and provide the necessary amount of electricity to other large base load generators such as fossil fuel and nuclear power plants so they can start up and restore the power grid.”

Another significant advantage of hydropower is its environmental benefits. It is a clean and renewable energy source that produces no greenhouse gas emissions during operation. By replacing fossil fuel-based power plants, hydropower can significantly reduce carbon dioxide emissions and help mitigate climate change.

Furthermore, hydropower plants have a long lifespan, often exceeding 50 years, and require relatively moderate maintenance. While moderate, it is a full-time job.

Webb said the Sam Rayburn Hydroelectric Power Plant was commissioned in September 1965. Even after a period of 58 years of operations, it still meets the electrical demands of our Southeast Texas communities and regional area daily thanks to the plant staff.

“At the power plant we’re basically working on the hydropower units, so we’re maintaining the turbines and any auxiliary equipment” said Michael Rogers, the Corps of Engineers senior mechanic for more than 10 years at the Sam Rayburn Hydroelectric Power Plant. “This includes the mechanical seals, hydraulic pumps, air compressors and air systems as well as the generators themselves.”

Hydropower also offers numerous social and economic benefits. It creates job opportunities in construction, operation, and maintenance, contributing to local economies.

“If I could have found a job like this when I was a lot younger, I would have really sought after it. I didn’t know jobs like this existed when I graduated high school,” said Gary Justice, the civil engineering technician at Sam Rayburn Lake. “I grew up about thirty minutes from here and started going to Mill Creek Park when I was 5 years old.  To be able to work at a place I’ve always dreamed about living, just down the road, has just been a blessing to me. It’s an awesome job and a great place to work.”

Additionally, hydropower projects can provide irrigation for agriculture, improve water supply, and control flooding, benefiting communities and enhancing their resilience to climate-related challenges. According to the Institute for Water Resources, hydropower is better for the environment than other major sources of electrical power, which use fossil fuels. Hydropower plants do not emit the waste heat and gases—common with fossil-fuel driven facilities—which are major contributors to air pollution, global warming, and acid rain.

However, it is essential to acknowledge that hydropower is not without its challenges and potential drawbacks. A Massachusetts Institute of Technology Climate Portal article from 2021 states hydropower can also cause environmental and social problems. Reservoirs drastically change the landscape and rivers they are built on. Dams and reservoirs can reduce river flows, raise water temperature, degrade water quality, and cause sediment to build up. This has negative impacts on fish, birds, and other wildlife.

“One might say a negative is that hydroelectric power plants use water, which can change reservoir levels that can impact recreational areas and boat ramp availability, especially during dry summers and drought years,” said Webb. “The positive side to that same scenario is that during hot and dry summers, usually power grids see more of a demand for electricity usage that is caused by air conditioning needs and other electric power consumption needs. Having available water as a constant resource for this needed electric power generation can play a significant role in assuring electric power is available to meet the power needs and demands of our local communities. There are many more pros than cons. Hydroelectric power is Renewable, Reliable, Ready, and Relevant.”

In the quest for sustainable and renewable sources, hydropower has emerged as a leader in green energy. Harnessing the power of water, this clean and reliable energy source has been utilized for centuries, and its potential for the future is immense. With the world's growing energy demands and the urgent need to combat climate change, hydropower offers a promising solution that can help us transition to a greener and more sustainable future.