When thousands of gallons of water flow through a dam, it generates a lot of force and power.

But what happens when you harness that power? You could provide electricity to a community or two, of course.

Recently, a developer announced they will construct four new hydropower plants at locking facilities on all three major rivers in the greater Pittsburgh region.

“Partnering with developers to provide hydropower to the community is an important function,” said Benjamin Sakmar, the hydropower coordinator for the U.S. Army Corps of Engineers Pittsburgh District. “Especially in this day and age, the push for renewable energy is getting a lot of focus. We want to be good partners with companies looking to provide hydropower construction within the district.”

Rye Development, a developer of low-impact renewable hydropower generation, will construct facilities at Emsworth Locks and Dams on the Ohio River, at Monongahela River Locks and Dam 4, also known as Charleroi, and at the Allegheny River Locks and Dam 2.

“The Pittsburgh region has some of the most productive low impact run of river hydroelectric opportunities available in the U.S.” said Ushakar Jha, vice president for project engineering at Rye. “The economic benefit of constructing these projects will be felt by the local labor force in the region.”

The Pittsburgh District already has nine licensed and operating hydropower plants at their federal facilities, including five at locks and dams and four at reservoirs. Private industries or local governments run the plants to provide electricity to residents.

“Hydropower uses a resource that we have plenty of in our region: water,” Sakmar said. “We have the ideal topography, which channels the flow of water into our rivers and into our reservoirs. Some of our projects have been around for 100 years, so they already have energy built up, ready to harness with hydropower plants.”

Generally, hydropower plants work the same way on the river as at reservoirs. They take the force from water flow to spin large turbines connected to generators, transforming mechanical energy into electricity.

“The market in this region is incredibly advantageous from a power-offtake standpoint. These are some of the most productive projects with a clear line to commercial operation,” Jha said.

The capacity of each project will vary, but Rye estimates the four facilities will generate 250,000 megawatt hours annually for the next 100 years or more, enough to power 25,000 households per year.

Once construction for a new hydropower plant begins, completion may take 24 to 36 months. Rye has not yet set a date for breaking ground.

“The Pittsburgh District is critical to realizing these projects,” Jha said. “We are excited to work with the district moving forward, and this effort represents a once in a lifetime opportunity for the Pittsburgh region.”

The Emsworth location will host two hydropower plants because of its two dams. Emsworth is adjacent to Neville Island, located on the main channel of the Ohio River, just downstream from downtown Pittsburgh. Allegheny County has entered into a power purchase agreement with Rye to supply renewable electricity to the county from the Emsworth Project.

The Allegheny River Lock and Dam 2 is next to the Highland Park Bridge. The project will provide the University of Pittsburgh with on-demand, locally generated renewable power.

The Monongahela River Locks and Dam 4 at Charleroi is finishing up a significant construction project to enlarge a chamber that began nearly 20 years ago. Rye will pursue hydropower construction sometime after the chamber is complete.

The constructor expects each project to generate 150-200 family wage jobs. In addition to providing renewable energy, some facilities include investment in new recreational fishing sites and a walkway leading from a parking area with designated parking spaces to the fishing platform.

The U.S. Army Corps of Engineers does not select the locations for new hydropower plants. Developers – whether private companies or local governments looking to provide power to their citizens – choose sites based on economic factors. Namely, they determine whether licensing, designing, planning, and constructing a hydropower plant will produce enough power for enough customers to remain in business.

“Choosing a hydropower site all boils down to economics,” Sakmar said. “Developers need to be sure choosing a location is going to be economical and profitable for them. Sometimes that includes making sure they have buyers for their electricity and investors ahead of time.”

Even though the Pittsburgh District operates 23 locks and dams and 16 reservoirs, only nine of those locations have hydropower plants in operation. Together, they have the potential to produce 570 megawatts, able to power 670,000 households per year.

In addition to the nine already in place, Rye and other developers have licensed 12 total hydropower facilities yet to be constructed.

Developers who want to build a hydropower facility must submit their plans through the Federal Energy Regulatory Commission. FERC has the authority to decide whether a developer can build and operate a hydropower facility at a requested location. In addition, FERC performs environmental reviews to ensure facilities will not degrade the environment. The U.S. Army Corps of Engineers assists with design reviews at various planning stages.

“We work with the developer every step of the way,” Sakmar said. “We make sure a new facility isn’t going to cause any undue risk to our infrastructure, the public, water quality or the environment.”

Hydropower has several environmental requirements to maintain quality downstream, including water temperature, dissolved oxygen levels, and flow.

Safety and impact on water operations are other important factors. The Pittsburgh District does not change its outflow projections at reservoirs or locking facilities to produce more electricity. Instead, the district determines outflow at reservoirs according to its mission to reduce the risk of flooding, keep river navigation flowing and meet specific water quality projections.

“Our primary mission is to protect lives and support inland navigation. We want to make sure new hydropower plants are not going to impair the mission for why our dams were built in the first place,” Sakmar said.

Reviewing a proposed plan and licensing each facility can take several years before construction can begin. It can be a long, arduous process, but one that helps ensure the quality of the nations’ waters while boosting local economies.

“Partnership with developers is key to transitioning our dams to meet 21st century needs,” Sakmar said. “Each of these partnerships we have with developers is beneficial in harnessing resources and energy we already have, rather than trying to depend on non-renewable materials. This is just one little piece of the puzzle to help solve the overall energy needs we’re all looking to navigate.”